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Vitamin K intake and all-cause and cause specific mortality

Type: Scientific papers in peer-reviewed journals 2017 Authors: Zwakenberg SR. den Braver NR. Engelen AIP. Feskens EJM. Vermeer C. Boer JMA. Verschuren WMM. van der Schouw YT. Beulens JWJ Source: Clinical Nutrition 36(5):. 1294-1300. doi: 10.1016/j.clnu.2016.08.017


A resource efficiency assessment of the industrial mushroom production chain: The influence of data variability

Type: Scientific papers in peer-reviewed journals 2017 Authors: Zisopoulos FK. Becerra Ramirez HA. Van der Goot AJ. Boom RM Source: Journal of Cleaner Production 126. 394-408. doi: 10.1016/j.jclepro.2016.03.066Document


Short communication: Growth of dairy isolates of Geobacillus thermoglucosidans in skim milk depends on lactose degradation products supplied by Anoxybacillus flavithermus as secondary species.

Type: Scientific papers in peer-reviewed journals 2017 Authors: Zhao Y. Kumar M. Caspers MPM. Nierop Groot MN. van der Vossen JMBM. Abee T Source: Journal of Dairy Science J airy Sci. 101(2):. . . 1013-1019. doi: 10.3168/jds.2017-13372


On the ecosystemic network of saliva in healthy young adults

Type: Scientific papers in peer-reviewed journals 2017 Authors: Zaura E. Brandt BW. Prodan A. Teixeira de Mattos M. Imangaliyev S. Kool J. Buijs MJ. Jagers FL. Hennequin-Hoenderdos NL. Slot DE. Nicu EA. Lagerweij MD. Janus MM. Fernandez-Gutierrez MM. Levin E. Krom BP. Brand HS Source: International Society for Microbial Ecology Journal (ISME) 11(5). 1218-1231. doi: 10.1038/ismej.2016.199


Draft Genome Sequences of 11 Lactococcus lactis subspecies cremoris

Type: Scientific papers in peer-reviewed journals 2017 Authors: Wels M . Backus L.Boekhorst J. Dijkstra A. Beerthuizen M. Siezen RJ. Bachmann H. van Hijum SAFT Source: Genome Announcements 5(11). e01739-16. doi: 10.1128/genomeA.01739-16


Linseed oil and DGAT1 K232A polymorphism: Effects on methane emission. energy and nitrogen metabolism. lactation performance. ruminal fermentation. and rumen microbial composition of Holstein-Friesian cows

Type: Scientific papers in peer-reviewed journals 2017 Authors: van Gastelen S. Visker MHPW. Edwards JE. Antunes-Fernandes EC. Hettinga KA. Alferink SJJ. Hendriks WH. Bovenhuis H. Smidt H. Dijkstra J Source: Journal of Dairy Science 100(11). 8939-8957 . doi: 10.3168/jds.2016-12367


Role of short-chain fatty acids in colonic inflammation. carcinogenesis. and mucosal protection and healing

Type: Scientific papers in peer-reviewed journals 2017 Authors: van der Beek CM. Dejong CHC. Troost FJ. Masclee AAM. Lenaerts K Source: Nutrition Reviews 75(4). 286-305. doi: 10.1093/nutrit/nuw067


Tryptophan restriction arrests B cell development and enhances microbial diversity in WT and prematurely aging Ercc1?/?7 mice

Type: Scientific papers in peer-reviewed journals 2017 Authors: Van Beek AA. Hugenholtz F. Meijer B. Sovran B. Perdijk O. Vermeij WP. Brandt RMC. Barnhoorn S. Hoeijmakers JHJ. De Vos P. Leenen PJM. Hendriks RW. Savelkoul HFJ Source: Journal of Leukocyte Biology 101(4). 811-821 . doi: 10.1189/jlb.1HI0216-062RR


Habitual diet and diet quality in Irritable Bowel Syndrome: A case-control study

Type: Scientific papers in peer-reviewed journals 2017 Authors: Tigchelaar EF. Mujagic Z. Zhernakova A. Hesselink MAM. Meijboom S. Perenboom CWM. Masclee AAM. Wijmenga C. Feskens EJM. Jonkers DMAE. Source: Neurogastroenterology and Motility 29(12). . doi: 10.1111/nmo.13151


Prevalence and effects of functional vitamin K insufficiency: The PREVEND study

Type: Scientific papers in peer-reviewed journals 2017 Authors: Riphagen IJ. Keyzer CA. Drummen NEA. de Borst MH. Beulens JWJ. Gansevoort RT. Geleijnse JM. Muskiet FAJ. Navis G. Visser ST. Vermeer C. Kema IP. Bakker SJL. Source: Nutrients 9(12). E1334. doi: 10.3390/nu9121334


Functional vitamin B-6 status and long-term mortality in renal transplant recipients

Type: Scientific papers in peer-reviewed journals 2017 Authors: Minovic I. van der Veen A. van Faassen M. Riphagen IJ. van den Berg E. van der Ley C. Gomes-Neto AW. GEleijnse JM. Eggersdorfer M. Navis GJ. Kema IP. Bakker SJ Source: American Journal of Clinical Nutrition 106(6). 1366-1374. doi: 10.3945/ajcn.117.164012


Circulating haptoglobin and metabolic syndrome in renal transplant recipients

Type: Scientific papers in peer-reviewed journals 2017 Authors: Minovic I. Eisenga MF. Riphagen IJ. Van den Berg E. Kootstra-Ros J. Fenay AS. van Goor H. Rimbach G. Esatbeyoglu T. Levy AP. Gaillard C. Geleijnse JM. Eggersdorfer ML. Navis GH. Kema IP. Bakker SJL Source: Scientific Reports .7(1). 14264. . doi: 10.1038/s41598-017-14302-2


Soluble vascular cell adhesion molecules may be protective of future cardiovascular disease risk: findings from the PREVEND Prospective Cohort Study.

Type: Scientific papers in peer-reviewed journals 2017 Authors: Kunutsor SK. Bakker SJL. Dullaart RPF Source: Journal of Atherosclerosis and Thrombosis 24(8). 804-818. doi: 10.5551/jat.38836


Associations of the fatty liver and hepatic steatosis indices with risk of cardiovascular disease: Interrelationship with age

Type: Scientific papers in peer-reviewed journals 2017 Authors: Kunutsor SK. Bakker SJL. Blokzijl H. Dullaart RPF Source: Clinica Chimica Acta 466. 54-60. doi: 10.1016/j.cca.2017.01.008


Protein ingestion before sleep increases overnight muscle protein synthesis rates in healthy older men: a randomized controlled trial

Type: Scientific papers in peer-reviewed journals 2017 Authors: Kouw IW. Holwerda AM. Trommelen J. Kramer IF. Bastiaanse J. Halson SL. Wodzig WK. Verdijk LB. van Loon LJ Source: Journal of Nutrition 147(12). 2252-2261. doi: 10.3945/jn.117.254532


Dietary protein sources differentially affect microbiota. mTOR activity and transcription of mTOR signaling pathways in the small intestine.

Type: Scientific papers in peer-reviewed journals 2017 Authors: Kar SK. Jansman AJM. Benis N. Ramiro-Garcia J. Schokker D. Kruijt L. Stolte EH. Taverne-Thiele JJ. Smits MA. Wells JM Source: PLoS One 12(11) . e0188282. doi: 10.1371/journal.pone.0188282


Effects of long-term magnesium supplementation on endothelial function and cardiometabolic risk markers: A randomized controlled trial in overweight/obese adults

Type: Scientific papers in peer-reviewed journals 2017 Authors: Joris PJ. Plat J. Bakker SJ. Mensink RP Source: Scientific Reports 7(1):. 106. doi: 10.1038/s41598-017-00205-9.


Effect of erythritol on microbial ecology of in vitro gingivitis biofilms

Type: Scientific papers in peer-reviewed journals 2017 Authors: Janus MM. Volgenant CMC. Brandt BW. Buijs MJ. Keijser BJF. Crielaard W. Zaura E. Krom BP Source: Journal of Oral Microbiology 9(1). 1337477. doi: 10.1080/20002297.2017.1337477.


Candida albicans alters the bacterial microbiome of early in vitro oral biofilms

Type: Scientific papers in peer-reviewed journals 2017 Authors: Janus MM. Crielaard W. Volgenant CMC. Van der Veen MH. Brandt BW. Krom BP Source: Journal of Oral Microbiology 9(1):. 1270613. doi: 10.1080/20002297.2016.1270613


Changes in taste and smell function. dietary intake. food preference. and body composition in testicular cancer patients treated with cisplatin-based chemotherapy.

Type: Scientific papers in peer-reviewed journals 2017 Authors: IJpma I.Renken RJ.Gietema. JA.ter Horst. GJ.Reyners. AKL Source: Clinical Nutrition 36(6) . 1642-1648. doi: 10.1016/j.clnu.2016.10.013.


Aged gut microbiota contributes to systemical inflammaging after transfer to germ-free mice

Type: Scientific papers in peer-reviewed journals 2017 Authors: Fransen F. Van Beek AA. Borghuis T. Aidy SE. Hugenholtz F. Van der Gaast-de Jongh C. Savelkoul HFJ. De Jonge MI. Boekschoten MV. Smidt H. Faas MM. De Vos P Source: Frontiers in Immunology 8. 1385. doi: 10.3389/fimmu.2017.01385


Streptococcus salivarius MS-oral-D6 promotes gingival re-epithelialization in vitro through a secreted protein

Type: Scientific papers in peer-reviewed journals 2017 Authors: Fernandez-Gutierrez MM. Roosjen PP. Ultee E. Agelink M. Vervoort JJM. Keijser B. Wells J. Kleerebezem M Source: Scientific Reports 7(1). 11100. doi: 10.1038/s41598-017-11446-z.


The effect of age on the intestinal mucus thickness. microbiota composition and immunity in relation to sex in mice

Type: Scientific papers in peer-reviewed journals 2017 Authors: Elderman M. Sovran B. Hugenholtz F. Graversen K. Huijskes M. Houtsma E. Belzer C. Boekschoten M. De Vos P. Dekker J. Wells J. Faas M Source: PLoS One 12(9) . e0184274. doi: 10.1371/journal.pone.0184274


Protein supplementation augments muscle fiber hypertrophy but does not modulate satellite cell content during prolonged resistance-type exercise training in frail elderly

Type: Scientific papers in peer-reviewed journals 2017 Authors: Dirks ML. Tieland M. Verdijk LB. Losen M. Nilwik R. Mensink M. de Groot LCPGM. van Loon LJC. Source: Journal of American Medical Directors Association 18(7):. 608-615. doi: 10.1016/j.jamda.2017.02.006


Bolus matters: the influence of food oral breakdown on dynamic texture perception

Type: Scientific papers in peer-reviewed journals 2017 Authors: Devezeaux de Lavergne M. van de Velde F. Stieger M. Source: Food & Function 8(2). 464-480. doi: 10.1039/c6fo01005a


The tryptophan/kynurenine pathway. systemic inflammation. and long-term outcome after kidney transplantation

Type: Scientific papers in peer-reviewed journals 2017 Authors: de Vries LV. Minovi? I. Franssen CFM. van Faassen M. Sanders JF. Berger SP. Navis G. Kema IP. Bakker SJL Source: American Journal of Physiology – Renal Physiology 313(2):. F475-F486. doi: 10.1152/ajprenal.00690.2016


Twenty-four hour urinary cortisol excretion and the metabolic syndrome in prednisolone-treated renal transplant recipitents

Type: Scientific papers in peer-reviewed journals 2017 Authors: de Vries LV. de Jong WHA. Touw DJ. Berger SP. Navis G. Kema IP. Source: Steroids 127. 31-39. doi: 10.1016/j.steroids.2017.09.001


Structuring oil by protein building blocks

Type: Dissertation 2017 Authors: De Vries A Source: Wageningen University. Wageningen. The Netherlands


Lactobacillus plantarum strains can enhance human mucosal and systemic immunity and prevent non-steroidal anti-inflammatory drug induced reduction in t regulatory cells

Type: Scientific papers in peer-reviewed journals 2017 Authors: de Vos P. Mujagic Z. de Haan BJ. Siezen RJ Bron PA. Meijerink M. Wells JM. Masclee AAM. Boekschoten MV. Faas MM. Troost FJ Source: Frontiers in Immunology 8. 1000. doi: 10.3389/fimmu.2017.01000


Draft Genome Sequences of 24 Lactococcus lactis subspecies lactis strains

Type: Scientific papers in peer-reviewed journals 2017 Authors: Backus L. Wels M. Boekhorst J. Dijkstra A. Beerthuyzen M. Kelly WJ. Siezen R J. van Hijum SAFT. Bachmann H Source: Genome Announcements 5(13). . e01737-16. doi: 10.1128/genomeA.01737-16.


Experimental evolution and the adjustment of metabolic strategies in lactic acid bacteria.

Type: Scientific papers in peer-reviewed journals 2017 Authors: Bachmann H .Molenaar D. Branco dos Santos F. Teusink B Source: FEMS Microbiology Reviews 41(Supp_1). S201-S219. doi: 10.1093/femsre/fux024


Molecular assessment of muscle health and function

Type: Dissertation
Year: 2017
Author(s): Hangelbroek RWJ
Source: Wageningen University, the Netherlands


Prolonged lifespan and decreased fertility will lead to an increased proportion of older adults in the world population (population aging). An important strategy to deal with population aging has been to promote healthy aging; not only to prevent mounting health care costs, but also to maintain independence and quality of life of older populations for as long as possible. Close to the opposite of the healthy aging is frailty. A major component of (physical) frailty is sarcopenia: age-related loss of muscle mass. Decreased muscle size and strength has been associated with a wide variety of negative health outcomes, including increased risk of hospitalization, physical disability and even death. Therefore, maintaining muscle size and strength is very important for healthy aging. Nutrition and physical activity are possible strategies to maintain or even improve muscle function with age. The effect of nutrition, age, frailty and physical activity on the function of skeletal muscle is complex. A better understanding of the molecular mechanisms involved can provide new insights in potential strategies to maintain muscle function over the life course. This thesis aims to investigate these mechanisms and processes that underlie the effects of age, frailty and physical activity by leveraging the sensitivity and comprehensiveness of transcriptomics and metabolomics. Chapter 2 and 3 describe the effects of age, frailty and resistance-type exercise training on the skeletal muscle transcriptome and metabolome. Both the transcriptome and metabolome show significant differences between frail and healthy older adults. These differences are similar to the differneces between healthy young men and healthy older adults, suggesting that frailty presents itself as a more pronounced form of aging, somewhat independent of chronological age. These age and frailty related differences in the transcriptome are partially reversed by resistance-type exercise training, in accordance with the observed improvement in muscle strength. Regression analysis revealed that the protocadherin gamma gene cluster may be important to skeletal muscle function. Protocadherin gamma is involved in axon guidance and may be upregulated due to the denervation-reinnervation cycles observed in skeletal muscle of older individuals. The metabolome suggested that resistance-type exercise training led to a decrease in branched-chain amino acid oxidation, as shown by a decrease in amino acid derived carnitines. Lastly, the blood metabolome showed little agreement with the metabolome in skeletal muscle, indicating that blood is a poor read-out of muscle metabolism. We assessed the effect of knee immobilization with creatine supplementation or placebo on the skeletal muscle transcriptome and metabolome in chapter 4. Knee immobilization caused muscle mass loss and strength loss in all participants, with no differences between creatine and placebo groups. Knee immobilization appeared to induce the HDAC4-myogenin axis, which is primarily associated with denervation and motor neuron diseases. The metabolome showed changes consistent with the decreased expression of energy metabolism genes. While acyl-carnitine levels tended to decrease with knee immobilization, one branched-chain amino acid-derived acyl carnitine was increased after knee immobilization, suggesting increased amino acid oxidation. Vitamin D deficiency is common among older adults and has been linked to muscle weakness. Vitamin D supplementation has been proposed as a strategy to improve muscle function among older populations. In chapter 5, supplementation with vitamin D (calcifediol, 25(OH)D) is investigated as nutritional strategy to improve muscle function among frail older adults. However, we observed no effect of vitamin D on the muscle transcriptome. These findings indicate the effects of vitamin D supplementation on skeletal muscle may be either absent, weak, or limited to a small subset of muscle cells. Transcriptomic changes due to different forms of muscle disuse are compared in chapter 6 (primarily knee immobilization and bed rest). The goal was to determine the similarities and differences among various causes of muscle atrophy in humans (primarily muscle disuse). Both knee immobilization and bed rest led to significant changes in the muscle transcriptome. However, the overlap in significantly changed genes was relatively small. Knee immobilization was characterized by ubiquitin-mediated proteolysis and induction of the HDAC4/Myogenin axis, whereas bed rest revealed increased expression of genes of the immune system and increased expression of lysosomal genes. Knee immobilization showed the highest similarity with age and frailty-related transcriptomic changes. This finding suggests that knee immobilization may be the most suitable form of disuse atrophy to assess the effectiveness of strategies to prevent age-related muscle loss in humans. The transcriptome and metabolome are incredibly useful tools in describing the wide array of biological systems within skeletal muscle. These systems can be modulated using physical activity (or lack thereof) as well as nutrition. This thesis describes some of these processes and highlights several unexplored genes and metabolites that may be important for maintaining or even optimizing muscle function. In the future, it may be possible to optimize both exercise and nutrition for each individual using these techniques; or even better, cheaper and less invasive alternatives.

The gut in control of health and disease

Type: Dissertation
Year: 2017
Author(s): Van der Beek CM
Source: Maastricht University, the Netherlands


In the last decade, it has become clear that gut microbiota play a prominent role in human colonic health and metabolism. Human gut microbiota have the ability to ferment otherwise indigestible dietary fibers into short-chain fatty acids (SCFAs), mostly acetate, propionate, and butyrate. These SCFAs have been suggested to contribute to the beneficial effects of fiber intake on colonic health as well as metabolic health. SCFAs influence several metabolic pathways, such as energy regulation, glucose homeostasis, lipid metabolism, and inflammation. Nonetheless, human evidence concerning the metabolic effects of SCFAs is scarce. The studies described in this thesis investigate the metabolic role of SCFAs and dietary fibers in overweight and obese human subjects, and advance our knowledge on SCFA receptors, and SCFA functioning and handling in the gut.

 

Vascular effects of sodium and potassium intake

Type: Dissertation
Year: 2017
Author(s): Gijsbers L
Wageningen University, The Netherlands


link to thesis

Diet plays a relevant role in the development and progression of lifestyle-related diseases like hypertension and type 2 diabetes and the subsequent risk of cardiovascular and renal disease. Riphagen used several diet-sensitive biomarkers to further explore the effects of diet on cardiovascular and renal health.
Lifestyle measures including dietary sodium restriction and increased potassium intake are recognized to lower blood pressure. Increased potassium intake during sodium restriction, however, was found to have little effect on blood pressure. Riphagen investigated the effects of potassium supplementation on blood pressure and fluid balance in 35 (pre)hypertensive subjects during a fully controlled sodium-restricted diet using a panel of biomarkers. Potassium supplementation was found to have a relatively small blood pressure-lowering effect during sodium restriction. The blood pressure-lowering effects seemed mitigated by activation of several counter regulatory mechanisms involved in regulation of fluid balance and blood pressure (i.e., vasopressin, the renin-angiotensin-aldosterone system [RAAS], and heart rate).
Vascular calcification is also an important risk factor for cardiovascular disease. Matrix Gla protein (MGP) is a vitamin K-dependent inhibitor of soft tissue calcification. During vitamin K insufficiency, MGP is inactive. Riphagen investigated the prevalence of vitamin K insufficiency and its health consequences through measurement of inactive MGP in a general population-based cohort. Vitamin K insufficiency was found to be a common phenomenon especially among elderly and subjects with chronic diseases and was associated with an increased (cardiovascular) mortality risk.
Diet-sensitive biomarkers are a useful tool to further explore the effects of diet on cardiovascular and renal health.

Diet-sensitive prognostic markers for cardiovascular and renal disease

Type: Dissertation
Year: 2016
Author(s): Riphagen IJ
University of Groningen, The Netherlands


link to thesis

Diet plays a relevant role in the development and progression of lifestyle-related diseases like hypertension and type 2 diabetes and the subsequent risk of cardiovascular and renal disease. Riphagen used several diet-sensitive biomarkers to further explore the effects of diet on cardiovascular and renal health.
Lifestyle measures including dietary sodium restriction and increased potassium intake are recognized to lower blood pressure. Increased potassium intake during sodium restriction, however, was found to have little effect on blood pressure. Riphagen investigated the effects of potassium supplementation on blood pressure and fluid balance in 35 (pre)hypertensive subjects during a fully controlled sodium-restricted diet using a panel of biomarkers. Potassium supplementation was found to have a relatively small blood pressure-lowering effect during sodium restriction. The blood pressure-lowering effects seemed mitigated by activation of several counter regulatory mechanisms involved in regulation of fluid balance and blood pressure (i.e., vasopressin, the renin-angiotensin-aldosterone system [RAAS], and heart rate).
Vascular calcification is also an important risk factor for cardiovascular disease. Matrix Gla protein (MGP) is a vitamin K-dependent inhibitor of soft tissue calcification. During vitamin K insufficiency, MGP is inactive. Riphagen investigated the prevalence of vitamin K insufficiency and its health consequences through measurement of inactive MGP in a general population-based cohort. Vitamin K insufficiency was found to be a common phenomenon especially among elderly and subjects with chronic diseases and was associated with an increased (cardiovascular) mortality risk.
Diet-sensitive biomarkers are a useful tool to further explore the effects of diet on cardiovascular and renal health.

Structuring oil by protein building blocks

Type: Thesis
Year: 2017
Author(s): De Vries A
Source: Wageningen University, the Netherlands


link to thesis

This thesis describes an alternative to crystalline triacylglycerides (TAGs) to structure lipid phases for food products. These TAGs contain mainly saturated and trans fatty acids capable of forming a space-spanning crystal network entrapping the liquid oil into a solid structure. Although solid fat has many advantages when it comes to providing the desired texture and stability to food products, consuming saturated and trans fatty acids has been related to adverse effects on human health, with the prevalence of cardiovascular diseases (CVD) in particular. On the other hand, consuming unsaturated fatty acids, as found in liquid oils, decreases these risks. For this reason, food researchers are looking for alternatives to transform a liquid oil into a semi-solid structure with similar properties as solid fat, but without using saturated or trans fatty acids.

“Everything tastes different”. The impact of changes in chemosensory perception on food preferences, food intake and quality of life during chemotherapy in cancer patients

Type: Thesis
Year: 2017
Author(s): De Vries YC
Source: Wageningen University, the Netherlands


Taste and smell changes are common side effects during chemotherapy in cancer patient and may have an impact on food preferences, food intake and quality of life. However, these relations have hardly been studied systematically in specific cancer populations. The overall aim of this thesis was to assess how the sense of taste and smell change upon treatment with chemotherapy in breast cancer and oesophagogastric ancer patients, and to investigate their consequences in terms of food preferences, food intake and quality of life.

Bacillus cereus growth and biofilm formation: the impact of substratum, iron sources, and transcriptional regulator Sigma 54

Type: Thesis
Year: 2017
Author(s): Hayrapetyan H
Source: Wageningen University, the Netherlands


link to thesis

Biofilms are surface-associated communities of microbial cells embedded in a matrix of extracellular polymers. It is generally accepted that the biofilm growth mode represents the most common lifestyle of microorganisms. Next to beneficial biofilms used in biotechnology applications, undesired biofilms can be formed by spoilage and pathogenic microorganisms in food production environments. Bacillus cereus is a foodborne human pathogen able to cause two types of food poisoning, emetic and diarrheal. B. cereus can persist in factory environments in the form of biofilms, which can become a source of food contamination. This thesis adds to the knowledge about (a)biotic factors and conditions that affect B. cereus biofilm formation, including the effect of type of substratum such as polystyrene and stainless steel, with the latter supporting the highest biofilm formation for all tested strains including two reference strains and 20 food isolates. The ability of B. cereus to use a variety of iron sources was subsequently studied in these 22 strains and linked to the genes encoding iron transport systems present in the respective genomes, revealing significant diversity in the capacity to use complex and non-complex iron sources for growth and biofilm formation. For spore forming Bacilli, biofilm formation and sporulation are two intertwined cellular processes and studies in wet and dry (airexposed) biofilms revealed differences in sporulation rate and efficacy, with biofilmderived spores showing higher heat resistance than their planktonic counterparts. Additionally, comparative phenotype and transcriptome analysis of B. cereus wild type and a Sigma 54 deletion mutant provided insight into the pleiotropic role of this transcriptional regulator in B. cereus biofilm formation and physiology in general. Taken together, this knowledge improves our understanding of the biofilm lifecycle of this notorious food-borne human pathogen and provides clues which can help to reduce the domestication of this microorganism in production environments.

Assessing methane emission from dairy cows; Modeling and experimental approaches on rumen microbial metabolism

Type: Thesis
Year: 2017
Author(s): Van Lingen H
Source: Wageningen University, the Netherlands


link to thesis

Methane (CH4) is a greenhouse gas (GHG) with a global warming potential of 28 CO2 equivalents. The livestock sector was estimated to emit 7.1 gigatonnes of CO2 equivalents, which is approximately 14.5% of total global anthropogenic GHG emissions. Enteric CH4 production is the main source of GHG emissions from dairy cattle, representing 46% of the global GHG emissions in dairy supply chains. Dairy production has great value in view of the ability of ruminants to e ectively turn human inedible biomass into human edible food and to produce food from non-arable land. Consequently, there is an urgent need to develop strategies to decrease dairy cattle enteric CH4 emission. Evaluation of these strategies requires meticulous quanti cation and increased understanding of anaerobic fermentation and methanogenesis in the rumen ecosystem. The overall aim of this PhD research was, therefore, to quantitatively evaluate enteric CH4 emission from dairy cows as a ected by feeding and rumen microbial metabolism.

Biochemical characterization and bioinformatic analysis of two large multidomain enzymes from Microbacterium aurum B8.A involved in native starch degradation

Type: Thesis
Year: 2017
Author(s): Valk V
Source: University of Groningen, the Netherlands


link to thesis

In this work we describe a synergistic enzyme system from M. aurum B8.A which is highly adapted to its environment. We characterized two large multi-domain enzymes, MaAmyA and MaAmyB, which are unlike any enzyme currently in databases, and speculate about their origin. We defined the novel GH13_42 subfamily to which MaAmyB belongs and show that all members share a general conserved domain organization which differs from other GH13 amylases, including N-terminal CBM25 and a FNIII domains as well as an enlarged ABregion and aberrant C-region. More research is needed to fully understand the structure/ function relations of this enzyme and gain insight in the roles of its additional domains.

The data shows that the CBM25 domains in MaAmyA have a clear role in raw starch degradation and demonstrate their requirement for pore formation. We also defined and characterized the C-terminal tail of MaAmyA as the novel CBM74 domain which seems to be involved in resistant starch degradation in the mammalian gut. Although it is known that all natural resistant starches (RS1, 2 and 3) cannot be degraded by human GIT enzymes but are instead fully fermented in the large intestine [244–246], it is currently unknown how the bacteria degrade resistant starches. We show that CBM74 is commonly found in large and complex amylase enzymes which are obtained from bacteria isolated from the human gut and related environments. However such enzymes have not yet been studied. More research is needed to fully understand the role and function of the CBM74 domain in these large and complex enzymes

How to measure health improvement? Assessment of subtle shifts in metabolic phenotype

Type: Thesis
Year: 2017
Author(s): Fazelzadeh P
Source: Wageningen University, the Netherlands


link to thesis

Human health is impacted by a complex network of interactions between biological pathways, mechanisms, processes, and organs, which need to be able to adapt to a continuously changing environment to maintain health. This adaptive ability is called ‘phenotypic flexibility’. It is thought that health is compromised and diseases develop when these adaptive processes fail. As the product of interactions between several factors such as genetic makeup, diet, lifestyle, environment and the gut microbiome, the ‘metabolic phenotype’ provides a readout of the metabolic state of an individual. Understanding these relationships will be one of a major challenges in nutrition and health research in the next decades. To address this challenge, the development of high-throughput omics tools combined with the application of elaborate statistical analyses will help characterize the complex relationship of (bio) chemicals in human systems and their interaction with other variables including environment and lifestyle to produce the measured phenotype. An important aim of this thesis was to identify phenotype shifts by looking at effect of prolonged resistance-type exercise training on skeletal muscle tissue in older subjects and the possible shift toward the features of younger subjects as a reference for a healthier phenotype. A second aim was to identify phenotype shifts by looking at the response to a challenge in obese subjects and the possible shift toward lean subjects as a reference for a healthier phenotype. Chapter 2 and 3 of this thesis show how the significant remaining plasticity of ageing skeletal muscle can adapt to resistance-type exercise training. The data indicate that frail and healthy older subjects have two distinct phenotypes according to the skeletal muscle tissue metabolite profiles and that exercise training shifts aged muscle towards a younger phenotype. We showed that the effect of exercise on amino acid derived acylcarnitines (AAAC’s) in older subjects points towards decreased branched chain amino acid catabolism, likely due to compromised activation of the branched chain α-keto acid hydrogenase (BCKDH) complex. Furthermore, we found that the protocadherin gamma gene cluster might be involved in aged-muscle denervation and re-innervation. Finally, plasma was found to be a poor indicator of muscle metabolism, emphasizing the need for direct assessment of metabolites in muscle tissue. Chapter 4 of this thesis examines whether a mixed meal challenge response provides a readout for a shift in phenotype upon weight loss in obese male subjects. We concluded that weight loss moderately affects the mixed meal challenge response of both plasma metabolome and transcriptome of peripheral blood mononuclear cells in obese subjects. Measurements at the fasted and postprandial state also provide us with a different type of information. In Chapter 5 it is demonstrated that the global testing of pathways could provide a concise summary of the multiple univariate testing approach used in Chapter 4. In Chapter 6 it is discussed how the findings of this thesis increase our understanding of how to measure phenotypic flexibility as a proxy of health. In this thesis it is shown that the correlations between tissue and plasma metabolites are rather weak, emphasising the need to perform organ-specific studies. Availability of less invasive/painful sampling techniques and the use of small amounts of tissue would enable larger scale human studies on adipose tissue and skeletal muscle to more accurately define phenotypical shifts due to diet or lifestyle interventions. With respect to the assessment of phenotypical flexibility by omics approaches, significant complications can be expected in trying to relate plasma metabolism to PBMC gene expression. Organ-focussed approaches that integrate multiple omics levels using system biology approaches are considered to be a lot more promising.

Taste and smell changes and their short and long-term consequences in cancer patients

Type: Thesis
Year: 2017
Author(s): IJpma I
Source: University of Groningen, the Netherlands


link to thesis

Taste and smell perception play a significant role in appetite, dietary intake, and food choice. Cancer patients often experience changes in taste and smell perception during chemotherapy. These chemosensory changes can result in malnutrition, weight loss, and a decreased quality of life. Furthermore, patients may develop unhealthy eating patterns due to taste and smell changes, resulting in overweight. revious studies regarding taste and smell changes are mostly performed in heterogeneous cancer populations with various malignancies, treatments, and treatment phases and found no consistency in the nature of taste and smell changes. This thesis aimed to investigate taste and smell changes and their short- and long-term consequences in a homogeneous population of testicular cancer patients treated with cisplatin-based chemotherapy. Moreover, metallic taste experienced by cancer patients was explored.

Vitamin D for older adults: Determinants of status, supplementation strategies and its role in muscle function

Type: Thesis
Year: 2017
Author(s): Vaes AMM
Source: Wageningen University, the Netherlands


link to thesis

Vitamin D has been identified as an important factor in healthy aging and as such, it is receiving growing attention in clinical research. Vitamin D is a fat-soluble molecule, which is synthesized by hepatic and renal or extra-renal hydroxylation into the active hormone 1,25-dihydroxyvitamin D (1,25(OH)2D). The main function of this metabolite is to regulate calcium and phosphorus homeostasis and to support bone mineralization. In the circulation, the 25-hydroxyvitamin D metabolite (25(OH)D) is most stable and thus, considered the best marker of vitamin D status. A serum 25(OH)D concentration <30-50 nmol/L is considered deficient. Given the increased risk of deficiency and the potential beneficial effect of supplementation on musculoskeletal health, older adults present a specific target group for vitamin D interventions. However, the optimal serum 25(OH)D concentration is a matter of ongoing debate as randomized trials show conflicting results. With the research presented in this thesis, we aimed to gain insight in the prevalence and main determinants of a low vitamin D status, to investigate strategies to prevent or reverse vitamin D deficiency, and to study the effect of vitamin D supplementation on muscle strength and physical performance in Dutch older adults.

Diversity in sporulation and spore properties of foodborne Bacillus strains

Type: Thesis
Year: 2017
Author(s): Krawczyk AO
Source: University of Groningen, the Netherlands


link to thesis

Bacterial sporulation is a last resort adaptive strategy against starvation, resulting in the formation of dormant and extremely resistant (endo)spores. Spores pose major problems for the food industry, as food processing treatments often fail to completely inactivate these contaminating agents. Consequently, revival of the vegetative growth by surviving spores via germination and outgrowth can lead to food spoilage. Significant heterogeneity on a single-cell/spore level and inter-strain variation is spore properties hinder prediction and control over spores in the food industry. In this thesis, we described an extent of these two phenomena in model laboratory strains and industrially relevant, foodborne Bacillus isolates. First, using time-lapse fluorescent microscopy, we showed the occurrence of “the sporulation lysis” phenotype in sporulating genetically-identical cells of B. subtilis, demonstrating another aspect of the sporulation-related heterogeneity. Secondly, the RNA-Seq analysis revealed conservation of sporulation gene expression programs in B. subtilis and B. amyloliquefaciens strains, suggesting that distinct phenotypic traits of their spores result rather from differences in the gene presence and sequences than from the strains’ transcriptional behavior. Finally, associating germination phenotypes with the genomic content of B. subtilis and B. thermoamylovorans strains allowed for the identification of genetic factors responsible for the inter-strain variation in germination, such as the spoVA2mob operon or sequences of ger genes. Overall, the findings presented in this study have important implications for practices in the food industry as they argue against standardization of risk assessment and preservation techniques and provide means for the detection of problematic spore-formers.

Multi-objective optimization for eco-efficient food supply chains

Type: Thesis
Year: 2017
Author(s): Banasik A
Source: Wageningen University, the Netherlands


link to thesis

Until recently, food production focused mainly on delivering high-quality products at low cost and little attention was paid to environmental impact and depletion of natural resources. As a result of the growing awareness of climate change, shrinking resources, and increasing world population, this trend is changing. A major concern in Food Supply Chains (FSCs) is food waste. To remain competitive, FSCs are challenged to adopt new technologies that reduce or valorize food waste. These technologies can contribute to maintaining or increasing economic output and concurrently reduce the environmental impact of current operations, i.e. achieving what has been defined as eco-efficiency. Designing eco-efficient supply chains requires complex decision support models that can deal with multiple dimensions of sustainability while taking into account the specific characteristics of products and their supply chain. Multi-Criteria Decision Making (MCDM), a research field within Operations Research, is particularly suitable to support decision making when multiple and (mostly) conflicting criteria are involved. In this research, multi-objective optimization was used to quantify trade-offs between conflicting objectives and derive eco-efficient solutions, i.e. solutions in which environmental performance can only be improved at higher cost. The overall objective of this thesis was to support decision making in FSCs by developing dedicated decision support models to optimize and re-design FSCs by balancing the economic and environmental criteria. The emphasis is directed towards valorization of product flows by means of closing loops and waste management at a chain level.

Habituation to low or high protein intake does not modulate basal or postprandial muscle protein synthesis rates: a randomized trial

Type: Journal
Year: 2017
Author(s): Gorissen SH, Horstman AM, Franssen R, Kouw IW, Wall BT, Burd NA, de Groot LC, van Loon LJ.
Source: American Journal of Clinical Nutrition 105(2), 332-342. doi: 10.3945/ajcn.115.129924


Background: Muscle mass maintenance is largely regulated by basal muscle protein synthesis rates and the ability to increase muscle protein synthesis after protein ingestion. To our knowledge, no previous studies have evaluated the impact of habituation to either low protein intake (LOW PRO) or high protein intake (HIGH PRO) on the postprandial muscle protein synthetic response. Objective: We assessed the impact of LOW PRO compared with HIGH PRO on basal and postprandial muscle protein synthesis rates after the ingestion of 25 g whey protein. Design: Twenty-four healthy, older men [age: 62 ± 1 y; body mass index (in kg/m2): 25.9 ± 0.4 (mean ± SEM)] participated in a parallel-group randomized trial in which they adapted to either a LOW PRO diet (0.7 g · kg–1 · d−1; n = 12) or a HIGH PRO diet (1.5 g · kg–1 · d–1; n = 12) for 14 d. On day 15, participants received primed continuous l-[ring-2H5]-phenylalanine and l-[1-13C]-leucine infusions and ingested 25 g intrinsically l-[1-13C]-phenylalanine– and l-[1-13C]-leucine–labeled whey protein. Muscle biopsies and blood samples were collected to assess muscle protein synthesis rates as well as dietary protein digestion and absorption kinetics. Results: Plasma leucine concentrations and exogenous phenylalanine appearance rates increased after protein ingestion (P < 0.01) with no differences between treatments (P > 0.05). Plasma exogenous phenylalanine availability over the 5-h postprandial period was greater after LOW PRO than after HIGH PRO (61% ± 1% compared with 56% ± 2%, respectively; P < 0.05). Muscle protein synthesis rates increased from 0.031% ± 0.004% compared with 0.039% ± 0.007%/h in the fasted state to 0.062% ± 0.005% compared with 0.057% ± 0.005%/h in the postprandial state after LOW PRO compared with HIGH PRO, respectively (P < 0.01), with no differences between treatments (P = 0.25). Conclusion: Habituation to LOW PRO (0.7 g · kg–1 · d–1) compared with HIGH PRO (1.5 g · kg–1 · d–1) augments the postprandial availability of dietary protein–derived amino acids in the circulation and does not lower basal muscle protein synthesis rates or increase postprandial muscle protein synthesis rates after ingestion of 25 g protein in older men.

The use of exergetic indicators in the food industry – A review

Type: Journal
Year: 2017
Author(s): Zisopoulos FK, Rossier-Miranda FJ, van der Goot AJ, Boom RM
Source: Critial Reviews in Food Science and Nutrition 2;57(1):197-211. doi:10.1080/10408398.2014.975335


Assessment of sustainability will become more relevant for the food industry in the years to come. Analysis based on exergy, including the use of exergetic indicators and Grassmann diagrams, is a useful tool for the quantitative and qualitative assessment of the efficiency of industrial food chains. In this paper, we review the methodology of exergy analysis and the exergetic indicators that are most appropriate for use in the food industry. The challenges of applying exergy analysis in industrial food chains and the specific features of food processes are also discussed.

Analysis of germination capacity and germinant receptor (sub)clusters of genome-sequenced bacillus cereus environmental isolates and model strains

Type: Journal
Year: 2017
Author(s): Warda AK, Yinghua X, Boekhorst J, Wells-Bennik MHJ, Nierop Groot MN, Abee T
Source: Applied and Environmental Microbiology 83(4), e02490-16


Spore germination of 17 Bacillus cereus food isolates and reference strains was evaluated using flow cytometry analysis in combination with fluorescent staining at a single-spore level. This approach allowed for rapid collection of germination data under more than 20 conditions, including heat activation of spores, germination in complex media (brain heart infusion [BHI] and tryptone soy broth [TSB]), and exposure to saturating concentrations of single amino acids and the combination of alanine and inosine. Whole-genome sequence comparison revealed a total of 11 clusters of operons encoding germinant receptors (GRs): GerK, GerI, and GerL were present in all strains, whereas GerR, GerS, GerG, GerQ, GerX, GerF, GerW, and GerZ (sub)clusters showed a more diverse presence/absence in different strains. The spores of tested strains displayed high diversity with regard to their sensitivity and responsiveness to selected germinants and heat activation. The two laboratory strains, B. cereus ATCC 14579 and ATCC 10987, and 11 food isolates showed a good germination response under a range of conditions, whereas four other strains (B. cereus B4085, B4086, B4116, and B4153) belonging to phylogenetic group IIIA showed a very weak germination response even in BHI and TSB media. Germination responses could not be linked to specific (combinations of) GRs, but it was noted that the four group IIIA strains contained pseudogenes or variants of subunit C in their gerL cluster. Additionally, two of those strains (B4086 and B4153) carried pseudogenes in the gerK and gerRI (sub)clusters that possibly affected the functionality of these GRs. IMPORTANCE: Germination of bacterial spores is a critical step before vegetative growth can resume. Food products may contain nutrient germinants that trigger germination and outgrowth of Bacillus species spores, possibly leading to food spoilage or foodborne illness. Prediction of spore germination behavior is, however, very challenging, especially for spores of natural isolates that tend to show more diverse germination responses than laboratory strains. The approach used has provided information on the genetic diversity in GRs and corresponding subclusters encoded by B. cereus strains, as well as their germination behavior and possible associations with GRs, and it provides a basis for further extension of knowledge on the role of GRs in B. cereus (group member) ecology and transmission to the host.

Isolation and characterization of Lactobacillus helveticus DSM 20075 variants 1 with improved autolytic capacity

Type: Journal
Year: 2017
Author(s): Spus M, Liu H, Wels M, Abee T, Smid EJ
Source: International Journal of Food Microbiology, 241, 173-180. doi: 10.1016/j.ijfoodmicro.2016.10.020


Lactobacillus helveticus is widely used in dairy fermentations and produces a range of enzymes, which upon cell lysis can be released into the cheese matrix and impact degradation of proteins, peptides and lipids. In our study we set out to explore the potential of Lb. helveticus DSM 20075 for increased autolytic capacity triggered by conditions such as low pH and high salt concentrations encountered in cheese environments. Lb. helveticus DSM 20075 was subjected to varied incubation temperatures (ranging from 37 to 50°C). High-temperature incubation (in the range of 45 to 50°C) allowed us to obtain a collection of six variant strains (V45-V50), which in comparison to the wild-type strain, showed higher growth rates at elevated temperatures (42°C-45°C). Moreover, variant strain V50 showed a 4-fold higher, in comparison to wild type, autolytic capacity in cheese-like conditions. Next, strain V50 was used as an adjunct in lab-scale cheese making trials to measure its impact on aroma formation during ripening. Specifically, in cheeses made with strain V50, the relative abundance of benzaldehyde increased 3-fold compared to cheeses made with the wild-type strain. Analysis of the genome sequence of strain V50 revealed multiple mutations in comparison to the wild-type strain DSM 20075 including a mutation found in a gene coding for a metal ion transporter, which can potentially be linked to intracellular accumulation of Mn2+ and benzaldehyde formation. The approach of high-temperature incubation can be applied in dairy industry for the selection of (adjunct) cultures targeted at accelerated cheese ripening and aroma formation.

Diet-induced weight loss not only improves cardiometabolic risk markers, but also markers of vascular function: A randomized controlled trial with abdominally obese men

Type: Journal
Year: 2017
Author(s): Joris PJ, Plat J, Kusters YH, Houben AJ, Stehouwer CD, Schalkwijk CG, Mensink RP
Source: American Journal of Clinical Nutrition 105(1),23-31. doi: 10.3945/ajcn.116.143552


Background: Many trials assessing effects of dietary weight loss on vascular function have been performed without no-weight loss control groups and in individuals with obesity-related morbidities. Usually a limited set of vascular function markers has been investigated. Objective: The objective of this study was to examine effects of diet-induced weight loss on various vascular function markers and differences between normal-weight and abdominally obese men at baseline and after weight reduction. Design: Twenty-five healthy, normal-weight men (waist circumference: <94 cm) and 54 abdominally obese men (waist circumference: 102-110 cm) participated. Abdominally obese participants were randomly allocated to a dietary weight-loss or a no-weight loss control group. Individuals from the weight-loss group followed a calorie-restricted diet for 6 wk to obtain a waist circumference <102 cm followed by a weight-maintenance period of 2 wk. The control group maintained their habitual diet and physical activity levels. The primary outcome was the change in brachial artery flow-mediated vasodilation (FMD). Results: Compared with the control group, FMD did not change in the weight-loss group, but carotid-to-femoral pulse wave velocity tended to decrease by 0.5 m/s (P = 0.065). The retinal arteriolar caliber increased by 5 μm (P < 0.001) and the arteriolar-to-venular ratio by 0.02 (P < 0.01). Soluble endothelial selectin and soluble intercellular adhesion molecule concentrations decreased (P < 0.001). Also, total cholesterol, low-density lipoprotein cholesterol, triacylglycerol, glucose, insulin, C-peptide, homeostasis model assessment of insulin resistance, and blood pressure improved (P < 0.05 for all variables). Except for FMD, these markers differed at baseline between normal-weight and abdominally obese men but became comparable after weight loss. Conclusions: In abdominally obese men, dietary weight loss targeting a waist circumference of <102 cm improved retinal microvascular caliber, plasma biomarkers of microvascular endothelial function, and the more conventional cardiometabolic risk markers. Aortic stiffness tended to decrease, but FMD was not changed

Challenges in simulating the human gut for understanding the role of the microbiota in obesity

Type: Journal
Year: 2017
Author(s): Aguirre M, Venema K
Source: Beneficial Microbes 8(1):31-53. doi: 10.3920/BM2016.0113


There is an elevated incidence of cases of obesity worldwide. Therefore, the development of strategies to tackle this condition is of vital importance. This review focuses on the necessity of optimising in vitro systems to model human colonic fermentation in obese subjects. This may allow to increase the resolution and the physiological relevance of the information obtained from this type of studies when evaluating the potential role that the human gut microbiota plays in obesity. In light of the parameters that are currently used for the in vitro simulation of the human gut (which are mostly based on information derived from healthy subjects) and the possible difference with an obese condition, we propose to revise and improve specific standard operating procedures.

Difference in postprandial GLP-1 response despite similar glucose; kinetics after consumption of wheat breads with different particle; size in healthy men

Type: Journal
Year: 2017
Author(s): Eelderink C, Noort MW, Sozer N, Koehorst M, Holst JJ, Deacon CF, Rehfeld JF, Poutanen K, Vonk RJ, Oudhuis L, Priebe MG
Source: European Journal of Nutriiton 56(3), 1063-1076. doi: 10.1007/s00394-016-1156-6


Purpose Underlying mechanisms of the beneficial health effects of low glycemic index starchy foods are not fully elucidated yet. We varied the wheat particle size to obtain fiber-rich breads with a high and low glycemic response and investigated the differences in postprandial glucose kinetics and metabolic response after their consumption.Methods Ten healthy male volunteers participated in a randomized, crossover study, consuming 13C-enriched breads with different structures; a control bread (CB) made from wheat flour combined with wheat bran, and a kernel bread (KB) where 85 % of flour was substituted with broken wheat kernels. The structure of the breads was characterized extensively. The use of stable isotopes enabled calculation of glucose kinetics: rate of appearance of exogenous glucose, endogenous glucose production, and glucose clearance rate. Additionally, postprandial plasma concentrations of glucose, insulin, glucagon, incretins, cholecystokinin, and bile acids were analyzed. Results Despite the attempt to obtain a bread with a low glycemic response by replacing flour by broken kernels, the glycemic response and glucose kinetics were quite similar after consumption of CB and KB. Interestingly, the glucagon-like peptide-1 (GLP-1) response was much lower after KB compared to CB (iAUC, P 0.005). A clear postprandial increase in plasma conjugated bile acids was observed after both meals. Conclusions Substitution of 85 % wheat flour by broken kernels in bread did not result in a difference in glucose response and kinetics, but in a pronounced difference in GLP-1 response. Thus, changing the processing conditions of wheat for baking bread can influence the metabolic response beyond glycemia and may therefore influence health.

Intraileal casein infusion increases casein specific amino acids in plasma

Type: Journal
Year: 2017
Author(s): Ripken D, van Avesaat M, Troost FJ, Masclee AA, Witkamp RF, Hendriks HF
Source: Clinical Nutrition 36(1), 143-149. doi: 10.1016/j.clnu.2016.01.012


Background: Activation of the ileal brake by casein induces satiety signals and reduces energy intake. However, adverse effects of intraileal casein administration have not been studied before. These adverse effects may include impaired amino acid digestion, absorption and immune activation. Objective: To investigate the effects of intraileal infusion of native casein on plasma amino acid appearance, immune activation and gastrointestinal (GI) symptoms. Design: A randomized single-blind cross over study was performed in 13 healthy subjects (6 male; mean age 26 ± 2.9 years; mean body mass index 22.8 ± 0.4 kg/m-2), who were intubated with a naso-ileal feeding catheter. Thirty minutes after intake of a standardized breakfast, participants received an ileal infusion, containing either control (C) consisting of saline, a low-dose (17.2 kcal) casein (LP) or a high-dose (51.7 kcal) of casein (HP) over a period of 90 min. Blood samples were collected for analysis of amino acids (AAs), C-reactive protein (CRP), pro-inflammatory cytokines and oxylipins at regular intervals. Furthermore, GI symptom questionnaires were collected before, during and after ileal infusion. Results: None of the subjects reported any GI symptoms before, during or after ileal infusion of C, LP and HP. Plasma concentrations of all AAs analyzed were significantly increased after infusion of HP as compared to C (p  0.001), and most AAs were increased after infusion of LP (p  0.001). In total, 12.49 ± 1.73 and 3.18 ± 0.87 g AAs were found in plasma after intraileal infusion of HP and LP, corresponding to 93 ± 13% (HP) and 72 ± 20% (LP) of AAs infused as casein, respectively. Ileal casein infusion did not affect plasma concentrations of CRP, IL-6, IL-8, IL-1β and TNF-α. Infusion of HP resulted in a decreased concentration of 11,12-dihydroxyeicosatrienoic acid whereas none of the other oxylipins analyzed were affected. Conclusions: A single intraileal infusion of native casein results in a concentration and time dependent increase of AAs in plasma, suggesting an effective digestion and absorption of AAs present in casein. Also, ileal infusion did not result in immune activation nor in GI symptoms.

Microbial variability in growth and heat resistance of a pathogen and a spoiler: All variabilities are equal but some are more equal than others

Type: Journal
Year: 2017
Author(s): den Besten HM, Aryani DC, Metselaar KI, Zwietering MH
Source: Internatinal Journal of Food Microbiology 240,24-31. doi: 10.1016/j.ijfoodmicro.2016.04025


Quantitative microbiology is used in risk assessment studies, microbial shelf life studies, product development, and experimental design. Realistic prediction is, however, complicated by different sources of variability. The final concentration of microorganisms at the moment of consumption is affected by different sources of variability: variability in the storage times and temperatures, variability in product characteristics, variability in process characteristics, variability in the initial contamination of the raw materials, and last but not least, microbiological variability. This article compares different sources of microbiological variability in growth and inactivation kinetics of a pathogen and a spoiler, namely experimental variability, reproduction variability (within strain variability), strain variability (between strain variability) and variability between individual cells within a population (population heterogeneity). Comparison of the different sources of microbiological variability also allows to prioritize their importance. In addition, the microbiological variability is compared to other variability factors encountered in a model food chain to evaluate the impact of different variability factors on the variability in microbial levels encountered in the final product.

Effects of in vitro fermentation of barley β-glucan and sugar beet pectin using human fecal inocula on cytokine expression by dendritic cells

Type: Journal
Year: 2017
Author(s): Rösch, C.;Taverne, N.;Gruppen, H.;Gruppen, H.;Wells, J.M.;Schols, H.A.
Source: Molecular Nutrition & Food Research 61(1),1600243. doi:10.1002/mnfr.201600243


Scope: This study simulates the fermentation process of barley β-glucan and sugar beet pectin in the human colon and monitors the degradation products formed. Additionally, immune effects of the degradation products were investigated. Methods and results: Immunostimulatory activity of fermentation digesta was investigated using bone marrow derived dendritic cells (BMDCs) from toll-like receptor 2/4 (TLR2/4) knockout mice, which were unresponsive to microbe-associated molecular patterns. Cytokine responses were elicited to dietary fibers and not to the SCFA and microbiota. The fermentation digesta were analyzed for their SCFA profiles and glycan metabolites over time. During fermentation the amount of insoluble precipitating fibers increased and induced as well as soluble molecules of lower molecular mass greater amounts of cytokines in BMDCs than the parental fiber. Additionally, high amounts of cytokines can be attributed to soluble galactose-rich beet pectin molecules. Conclusions: The fermentation of the two fibers led to fiber-specific amounts of SCFA, glycosidic metabolites, and different immunomodulatory properties. BMDC from TLR2/4 knockout mice did not respond to the digest microbiota and SCFA, making it a useful approach to study temporal effects of fermentation on the immunomodulatory effects of fibers.

Effect of endoscopic gastroplication on the genome-wide transcriptome in the upper gastrointestinal tract

Type: Journal
Year: 2017
Author(s): Van der Wielen N, Paulus G, van Avesaat M, Masclee A, Meijerink J, Bouvy N
Source: Obesity Surgery 27(3), 740-748. doi: 10.1107/s11695-016-2356-0


Background: Bariatric surgery is an effective intervention strategy in obesity, resulting in sustained weight loss and a reduction of comorbidities. Gastroplication, using the articulating circular endoscopic stapler, was recently introduced as a transoral bariatric technique. This procedure reduces gastric volume and induced 34.9 % of excess weight loss in the first year (paulus et al. Gastrointest endosc. 81(2):312-20, 3). The aim of the present study was to gain insight in the long-term effects and underlying mechanisms of gastroplication by investigating differences in the genome-wide gastric and duodenal transcriptome before and 1 year after intervention. Methods: Ten morbidly obese patients (bmi 39.8 ± 0.9 kg/m2 (mean ± sem)) underwent gastroplication. Previous to the procedure and after 1 year, blood samples were taken, and mucosal biopsies were collected from the fundus, antrum and duodenum. Gene expression was measured using microarray analysis. Plasma adiponectin, hba1c, il-1β, il-6, il-7, tnf-α, ifn-γ, mcp-1, il-8, tgf-1 and crp levels were determined. Results: Downregulation of inflammatory genes and gene sets was observed in the fundus and duodenum 1 year after surgery. Gene expression of ghrelin and its activating enzyme goat were downregulated in the upper gastrointestinal tract. Patients showed a reduction in plasma hba1c levels (from 6.17 ± 0.51 to 5.32 ± 0.14 %, p = 0.004) and an increase of plasma adiponectin (from 16.87 ± 3.67 to 27.67 ± 5.92 μg/ml, p = 0.002). Conclusions: Individuals undergoing gastroplication displayed a downregulation of inflammatory tone in the stomach and duodenum, which coincided with improved hba1c and adiponectin levels. The reduction of inflammatory tone in the upper gastrointestinal tract may be a consequence of an improved metabolic health status or alternatively caused by the procedure itself.

Frontline Science: Tryptophan restriction arrests B cell development and enhances microbial diversity in WT and prematurely aging Ercc1-/Δ7 mice.

Type: Journal
Year: 2017
Author(s): Van Beek AA, Hugenholtz F, Meijer B, Sovran B, Perdijk O, Vermeij WP, Brandt RM, Barnhoorn S, Hoeijmakers JH, de Vos P, Leenen PJ, Hendriks RW, Savelkoul HF
Source: Journal of Leukocyte Biology 101(4):811-821. doi: 10.1189/jlb.1HI0216-062RR


With aging, tryptophan metabolism is affected. Tryptophan has a crucial role in the induction of immune tolerance and the maintenance of gut microbiota. We, therefore, studied the effect of dietary tryptophan restriction in young wild-type (WT) mice (118-wk life span) and in DNA-repair deficient, premature-aged (Ercc1-/Δ7 ) mice (20-wk life span). First, we found that the effect of aging on the distribution of B and T cells in bone marrow (BM) and in the periphery of 16-wk-old Ercc1-/Δ7 mice was comparable to that in 18-mo-old WT mice. Dietary tryptophan restriction caused an arrest of B cell development in the BM, accompanied by diminished B cell frequencies in the periphery. In general, old Ercc1-/Δ7 mice showed similar responses to tryptophan restriction compared with young WT mice, indicative of age-independent effects. Dietary tryptophan restriction increased microbial diversity and made the gut microbiota composition of old Ercc1-/Δ7 mice more similar to that of young WT mice. The decreased abundances of Alistipes and Akkermansia spp. after dietary tryptophan restriction correlated significantly with decreased B cell precursor numbers. In conclusion, we report that dietary tryptophan restriction arrests B cell development and concomitantly changes gut microbiota composition. Our study suggests a beneficial interplay between dietary tryptophan, B cell development, and gut microbial composition on several aspects of age-induced changes.

Letter: A GWAS meta-analysis suggests roles for xenobiotic metabolism and ion channel activity in the biology of stool frequency

Type: Journal
Year: 2017
Author(s): Jankipersadsing SA, Hadizadeh F, Bonder MJ, Tigchelaar EF, Deelen P, Fu J, Andreasson A, Agreus L, Walter S, Wijmenga C, Hysi P, D’Amato M, Zhernakova A
Source: Gut 66(4), 756-758. doi: 10.1136/gutjnl-2016-312398


Blood urea nitrogen-to-creatinine ratio in the general population and in patients with acute heart failure

Type: Journal
Year: 2017
Author(s): Matsue Y, van der Meer P, Damman K, Metra M, O’Connor CM, Ponikowski P, Teerlink JR, Cotter G, Davison B, Cleland JG, Givertz MM, Bloomfield DM, Dittrich HC, Gansevoort RT, Bakker SJ, van der Harst P, Hillege HL, van Veldhuisen DJ, Voors AA
Source: Heart 103(6):407-413. doi: 10.1136/heartjnl-2016-310112


Objective The blood urea nitrogen-to-creatinine (BUN/creatinine) ratio has been proposed as a useful parameter in acute heart failure (AHF), but data on the normal range and the added value of the ratio compared with its separate components in patients with AHF are lacking. The aim of this study is to define the normal range of BUN/creatinine ratio and to investigate its clinical significance in patients with AHF. Methods In 4484 subjects from the general population without cardiovascular comorbidities, we calculated age-specific and sex-specific normal values of the BUN/creatinine ratio, deriving a higher and lower than normal range of BUN/creatinine ratio (exceeding the 95% prediction intervals). Association of abnormal range to prognosis was tested in 2033 patients with AHF for the outcome of all-cause death through 180 days, death or cardiovascular or renal rehospitalisation through 60 days and heart failure (HF) rehospitalisation within 60 days. Results In a cohort of patients with AHF, 482 (24.6%) and 28 (1.4%) patients with HF were classified into higher and lower than normal range groups, respectively. In Cox regression analysis, higher than normal range of BUN/creatinine ratio group was an independent predictor for all-cause death (HR: 1.86, 95% CI 1.29 to 2.66) and death or cardiovascular or renal rehospitalisation (HR: 1.37, 95% CI 1.03 to 1.82), but not for HF rehospitalisation (HR: 1.23, 95% CI 0.81 to 1.86) after adjustment for other prognostic factors including both creatinine and BUN. Conclusions In patients with AHF, BUN/creatinine higher than age-specific and sex-specific normal range is associated with worse prognosis independently from both creatinine and BUN. Clinical Trials gov identifier NCT00328692 and NCT00354458

Human splanchnic amino-acid metabolism

Type: Journal
Year: 2017
Author(s): Neis EPGJ, Sabrkhany S, Hundscheid I, Schellekens D, Lenaerts K, Olde Damink SW, Blaak EE, Dejong CHC, Rensen SS
Source: Journal of Amino Acids 49(1), 161-172. doi: 10.1007/s00726-016-2344-7


Plasma levels of several amino acids are correlated with metabolic dysregulation in obesity and type 2 diabetes. To increase our understanding of human amino-acid metabolism, we aimed to determine splanchnic interorgan amino-acid handling. Twenty patients planned to undergo a pylorus preserving pancreatico-duodenectomy were included in this study. Blood was sampled from the portal vein, hepatic vein, superior mesenteric vein, inferior mesenteric vein, splenic vein, renal vein, and the radial artery during surgery. The difference between arterial and venous concentrations of 21 amino acids was determined using liquid chromatography as a measure of amino-acid metabolism across a given organ. Whereas glutamine was significantly taken up by the small intestine (121.0 ± 23.8 µmol/L; P < 0.0001), citrulline was released (-36.1 ± 4.6 µmol/L; P < 0.0001). This, however, was not seen for the colon. Interestingly, the liver showed a small, but a significant uptake of citrulline from the circulation (4.8 ± 1.6 µmol/L; P = 0.0138) next to many other amino acids. The kidneys showed a marked release of serine and alanine into the circulation (-58.0 ± 4.4 µmol/L and -61.8 ± 5.2 µmol/L, P < 0.0001), and a smaller, but statistically significant release of tyrosine (-12.0 ± 1.3 µmol/L, P < 0.0001). The spleen only released taurine (-9.6 ± 3.3 µmol/L; P = 0.0078). Simultaneous blood sampling in different veins provides unique qualitative and quantitative information on integrative amino-acid physiology, and reveals that the well-known intestinal glutamine-citrulline pathway appears to be functional in the small intestine but not in the colon.

Interfacial properties, thin film stability and foam stability of casein micelle dispersions

Type: Journal
Year: 2017
Author(s): Chen M, Sala G, Meinders MB, Van Valenberg HJ, Van der Linden E, Sagis LM
Source: Colloids and Surfaces B-Biointerfaces 149, 56-63. doi: 10.1016/j.colsurfb.201610.010


Foam stability of casein micelle dispersions (CMDs) strongly depends on aggregate size. To elucidate the underlying mechanism, the role of interfacial and thin film properties was investigated. CMDs were prepared at 4°C and 20°C, designated as CMD4°C and CMD20°C. At equal protein concentrations, foam stability of CMD4°C (with casein micelle aggregates) was markedly higher than CMD20°C (without aggregates). Although the elastic modulus of CMD4°C was twice as that of CMD20°C at 0.005Hz, the protein adsorbed amount was slightly higher for CMD20°C than for CMD4°C, which indicated a slight difference in interfacial composition of the air/water interface. Non-linear surface dilatational rheology showed minor differences between mechanical properties of air/water interfaces stabilized by two CMDs. These differences in interfacial properties could not explain the large difference in foam stability between two CMDs. Thin film analysis showed that films made with CMD20°C drained to a more homogeneous film compared to films stabilized by CMD4°C. Large casein micelle aggregates trapped in the thin film of CMD4°C made the film more heterogeneous. The rupture time of thin films was significantly longer for CMD4°C (>1h) than for CMD20°C (<600s) at equal protein concentration. After homogenization, which broke down the aggregates, the thin films of CMD4°C became much more homogeneous, and both the rupture time of thin films and foam stability decreased significantly. In conclusion, the increased stability of foam prepared with CMD4°C appears to be the result of entrapment of casein micelle aggregates in the liquid films of the foam.

Protein oleogels from heat-set whey protein aggregates

Type: Journal
Year: 2017
Author(s): De Vries A, Wesseling A, Van der Linden E, Scholten E
Source: Journal of Colloid and Interface Science 486, 75-83


In this research we use heat-set whey protein aggregates (diameter  200 nm) as novel building blocks for structure formation in liquid oil to form oleogels. To transfer the aggregates to the oil phase, a solvent exchange procedure to sunflower oil was applied using acetone as an intermediate solvent. We found that agglomeration of the aggregates was prevented and the particle size in oil did not change from that in the initial aqueous phase. The small protein aggregates assemble into a space-spanning network, thereby providing solid-like properties to liquid oil. From oscillatory rheology we conclude that the aggregates are highly effective in forming a network. Already at 3% we found that G0 > G00 and G0 scales with protein concentration as G0  cp 5.3. Applying a fractal gel network theory to the rheological data we deduce that the gels are in the strong link regime with a fractal dimension of 2.2. The results show that protein aggregates, besides their well-known functionality in aqueous solvents, are capable of forming a network in liquid oil. This provides a novel and promising way to design oleogels with tuneable rheological properties, applicable to e.g. foods, pharmaceuticals and/or cosmetics.

Small intestinal protein infusion in humans: evidence for a location-specific gradient in intestinal feedback on food intake and GI peptide release.

Type: Journal
Year: 2017
Author(s): Van Avesaat M, Ripken D, Hendriks HF, Masclee AA, Troost FJ
Source: International Journal of Obesity 41(2), 217-224. doi: 10.108/ijo.2016.196


Background: Protein infusion in the small intestine results in intestinal brake activation: a negative feedback mechanism that may be mediated by the release of gastrointestinal peptides resulting in a reduction in food intake. It has been proposed that duodenum, jejunum and ileum may respond differently to infused proteins. Objective: To investigate differences in ad libitum food intake, feelings of hunger and satiety and the systemic levels of cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), peptide YY (PYY), glucose and insulin after intraduodenal, intrajejunal and intraileal protein infusion. Methods: Fourteen subjects (four male, mean age: 23±2.1 years, mean body mass index: 21.6±1.8 kg m-2) were intubated with a naso-ileal catheter in this double-blind, randomized, placebo-controlled crossover study. Test days (four in total, executed on consecutive days) started with the ingestion of a standardized breakfast, followed by the infusion of 15 g of protein in the duodenum, jejunum or ileum over a period of 60 min. Food intake was measured by offering an ad libitum meal and Visual Analogue Scale (VAS) scores were used to assess feelings of hunger and satiety. Blood samples were drawn at regular intervals for CCK, GLP-1, PYY, glucose and insulin analyses. Results: Intraileal protein infusion decreased ad libitum food intake compared with both intraduodenal and placebo infusion (ileum: 628.5±63 kcal vs duodenum: 733.6±50 kcal, P<0.01 and placebo: 712.2±53 kcal, P<0.05). GLP-1 concentrations were increased after ileal infusion compared with jejunal and placebo infusion, whereas CCK concentrations were only increased after intraileal protein infusion compared with placebo. None of the treatments affected VAS scores for hunger and satiety nor plasma concentrations of PYY and glucose. Conclusions: Protein infusion into the ileum decreases food intake during the next meal compared with intraduodenal infusion, whereas it increases systemic levels of GLP-1 compared with protein infusion into the jejunum and placebo respectively.

Metallic taste in cancer patients treated with systemic therapy: a questionnaire-based study

Type: Journal
Year: 2017
Author(s): IJpma I, Timmermans ER, Renken RJ, Ter Horst GJ, Reyners AK
Source: Nutrition and Cancer 69(1):140-145. doi: 10.1080/01635581.2017.1250922.


A metallic taste is reported by cancer patients as a side effect of systemic therapy. Despite the high prevalence, this taste alteration has received limited attention. The present study investigated: 1) the prevalence of metallic taste in cancer patients treated with systemic therapy; 2) possible predictors of metallic taste; and 3) characteristics of metallic taste. A heterogeneous population of 127 cancer patients, who had received systemic treatment in the past year or were still on treatment, completed a questionnaire developed for this study. Fifty-eight of 127 (46%) patients reported taste changes in the preceding week. Of these patients, 20 (34%) reported a metallic taste. Patients treated with chemotherapy, concomitant radiotherapy, as well as targeted therapy reported metallic taste. Women experienced metallic taste more often than men. Patients experiencing a metallic taste also reported more frequently that they were bothered by sour food and that everything tasted bitter. The experience of metallic taste was highly variable among patients. In conclusion, metallic taste is a frequently experienced taste alteration by cancer patients. Patients treated with chemotherapy, concomitant radiotherapy, and targeted therapy are all at risk for this taste alteration. However, not all patients reported this alteration as bothersome.

Quantitative assessment of viable cells of Lactobacillus plantarum strains in single

Type: Journal
Year: 2017
Author(s): Fernández Ramírez MD, Kostopoulos I, Smid EH, Nierop Groot MN, Abee T
Source: International Journal of Food Microbiology 244:43-51. doi: 10.1016/j.ijfoodmicro.2016.12.014


Biofilms of Lactobacillus plantarum are a potential source for contamination and recontamination of food products. Although biofilms have been mostly studied using single species or even single strains, it is conceivable that in a range of environmental settings including food processing areas, biofilms are composed of multiple species with each species represented by multiple strains. In this study six spoilage related L. plantarum strains FBR1-FBR6 and the model strain L. plantarum WCFS1 were characterised in single, dual and multiple strain competition models. A quantitative PCR approach was used with added propidium monoazide (PMA) enabling quantification of intact cells in the biofilm, representing the viable cell fraction that determines the food spoilage risk. Our results show that the performance of individual strains in multi-strain cultures generally correlates with their performance in pure culture, and relative strain abundance in multi-strain biofilms positively correlated with the relative strain abundance in suspended (planktonic) cultures. Performance of individual strains in dual-strain biofilms was highly influenced by the presence of the secondary strain, and in most cases no correlation between the relative contributions of viable planktonic cells and viable cells in the biofilm was noted. The total biofilm quantified by CV staining of the dual and multi-strain biofilms formed was mainly correlated to CV values of the dominant strain obtained in single strain studies. However, the combination of strain FBR5 and strain WCFS1 showed significantly higher CV values compared to the individual performances of both strains indicating that total biofilm formation was higher in this specific condition. Notably, L. plantarum FBR5 was able to outgrow all other strains and showed the highest relative abundance in dual and multi-strain biofilms. All the dual and multi-strain biofilms contained a considerable number of viable cells, representing a potential source of contamination.

Creatine loading does not preserve muscle mass or strength during leg immobilization in healthy, young males

Type: Journal
Year: 2017
Author(s): Backx EM, Hangelbroek R, Snijders T, Verscheijden ML, Verdijk LB, De Groot LC, Van Loon LJ
Source: Sports Medicine 47(8):1661-1671. doi: 10.1007/s40279-016-0670-2


A short period of leg immobilization leads to rapid loss of muscle mass and strength. Creatine supplementation has been shown to increase lean body mass in active individuals and can be used to augment gains in muscle mass and strength during prolonged resistance-type exercise training. Objective: Our objective was to investigate whether creatine loading can attenuate the loss of muscle mass and strength during short-term leg immobilization. Methods: Healthy young men (n = 30; aged 23 ± 1 years; body mass index [BMI] 23.3 ± 0.5 kg/m-2) were randomly assigned to either a creatine or a placebo group. Subjects received placebo or creatine supplements (20 g/d) for 5 days before one leg was immobilized by means of a full-leg cast for 7 days. Muscle biopsies were taken before creatine loading, prior to and immediately after leg immobilization, and after 7 days of subsequent recovery. Quadriceps cross-sectional area (CSA) (computed tomography [CT] scan) and leg muscle strength (one-repetition maximum [1-RM] knee extension) were assessed before and immediately after immobilization and after 1 week of recovery. Data were analyzed using repeated measures analysis of variance (ANOVA). Data are presented consistently as mean ± standard error of the mean (SEM). Results: There was a significant overall increase in muscle total creatine content following the 5-day loading phase (p = 0.049), which appeared driven by an increase in the creatine group (from 90 ± 9 to 107 ± 4 mmol/kg-1 dry muscle) with no apparent change in the placebo group (from 88 ± 4 to 90 ± 3 mmol/kg-1; p = 0.066 for time × treatment interaction). Quadriceps muscle CSA had declined by 465 ± 59 and 425 ± 69 mm2 (p < 0.01) in the creatine and placebo group, respectively, with no differences between groups (p = 0.76). Leg muscle strength decreased from 56 ± 4 to 53 ± 4 kg in the creatine and from 59 ± 3 to 53 ± 3 kg in the placebo group, with no differences between groups (p = 0.20). Muscle fiber size did not change significantly over time in either group (p > 0.05). When non-responders to creatine loading were excluded (n = 6), responders (n = 8; total creatine content increasing from 70 to 106 mmol/kg-1) showed similar findings, with no signs of preservation of muscle mass or strength during immobilization. During the subsequent recovery phase, no differences in muscle mass or strength were found between the two groups (p > 0.05). Conclusion: Creatine supplementation prior to and during leg immobilization does not prevent or attenuate the loss of muscle mass or strength during short-term muscle disuse.

The impact of gut microbiota on gender-specific differences in immunity

Type: Journal
Year: 2017
Author(s): Fransen F, van Beek AA, Borghuis T, Meijer B, Hugenholtz F, van der Gaast-de Jongh C, Savelkoul HF, de Jonge MI, Faas MM, Boekschoten MV, Smidt H, El Aidy S, de Vos P
Source: Frontiers in Immunology. 8,754. doi: 10.3389/fimmu.2017.00754.


Males and females are known to have gender-specific differences in their immune system and gut microbiota composition. Whether these differences in gut microbiota composition are a cause or consequence of differences in the immune system is not known. To investigate this issue, gut microbiota from conventional males or females was transferred to germ-free (GF) animals of the same or opposing gender. We demonstrate that microbiota-independent gender differences in immunity are already present in GF mice. In particular, type I interferon signaling was enhanced in the intestine of GF females. Presumably, due to these immune differences bacterial groups, such as Alistipes, Rikenella, and Porphyromonadaceae, known to expand in the absence of innate immune defense mechanism were overrepresented in the male microbiota. The presence of these bacterial groups was associated with induction of weight loss, inflammation, and DNA damage upon transfer of the male microbiota to female GF recipients. In summary, our data suggest that microbiota-independent gender differences in the immune system select a gender-specific gut microbiota composition, which in turn further contributes to gender differences in the immune system.

Harnessing the advantages of hard and soft colloids by the use of core-shell particles as interfacial stabilizers

Type: Journal
Year: 2017
Author(s): Buchcic C, Tromp RH, Meinders MB, Cohen Stuart MA
Source: Soft Matter 13(7), 1326-1334. doi: 10.1039/c6m02159j


The ability of colloidal particles to penetrate fluid interfaces is a crucial factor in the preparation of particle stabilized disperse systems such as foams and emulsions. For hard micron-sized particles the insertion into fluid interfaces requires substantial energy input, but soft particles are known to adsorb spontaneously. Particle hardness, however, may also affect foam and emulsion stability. The high compliance of soft particles may compromise their ability to withstand the lateral compression associated with disproportionation. Hence, particles which can spontaneously adsorb onto fluid interfaces, and yet depict low compliance may be ideal as interfacial stabilizers. In the present work, we prepared core-shell particles comprising a hard, polystyrene core and a soft poly(N-isopropylacrylamide) based shell. We found that such core-shell particles adsorb spontaneously onto various fluid interfaces. The absence of a pronounced energy barrier for interfacial adsorption allowed the facile preparation of particle-stabilized bubbles as well as emulsion droplets. For bubbles, the stability was better than that of bubbles stabilized by entirely soft particles, but disproportionation was not stopped completely. Emulsion droplets, in contrast, showed excellent stability against both coalescence and disproportionation. Lateral compression of core-shell particles due to disproportionation was clearly limited by the presence of the polystyrene core, leading to long-lasting stability. For emulsions, we even observed non-spherical droplets, indicating a negligible Laplace pressure. Our results indicate that core-shell particles comprising a hard core and a soft shell combine the advantageous properties of hard and soft particles, namely spontaneous adsorption and limited compliance, and can therefore be superior materials for the preparation of particle-stabilized dispersions.

Spore heat activation requirements and germination responses correlate with seuences of germinant receptors and with the presence of a specific spoVA(2mob) operon in foodborne strains of bacillus subtilis

Type: Journal
Year: 2017
Author(s): Krawczyk AO, De Jong A, Omony J, Holsappel S, Wells-Bennik MH, Kuipers OP, Eijlander RT
Source: Applied and Environmental Microbiology 83(7), e03122-16. doi: 10.1128/AEM.03122-16


Spore heat resistance, germination, and outgrowth are problematic bacterial properties compromising food safety and quality. Large interstrain variation in these properties makes prediction and control of spore behavior challenging. High-level heat resistance and slow germination of spores of some natural Bacillus subtilis isolates, encountered in foods, have been attributed to the occurrence of the spoVA2mob operon carried on the Tn1546 transposon. In this study, we further investigate the correlation between the presence of this operon in high-level-heat-resistant spores and their germination efficiencies before and after exposure to various sublethal heat treatments (heat activation, or HA), which are known to significantly improve spore responses to nutrient germinants. We show that high-level-heat-resistant spores harboring spoVA2mob required higher HA temperatures for efficient germination than spores lacking spoVA2mob The optimal spore HA requirements additionally depended on the nutrients used to trigger germination, l-alanine (l-Ala), or a mixture of l-asparagine, d-glucose, d-fructose, and K+ (AGFK). The distinct HA requirements of these two spore germination pathways are likely related to differences in properties of specific germinant receptors. Moreover, spores that germinated inefficiently in AGFK contained specific changes in sequences of the GerB and GerK germinant receptors, which are involved in this germination response. In contrast, no relation was found between transcription levels of main germination genes and spore germination phenotypes. The findings presented in this study have great implications for practices in the food industry, where heat treatments are commonly used to inactivate pathogenic and spoilage microbes, including bacterial spore formers.IMPORTANCE This study describes a strong variation in spore germination capacities and requirements for a heat activation treatment, i.e., an exposure to sublethal heat that increases spore responsiveness to nutrient germination triggers, among 17 strains of B. subtilis, including 9 isolates from spoiled food products. Spores of industrial foodborne isolates exhibited, on average, less efficient and slower germination responses and required more severe heat activation than spores from other sources. High heat activation requirements and inefficient, slow germination correlated with elevated resistance of spores to heat and with specific genetic features, indicating a common genetic basis of these three phenotypic traits. Clearly, interstrain variation and numerous factors that shape spore germination behavior challenge standardization of methods to recover highly heat-resistant spores from the environment and have an impact on the efficacy of preservation techniques used by the food industry to control spores.

Factors that influence the volatile organic compound content in human breath

Type: Journal
Year: 2017
Author(s): Blanchet L, Smolinska A, Baranska A, Tigchelaar E, Swertz M, Zhernakova A, Dallinga JW, Wijmenga C, van Schooten FJ
Source: Journal of Breath Research 11(1), 016013. doi:10.1088/1752-7163/115cc5


Background: Thousands of endogenous and exogenous volatile organic compounds (VOCs) are excreted in each breath. Inflammatory and deviant metabolic processes affect the level of endogeneous VOCs, which can serve as specific biomarkers for clinical diagnosis and disease monitoring. Important issues that still need to be tackled are related to potential confounding factors like gender and age and endogenous and exogenous factors, like f.i. smoking. Methods: The aim of this study was to systematically access the effect of endogenous and exogenous factors on VOC composition of exhaled breath. In the current study breath samples from 1417 adult participants from the LifeLines cohort, a general population cohort in the Netherlands, were collected and the total content of VOCs was measured using gas chromatography-time-of-flight-mass spectrometry. Breath samples were collected in Groningen and transferred to carbon tubes immediately. These samples were then shipped to Maastricht and measured in batches. VOCs profiles were correlated to 14 relevant characteristics of all participants including age, BMI, smoking and blood cell counts and metabolic parameters as well as to 16 classes of medications. Results: VOCs profiles were shown to be significantly influenced by smoking behavior and to a lesser extent by age, BMI and gender. These factors need to be controlled for in breath analysis studies. We found no evidence whatsoever in this 1417 subjects’ cohort that white blood cell counts, cholesterol or triglycerides levels have an influence on the VOC profile. Thus they may not have to be controlled for in exhaled breath studies. Conclusion: The large cohort of volunteers used here represents a unique opportunity to gauge the factors influencing VOCs profiles in a general population i.e. the most clinically relevant population. Classical clinical parameters and smoking habits clearly influence breath content and should therefore be accounted for in future clinical studies involving breath analysis.

Flavor pleasantness processing in the ventral emotion network

Type: Journal
Year: 2017
Author(s): Dalenberg JR, Weitkamp L, Renken RJ, Nanetti L, Ter Horst GJ
Source: PLoS One 12(2): e0180310. doi: 10.1371/journal.pone.0170310


The ventral emotion network-encompassing the amygdala, insula, ventral striatum, and ventral regions of the prefrontal cortex-has been associated with the identification of emotional significance of perceived external stimuli and the production of affective states. Functional magnetic resonance imaging (fMRI) studies investigating chemosensory stimuli have associated parts of this network with pleasantness coding. In the current study, we independently analyzed two datasets in which we measured brain responses to flavor stimuli in young adult men. In the first dataset, participants evaluated eight regular off the shelf drinking products while participants evaluated six less familiar oral nutritional supplements (ONS) in the second dataset. Participants provided pleasantness ratings 20 seconds after tasting. Using independent component analysis (ICA) and mixed effect models, we identified one brain network in the regular products dataset that was associated with flavor pleasantness. This network was very similar to the ventral emotion network. Although we identified an identical network in the ONS dataset using ICA, we found no linear relation between activation of any network and pleasantness scores within this dataset. Our results indicate that flavor pleasantness is processed in a network encompassing amygdala, ventral prefrontal, insular, striatal and parahippocampal regions for familiar drinking products. For more unfamiliar ONS products the association is not obvious, which could be related to the unfamiliarity of these products.

Controlling agglomeration of protein aggregates for structure formation in liquid oil: a sticky business

Type: Journal
Year: 2017
Author(s): De Vries A, Lopez Gomez Y, Jansen B, Van der Linden E, Scholten E
Source: ACS Applied Material and Interfaces 9(11), 10136-0147. doi: 10.1021/acsami.7b00443


Proteins are known to be effective building blocks when it comes to structure formation in aqueous environments. Recently, we have shown that submicron colloidal protein particles can also be used to provide structure to liquid oil and form so-called oleogels ( de Vries , A. J. Colloid Interface Sci. 2017 , 486 , 75 – 83 ) . To prevent particle agglomeration, a solvent exchange procedure was used to transfer the aggregates from water to the oil phase. The aim of the current paper was to elucidate on the enhanced stability against agglomeration of heat-set whey protein isolate (WPI) aggregates to develop an alternative for the solvent exchange procedure. Protein aggregates were transferred from water to several solvents differing in polarity to investigate the effect on agglomeration and changes in protein composition. We show that after drying protein aggregates by evaporation from solvents with a low polarity (e.g., hexane), the protein powder shows good dispersibility in liquid oil compared to powders dried from solvents with a high polarity. This difference in dispersibility could not be related to changes in protein composition or conformation but was instead related to the reduction of attractive capillary forces between the protein aggregates during drying. Following another route, agglomeration was also prevented by applying high freezing rates prior to freeze-drying. The rheological properties of the oleogels prepared with such freeze-dried protein aggregates were shown to be similar to that of oleogels prepared using a solvent exchange procedure. This Research Article provides valuable insights in how to tune the drying process to control protein agglomeration to allow for subsequent structure formation of proteins in liquid oil

β2→1-Fructans modulate the immune system in vivo in a bicrobiota-dependent and -independent fashion

Type: Journal
Year: 2017
Author(s): Fransen Fl Sahasrabudhe N, Elderman M, Bosveld M, El Aidy S, Hugenholtz F, Borghuis T, Kousemaker B, Winkel Sm, Van der Gaast-de Jongh C, De Jonge MI, Boekschoten MV, Smidt H, Schols HA, De Vos P
Source: Frontiers in Immunology 8:154. doi: 10.3389/fimmu.2017.00154


It has been shown in vitro that only specific dietary fibers contribute to immunity, but studies in vivo are not conclusive. Here, we investigated degree of polymerization (DP) dependent effects of β2→1-fructans on immunity via microbiota-dependent and -independent effects. To this end, conventional or germ-free mice received short- or long-chain β2→1-fructan for 5 days. Immune cell populations in the spleen, mesenteric lymph nodes (MLNs), and Peyer’s patches (PPs) were analyzed with flow cytometry, genome-wide gene expression in the ileum was measured with microarray, and gut microbiota composition was analyzed with 16S rRNA sequencing of fecal samples. We found that β2→1-fructans modulated immunity by both microbiota and microbiota-independent effects. Moreover, effects were dependent on the chain-length of the β2→1-fructans type polymer. Both short- and long-chain β2→1-fructans enhanced T-helper 1 cells in PPs, whereas only short-chain β2→1-fructans increased regulatory T cells and CD11b-CD103- dendritic cells (DCs) in the MLN. A common feature after short- and long-chain β2→1-fructan treatment was enhanced 2-alpha-l-fucosyltransferase 2 expression and other IL-22-dependent genes in the ileum of conventional mice. These effects were not associated with shifts in gut microbiota composition, or altered production of short-chain fatty acids. Both short- and long-chain β2→1-fructans also induced immune effects in germ-free animals, demonstrating direct effect independent from the gut microbiota. Also, these effects were dependent on the chain-length of the β2→1-fructans. Short-chain β2→1-fructan induced lower CD80 expression by CD11b-CD103- DCs in PPs, whereas long-chain β2→1-fructan specifically modulated B cell responses in germ-free mice. In conclusion, support of immunity is determined by the chemical structure of β2→1-fructans and is partially microbiota independent.

Differences in dietary intake during chemotherapy in breast cancer patients compared to women without cancer

Type: Journal
Year: 2017
Author(s): De Vries YC, Van den Berg MMGA, De Vries JHM, Boesveldt S, De Kruif JTCM, Buist N, Haringhuizen A, Los M, Sommeijer DW, Timmer-Bonte JHN, Van Laarhoven HWM, Visser M, Kampman E, Winkels RM
Source: Supportive Care Cancer 25(8), 2581-2591


Purpose: Breast cancer patients receiving chemotherapy often experience symptoms such as nausea, vomiting and loss of appetite that potentially affect dietary habits. This study assessed the intake of energy, macronutrients and food groups before and during chemotherapy in breast cancer patients compared with women without cancer, and determined the association between symptoms and energy and macronutrient intake.

Methods: This study included 117 newly diagnosed breast cancer patients scheduled for chemotherapy and 88 women without cancer. Habitual intake before chemotherapy was assessed with a food frequency questionnaire. Two 24-h dietary recalls were completed on random days for each participant during the whole chemotherapy treatment for patients and within 6 months after recruitment for women without cancer. Shortly, after the dietary recall, participants filled out questionnaires on symptoms.

Results: Before chemotherapy, habitual energy and macronutrient intake was similar for breast cancer patients and women without cancer. During chemotherapy, breast cancer patients reported a significantly lower total energy, fat, protein and alcohol intake than women without cancer, as shown by a lower intake of pastry and biscuits, cheese, legumes and meat products. A decline in subjective taste perception, appetite and hunger and experiencing a dry mouth, difficulty chewing, lack of energy and nausea were associated with a lower energy intake.

Conclusions: Symptoms induced by chemotherapy are associated with lower dietary intake and manifested by a lower intake of specific food groups. To ensure an optimal dietary intake during chemotherapy, it is important to monitor nutritional status and symptom burden during chemotherapy in breast cancer patients.

The impact of protein quantity during energy restriction on genom-wide gene expression analysis in human adipose tissue of obese humans

Type: Journal
Year: 2017
Author(s): Van Bussel IPG,; Backx EMP, De Groot LCPGM, Tieland M, Afman L
Source: International Journal of Obesity 41, 1114–1120. doi:10.1038/ijo.2017.76


Background: Overweight and obesity is a growing health problem worldwide. The most effective strategy to reduce weight is energy restriction (ER). ER has been shown to be beneficial in disease prevention and it reduces chronic inflammation. Recent studies suggest that reducing the protein quantity of a diet contributes to the beneficial effects by ER. The organ most extensively affected during ER is white adipose tissue (WAT). Objective: The first objective was to assess changes in gene expression between a high protein diet and a normal protein diet during ER. Secondly, the total effect of ER on changes in gene expression in WAT was assessed. Methods: In a parallel double-blinded controlled study, overweight older participants adhered to a 25% ER diet, either combined with high protein intake (HP-ER, 1.7 g/kg per day), or with normal protein intake (NP-ER, 0.9 g/kg per day) for 12 weeks. From 10 HP-ER participants and 12 NP-ER participants subcutaneous WAT biopsies were collected before and after the diet intervention. Adipose tissue was used to isolate total RNA and to evaluate whole genome gene expression changes upon a HP-ER and NP-ER diet. Results: A different gene expression response between HP-ER and NP-ER was observed for 530 genes. After NP-ER a downregulation in expression of genes linked to immune cell infiltration, adaptive immune response, and inflammasome was found whereas no such effect was found after HP-ER. HP-ER resulted in upregulation in expression of genes linked to cell cycle, GPCR signalling, olfactory signalling and nitrogen metabolism. Upon 25% ER, gene sets related to energy metabolism and immune response were decreased. Conclusions: Based on gene expression changes, we concluded that consumption of normal protein quantity compared to high protein quantity during ER has a more beneficial effect on inflammation-related gene expression in WAT.

Alcohol and red wine consumption, but not fruit, vegetables, fish or dairy products, are associated with less endothelial dysfunction and less low-grade inflammation: the Hoorn Study

Type: Journal
Year: 2017
Author(s): Van Bussel BC, Henry RM, Schalkwijk CG, Dekker JM, Nijpels G, Feskens EJ, Stehouwer CD
Source: European Journal of Nutrition. doi:10.1007/s00394-017-1420-4


Purpose: Endothelial dysfunction and low-grade inflammation are key phenomena in the pathobiology of cardiovascular disease (CVD). Their dietary modification might explain the observed reduction in CVD that has been associated with a healthy diet rich in fruit, vegetables and fish, low in dairy products and with moderate alcohol and red wine consumption. We investigated the associations between the above food groups and endothelial dysfunction and low-grade inflammation in a population-based cohort of Dutch elderly individuals.

Methods: Diet was measured by food frequency questionnaire (n = 801; women = 399; age 68.5 ± 7.2 years). Endothelial dysfunction was determined (1) by combining von Willebrand factor, and soluble intercellular adhesion molecule 1 (sICAM-1), vascular cell adhesion molecule 1, endothelial selectin and thrombomodulin, using Z-scores, into a biomarker score and (2) by flow-mediated vasodilation (FMD), and low-grade inflammation by combining C-reactive protein, serum amyloid A, interleukin 6, interleukin 8, tumour necrosis factor α and sICAM-1 into a biomarker score, with smaller FMD and higher scores representing more dysfunction and inflammation, respectively. We used linear regression analyses to adjust associations for sex, age, energy, glucose metabolism, body mass index, smoking, prior CVD, educational level, physical activity and each of the other food groups.

Results: Moderate [β (95% CI) -0.13 (-0.33; 0.07)] and high [-0.22 (-0.45; -0.003)] alcohol consumption, and red wine [-0.16 (-0.30; -0.01)] consumption, but none of the other food groups, were associated with a lower endothelial dysfunction biomarker score and a greater FMD. The associations for FMD were, however, not statistically significant. Only red wine consumption was associated with a lower low-grade inflammation biomarker score [-0.18 (-0.33; -0.04)].

Conclusions: Alcohol and red wine consumption may favourably influence processes involved in atherothrombosis.

Supplementation of diet with galacto-oligosaccharides increases bifidobacterial but not insulin sensitivity, in obese prediabetic individuals

Type: Journal
Year: 2017
Author(s): Canfora, E.E., van der Beek, C.M.E., Hermes, G.D.A., Goossens, G., Jocken, J.W.E., Holst, J.J., Venema, K., Smidt, H., Zoetendal, E., Dejong, C.H.C., Lenaerts, K., Blaak, E.E.
Source: Gastroenterology 153(1), 87-97.e3. doi:10.1053/j.gastro.2017.03.051


Background & aims: The gut microbiota affects host lipid and glucose metabolism, satiety, and chronic low-grade inflammation to contribute to obesity and type 2 diabetes. Fermentation end products, in particular the short-chain fatty acid (SCFA) acetate, are believed to be involved in these processes. We investigated the long-term effects of supplementation with galacto-oligosaccharides (GOS), an acetogenic fiber, on the composition of the human gut microbiota and human metabolism.
Methods: We performed a double-blinded, placebo-controlled, parallel intervention study of 44 overweight or obese (body mass index, 28-40 kg/m2) prediabetic men and women (ages, 45-70 y) from October 2014 through October 2015 in Maastricht, The Netherlands. The participants were assigned randomly to groups who ingested 15 g GOS or isocaloric placebo (maltodextrin) daily with their regular meals for 12 weeks. Before and after this period, we collected data on peripheral and adipose tissue insulin sensitivity, fecal microbiota composition, plasma and fecal SCFA, energy expenditure and substrate oxidation, body composition, and hormonal and inflammatory responses. The primary outcome was the effect of GOS on peripheral insulin sensitivity, measured by the hyperinsulinemic-euglycemic clamp method.
Results: Supplementation of diets with GOS, but not placebo, increased the abundance of Bifidobacterium species in feces by 5-fold (P = .009; q = 0.144). Microbial richness or diversity in fecal samples were not affected. We did not observe any differences in fecal or fasting plasma SCFA concentrations or in systemic concentrations of gut-derived hormones, incretins, lipopolysaccharide-binding protein, or other markers of inflammation. In addition, no significant alterations in peripheral and adipose tissue insulin sensitivity, body composition, and energy and substrate metabolism were found.
Conclusions: Twelve-week supplementation of GOS selectively increased fecal Bifidobacterium species abundance, but this did not produce significant changes in insulin sensitivity or related substrate and energy metabolism in overweight or obese prediabetic men and women.

 

Weight change during chemotherapy in breast cancer patients: a meta-analysis

Type: Journal
Year: 2017
Author(s): Van den Berg M, Winkels RM, De Kruif JT, Van Laarhoven HW, Visser M, De Vries JH, De Vries YC, Kampman E
Source: BMC Cancer 17(1), 259. doi:10.1186/s12885-017-3242-4


Background: Weight gain during chemotherapy in women with breast cancer is commonly reported. However, there are important differences between studies that examined weight change during chemotherapy; e.g. type of chemotherapy, menopausal status, time between body weight measurements and sample size. The purpose of this meta-analysis was to quantify changes in body weight during chemotherapy for women with breast cancer, taking these differences into account. Methods: We identified relevant studies using PubMed, Scopus and Embase databases. The search was limited to human studies published in English up to and including December 2015. Only studies among women with early stage breast cancer treated with chemotherapy, with reported body weight before and after chemotherapy and type of chemotherapy were included. Random-effect models were used, and heterogeneity between studies was explored through stratified analyses and meta-regression. Sensitivity analyses were done to explore whether a specific study markedly affected the results. Results: In total 25 papers were found, including data from 2620 women. Overall, body weight increased during chemotherapy: 2.7 kg (95% CI 2.0, 7.5) with a high degree of heterogeneity (I2 = 94.2%). Stratified analyses showed weight gain in all strata, but did not substantially reduce heterogeneity. Univariate meta-regression showed less weight gain in prospective studies compared to chart review studies (-2.0, 95% CI: -3.1, -0.8). Studies including cyclophosphamide, methotrexate and 5-fluorouracil (CMF) regimes showed a greater weight gain compared to those that did not (2.2, 95% CI: 1.1, 3.3); and papers published until the year 2000 showed a greater weight gain compared to those published after 2000 (1.9, 95% CI:-0.8, 3.1). In the multivariate models only studies including CMF regimes and studies published until 2000 were associated with significant weight gain of respectively 1.3 and 1.4 kg. Conclusion: Despite the high heterogeneity, this meta-analysis shows significant weight gain during chemotherapy for women with breast cancer. Weight gain was more pronounced in papers published until 2000 and women receiving CMF as chemotherapy regime. Although weight gain after chemotherapy has decreased over the course of time, weight gain is still substantial and deserves clinical attention.

Vitamin and mineral status in chronic fatigue syndrome and fibromyalgia syndrome: A systematic review and meta-analysis.

Type: Journal
Year: 2017
Author(s): Joustra ML, Minovic I, Janssens KAM, Bakker SJL, Rosmalen JGM
Source: PLoS One 12(4), e0176631. doi:10.1371/journal.pone.0176631


Background: Many chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS) patients (35-68%) use nutritional supplements, while it is unclear whether deficiencies in vitamins and minerals contribute to symptoms in these patients. Objectives were (1) to determine vitamin and mineral status in CFS and FMS patients as compared to healthy controls; (2) to investigate the association between vitamin and mineral status and clinical parameters, including symptom severity and quality of life; and (3) to determine the effect of supplementation on clinical parameters. Methods: The databases PubMed, EMBASE, Web of Knowledge, and PsycINFO were searched for eligible studies. Articles published from January 1st 1994 for CFS patients and 1990 for FMS patients till March 1st 2017 were included. Articles were included if the status of one or more vitamins or minerals were reported, or an intervention concerning vitamins or minerals was performed. Two reviewers independently extracted data and assessed the risk of bias. Results: A total of 5 RCTs and 40 observational studies were included in the qualitative synthesis, of which 27 studies were included in the meta-analyses. Circulating concentrations of vitamin E were lower in patients compared to controls (pooled standardized mean difference (SMD): -1.57, 95%CI: -3.09, -0.05; p = .042). However, this difference was not present when restricting the analyses to the subgroup of studies with high quality scores. Poor study quality and a substantial heterogeneity in most studies was found. No vitamins or minerals have been repeatedly or consistently linked to clinical parameters. In addition, RCTs testing supplements containing these vitamins and/or minerals did not result in clinical improvements. Discussion:Little evidence was found to support the hypothesis that vitamin and mineral deficiencies play a role in the pathophysiology of CFS and FMS, and that the use of supplements is effective in these patients. Registration: Study methods were documented in an international prospective register of systematic reviews (PROSPERO) protocol, registration number: http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015032528.

High dietary protein content has an antisteatotic and antiobesogenic effect in mice

Type: Journal
Year: 2017
Author(s): Garcia Caraballo SC, Comhair TM, Dejong CHC, Lamers WH, Koehler SE
Source: Biochimica et Biophysica Acta, 1863(7), 1789-1804. doi:10.1016/j.bbadis.2017.04.022


The hallmark of nonalcoholic fatty liver disease is steatosis of unknown etiology. To test how dietary protein decreases steatosis, we fed female C57BL/6 J mice low-fat (8 en%) or high-fat (42 en%) combined with low-protein (11 en%), high-protein (HP; 35 en%) or extra-high-protein (HPX; 58 en%) diets for 3 weeks. The 35 en% protein diets reduced hepatic triglyceride, free fatty acid, cholesterol and phospholipid contents to ~50% of that in 11 en% protein diets. Every additional 10 en% protein reduced hepatic fat content ~1.5 g%. HP diets had no effect on lipogenic or fatty acid-oxidizing genes except Ppargc1α (+30%), increased hepatic PCK1 content 3- to 5-fold, left plasma glucose and hepatic glycogen concentration unchanged, and decreased inflammation and cell stress (decreased Fgf21 and increased Gsta expression). The HP-mediated decrease in steatosis correlated inversely with plasma branched-chain amino-acid (BCAA) concentrations and hepatic content of BCAA-derived monomethyl branched-chain fatty acids (mmBCFAs) 14-methylpentadecanoic (14-MPDA; valine-derived) and, to a lesser extent, 14-methylhexadecanoic acid (isoleucine-derived). Liver lipid content was 1.6- to 1.8-fold higher in females than in males, but the anti-steatotic effect of HP diets was equally strong. The strong up-regulation of PCK1 and literature data showing an increase in phosphoenolpyruvate and a decline in tricarboxylic acid cycle intermediates in liver reveal that an increased efflux of these intermediates from mitochondria represents an important effect of an HP diet. The HP diet-induced increase in 14-MPDA and the dietary response in gene expression were more pronounced in females than males. Our findings are compatible with a facilitating role of valine-derived mmBCFAs in the antisteatotic effect of HP diets.

Vitamin B-6 deficiency is common and associated with poor long-term outcome in renal transplant recipients

Type: Journal
Year: 2017
Author(s): Minovic I, Riphagen IJ, Van den Berg E, Kootstra-Ros JE, Van Faassen M, Gomes Neto AW, Geleijnse JM, Gans RO, Eggersdorfer M, Navis GJ, Kema IP, Bakker SJ
Source: American Journal of Clinical Nutrition 105(6), 1344-1350. doi:10.3945/ajcn.116.151431


Background: Previous studies have reported low circulating concentrations of pyridoxal-5-phospate (PLP) in renal transplant recipients (RTRs). It is unknown whether this is because of low intake or altered handling, and it is also unknown whether variation in circulating concentrations of PLP influences long-term outcome.Objective: We compared vitamin B-6 intake and circulating PLP concentrations of RTRs with those of healthy controls and investigated long-term clinical implications of vitamin B-6 deficiency in stable outpatient RTRs.Design: In a longitudinal cohort of 687 stable RTRs (57% male; mean ± SD age: 53 ± 13 y) with a median (IQR) follow-up of 5.3 y (4.8-6.1 y) and 357 healthy controls (47% male; age 54 ± 11 y), baseline vitamin B-6 was measured as plasma PLP by high-performance liquid chromatography (HPLC). Vitamin B-6 deficiency was defined as PLP <20 nmol/L, and insufficiency as PLP 20-30 nmol/L. Dietary intake was assessed by validated food-frequency questionnaires.Results: At inclusion [5.3 y (1.8-12.1 y) after transplantation], the mean vitamin B-6 intakes in RTRs and healthy controls were 1.77 ± 0.49 and 1.85 ± 0.56 mg/d, respectively (P = 0.23). In these groups, the median plasma PLP concentrations were 29 nmol/L (17-50 nmol/L) and 41 nmol/L (29-60 nmol/L), respectively (P < 0.001). Accordingly, deficiency was present in 30% of RTRs compared with 11% of healthy controls. PLP concentrations were inversely associated with glucose homeostasis variables and inflammation variables (all P < 0.01). During follow-up, 149 (21%) RTRs died and 82 (12%) developed graft failure. In RTRs, vitamin B-6 deficiency was associated with considerably higher mortality risk (HR 2.14; 95% CI: 1.48, 3.08) than a sufficient vitamin B-6 status, independent of potential confounders. No associations were observed for graft failure (P = 0.18).Conclusions: Vitamin B-6 deficiency is common in RTRs and does not seem to be a consequence of inadequate intake. In addition, this deficient state is clinically relevant and independently associated with an increased risk of mortality in RTRs.

Two complementary approaches to quantify variability in heat resistance of spores of Bacillus subtilis

Type: Journal
Year: 2017
Author(s): Den Besten HMW, Berendsen EM, Wells-Bennik MHJ, Straatsma H, Zwietering MH
Source: International Journal of Food Microbiology 254, 48-35. doi:10.1016/j.ijfoodmicro.2017.04.014


Realistic prediction of microbial inactivation in food requires quantitative information on variability introduced by the microorganisms. Bacillus subtilis forms heat resistant spores and in this study the impact of strain variability on spore heat resistance was quantified using 20 strains. In addition, experimental variability was quantified by using technical replicates per heat treatment experiment, and reproduction variability was quantified by using two biologically independent spore crops for each strain that were heat treated on different days. The fourth-decimal reduction times and z-values were estimated by a one-step and two-step model fitting procedure. Grouping of the 20 B. subtilis strains into two statistically distinguishable groups could be confirmed based on their spore heat resistance. The reproduction variability was higher than experimental variability, but both variabilities were much lower than strain variability. The model fitting approach did not significantly affect the quantification of variability. Remarkably, when strain variability in spore heat resistance was quantified using only the strains producing low-level heat resistant spores, then this strain variability was comparable with the previously reported strain variability in heat resistance of vegetative cells of Listeria monocytogenes, although in a totally other temperature range. Strains that produced spores with high-level heat resistance showed similar temperature range for growth as strains that produced low-level heat resistance. Strain variability affected heat resistance of spores most, and therefore integration of this variability factor in modelling of spore heat resistance will make predictions more realistic.

Docosahexaenoyl serotonin emerges as most potent inhibitor of IL-17 and CCL-20 released by blood mononuclear cells from a series of N-acyl serotonins identified in human intestinal tissue

Type: Journal
Year: 2017
Author(s): Wang Y, Balvers MGJ, Hendriks HFJ, Wilpshaar T, van Heek T, Witkamp RF, Meijerink J
Source: Biochimica et Biophysica Acta 1862(9), 823-831


Fatty acid amides (FAAs), conjugates of fatty acids with ethanolamine, mono-amine neurotransmitters or amino acids are a class of molecules that display diverse functional roles in different cells and tissues. Recently we reported that one of the serotonin-fatty acid conjugates, docosahexaenoyl serotonin (DHA-5-HT), previously found in gut tissue of mouse and pig, attenuates the IL-23-IL-17 signaling axis in LPS-stimulated mice macrophages. However, its presence and effects in humans remained to be elucidated. Here, we report for the first time its identification in human intestinal (colon) tissue, along with a series of related N-acyl serotonins. Furthermore, we tested these fatty acid conjugates for their ability to inhibit the release of IL-17 and CCL-20 by stimulated human peripheral blood mononuclear cells (PBMCs). Serotonin conjugates with palmitic acid (PA-5-HT), stearic acid (SA-5-HT) and oleic acid (OA-5-HT) were detected in higher levels than arachidonoyl serotonin (AA-5-HT) and DHA-5-HT, while eicosapentaenoyl serotonin (EPA-5-HT) could not be quantified. Among these, DHA-5-HT was the most potent in inhibiting IL-17 and CCL-20, typical Th17 pro-inflammatory mediators, by Concanavalin A (ConA)-stimulated human PBMCs. These results underline the idea that DHA-5-HT is a gut-specific endogenously produced mediator with the capacity to modulate the IL-17/Th17 signaling response. Our findings may be of relevance in relation to intestinal inflammatory diseases like Crohn’s disease and Ulcerative colitis.

Colonic infusions of short-chain fatty acids mixtures promote energy metabolism in overweight/obese men: a randomized crossover trial

Type: Journal
Year: 2017
Author(s): Canfora EE, van der Beek CM, Jocken JWE, Goossens GH, Holst JJ, Olde Damink SWM, Lenaerts K, Dejong CHC, Blaak EE
Source: Scientific Reports 7(1), 2360. doi:10.1038/s41598-017-02546-x


Background & aims: Gut-derived short-chain fatty acids (SCFA), formed by microbial fermentation of dietary fibre(s), are believed to be involved in the aetiology of obesity and diabetes. The study aim was to investigate effects of colonic administration of physiologically relevant mixtures of the SCFA acetate, propionate and butyrate on human substrate and energy metabolism. Methods: In this randomized, double-blind, placebo-controlled, crossover study, twelve normoglycemic males (BMI ≥ 25 – 34.9 kg/m2) underwent four investigational days with rectal administration of 200 mmol/L SCFA mixtures high in acetate (HA), propionate (HP), butyrate (HB) and placebo (PLA). The primary outcomes fat oxidation and energy expenditure (EE) were measured via an open-circuit ventilated hood system. Blood samples were collected during fasting and postprandial conditions (oral glucose load), before and 30, 60, 90 and 120 minutes after colonic infusions to determine circulating metabolites and hormones. Results: All three SCFA mixtures increased fasting fat oxidation (P.01), whilst resting EE increased only after HA and HP, when compared to PLA (P.05). HA and HP increased fasting plasma acetate concentrations, and all three SCFA mixtures increased fasting and postprandial plasma butyrate concentrations, when compared to PLA (all P.05). Postprandial plasma propionate increased after HP as compared to PLA (P=.008). All three SCFA mixtures increased fasting and postprandial plasma PYY concentrations, and decreased fasting free glycerol concentrations, when compared to PLA (all P.05). Conclusion: Colonic infusions of SCFA mixtures, in concentrations and ratios putatively reached after dietary fibre intake, beneficially modulated whole body energy metabolism, with a pronounced increase in fat oxidation, EE and satietystimulating hormone PYY, next to a decrease in whole-body lipolysis. Increasing colonic SCFA concentrations may yield new mechanisms for treating or preventing metabolic disorders. Key words: gut microbiota, dietary fibres, substrate metabolism, and obesity

Trans-resveratrol supplementation and endothelial function during the fasting and postprandial phase: a randomized placebo-controlled trial in overweight and slightly obese participants

Type: Journal
Year: 2017
Author(s): Van der Made SM, Plat J, Mensink RP
Source: Nutrients 9(6), E596. doi: 10.3390/nu9060596


Background: Studies on the effects of longer-term intake of trans-resveratrol on flow-mediated vasodilation (FMD) are conflicting. In addition, effects of longer-term trans-resveratrol intake on endothelial function during the postprandial phase are not known. Objective: To study in overweight and slightly obese subjects the effect of longer-term trans-resveratrol intake on FMD. Furthermore, effects on arterial stiffness, as measured by pulse wave velocity (PWV) were assessed, as well as effects on vascular function after the intake of a mixed meal. Design: A randomized, placebo-controlled crossover study was conducted in 45 overweight and slightly obese men (n = 25) and women (n = 20) with a mean age of 61 ± 7 years. Subjects received in random order resveratrol (150 mg per day) or placebo capsules for 4 weeks, separated by a 4-week wash-out period. At the end of each intervention period, FMD and PWV measurements were performed before and after a mixed meal challenge. Results: Compared with placebo, resveratrol had no effects on endothelial function. After resveratrol supplementation, fasting FMD was 0.1% lower (P=0.692), and PWV was 0.6 m/s higher (P=0.159). These parameters were also not differently affected after the postprandial test. Also, biomarkers for endothelial function (sE-selectin, sICAM-3, sP-selectin, sThrombomodulin, sVCAM-1), inflammation (IL-6, TNF), glucose and lipid metabolism were comparable during the postprandial tests. Conclusion: 150 mg of daily resveratrol intake does not change endothelial function and markers for endothelial activation and inflammation in the fasting state or postprandial phase in overweight and slightly obese men and women.

Potential of microbubbles as fat replacer: Effect on rheological, tribological and sensorial propertiesof model food systems

Type: Journal
Year: 2016
Author(s): Rovers TAM, Sala G, Van der Linden E, Meinders MBJ
Source: Microbubble, microstructure, rheology, sensory, tribology doi:10.1111/jtxs.12175


ABSTRACT The potential of microbubbles as fat replacers and texture modifiers was assessed by comparison of the rheological and tribological properties of model food systems that contained (1) microbubbles, (2) emulsion droplets or (3) no added colloidal structures. We used (a) liquids with thickener, (b) liquids without thickener and (c) gels as model food systems. A sensory test was performed in which we investigated whether panellists could discriminate between the different samples. It was found that the food system containing emulsion droplets had better lubrication properties than the dispersions containing microbubbles and solutions without any colloidal structures. The systems with emulsion droplets could be well discriminated sensorially from those with microbubbles or those without an added colloidal structures. Samples containing a mixture of emulsion droplets and microbubbles were comparable to those of samples containing only emulsion droplets.We conclude that at the studied volume fraction of 5% the measured friction and perceived mouthfeel of systems containing microbubbles is rather different from those of systems containing emulsion droplets, while both have a diameter of about 1 lm. At this volume fraction microbubbles cannot simply replace emulsion droplets.

The palatability of oral nutritional supplements: before, during, and after chemotherapy

Type: Journal
Year: 2016
Author(s): IJpma I, Renken RJ, ter Horst GJ, Reyners AKL
Source:The online version of this article doi:10.1007/s00520-016-3263-6)


Abstract Purpose Oral nutritional supplements (ONS) are commonly prescribed to malnourished patients to improve their nutritional status. Taste and smell changes in patients with cancer can affect the palatability of ONS. The present study investigated: (1) the palatability of six ONS in testicular cancer patients before, during the first two cycles, and after chemotherapy; (2) the relation between the palatability and taste and smell function; (3) the metallic taste of these ONS. Methods Twenty-one testicular cancer patients undergoing first-line cisplatin-based chemotherapy participated. Two milkbased (vanilla; strawberry), two juice-based (apple; orange), and two yoghurt-based (vanilla-lemon; peach-orange) ONS were tested. A questionnaire was used to assess the palatability of ONS and to which extent the attribute metallicwas applicable. Taste and smell function were measured using taste strips and SniffinSticks, respectively. Results The palatability of ONS was highly variable among patients. The milk-based strawberry ONS was preferred most before, during, and after chemotherapy. The liking of the milkbased vanilla ONS tended to decrease over time (p = 0.053), whereas the liking of the other ONS remained stable. A higher smell threshold and a lower sour taste threshold were correlated to a decreased liking of the milk-based vanilla ONS. The two juice-based ONS tended to taste more metallic during than before chemotherapy. Conclusion Health care professionals and patients should be aware that the palatability of ONS can change over time. Regular structured contact between health care professionals and patients regarding the choice of ONS seems warranted.

 

Identification of critical concentrations determining foam ability and stability of beta-locatoglobulin

Type: Journal
Year: 2016
Author(s): Lech FJ, Delahajie RJBM, Meinders MBJ, Gruppen H, Wierenga PA
Source: Scientific Reports | 6:36100 | DOI: 10.1038/srep36100


To understand the properties of protein stabilized foam, quantitative parameters, such as the concentration dependence of the foam properties need to be determined. Recently, a concept was proposed that predicts the emulsifying ability (i.e. the droplet size in emulsions) based on different parameters, including the protein concentration. The aim of the present study is to investigate whether a similar concept can be applied to describe the foam ability and stability of protein stabilized foams. To achieve this, the foam, thin film and molecular properties of b-lactoglobulin (BLG) were determined at different concentrations and different pH values (pH 3e7). At each pH, a certain critical concentration for foam ability CFA, could be identified above which the set foam volume was reached, while below that value the set volume was not reached. Furthermore, for all pH another critical concentration (Ccrr32) at C > CFA was identified as the point where the bubble radius (measured at the end of foam formation) reached a minimal value. The foam ability increased with increasing pH (pH 3e7). The difference in foam ability as a function of pH was reflected in the adsorption rate (slope P/t0.5 curve) of BLG. The foam stability increased with increasing concentration at each pH value but even in the protein rich regime where C > Ccrr32 different foam stabilities were observed, which were highest at pH 7.

Characterization of the starchacting MaAmyB enzyme from Microbacterium aurum B8.A representing the novel subfamily GH13_42 with an unusual, multidomain organization

Type: Journal
Year: 2016
Author(s): Valk V, van der Kaaji RM, Dijkhuizen L,
Source:Scientific Reports | 6:36100 | DOI: 10.1038/srep36100


The bacterium Microbacterium aurum strain B8.A degrades granular starches, using the multi-domain MaAmyA α-amylase to initiate granule degradation through pore formation. This paper reports the characterization of the M. aurum B8.A MaAmyB enzyme, a second starch-acting enzyme with multiple FNIII and CBM25 domains. MaAmyB was characterized as an α-glucan 1,4-α-maltohexaosidase with the ability to subsequently hydrolyze maltohexaose to maltose through the release of glucose. MaAmyB also displays exo-activity with a double blocked PNPG7 substrate, releasing PNP. In M. aurum B8.A, MaAmyB may contribute to degradation of starch granules by rapidly hydrolyzing the helical and linear starch chains that become exposed after pore formation by MaAmyA. Bioinformatics analysis showed that MaAmyB represents a novel GH13 subfamily, designated GH13_42, currently with 165 members, all in Gram-positive soil dwelling bacteria, mostly Streptomyces. All members have an unusually large catalytic domain (AB-regions), due to three insertions compared to established α-amylases, and an aberrant C-region, which has only 30% identity to established GH13 C-regions. Most GH13_42 members have three N-terminal domains (2 CBM25 and 1 FNIII). This is unusual as starch binding domains are commonly found at the C-termini of α-amylases. The evolution of the multidomain M. aurum B8.A MaAmyA and MaAmyB enzymes is discussed.

Carbohydrate-binding module 74 is a novel starch-binding domain associated with large and multidomain a-amylase enzymes

Type: Journal
Year: 2016
Author(s): Valk V, Lammerts van Bueren A, van der Kaaij RM, Dijkhuizen L
Source:Carbohydrate-binding doi:10.1111/febs.13745


Microbacterium aurum B8.A is a bacterium that originates from a potato starch-processing plant and employs a GH13 a-amylase (MaAmyA) enzyme that forms pores in potato starch granules. MaAmyA is a large and multi-modular protein that contains a novel domain at its C terminus (Domain 2). Deletion of Domain 2 from MaAmyA did not affect its ability to degrade starch granules but resulted in a strong reduction in granular pore size. Here, we separately expressed and purified this Domain 2 in Escherichia coli and determined its likely function in starch pore formation.

Domain 2 independently binds amylose, amylopectin, and granular starch but does not have any detectable catalytic (hydrolytic or oxidizing) activity on a-glucan substrates. Therefore, we propose that this novel starchbinding domain is a new carbohydrate-binding module (CBM), the first representative of family CBM74 that assists MaAmyA in efficient pore formation in starch granules. Protein sequence-based BLAST searches revealed that CBM74 occurs widespread, but in bacteria only, and is often associated with large and multi-domain a-amylases containing family

CBM25 or CBM26 domains. CBM74 may specifically function in binding to granular starches to enhance the capability of a-amylase enzymes to degrade resistant starches (RSs). Interestingly, the majority of family CBM74 representatives are found in a-amylases originating from human gut-associated Bifidobacteria, where they may assist in resistant starch degradation. The CBM74 domain thus may have a strong impact on the efficiency of RS digestion in the mammalian gastrointestinal tract.

The impact of protein quantity during energy restriction on genom-wide gene expression analysis in human adipose tissue of obese humans

Type: Journal
Year: 2016
Author(s): Van Bussel IPG, Backx EMP, De Groot LCPGM, Tieland M, Afman L
Source:International Journal of Obesity accepted article preview 24 March 2017; doi: 10.1038/ijo.2017.76.


BACKGROUND: Overweight and obesity is a growing health problem worldwide. The most effective strategy to reduce weight is energy restriction (ER). ER has been shown to be beneficial in disease prevention and it reduces chronic inflammation. Recent studies suggest that reducing the protein quantity of a diet contributes to the beneficial effects by ER. The organ most extensively affected during ER is white adipose tissue (WAT).

OBJECTIVE: The first objective was to assess changes in gene expression between a high protein diet and a normal protein diet during ER. Secondly, the total effect of ER on changes in gene expression in WAT was assessed.

METHODS: In a parallel double-blinded controlled study, overweight older participants adhered to a 25% ER diet, either combined with high protein intake (HP-ER, 1.7 g/kg per day), or with normal protein intake (NP-ER, 0.9 g/kg per day) for 12 weeks. From 10 HP-ER participants and 12 NP-ER participants subcutaneous WAT biopsies were collected before and after the diet intervention. Adipose tissue was used to isolate total RNA and to evaluate whole genome gene expression changes upon a HP-ER and NP-ER diet.

RESULTS: A different gene expression response between HP-ER and NP-ER was observed for 530 genes. After NP-ER a downregulation in expression of genes linked to immune cell infiltration, adaptive immune response, and inflammasome was found whereas no such effect was found after HP-ER. HP-ER resulted in upregulation in expression of genes linked to cell cycle, GPCR signalling, olfactory signalling and nitrogen metabolism. Upon 25% ER, gene sets related to energy metabolism and immune response were decreased.

Dynamics of red fluorescent dental plaque during experimental gingivitis—A cohort study

Type: Journal
Year: 2016
Author(s): Van der Veen MH, Crielaard W, Ten Cate JM, Keijser B, Volgenant MH
Source: Journal of Dentistry http://dx.doi.org/10.1016/j.jdent.2016.02.010


Dental plaque and bleeding on probing indices are commonly used as indicators of oral hygiene and gingival health, respectively. Presence or absence of plaque is considered a measure indicating the current status of oral hygiene, which fluctuates per person per day. As reported in an experimental gingivitis study [1] bleeding on probing increases when plaque remains present during a period of three weeks refraining from all oral hygiene. Bleeding is therefore often considered as an indicator of the average level of oral hygiene and gingiva inflammation. While young plaque is considered healthy, old or matured plaque is considered to cause caries and/or gingivitis and to stimulate the development of periodontitis [2]. Hence, (re)viewing the presence or absence of matured plaque could provide a more reliable impression of the oral health risks in a mouth. When an oral cavity is examined with quantitative light induced fluorescence (QLF), often red fluorescent plaque (RFP) is observed. This phenomenon is generally attributed to matured plaque and not young plaque [3,4]. In general matured plaque is considered to be old plaque (>48 h), however the definition of what constitutes matured plaque is not unambiguous. Recent in vitro studies on red biofilm fluorescence have reported a relationship with biofilm age and thickness, but more specifically with the cariogenin city of the biofilm related to level or frequency of sucrose.

 

 

Creatine loading does not preserve muscle mass or strength during leg immobilization in healthy, young males.

Type: Journal
Year: 2016
Author(s): Backx EMP, Hangelbroek R, Snijders T, Verdijk LB, De Groot LCPGM, Van Loon LJC
Source: International Journal of Obesity accepted article preview 24 March 2017; doi: 10.1038/ijo.2017.76.


BACKGROUND: Overweight and obesity is a growing health problem worldwide. The most effective strategy to reduce weight is energy restriction (ER). ER has been shown to be beneficial in disease prevention and it reduces chronic inflammation. Recent studies suggest that reducing the protein quantity of a diet contributes to the beneficial effects by ER. The organ most extensively affected during ER is white adipose tissue (WAT).

OBJECTIVE: The first objective was to assess changes in gene expression between a high protein diet and a normal protein diet during ER. Secondly, the total effect of ER on changes in gene expression in WAT was assessed.

METHODS: In a parallel double-blinded controlled study, overweight older participants adhered to a 25% ER diet, either combined with high protein intake (HP-ER, 1.7 g/kg per day), or with normal protein intake (NP-ER, 0.9 g/kg per day) for 12 weeks. From 10 HP-ER participants and 12 NP-ER participants subcutaneous WAT biopsies were collected before and after the diet intervention. Adipose tissue was used to isolate total RNA and to evaluate whole genome geneexpression changes upon a HP-ER and NP-ER diet.

Tryptophan restriction arrests B cell development and improves gut 1 microbial diversity in young WT and DNA repair deficient, prematurely aging 2 Ercc1-/Δ7 mice

Type: Journal
Year: 2016
Author(s): Van Beek AA, Hadizadeh F, Meijer B, Sovran B, Perdijk O, Vermij WP, Brandt RMC, Barnhoorn S, Hoeijmakers JHJ, De Vos P, Leenen PJM, Hendriks RW, Savelkoul HFJ
Source:


This work was partly funded by TI Food and Nutrition, a public-private partnership on precompetitive research in food and 17 nutrition. The public partners are responsible for the study design, data collection and analysis, decision to publish, and 18 preparation of the manuscript. The private partners have contributed to the project through regular discussion. JHJH, WPV, 19 RMCB, and SB acknowledge financial support of the European commission FP7 Markage (FP7-Health-2008-200880) and 20 LifeSpan (LSHG-CT-2007-036894), National Institute of Health (NIH)/National Institute of Ageing (NIA) (1PO1 AG-17242-02), 21 NIEHS (1UO1 ES011044), and the Royal Academy of Arts and Sciences of the Netherlands (academia professorship to JHJH) 22 and a European Research Council (ERC) advanced grant “DamAge” with project number GA 233424 to JHJH. The research 23 leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-24 2013) under grant agreement No. HEALTH-F2-2010-259893.

ABSTRACT 1 With aging, tryptophan metabolism is affected. Tryptophan plays a crucial role in 2 induction of immune tolerance and maintenance of gut microbiota. We therefore 3 studied the effect of dietary tryptophan restriction in young wild-type (WT) mice (118-4 wk lifespan) and DNA repair deficient, premature aged (Ercc1-/Δ7) mice (20-wk 5 lifespan). First, the impact of aging on immune cell composition of 16-week-old 6 (young) and 18-month-old (old) WT mice was compared with 6-week-old and 16-7 week-old Ercc1-/Δ7 mice. Ercc1-/Δ7 mice serve as a suitable model for the aging 8 immune system, because we found a comparable decline in lymphoid precursors and 9 increased memory cell frequencies in old WT and Ercc1-/Δ7 mice. Dietary tryptophan 10 restriction caused an arrest of B cell development in the bone marrow, accompanied 11 by diminished B cell frequencies in periphery. In many aspects of immune cell 12 distribution, old Ercc1-/Δ7 mice showed similar responses to tryptophan restriction 13 compared with young WT mice, indicative of age-independent effects. The gut 14 microbial diversity in old Ercc1-/Δ7 mice was reduced compared with young WT mice, 15 with lower abundances of Parabacteroides, Lachnospiraceae, and 16 Ruminococcaceae. Dietary tryptophan restriction increased microbial diversity and 17 made the gut microbiota composition of old Ercc1-/Δ7 mice similar to young WT mice. 18 The decreased abundances of Alistipes and Akkermansia after dietary tryptophan 19 restriction correlated significantly with decreased B cell precursor numbers. In 20 conclusion, we report that dietary tryptophan restriction arrests B cell development 21 and concomitantly changes gut microbiota composition. Our study might indicate a 22 link between (dietary) tryptophan, B cell development, and gut microbial composition.

A GWAS meta-analysis suggests roles for xenobiotic metabolism and ion channel activity in the biology of stool frequency

Type: Journal
Year: 2016
Author(s): Jankipersadsing SA, Hadizadeh F, Bonder MJ, Tigchelaar EF, Deelen P, Fu J, Andreasson A, Agreus L, Walter S, Wijmenga C, Hysi P, D’Amato M, Zherakova A
Source: Jankipersadsing SA, Hadizadeh F, Bonder MJ, et al. Gut Published Online doi:10.1136/gutjnl-2016-312398


Stool consistency and frequency patterns are complex traits that are often altered in GI disease, and recent studies published in Gut highlight the importance of stool frequency in relation to gut microbiota composition and the efficacy of pharmacological and dietary treatments in IBS.1–3 Despite reported heritability in invertebrates4 and similar evidence from open-field defaecation models in rats,5 the genetics of stool frequency has not been explored in humans. We undertook a genome-wide association study (GWAS) in two well-characterised population-based cohorts with genotype and defaecation data available: LifeLines-Deep (LLD) from the Netherlands (N=1546; 58% females; mean age 44 years (range 18–86)) and PopCol (PC) from Sweden (N=284; 60% females; mean age 54 years (range 22–71)).6 7 The average number of bowel movements per day (BM/d) was extracted from daily records kept by both populations and did not differ between cohorts (LLD=1.39 ±0.64SD; PC=1.42±0.74SD).

Effect of increased protein intake on renal acid load and renal hemodynamic responses

Type: Journal
Year: 2016
Author(s): Van Baak MA, De leeuw PW, Brink EJ, Bakker SJL, Geleijnse J, Dopheide KFM, Teunissen – Beekman
Source: Physiological Reports ISSN 2051-817X doi: 10.14814/phy2.12687


Increased protein intake versus maltodextrin intake for 4 weeks lowers blood pressure. Concerns exist that high-protein diets reduce renal function. Effects of acute and 4-week protein intake versus maltodextrin intake on renal acid load, glomerular filtration rate and related parameters were compared in this study. Seventy-nine overweight individuals with untreated elevated blood pressure and normal kidney function were randomized to consume a mix of protein isolates (60 g/day) or maltodextrin (60 g/day) for 4 weeks in energy balance. Twenty-four-hour urinary potential renal acid load (uPRAL) was compared between groups. A subgroup (maltodextrin N = 27, protein mix N = 25) participated in extra test days investigating fasting levels and postprandial effects of meals supplemented with a moderate protein- or maltodextrin- load on glomerular filtration rate, effective renal plasma flow, plasma renin, aldosterone, pH, and bicarbonate. uPRAL was significantly higher in the protein group after 4 weeks (P ≤ 0.001). Postprandial filtration fraction decreased further after the protein-supplemented breakfast than after the maltodextrin-supplemented breakfast after 4 weeks of supplementation (P ≤ 0.001). Fasting and postprandial levels of glomerular filtration rate, effective renal plasma flow, renin, aldosterone, angiotensin-converting enzyme, pH and bicarbonate did not differ between groups. In conclusion, 4 weeks on an increased protein diet (25% of energy intake) increased renal acid load, but did not affect renal function. Postprandial changes, except for filtration fraction, also did not differ between groups. These data suggest that a moderate increase in protein intake by consumption of a protein mix for 4 weeks causes no (undesirable) effects on kidney function in overweight and obese individuals with normal kidney function.

 

Protein intake and lean body mass preservation during energy intake restriction in overweight older adults

Type: Journal
Year: 2016
Author(s): Backx EMP, Tieland M, Borgonjen-van den Berg, Claessen KJ, Van Loon PR, De Groot LCPGM
Source:International Journal of Obesity (2016) 40, 299–304; doi:10.1038/ijo.2015.182


BACKGROUND: Dietary-induced weight loss is generally accompanied by a decline in skeletal muscle mass. The loss of muscle mass leads to a decline in muscle strength and impairs physical performance. A high dietary protein intake has been suggested to allow muscle mass preservation during energy intake restriction.

OBJECTIVE: To investigate the impact of increasing dietary protein intake on lean body mass, strength and physical performanceduring 12 weeks of energy intake restriction in overweight older adults.

DESIGN: Sixty-one overweight and obese men and women (63 ± 5 years) were randomly assigned to either a high protein diet (HP; 1.7 g kg− 1 per day; n=31) or normal protein diet (NP; 0.9 g kg− 1 per day; n=30) during a 12-week 25% energy intake restriction. During this controlled dietary intervention, 90% of the diet was provided by the university. At baseline and after the intervention, body weight, lean body mass (dual-energy X-ray absorptiometry), leg strength (1-repetition maximum), physical performance (Short Physical Performance Battery, 400 m) and habitual physical activity (actigraph) were assessed.

RESULTS: Body weight declined in both groups with no differences between the HP and NP groups (−8.9 ± 2.9 versus −9.1 ± 3.4 kg, respectively; P = 0.584). Lean body mass declined by 1.8 ± 2.2 and 2.1 ± 1.4 kg, respectively, with no significant differences between groups (P = 0.213). Leg strength had decreased during the intervention by 8.8 ± 14.0 and 8.9 ± 12.8 kg, with no differences between groups (P = 0.689). Physical performance as measured by 400m walking speed improved in both groups, with no differences between groups (P = 0.219).

CONCLUSIONS: Increasing protein intake above habitual intake levels (0.9 g kg− 1 per day) does not preserve lean body mass,strength or physical performance during prolonged energy intake restriction in overweight older adults.

The Noncaloric Sweetener Rebaudioside A Stimulates Glucagon-Like Peptide 1 Release and Increases Enteroendocrine Cell Numbers in 2-Dimensional Mouse Organoids Derived from Different Locations of the Intestine1–4

Type: Journal
Year: 2016
Author(s): van der Wielen, Ten Klooster JP, Muckenschnabi S, Pieters R, Hendriks HF, Witkamp RF, Meijerink J,
Source: First published online October 26, 2016; doi:10.3945/jn.116.232678


Background: Glucagon-like peptide 1 (GLP-1) contributes to satiety and plays a pivotal role in insulin secretion and glucose homeostasis. Similar to GLP-1, peptide YY (PYY) and cholecystokinin also influence food intake. The secretion of these hormones by enteroendocrine cells along the intestine is modulated by nutrients. Preparations from the Stevia rebaudiana plant, including rebaudioside A, are increasingly being used as noncaloric sweeteners.

Objective: We investigated the effects of rebaudioside A on enteroendocrine cells by assessing both cell numbers as well as their secretory capacity in an organoid model.

Methods: A 2-dimensional organoid model derived from duodenal, jejunal, and ileal crypts of a C57BL/6J mouse was developed and characterized with the use of gene expression and immunofluorescence. We stimulated these organoids with 10 mmol/L rebaudioside A for 1 h and measured their GLP-1, PYY, and cholecystokinin release. We also analyzed the effects of rebaudioside A on gene expression in enteroendocrine cells after an 18-h incubation.

Results: The 2-dimensional organoids contained crypt cells and differentiated villus cells, including enterocytes and goblet and enteroendocrine cells. These enteroendocrine cells stained positive for GLP-1, PYY, and serotonin. The cultured 2-dimensional organoids maintained their location-specific gene expression patterns. Compared with the control, rebaudioside A induced GLP 1 secretion 1.7-fold in the duodenum (P < 0.01), 2.2-fold in the jejunum (P < 0.01), and 4.3-fold in the ileum (P < 0.001). PYY release was increased by rebaudioside A 3-fold in the ileumcompared with the control (P < 0.05). Long-term(18-h) stimulation with the sweetener induced the expression of the enteroendocrine-specific markers chromogranin A, glucagon, Pyy, and cholecystokinin 3.5- (P < 0.001), 3.5- (P < 0.001), 3.8- (P < 0.05), and 6.5-fold (P < 0.001), respectively.

Conclusions: These results show novel ex vivo effects of rebaudioside A on enteroendocrine cells of the mouse small intestine and highlight potentially new applications for rebaudioside A in metabolic diseases.

Nutrient-induced glucagon like peptide-1 release is modulated by serotonin

Type: Journal
Year: 2016
Author(s): Ripken D, van der Wielen N, Wortelboer HM, Meijerink J, Witkamp RF, Hendriks HF
Source: Serotonin; GLP-1; nutrients; rebaudioside A; small intestine http://dx.doi.org/10.1016/j.jnutbio.2016.03.006


Abstract Glucagon like peptide-1 (GLP-1) and serotonin are both involved in food intake regulation. GLP-1 release is stimulated upon nutrient interaction with Gprotein coupled receptors by enteroendocrine cells (EEC), whereas serotonin is released from enterochromaffin cells (ECC). The central hypothesis for the current study was that nutrient-induced GLP-1 release from EECs is modulated by serotonin through a process involving serotonin receptor interaction. This was studied by assessing the effects of serotonin reuptake inhibition by fluoxetine on nutrient-induced GLP-1, PYY and CCK release from isolated pig intestinal segments. Next, serotonin-induced GLP-1 release was studied in enteroendocrine STC-1 cells, where effects of serotonin receptor inhibition were studied using specific and non-specific antagonists. Casein (1% w/v), safflower oil (3.35% w/v), sucrose (50 mM) and rebaudioside A (12.5 mM) stimulated GLP-1 release from intestinal segments, whereas casein only stimulated PYY and CCK release. Combining nutrients with fluoxetine further increased nutrient-induced GLP-1, PYY and CCK release.Serotonin release from intestinal tissue segments was stimulated by casein and safflower oil while sucrose and rebaudioside A had no effect. The combination with fluoxetine (0.155 μM) further enhanced casein and safflower oil induced-serotonin release. Exposure of ileal tissue segments to serotonin (30 μM) stimulated GLP-1 release whereas it did not induce PYY and CCK release. Serotonin (30 and 100 μM) also stimulated GLP-1 release from STC-1 cells, which was inhibited by the non-specific 5HT receptor antagonist asenapine (1 and 10 μM). These data suggest that nutrient-induced GLP-1 release is modulated by serotonin through a receptor mediated process.

Effect of experimental gingivitis induction and erythritol on the salivary metabolome and functional biochemistry of systemically healthy young adults

Type: Journal
Year: 2016
Author(s): Pordan A, Imangaliyev S, Brand HS, Rosema MNA, Levin E, Crielaard W, Keijser BJF, Veerman ECI
Source: Metabolomics 12:147. doi: 10.1007/s11306-016-1096-4


Introduction Understanding the changes occurring in the oral ecosystem during development of gingivitis could help improve prevention and treatment strategies for oral health. Erythritol is a non-caloric polyol proposed to have beneficial effects on oral health. Objectives To examine the effect of experimental gingivitis and the effect of erythritol on the salivary metabolome and salivary functional biochemistry. Methods In a two-week experimental gingivitis challenge intervention study, non-targeted, mass spectrometry-based metabolomic profiling was performed on saliva samples from 61 healthy adults, collected at five time-points. The effect of erythritol was studied in a randomized, controlled trial setting. Fourteen salivary biochemistry variables were measured with antibody- or enzymatic activity-based assays. Results Bacterial amino acid catabolites (cadaverine, N-acetylcadaverine, and a-hydroxyisovalerate) and endproducts of bacterial alkali-producing pathways (N-aacetylornithine and c-aminobutyrate) increased significantly during the experimental gingivitis. Significant changes were found in a set of 13 salivary metabolite ratios composed of host cell membrane lipids involved in cell signaling, host responses to bacteria, and defense against free radicals. An increase in mevalonate was also observed. There were no significant effects of erythritol. No significant changes were found in functional salivary biochemistry. Conclusions The findings underline a dynamic interaction between the host and the oral microbial biofilm during an experimental induction of gingivitis.