Unravelling the biochemistry of a healthy mouth

18 January 2017 – Males’ saliva has a higher pH and buffering capacity than female’s; one of the most interesting outcomes of research by Dr Andrei Prodan. The TiFN PhD fellow defended his thesis on 17 January, 2017 at the Free University of Amsterdam. His work provides leads for the development of better-targeted oral-hygiene strategies.

Despite good oral hygiene and regular visits to the dentist, caries and periodontitis remain a major health issue for people in developed countries. “Oral disorders can have a significant impact on systemic health, social functioning and wellbeing”, says Prodan. “Why some people have a ‘healthy’ mouth whereas others do not – despite regular brushing and flossing – remains unclear.” Prodan’s research, part of the TiFN project Novel strategies to promote oral health, aimed to identify the biochemistry of saliva which, together with the teeth, mucosal tissues and the oral microbiota, comprises the oral ecosystem.

Extensive trials
The PhD fellow carried out two extensive clinical trials: a cross-sectional observational study (268 participants) aimed at estimating the boundaries of a healthy oral ecosystem, and a randomized challenge intervention study (61 subjects) exploring the dynamic interactions in the oral ecosystem during the induction of mild gingival inflammation. “People volunteered to abstain from tooth brushing, flossing and any other kind of oral hygiene for two weeks”, he says.

The first study revealed that males’ saliva has a higher pH and buffering capacity than women’s. “This is probably caused by hormonal differences”, says the food scientist, a specialist in protein chemistry. “This finding, however, does not necessarily mean that women are more vulnerable to oral health problems.”

The second study revealed that oral bacteria – which grow in biofilms consisting of different types of bacteria – increased their metabolism to adapt to the acidic conditions created by lactic-acid bacteria”, says Prodan. The amount of certain types of bacteria increased, whereas other bacteria were reduced.

Better-targeted strategies
Prodan – whose contract has been extended until April to finalize the research – and his colleagues are still analysing the data from the first study. The second study will continue for a few months. “We expect the final results will substantially improve our understanding of how the microbiota interacts with oral hygiene and nutrition, making better-targeted oral-hygiene strategies possible.” Industry partners are committed to the research.

‘Teaching’ each other
According to the PhD fellow TiFN’s oral health-project is globally unique. “We have taken a very multidisciplinary approach, with expertise ranging from biochemists, clinicians and microbiologists to specialists in mathematical modelling”, he says. “It has been very nice to be part of such a large and diverse team in a vibrant working environment. “A mathematician sees points on a line, where a biochemist sees peaks on a line; so we really had to ‘teach’ each other our specialist languages.”