Have We Been Taught Wrongly About S. mutans?

Most of the dental caries is thought to be caused by Streptococcus mutans. However, the researchers at the Okayama University identified other members of oral microbiome that may be responsible for causing dental caries using next generation DNA sequencing.

At the beginning of study, student volunteers at the university received an oral examination and answered a survey about their dental health. There was a follow-up after three years which provided the data regarding which students had significantly increased dental caries and who didn’t.

The students were then divided into two groups during the follow-up and collected saliva samples of randomly selected students from these groups were analysed using next-generation DNA sequencing to obtain microbial profiles.

Both groups had very similar oral microbial diversities. But the abundance of the Prevotellaceae and Veillonellaceae bacterial families and Alloprevotella and Dialister genera were greater in the first group than in the second.

These two families are also known to comprise of species producing acids. According to the researchers, this study will open new doors to prevention of caries using strategies which will not focus only on checking the growth of S.mutans.

One interesting finding of the study was that both the groups demonstrated low level of S.mutans contrary to the common belief. However, there are limitations to the applicability of this study at present.

“Among other things, all our participants were from Okayama University, so our results may not be generalizable to the wider population,” said Dr. Yoko Uchida-Fukuhara, leader of the study, who was nevertheless hopeful about the results.

“For many years, our group has been conducting population studies to reduce oral diseases. We believe that the results of this new study will help us develop novel strategies to prevent dental caries, and our students will achieve greater life satisfaction because of better teeth and oral health,” she said.

SOURCE: The International Journal of Environmental Research and Public Health.