Scientists sink teeth into identifying several new bacteria that cause dental caries

August 21, 2020

The human body is home to trillions of microbes. Through its natural functioning, much of the time, this ecosystem regulates our health. But like the environment of the world at large, this bodily ecosystem is delicate, and any change in the composition of the microbial community, also called the "microbiome," can cause an overall imbalance in their collective functioning, resulting in disease.

Now, advances in research in this field have yielded a technique called next-generation DNA sequencing, which allows for very accurate identification of the members of this microbial community, thereby offering insights into microbial community composition. For several diseases, knowing which microbes densely populate the organ/tissue in question or become absent from it during disease can help develop effective treatments. Such is the case for dental caries, a type of tooth decay in which acid-producing bacteria eat away at the out layer of teeth and cause cavities.

A type of bacteria called the mutans streptococci are the most commonly implicated microbes in dental caries. Their increase causes dental decay. But, could other microbes be responsible as well?

Scientists globally have looked into this question. However, focus on the younger demographic has been low. Meanwhile, in Japan, the number of young adults developing dental caries is increasing.

Spurred by this increase and this insufficient literature, a team of researchers from Japan, led by Dr. Uchida-Fukuhara from Okayama University, called for Japanese university student volunteers for oral examinations at the Health Service Center in Okayama University.

The students answered a survey about their dental health at the beginning of the study and during a follow-up after three years. This told the researchers which students had significantly increased dental caries after this time and who didn't. The researchers grouped the students accordingly during the follow-up (let's say, Groups A and B respectively). They then collected saliva samples of randomly selected students from these groups, which they analyzed via next-generation DNA sequencing to obtain microbial profiles.

It turned out that very similar oral microbial diversities existed in both groups. But in Group A, the abundances of the bacterial families Prevotellaceae and Veillonellaceae, and genera Alloprevotella and Dialister, were greater than those in Group B. These two families are known to comprise species that produce acid as well. This finding, therefore, suggests new prevention possibilities for dental caries that does not focus on keeping mutans streptococci populations in check.

Interestingly, both groups had low levels of mutans streptococci. Should the focus of research on what causes dental caries change?

The striking results of the study, published in the International Journal of Environmental Research and Public Health, underscore the necessity of updating current knowledge on the oral microbial community and its role in the development of dental caries. But Dr. Uchida highlights limitations in the study's applicability and advises taking these findings with a pinch of salt. "Among other things, all our participants were from Okayama University, so our results may not be generalizable to the wider population," she says.

Yet, Dr. Uchida is hopeful, "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."

Perhaps, in the future, students' teeth will be clean as a hound's tooth.

Okayama University

Related Microbes Articles from Brightsurf:

A new look at deep-sea microbes
Microbes found deeper in the ocean are believed to have slow population turnover rates and low amounts of available energy.

Microbes might manage your cholesterol
Researchers discover a link between human blood cholesterol levels and a gene in the microbiome that could one day help people manage their cholesterol through diet, probiotics, or entirely new types of treatment.

Can your gut microbes tell you how old you really are?
Harvard longevity researchers in collaboration with Insilico Medicine develop the first AI-powered microbiomic aging clock

What can be learned from the microbes on a turtle's shell?
Research published in the journal Microbiology has found that a unique type of algae, usually only seen on the shells of turtles, affects the surrounding microbial communities.

Life, liberty -- and access to microbes?
Poverty increases the risk for numerous diseases by limiting people's access to healthy food, environments and stress-free conditions.

Rye is healthy, thanks to an interplay of microbes
Eating rye comes with a variety of health benefits. A new study from the University of Eastern Finland now shows that both lactic acid bacteria and gut bacteria contribute to the health benefits of rye.

Gut microbes may affect the course of ALS
Researchers isolated a molecule that may be under-produced in the guts of patients.

Gut microbes associated with temperament traits in children
Scientists in the FinnBrain research project of the University of Turku discovered that the gut microbes of a 2.5-month-old infant are associated with the temperament traits manifested at six months of age.

Gut microbes eat our medication
Researchers have discovered one of the first concrete examples of how the microbiome can interfere with a drug's intended path through the body.

Microbes can grow on nitric oxide
Nitric oxide (NO) is a central molecule of the global nitrogen cycle.

Read More: Microbes News and Microbes Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to