New Species of Bacteria Found to Play a Role in Tooth Decay

A new bacterial discovery sheds light on a key factor in the development of cavities, potentially leading to better prevention methods in the future.

For many years, it has been believed that the bacterial species Streptococcus mutans (S. mutans) is the leading cause of dental cavities, also known as dental caries. However, a recent study revealed an unexpected discovery. Selenomonas sputigena, a bacterium commonly associated with gum disease, was found to work in partnership with S. mutans, significantly increasing its ability to cause cavities.

Why should you care about this discovery? Caries is considered the most common chronic disease in children and adults in the U.S. and worldwide. When teeth-brushing and other dental cleaning methods fail to adequately remove acid-producing bacteria like S. mutans, these bacteria form a sticky biofilm called plaque, which clings to your teeth. Within plaque, these bacteria consume sugars from the foods and drinks you consume and convert them to acids. If this plaque stays on your teeth for a long time, the acids produced by these bacteria can erode your teeth and lead to the formation of cavities. 

The data from this novel discovery showed that although S. sputigena does not cause caries on its own, it has a distinctive ability to partner and enhance the S. mutans acid-producing ability, significantly worsening caries severity. S. mutans, an aerobic bacterium that needs oxygen to survive, uses available sugar to create sticky structures known as glucans that are part of the plaque environment. On the other hand, S. sputigena is an anaerobic bacterium that doesn't require oxygen and has small appendages that allow it to move across surfaces and get trapped in the glucans. Once trapped, S. sputigena multiplies to create a honeycomb-like multicellular structure that encapsulates S. mutans and enhances its acid production. This partnership between S. mutans and S. sputigena highlights the significance of thoroughly exploring tooth decay development. Identifying potential targets for preventing caries can be achieved by diving deep into this area of research.

Scientists plan to delve deeper into the phenomenon of a bacterium from one environment moving into a new one and collaborating with bacteria living there. This discovery shows a more intricate microbial interaction than previously thought, shedding new light on the development of childhood tooth decay. This deeper understanding paves the way for the development of far more effective preventive methods, potentially leading to a significant breakthrough in protecting children's oral health. One possible method to disrupt the protective property of S. sputigena is to use specific enzymes that target the superstructures. Another approach could involve developing a more precise and effective tooth-brushing method. This is particularly relevant now that the internal structure of the plaque biofilm is being better analyzed and understood.

This groundbreaking discovery presents a potential turning point in how we prevent childhood tooth decay. Scientists are actively exploring the implications of this research, which could lead to the development of entirely new preventive strategies. Stay tuned for exciting advancements in this field!

Written by Dima Bader

Edited by Iana Malasevskaia, MD

References: 

1. Alaluusua S, Renkonen OV. Streptococcus mutans establishment and dental caries experience in children from 2 to 4 years old. Scand J Dent Res. 1983;91(6):453-457. doi:10.1111/j.1600-0722.1983.tb00845.x

2. Cho H, Ren Z, Divaris K, et al. Selenomonas sputigena acts as a pathobiont mediating spatial structure and biofilm virulence in early childhood caries. Nat Commun. 2023;14(1):2919. Published 2023 May 22. doi:10.1038/s41467-023-38346-3

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4. Lemos JA, Palmer SR, Zeng L, et al. The Biology of Streptococcus mutans. Microbiol Spectr. 2019;7(1):10.1128/microbiolspec.GPP3-0051-2018. doi:10.1128/microbiolspec.GPP3-0051-2018