Tooth Decay and the Role of Genetics

Have you ever heard that you got your “bad teeth” from your mom/dad/aunt/great-great-great grandfather/etc? According to a recent Medical News Today article, the oral bacteria found in your mouth when you are very young is in fact influenced by your genetic background. But a recent study has found that as we age, the heritable factor wanes and non-heritable influences, like diet and oral hygiene habits, play a stronger role in determining our oral microbiome.

The new study was led by the J. Craig Venter Institute (JCVI) in La Jolla, California and published in the journal Cell Host & Microbe. Researchers investigated the oral microbiomes of identical and non-identical twins in childhood. According to Karen E. Nelson, Ph.D., president of the JCVI, they chose to investigate twins because they are likely to have a very similar upbringings and are ideal for studying the “nature versus nurture” question in regards to oral health.

Tooth decay is a major health issue around the world, with up to 90% of school-age children and nearly 100% of adults worldwide having dental cavities. Nearly 20% of middle-aged adults have severe periodontal/gum disease, which can ultimately lead to tooth loss and other health issues. In the U.S., 37% of kids aged 2 to 8 have decay in their primary teeth, 58% of teenagers have or have had it, and more than 90% of adults have it. It’s a serious problem, and researchers hope to find out as much as they can about it in order to reverse the trend.

In this study, researchers explain that tooth decay results when certain types of bacteria metabolize “frequent sugar intake.” This leads to an acidic environment in the mouth that attacks the tooth enamel and causes cavities. They also describe how specific groups of bacteria can trigger inflammation in adults with gum disease, leading to destruction of gum tissue and the formation of “pockets,” eventually leading to tooth loss. And while there is a mountain of evidence linking oral microbiome and other illnesses like cancer and cardiovascular disease, there hasn’t been much research into the extent of influence genetic background plays in the relationship.

For this study, Dr. Nelson and colleagues used mouth swabs of 485 pairs of twins between the ages of 5 and 11. 205 pairs were identical with the other 280 being fraternal. There was also one set of triplets. As anticipated, the oral microbiomes of the identical twins were found to be more similar than those of non-identical twins. According to researchers, this suggests that the host genetic background influences the types of bacteria present in the mouth. But they also found that the heritable bacteria were not those that play a role in tooth decay. Furthermore, they found that as the children aged, the heritable bacteria decreased significantly. The most significant finding was that the twins whose diet included a lot of added sugar had fewer of the types of bacteria that are linked to lower rates of tooth decay and more of the types that are linked to higher rates of tooth decay.

The researchers are planning to follow the twins and continue the study of their oral microbiomes. They also hope to compare the health of identical and non-identical twins with functional differences in their oral microbiomes.

Written by

Follow me on Twitter: https://twitter.com/MPaulsort78