Clinical implications:
- Personalized prevention strategies could become more effective, since patients with genetically driven microbiome profiles may benefit from individualized recall intervals, targeted antimicrobial approaches, or diet counseling.
- Salivary function becomes even more clinically relevant, as the AMY1 copy number influences starch breakdown and downstream effects with the oral microbiome, potentially guiding dietary recommendations and caries‑risk management.
- Future denture risk may be partially predictable, with certain genetic–microbiome signatures associated with long‑term tooth loss, supporting earlier intervention to preserve dentition.
DNA may play a much bigger role in a person’s predisposition to developing caries and tooth loss than previously thought, according to a news article published on January 28 from the nonprofit Broad Institute.
Genetics appear to play a role in determining the microbial community living in patients’ mouths, according to the article.
“The abundance of many bacterial species in our mouths is strongly influenced by human genetics,” Po-Ru Loh, an associate member at the Broad Institute and the senior author of the study, which is published in Nature, said in the article. “We know that the microbial environment in one person's mouth is going to be quite different from another person's mouth due to many factors, but genetics is a pretty strong one.”
To investigate potential associations between human DNA and microbiota, researchers from the Broad Institute and Mass General Brigham analyzed the saliva samples of 12,500 people, sequencing the data of 439 common microbial species with human DNA. They found 11 regions of the human genome that corresponded with individual differences in oral bacteria.
The team uncovered specific genomic ties between DNA and the oral microbiome that may predict future dental troubles for individuals. For instance, the AMY1 (amylase alpha 1) gene was “strongly linked” to the makeup of the oral microbiome and future denture use.
AMY1 encodes salivary amylase, which breaks down starches into glucose. The more copies of AMY1 that were in a person’s genome in turn influenced more than 40 bacterial species that were linked with downstream effects on oral health. The findings suggest that this altered ecology of the oral microbiome contributes to one in which the risk of caries, plaque buildup, and tooth loss is increased.
Another strong relationship researchers discovered was a genetic variant that breaks the FUT2 gene, strongly associated with gut microbiome composition, and 58 species of oral bacteria that also were strongly associated with future denture use, according to the study’s authors.
“I hope these initial results can inspire the field to get excited about what you can learn about human genetic effects on microbiomes in general, but particularly oral microbiomes, because there seem to be such strong genetic effects,” Loh said.
