How your genes influence the microbes and cavities in our mouth

Amazing stuff!

"Highlights

• A new study suggests that our genetics plays a role in determining the microbial community living in our mouths.
• Scientists discovered 11 regions of the human genome that influence the abundances of dozens of bacterial species in the mouth.
• The authors found a relationship between a human gene and oral bacteria that plays a role in dental health.

...

found a surprisingly large effect of human genetics on the abundance of microbes in the mouth. The researchers discovered genome-to-genome interactions between human DNA and the DNA of the oral microbiome. For example, they found that a human gene, AMY1, was strongly linked to the composition of the oral microbial community, and even to dentures use, suggesting that the relationship between this gene and the bacteria in the mouth plays a role in oral health. ..."

From the abstract:

"Human genetic variation influences all aspects of our biology, including the oral cavity, through which nutrients and microbes enter the body. Yet it is largely unknown which human genetic variants shape a person’s oral microbiome and potentially promote its dysbiosis.

We characterized the oral microbiomes of 12,519 people by re-analysing whole-genome sequencing reads from previously sequenced saliva-derived DNA. Human genetic variation at 11 loci (10 new) associated with variation in oral microbiome composition.

Several of these related to carbohydrate availability; the strongest association (P = 3.0 × 10−188) involved the common FUT2 W154X loss-of-function variant, which associated with the abundances of 58 bacterial species.

Human host genetics also seemed to powerfully shape genetic variation in oral bacterial species: these 11 host genetic variants also associated with variation of gene dosages in 68 regions of bacterial genomes. Common, multi-allelic copy number variation of AMY1, which encodes salivary amylase, associated with oral microbiome composition (P = 1.5 × 10−53) and with dentures use in UK Biobank (P = 5.9 × 10−35, n = 418,039) but not with body mass index (P = 0.85), suggesting that salivary amylase abundance impacts health by influencing the oral microbiome.

Two other microbiome composition-associated loci, FUT2 and PITX1, also significantly associated with dentures risk, collectively nominating numerous host–microbial interactions that contribute to tooth decay."

How genes influence the microbes in our mouths | Broad Institute "Analysis of the now largest collection of oral microbiome profiles reveals interactions between human and bacterial DNA. "

Human and bacterial genetic variation shape oral microbiomes and health (open access)

Fig. 1: Oral microbiomes in 12,519 individuals measured by WGS [whole-genome sequencing] of saliva samples.