Mouth bacteria slow aging in worms and mice
A common bacterium that lives in the human mouth appears to slow aging. That sounds unlikely, but researchers found the link across multiple species. They also tied it to aging data from humans.
The mouth harbours hundreds of bacterial species. Most microbiome and aging research focuses on the gut. But a new study published in Nature Aging turns the spotlight on the oral cavity. At its centre is Neisseria flavescens, an organism commonly found in the human throat and mouth that is generally considered harmless.
From oral flora to extended lifespan
Researchers used a framework called AURORA, an AI-driven analytical method, to identify links between the composition of the oral microbiome (the community of micro-organisms in the mouth) and aging markers in humans. Neisseria flavescens stood out as a species associated with decelerated biological aging. The researchers then tested this in worms and mice. Administering live or heat-killed bacteria had a protective effect on aging in both species. The fact that heat-killed bacteria also worked is notable: it opens the door for supplements or probiotics that do not require living organisms.
Exactly how Neisseria flavescens produces this effect is not yet fully understood. The researchers suggest the bacterium influences the immune system or metabolism via signalling molecules, but the precise mechanisms require further investigation. The leap from worms and mice to humans also remains substantial.
Promising, but cautious
The human data are associative: people with more Neisseria flavescens in their mouths aged more slowly biologically, but that could also reflect other factors such as overall health or lifestyle. The animal experiments provide stronger evidence for a causal link, with the usual caveats that apply to animal models. Even so, this is an unusual entry point for aging research. It suggests the oral microbiome deserves more attention as part of the broader study of how microbes influence lifespan.
Search terms to explore further: oral microbiome aging biomarkers | Neisseria flavescens geroprotection | oral commensal bacteria lifespan