Some people remain remarkably healthy into their 80s, 90s and beyond. Researchers are studying their gut microbiomes to understand whether they share microbial features linked to healthy longevity.
So far, there is no single gut microbiome that defines healthy ageing.
The gut contains a complex community of bacteria and other microorganisms. Its composition differs considerably between people. It also changes throughout life.
This makes it difficult to identify one combination of bacteria that everyone should have.
What can we learn from people who age well?
Older adults and centenarians are particularly interesting to longevity researchers. They have reached advanced age and, in some cases, remained in good health for much of their lives.
Studies have found differences between the gut microbiomes of healthy older people and those experiencing poorer health or frailty. Research in centenarians has also identified microbial patterns that differ from those seen at younger ages.
But these findings do not define one ideal microbiome.
Different microbial communities may support similar functions. Diet, lifestyle, environment, medications and individual biology can also influence which microorganisms are present.
Healthy ageing may depend on more than individual bacteria
Researchers increasingly examine more than the presence or absence of particular bacteria.
They also study microbial diversity, microbiome function and the substances produced by gut microorganisms. Another question is how well the microbiome responds to changes in diet, illness, medication or other disturbances.
This broader approach may be more useful for understanding the relationship between the microbiome and ageing.
A microbiome that looks different from another healthy person’s microbiome is therefore not necessarily unhealthy.
For longevity medicine, the important question is not whether everyone has the same bacteria. It is whether the microbiome functions well within the context of the person’s age, health, diet and lifestyle.
