Media releaseFrom: Springer Nature
Microbiology: Gut microbe metabolism implicated in longevity
In people over the age of 100, an enrichment in a distinct set of gut microbes that can generate unique bile acids might contribute to longevity by inhibiting the growth of gut pathogens. This finding is published online this week in Nature. The study, which compares the gut microbes of centenarians, elderly individuals and younger people in Japan, raises the possibility of manipulating the bile acid pool for health benefits.
The community of microbes in our gut has a role in our health, and changes as we age. Centenarians are less susceptible to age-related chronic diseases and infection than are elderly individuals below the age of 100. It is thought that the composition of the gut microbiota in centenarians may be associated with extreme longevity, but the mechanisms have been unclear.
To probe the potential link between microbiota composition and longevity, Kenya Honda and colleagues studied 3 groups of Japanese people: 160 centenarians (aged over 100 years old), 112 elderly individuals (aged 85–89 years old) and 47 younger individuals (aged 21–55 years old). They found that, compared with elderly and young individuals, centenarians are enriched in gut microbes that are capable of generating unique secondary bile acids through novel biosynthetic pathways. The authors identify a range of bacteria responsible for producing these bile acids, and map the pathway that leads to the production of isoallo-lithocholic acid (isoalloLCA). IsoalloLCA is shown to have antimicrobial effects against a range of gut pathogens. Experiments in mice suggest that isoalloLCA can inhibit the growth of Clostridium difficile — a bacterium that can cause severe diarrhoea, especially in people who are being treated with antibiotics.
The authors suggest that it may be possible to exploit the bile-acid-metabolizing capabilities of bacterial strains identified in this study to manipulate the bile acid pool for health benefits. However, they add that further studies are needed to validate the association between bile acids and longevity.