Gut health may affect ageing, researchers explore

Researchers report links between gut microbiome diversity and healthier ageing, and individual tests can show differences in gut profiles; studies and experts say evidence is promising but still emerging.

Interest in the gut microbiome has grown, with doctors and researchers examining whether the communities of microbes in our intestines influence how we age. The author visited St Mary's Hospital in London for a personal stool test and discussed results with Dr James Kinross and other specialists. Several studies of centenarians and laboratory experiments have shown differences in gut bacterial diversity that researchers link to longevity and measures of frailty. Experts stress that the field is still developing and that diet, genes and other lifestyle factors are also important. Key findings: - Studies of very old people, including analyses tied to the late Maria Branyas Morera and a 2022 Nature study of centenarians in Jiaoling County, found higher gut bacterial diversity compared with younger adults. - Microbiome diversity typically falls with age, and people who maintain higher diversity into old age have been associated with longer, healthier lives. - A 2020 faecal transplant experiment in mice reported that transferring microbiota from older animals produced behavioural and memory changes in younger recipients, suggesting a possible causal link in controlled settings. - The author's clinical test at St Mary's showed broadly healthy gut diversity but also detected common bacteria such as E. coli and C. difficile; a comparison to an Italian dataset suggested the author’s microbiome resembled that of someone slightly older. - Researchers and clinicians quoted in the reporting note that diet and lifestyle influence the microbiome; Dr Manel Esteller says diet may account for about one-third of ageing outcomes, while other factors remain significant. Summary: Research to date suggests a relationship between gut microbiome diversity and aspects of ageing, and some small studies and laboratory experiments indicate the gut can influence physiological and behavioural measures associated with ageing. Larger, longer and more diverse human studies are needed to clarify how much altering the microbiome changes ageing outcomes, and researchers say individual assessment remains important.