Healthy Ageing: Study Finds Microbiome ‘Signature’

While the importance of the gut microbiome is well documented, its role in the human ageing process is still unclear, however, a large set of longitudinal data has revealed a distinct gut microbiome signature that is associated with healthy ageing and survival in the latest decades of life.

New research published in the journal Nature Metabolism has identified distinct signatures in the gut microbiome that are associated with either healthy or unhealthy ageing trajectories, which in turn can predict the survival of older individuals.

ISB researchers and collaborators took three independent cohorts and analysed gut microbiome, phenotypic and clinical data from over 9,000 people between the ages of 18 and 101 years old. The team then zoomed in on longitudinal data from a cohort of over 900 community-dwelling older individuals aged 78-98 years old, who allowed researchers to track health and survival outcomes.

As individuals aged, the data showed that gut microbiomes became increasingly unique, starting in mid-to-late adulthood. This corresponded with a steady decline in the abundance of core bacterial genera that tend to be shared across humans.

“The most striking pattern characteristic of healthy ageing in our study was the observed gradual decline in the genus Bacteroides, which is one of the most prevalent and abundant bacterial microbes present in the human large intestine. The same decline was not present in older individuals who were defined as not health based on strict criteria,” explained ISB research scientist, Tomasz Wilmanski.

“Although preliminary, these results led us to hypothesise that a healthy gut microbiome is one that gradually shifts and develops within its host over a lifetime.”

Wilmanski added that this unique signature can predict patient survival in the latest decades of life. The research also suggests that microbiome compositions associated with health in early-to-mid adulthood may not be compatible with health in late adulthood. It appears that a healthy gut microbiome doesn’t remain static throughout life but changes as one ages.

One major implication of this would be that how microbiome health is defined in older age cannot be defined within the context of younger and generally healthier individuals.

“While our results are still preliminary, one possible take-home message is that healthy gut microbiome when we are 60 or 70 years old will not look the same as when we were 20 or 30 years old,” noted Wilmanski.

“This suggests that dietary and probiotic recommendations aimed at improving gut microbiome health may need to be tailored to each individual’s age and their personal microbiome footprint.”