Washington [US]February 21 (ANI). A team of researchers and their staff have identified different signatures in the gut microbiome that are associated with either healthy or unhealthy aging patterns, which in turn predict the survival of a population of elderly people.
The work is to be published in the journal ‘Nature Metabolism’.
The research team analyzed gut microbiome, phenotypic and clinical data from over 9,000 people between the ages of 18 and 101 years in three independent cohorts. In particular, the team focused on longitudinal data from a cohort of over 900 shared elderly people (78-98 years of age) that they could use to track health and survival outcomes.
The data showed that gut microbiomes became increasingly unique (that is, increasingly different from others) with age, beginning in middle to late adulthood, reflecting a steady decline in the incidence of core bacterial genera (e.g., Bacteroides) shared between people.
Notably, although the microbiomes became more and more unique to each individual as they grew older, the metabolic functions that the microbiomes performed became common. This signature of gut uniqueness was strongly correlated with several microbially derived metabolites in blood plasma, including one – tryptophan-derived indole – previously shown to extend the lifespan of mice. Blood levels of another metabolite – phenylacetylglutamine – showed the strongest association with uniqueness, and previous work has shown that this metabolite is indeed greatly elevated in centenarians’ blood.
“This uniqueness signature can predict patient survival over the last few decades of life,” said ISB research scientist Dr. Tomasz Wilmanski, who led the study. Healthy individuals around the age of 80 showed a sustained microbial drift towards a unique compositional state, but this drift was absent in less healthy individuals.
“Interestingly, this pattern of uniqueness appears to begin in mid-life – 40-50 years old – and is associated with a distinct metabolomic signature of the blood, suggesting that these microbiome changes may not only be, but also carry, a diagnosis of healthy aging also directly contributes to health as we get older, “said Dr. Wilmanski. For example, indoles are known to reduce inflammation in the bowel and chronic inflammation is believed to be a major driver of the progression of age-related morbidities.
“Previous results in microbiome aging research appear to be inconsistent. Some reports show a decline in nucleus genus in hundred-year-old populations, while others show relative stability of the microbiome until the onset of age-related health decline,” said microbiome specialist Dr. Sean Gibbons, co-author of the paper.
“Our work, which is the first to include a detailed analysis of health and survival, can resolve these inconsistencies. In particular, we show two different aging trajectories: 1) a decrease in core microbes and an associated increase in uniqueness in healthier individuals, consistent with previous results centenarians living in the community and 2) the maintenance of nuclear microbes in less healthy individuals, “added DrGibbons.
This analysis highlighted the fact that the adult gut microbiome evolves in healthy individuals with advanced age, but not in unhealthy individuals, and that microbiome compositions associated with health in early to middle adulthood may not be associated with health in late Adulthood are compatible.
“This is exciting work that we believe will have important clinical implications for monitoring and modifying gut microbiome health throughout a person’s lifetime,” said ISB Professor Dr. Nathan Price, co-corresponding author of the paper.
This research project was conducted by ISB and staff at Oregon Health and Science University, the University of California at San Diego, the University of Pittsburgh, the University of California at Davis, the Lifestyle Medicine Institute, and the University of Washington. It was supported in part by a Catalyst Award for Healthy Longevity from the National Academy of Medicine and the Longevity Consortium of the National Institute on Aging. (ANI)