Scientists say that the intestinal microbiome – the powerful community of trillions of microorganisms in the stomach – can help predict a long and healthy life.
U.S. researchers have identified distinct signatures in the gut microbiome that are associated with either healthy or unhealthy aging trajectories.
In healthy people, intestinal microbiomes become more and more unique, diverging in different ways specific to the individual, compared to unhealthy individuals.
This uniqueness is strongly associated with microbial amino acid derivatives circulating in the bloodstream, suggesting expanding chemicals.
This knowledge means that microbiomes can be used to predict survival in an older population, according to experts.
The human microbiome is made up of communities of bacteria (and viruses and fungi). Data from over 9,000 people reveal a distinct signature of the gut microbiome that is associated with healthy aging and survival in the last decades of life.
Researchers say that the intestinal microbiome of adults continues to grow with age in healthy people, but not in unhealthy ones.
In addition, microbiome compositions associated with health in early to mid adulthood may not be compatible with health in late adulthood.
“Previous research results on microbiome aging appear to be inconsistent, with some reports showing a decline in basic gut genes in century-old populations, while others show relative microbiome stability until health-related declines occur,” he said. study author Dr. Sean Gibbons at the US Institute of Systems Biology.
“Our work, which is the first to incorporate a detailed analysis of health and survival, can resolve these inconsistencies. Specifically, we present two distinct aging trajectories.
One, a decrease in basic microbes and an accompanying increase in uniqueness in healthier individuals, consistent with previous results in centenarians living in the community, and two, the maintenance of basic microbes in less healthy individuals.
The microbiota is also known as the microbiome – although the latter term includes the collective genomes of microorganisms in a particular environment, as well as the microorganisms themselves.
The intestinal microbiome is an integral component of the body, but its importance in the aging process of man has been unclear.
The research team analyzed intestinal, phenotypic and clinical microbiome data from more than 9,000 people aged 18 to 101 years in three independent cohorts.
The team focused in particular on the longitudinal data of a cohort of over 900 elderly people living in the community, aged between 78 and 98, allowing them to track health and survival outcomes.
The data showed that intestinal microbiomes became more and more unique and different from other people’s microbiomes as they got older, from middle adulthood to the end of the year.
This corresponded to a steady decrease in the abundance of basic bacterial genera (e.g., Bacteroides) that tend to be shared between humans.
As microbiomes became increasingly unique to each individual during healthy aging, the metabolic functions that microbiomes performed shared common traits.
The data showed that intestinal microbiomes became increasingly unique (i.e., increasingly divergent from others) as older individuals, beginning in middle adulthood through the end of the year, which corresponded to a steady decline in abundance. basic bacterial genera (e.g., Bacteroides) that tend to be shared between humans. In the artist’s image, Bacteroides fragilis, one of the major components of the normal microbiome of the human intestine
This signature of intestinal uniqueness has been strongly correlated with several microbially derived metabolites in blood plasma, including one – tryptophan-derived indole – which has previously been shown to prolong life in mice.
Blood levels of another metabolite – phenylacetylglutamine – showed the strongest association with uniqueness.
Previous work has shown that this metabolite is highly elevated in the blood of people over the age of 100.
“Interestingly, this type of uniqueness seems to begin in the middle of life – 40-50 years – and is associated with a clear metabolomic signature in the blood, suggesting that these changes in the microbiome cannot simply be diagnoses of healthy aging,” but that they can also contribute directly to health as we age, ”said Wilmanski.
The study was published in the journal Nature Metabolism.