Scientists say your gut microbiome – the strong community of trillions of microorganisms in your belly – can help predict whether you have a long, healthy life.
American researchers have identified distinct signatures in the gut microbiome that are associated with healthy or unhealthy aging trajectories.
In healthy individuals, intestinal microbiomes become increasingly unique, diverging in different ways that are specific to the individual, compared to unhealthy individuals.
This uniqueness is strongly associated with amino acid derivatives produced by microorganisms that circulate in the bloodstream, suggesting chemical substances that prolong life.
This knowledge means that microbiomes can be used to predict survival in a population of older individuals, according to experts.
The human microbiome is made up of communities of bacteria (and viruses and fungi). Data from more than 9,000 people reveal a distinctive signature of the intestinal microbiome associated with healthy aging and survival in the last decades of life
The researchers say that the adult gut microbiome continues to develop with advanced age in healthy individuals, but not in unhealthy individuals.
In addition, health-associated microbiome compositions in the early to mid-adulthood may not be compatible with health in late adulthood.
“Previous results in the microbiome aging survey seem inconsistent, with some reports showing a decline in central intestinal genera in centuries-old populations, while others show relative stability of the microbiome until the beginning of health-related declines,” said the study co. – author, Dr. Sean Gibbons, from the United States 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 show two distinct aging trajectories.
‘One, a decline in central microbes and a concomitant increase in uniqueness in healthier individuals, consistent with previous results in centenarians living in the community, and two, the maintenance of central microbes in less healthy individuals.’
Microbiota is also known as a microbiome – although the latter term includes the collective genomes of microorganisms in a given environment, as well as the microorganisms themselves.
The intestinal microbiome is an integral component of the body, but its importance in the human aging process is unclear.
The research team analyzed the intestinal microbiome, phenotypic and clinical data from more than 9,000 people aged 18 to 101 years in three independent cohorts.
The team focused in particular on longitudinal data from a cohort of more than 900 elderly individuals living in the community between 78 and 98 years, allowing them to track health and survival results.
The data showed that intestinal microbiomes became increasingly unique and divergent from other people’s microbiomes as they aged, beginning in late adulthood.
This corresponded to a steady decline in the abundance of central bacterial genera (eg, Bacteroides) that tend to be shared among humans.
While microbiomes became increasingly unique for each individual in healthy aging, the metabolic functions that microbiomes played shared common characteristics.
The data showed that intestinal microbiomes became increasingly unique (that is, increasingly divergent from others) as individuals aged, beginning in late adulthood, which corresponded to a steady decline in the abundance of genders central bacterials (eg, Bacteroides) that tend to be shared between humans. Pictured in the artist’s impression, Bacteroides fragilis, one of the main components of the normal human gut microbiome
This signature of intestinal exclusivity has been highly correlated with various microbial-derived metabolites in blood plasma, including one – tryptophan-derived indole – which has already been shown to extend life in mice.
Blood levels of another metabolite – phenylacetylglutamine – showed the strongest association with exclusivity.
Previous work has shown that this metabolite is highly elevated in the blood of people aged 100 and over.
‘Interestingly, this pattern of exclusivity seems to start in middle age – 40-50 years – and is associated with a clear blood metabolomic signature, suggesting that these changes in the microbiome may not simply be diagnoses of healthy aging, but may also contribute directly to health as we age, ‘said Wilmanski.
The study was published in the journal Nature Metabolism.