Scientists say your gut microbiome – the trillion-strong community of microorganisms in your gut – can help predict whether you’ll have a long, healthy life.
American researchers have identified several characteristics in the gut microbiome that are associated with healthy or unhealthy aging pathways.
In healthy individuals, gut microbiomes are becoming increasingly unique and diverge in different ways specific to the individual, compared to unhealthy individuals.
This uniqueness is strongly associated with microbially produced amino acid derivatives circulating in the bloodstream, indicating life-extending chemicals.
This knowledge means that microbiomes can be used to predict the survival of a population of older individuals, the experts said.
The human microbiome is made up of communities of bacteria (and viruses and fungi). Data from over 9,000 people reveal a clear signature of the gut microbiome associated with healthy aging and survival in the last decades of life
Researchers say the adult gut microbiome continues to develop with age in healthy individuals, but not unhealthy ones.
In addition, microbiome compositions related to early to mid adult health may not be compatible with late adult health.
“ Previous results in microbiome aging research appear inconsistent, with some reports showing a decline in core gut generations in centenarian populations, while others show relative stability of the microbiome until the onset of aging-related health decline, ” said co- author Dr. Sean Gibbons of the US Institute of Systems Biology.
Our work, which is the first to include a detailed analysis of health and survival, can resolve these inconsistencies. In concrete terms, we show two different aging trajectories.
“First, a decrease in core microbes and a concomitant increase in uniqueness in healthier individuals, consistent with previous results in centenarians living at home, and two, the preservation of core microbes in less healthy individuals.”
Microbiota is also known as the microbiome – although the latter term includes the collective genomes of the microorganisms in a particular environment, as well as the microorganisms themselves.
The gut microbiome is an integral part of the body, but its importance in the aging process of humans is unclear.
The research team analyzed the gut microbiome, phenotypic and clinical data from more than 9,000 people between the ages of 18 and 101 in three independent cohorts.
In particular, the team focused on longitudinal data from a cohort of more than 900 elderly people living at home between 78 and 98 years old, which allowed them to track health and survival outcomes.
The data showed that gut microbiomes became increasingly unique and diverge from other people’s microbiomes as they age, starting in mid to late adulthood.
This was consistent with a steady decline in the abundance of bacterial genera (eg Bacteroides) that tend to be shared by humans.
While microbiomes became more and more unique to each individual with healthy aging, the metabolic functions common to the microbiomes had common features.
The data showed that gut microbiomes became increasingly unique (i.e., increasingly different from others) as individuals aged, beginning in mid to late adulthood, which was consistent with a steady decline in the abundance of bacterial genera (e.g., Bacteroides) that tended to have to be shared by people. Shown in the artist’s impression, Bacteroides fragilis, one of the main components of the normal human gut microbiome
This signature of gut uniqueness was highly 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.
Previous research has shown that this metabolite is highly elevated in the blood of people 100 years and older.
Interestingly, this unique pattern appears to begin mid-life – 40-50 years old – and is associated with a clear metabolomic signature in the blood, suggesting that these microbiome changes are not only diagnostic of healthy aging, but that they are also can contribute directly to health as we age, ‘said Wilmanski.
The study is published in the journal Nature Metabolism.