A new, large study on the gut microbiome shows promising new data about gut aging and longevity.
Healthy aging and a long life is on most people’s to do list, and, as it turns out, a healthy gut microbiome could play a key role in bringing this about.
Longevity.Technology: The human gut microbiome is unique, with its vast array of various types of bacteria, protozoa, archaea, viruses and fungi; at any one point, there are approximately 40 trillion bacteria in the system. Maintaining its health is crucial to the alimentary canal, and to the organism as a whole. But is there a way to “hack the system,” and allow humans to live for longer as a result of recent advances in research?
A research team from the Seattle-based Institute of Science Biology was able to analyse the gut microbiome, phenotypic and clinical data from more than 9,000 people aged 18 to 101 years, across three independent cohorts. Because the study incorporated patients aged 78 to 98 years old, they were able track both health and survival outcomes as people age.
According to the data that resulted, as an individual ages, their gut microbiome appears to become more and more divergent from others [1] – that is, they gain more of a unique metabolic signature. The process seems to start in mid-to-late adulthood, and interestingly corresponds with the start of steady decline in core bacterial genera. Core bacterial genera is the agreed-upon set of common bacteria found in the tract.
Why is the gut microbiome important in aging?
So far, so gut. However, while individual microbiomes became increasingly unique, the metabolic functions they perform share common characteristics.
The researchers determined that there is a clear metabolomic structure associated with the pattern of uniqueness. One example given was indoles, heterocyclic organic compounds which are known to reduce inflammation of the gut. Chronic inflammation is thought to drive aging-related morbidities in its progression. Finding a way to maintain the indoles in the gut as we age could promote health and help to stave off age-related morbidity.
“This uniqueness signature can predict patient survival in the latest decades of life,” said Dr Tomasz Wilmanski, who led the study [2], explaining that healthy individuals around 80 years of age showed “continued microbial drift toward a unique compositional state, but this drift was absent in less healthy individuals”.
When it comes to core gut genera, it seems that some centenarian populations suffer a steady decline, whereas others are more stable; this brings into question the frequency of the loss of microbiome variance as people age.
“Prior results in microbiome-aging research appear inconsistent, with some reports showing a decline in core gut genera in centenarian populations, while others show relative stability of the microbiome up until the onset of aging-related declines in health,” says microbiome specialist Dr Sean Gibbons, co-corresponding author of the paper [2].
“Our work, which is the first to incorporate a detailed analysis of health and survival, may resolve these inconsistencies,” he continues. “Specifically, we show two distinct aging trajectories: 1) a decline in core microbes and an accompanying rise in uniqueness in healthier individuals, consistent with prior results in community-dwelling centenarians, and 2) the maintenance of core microbes in less healthy individuals.”
The analysis was also able to highlight the adult microbiome as it continues to develop with advanced age in healthy individuals. In unhealthy people, the microbiome compositions associated with health in early-to-mid adulthood may not be compatible from health in late adulthood. This shows how individualistic the aging of the alimentary system is.
“This is exciting work that we think will have major clinical implications for monitoring and modifying gut microbiome health throughout a person’s life,” said ISB Professor Nathan Price, PhD, co-corresponding author of the paper [2].
What next for gut microbiome research?
When it comes to the concept of monitoring individual gut health as people age, what would that mean from the perspective of the patient? There is already home testing for gut microbiome sequencing, such as Thryve, and as Professor Price says, he hopes this research will progress into not only being able to monitor gut health, but being able to modify it to improve individual outcomes.
Regular, easy tests, that link with apps that monitor diet and other areas of fitness could feed into a holistic approach to improving healthspan; it seems when it comes to improving our health, we really are what we eat.
[1] https://www.nature.com/articles/s42255-021-00348-0
[2] https://isbscience.org/news/2021/02/18/gut-microbiome-implicated-in-healthy-aging-and-longevity/
