The more scientists look at the bacteria in the gut, the more clear its importance to our overall health becomes, and new research links a certain type of gut microbiome development to longer life and healthier old age.
In a study of more than 9,000 people in three different cohorts, new research found that our gut microbiomes become more unique and personal to us as we age, and that the number of core bacteria (such as Bacteroides) also tend to decrease.
This pattern also appears to be related to physical health and longevity. So people whose microbiomes don’t keep changing in old age, and who don’t see a reduction in core bacteria, are usually not that healthy or don’t live that long.
“This unique signature can predict patient survival in the last decades of life,” said biochemist Tomasz Wilmanski of the Institute for Systems Biology (ISB).
Interestingly, this unique pattern appears to begin in middle age – 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. “
Remarkably, even when microbiomes diverged in design in old age, the metabolic functions they performed were consistent across individuals – the researchers found certain metabolites linked to longevity in the gut of humans (and various animals) whose microbiomes had a healthier form followed. pattern.
As Wilmanski points out, whether these shifts in microbiome composition actually contribute to good health or just reflect it remains, but it is certainly worth further investigation, the scientists say – and it adds some clarity to an area of research where findings were not always clear. .
For example, metabolites called indoles have been discovered that have previously been associated with decreased inflammation in the intestines of mice – and chronic inflammation is one of the health problems known to increase the risk of death in the elderly.
“Previous results in microbiome aging studies appear inconsistent, with some reports showing a decline in core gut lesions in centenarian populations, while others show relative stability of the microbiome until the onset of aging-related health decline,” says microbiologist Sean Gibbons. , from ISB.
“Our work, which is the first to include a detailed analysis of health and survival, can resolve these inconsistencies.”
While the study as a whole included people ages 18 to 101, it was a particular cohort of individuals between the ages of 78 and 98 that allowed the researchers to take a closer look at how microbiomes and mortality may be related.
We know it’s at the beginning and end of our lives when our gut bacteria mix goes through the greatest changes, and this latest study supports the idea that a constantly evolving belly bacteria mix late in life is a good sign: it might be an indicator of a still flourishing body until the last years of life.
The study suggests that a healthy gut microbiome – whatever that is – may not look the same at different stages of life, and that’s a useful avenue for future research to explore. It seems that our microbiomes can develop in different ways in the elderly, and some of those developments may be healthier than others.
“This is exciting work that we believe will have major clinical implications for monitoring and modifying the health of the gut flora throughout life,” said ISB bioengineer Nathan Price.
The research is published in Nature Metabolism