Healthier Older People have a Gut Microbiome More Like that of Younger People

The research community has amassed a fair amount of evidence to show that the composition of the gut microbiome changes with aging and has some influence over the pace of aging. Consider interactions between gut bacteria and the immune system, and the degree to which it promotes chronic inflammation, for example. Other mechanisms by which our gut microbes influence systems and organs are also being uncovered of late. Just how much the gut microbiome contributes to natural variations in human life span remains an open question: is it on a par with exercise and calorie intake, or a lesser influence? Further, are changes in the gut microbiome a consequence of lifestyle choices or are they a more independent factor? Research such as the program noted here attempts to put some bounds to the possible range of answers.

In one of the largest microbiota studies conducted in humans, researchers have shown a potential link between healthy aging and a healthy gut. The researchers studied the gut bacteria in a cohort of more than 1,000 Chinese individuals in a variety of age-ranges from 3 to over 100 years-old who were self-selected to be extremely healthy with no known health issues and no family history of disease. The results showed a direct correlation between health and the microbes in the intestine. "It begs the question - if you can stay active and eat well, will you age better, or is healthy aging predicated by the bacteria in your gut?"

The study showed that the overall microbiota composition of the healthy elderly group was similar to that of people decades younger, and that the gut microbiota differed little between individuals from the ages of 30 to over 100. "The main conclusion is that if you are ridiculously healthy and 90 years old, your gut microbiota is not that different from a healthy 30 year old in the same population." Whether this is cause or effect is unknown, but the study authors point out that it is the diversity of the gut microbiota that remained the same through their study group. "This demonstrates that maintaining diversity of your gut as you age is a low-cholesterol is a biomarker of a healthy circulatory system." The researchers suggest that resetting an elderly microbiota to that of a 30-year-old might help promote health.



One conclusion of the Chinese study is that a low-cholesterol level is a biomarker of a healthy circulatory system. I question whether this is always true, as many other factors are involved in a healthy circulatory system, such as a high HDL level, as many researchers have found that most Centenarians have a relatively high level of HDL, the good cholesterol.

Posted by: Biotechy at October 12th, 2017 9:55 AM

The connection between gut microbiota and age-related inflammation aka inflammaging is established so it isn't a stretch to consider that this is the mechanism that improves health. Less inflammation from the microbiota = less inflammaging and thus the host of problems that causes.

One recent study shows that mice kept in germ-free environments do not even have age-related inflammatory cytokines which again strongly suggests the microbiome in the gut is the origin point that starts the cascade of inflammation off.

The researchers observed that when germ-free mice are mixed with regular mice their microbiomes are affected and they get inflammation. Same happens when flora from aged mice is added to the microbiome of germ-free mice.

Posted by: Steve Hill at October 16th, 2017 6:11 AM

My hunch is the gut microbiota changes due to exposure over a lifetime to pathogens and the balance in the gut changes to pro-inflammatory. This then kicks off the cascade that causes macrophages to stop clearing house and removing senescent cells and the inflammatory downward spiral begins.

Thevaranjan, N., Puchta, A., Schulz, C., Naidoo, A., Szamosi, J. C., Verschoor, C. P., … & Schertzer, J. D. (2017). Age-Associated Microbial Dysbiosis Promotes Intestinal Permeability, Systemic Inflammation, and Macrophage Dysfunction. Cell Host & Microbe, 21(4), 455-466.

Posted by: Steve Hill at October 16th, 2017 6:14 AM

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