A number of recent studies have suggested that as people age, the community of gut microbes (gut microbiota or gut microbiome) becomes less diverse than in younger people. And note that greater gut microbial diversity is generally viewed as healthy and good. However, now a study done in China finds a different result. The study examined the gut microbes of more than 1000 very healthy people, from ages 3 to over 100, and found that the gut microbial communities were very similar among very healthy people in their mid 30s to over 100 years in age.
Whether this is cause or effect is unknown. But the researchers speculate that the similarities in the gut microbiota among people from their 30s to 100+ is a consequence of an active healthy lifestyle and diet. And it suggests that somehow changing an elderly person's gut microbial community (if it's not "normal") to that of a 30-year-old might help promote health. From Science Daily:
In one of the largest microbiota studies conducted in humans, researchers at Western University, Lawson Health Research Institute and Tianyi Health Science Institute in Zhenjiang, Jiangsu, China have shown a potential link between healthy aging and a healthy gut.
With the establishment of the China-Canada Institute, 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. ....The study, published this month in the journal mSphere, 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," said Greg Gloor, the principal investigator on the study and also a professor at Western's Schulich School of Medicine & Dentistry and Scientist at Lawson Health Research Institute. 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 biomarker of healthy aging, just like low-cholesterol is a biomarker of a healthy circulatory system," Gloor said. The researchers suggest that resetting an elderly microbiota to that of a 30-year-old might help promote health. "By studying healthy people, we hope to know what we are striving for when people get sick," said Reid. [Original study.]
Centenarian in Bama County, China. Credit: National Geographic.