In one of the largest microbiota studies conducted in humans, scientists have shown a potential link between healthy aging and a healthy gut – finding that the overall microbiome composition of healthy elderly people 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.
Led by researchers from the Lawson Health Research Institute at Western University, Canada, and Tianyi Health Science Institute in Zhenjiang, Jiangsu, China the study analysed 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 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 lead researcher Greg Gloor at the Lawson Health Research Institute.
"The aim is to bring novel microbiome diagnostic systems to populations, then use food and probiotics to try and improve biomarkers of health," added Professor Gregor Reid, also of the Lawson Health Research Institute. "It begs the question - if you can stay active and eat well, will you age better, or is healthy ageing predicated by the bacteria in your gut?"
Cause or effect?
Whether findings are the result of cause or effect is unknown, but the team behind the study 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," said Gloor.
However, the team go further, by 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.
The team noted that the present findings suggest that the microbiota of the healthy aged differ little from that of the healthy young in the same population, although the minor variations that do exist depend upon the comparison cohort.
“This baseline will serve for comparison for future cohorts with chronic or acute disease,” wrote the team. “We speculate that this similarity is a consequence of an active healthy lifestyle and diet, although cause and effect cannot be ascribed in this (or any other) cross-sectional design.”
They added that one surprising result was that the gut microbiota of persons in their 20s was distinct from those of other age cohorts.
“This result was replicated, suggesting that it is a reproducible finding and distinct from those of other populations,” said the team – who noted that further work will now investigate this ‘unexpected’ finding.
“This observation may result from an altered diet, altered energy requirements, or an unknown cohort effect, although if the latter, it must have occurred countrywide as the same effect was observed in a population of university age students from Jiangsu Province and from police and military recruits originating from all provinces in China,” the Canadian and Chinese team concluded.
Published online ahead of print, doi: 10.1128/mSphere.00327-17
“The Gut Microbiota of Healthy Aged Chinese Is Similar to That of the Healthy Young”
Authors: Gaorui Bian, Gregory B. Gloor, et al