The human gut is a complex ecosystem, home to trillions of microorganisms that play a vital role in maintaining our health.
Recent findings published in the journal of Developmental Cognitive Neuroscience have found that the diversity of microbes in the gut may not only influence our physical fitness but also affect how fast we age.
The revelations by a team at the Hungarian University of Sports Science open up new possibilities for harnessing the power of probiotics to promote health and longevity, said Professor Zsolt Radak, lead author of the study.
With his team in Budapest, Radak examined the relationship between gut microbiome diversity, biological age - our age as determined by the state of our overall health, and not our years of life - and physical fitness of 80 amateur rowers.
For the purposes of the study, each participant underwent a series of fitness assessments and provided a stool sample to analyse the bacteria in their gut, as well as blood samples to determine their biological age using epigenetic markers.
Epigenetic markers are like switches in our DNA that can control whether certain genes are turned on or off, and play a crucial role in determining how our cells develop, function, and respond to our environment.
The quality of our cells can be influenced by factors such as our lifestyle, diet, and exposure to environmental factors, which can ultimately impact our health and how we age.
Epigenetic markers allow scientists to measure this cellular decline, which provides a snapshot of our "epigenetic clocks," or "biological age".
"We found that inflammatory bacteria are actually accelerating the ageing process, so if you have more inflammatory bacteria. Then you have advanced ageing," Radak told Euronews Next, adding that accelerated ageing "means that you are older than your chronological age".
Likewise, upon analysing the specific bacteria present in the rowers' gut microbiomes, the researchers found that higher levels of anti-inflammatory bacteria were correlated with improved fitness indicators and a slower rate of ageing.
Conversely, the presence of inflammatory bacteria was associated with poorer performance in fitness tests.
The athletes were between the ages of 38 and 84 and had participated in the 2019 World Rowing Masters Regatta, an international rowing competition specifically designed for masters rowers.
A crucial link between gut and ageing
The findings suggest a crucial link between gut bacteria, inflammation, fitness, and the ageing process, challenging the common assumption that more bacteria simply means better health, says Radak.
The study, however, did not determine a cause and effect. It could well be that athletes' presumably healthier dietary choices are positively influencing the abundance of beneficial bacteria in their gut.
However, "these bacteria do not relate to chronological ageing. Which I think is a pretty interesting observation because it means that these bacteria are actually involved in DNA methylation ageing [epigenetic ageing], [and are hence] not the result of [chronological] ageing," Radak said.
In other words, inflammatory bacteria, when abundant, are linked to accelerated ageing.
"I think these findings are important because we first have to identify the relationships. And then, of course, if you can confirm it, the next step is to modify [treat] this kind of abundance [of inflammatory bacteria] and then make modifications in the gut microbiome which allow, maybe, a deceleration of ageing and healthier life," he said.
Radak’s team is currently conducting a follow-up six-month study where they have altered the rowers’ gut microbiome using probiotics to assess if this intervention directly affects biological age.
The findings are expected to be published in early 2024.
Meanwhile, they are also working on a different study involving 60 Olympic champions between the ages of 25 and 102, which aims to explore the impact of early high-level physical activity on the ageing process.
Preliminary results have already revealed that elite athletes have a younger epigenetic age than their chronological age, Radak told Euronews Next.