The longer the physical activity, the better for the microbiota
Intense physical exercise is not necessary for a healthy microbiota. According to a recent study, what really counts is staying active for at least 2.5 hours a week and keeping in shape.1
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About this article
We already knew that top athletes’ microbiota differs from that of sedentary people, and that intense physical activity has a significant impact on the gut flora.
But how does more moderate physical activity affect our health? Moreover, is the impact the same regardless of weight?
Several hundred volunteers enrolled
To answer these questions, researchers from Canada and European research institutes recruited 350 men and women aged between 38 and 65 and divided them into two groups: one made up of volunteers of normal weight ( (sidenote: Body Mass Index (BMI) Body Mass Index (BMI) assesses the corpulence of an individual by estimating the body fat mass calculated by a ratio between weight ((kg) and height squared (m2). https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm https://www.euro.who.int/en/health-topics/disease-prevention/nutrition/a-healthy-lifestyle/body-mass-index-bmi ) between 18.5 and 25) and the other of overweight people only (BMI between 25 and 30, i.e., not obese).
The scientists asked them what types of physical activity they performed on a daily basis: rather light (walking, washing up, cooking, etc.), moderate (brisk walking, gardening, cycling, badminton, etc.), or intense (heavy work, running, weight training, basketball, football, etc.).
They also recorded the number of hours devoted to these activities for each participant (less than 2.5 hours, between 2.5 and 8 hours, or more than 8 hours).
Lastly, the researchers collected stools from all participants in order to analyze their gut microbiota.
Health benefits for all, but more comprehensive benefits in slim people
The results showed that improvements in the diversity and richness of the microbiota are linked more to total hours of physical activity than to the intensity of that activity. Regardless of your weight, at least 2.5 hours of physical activity a week is enough to benefit your gut.
This is good news for those who are overweight, since diversity and richness are associated with a lower risk of chronic illness (diabetes, obesity, cardiovascular disease, etc.) and a more resilient microbiota.
Despite this, only the normal-weight volunteers (BMI < 25) saw changes in bacterial composition. The more time these volunteers devoted to physical activity, the richer their microbiota became in:
- Actinobacteria, a group of bacteria known for multiple benefits to cardiometabolic health, e.g., lower cholesterol, the production of acetate – (sidenote: Short chain fatty acids (SCFA) Short chain fatty acids (SCFA) are a source of energy (fuel) for an individual’s cells. They interact with the immune system and are involved in communication between the intestine and the brain. Silva YP, Bernardi A, Frozza RL. The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Front Endocrinol (Lausanne). 2020;11:25. ) –, the digestion of complex carbohydrates such as resistant starch;
- Collinsella, bacteria belonging to the Actinobacteria family, which protect against gut permeability and produce butyrate, another SCFA with anti-inflammatory properties.
Impact also depends on gender
Another finding was that in normal weight men, as well as overweight women, the greater the grip strength, the higher the abundance of Faecalibacterium prausnitzii, bacteria known for their anti-inflammatory properties and effects countering (sidenote: Dysbiosis Generally defined as an alteration in the composition and function of the microbiota caused by a combination of environmental and individual-specific factors. Levy M, Kolodziejczyk AA, Thaiss CA, et al. Dysbiosis and the immune system. Nat Rev Immunol. 2017;17(4):219-232. ) .
BMI and gender therefore play a role in how physical activity impacts the microbiota. This is another major advance in our understanding of how the gut-muscle axis works.
The gut microbiota
"That's fascinating! Physical activity can indeed have a positive impact on your gut microbiota. It's all about nurturing a diverse microbial ecosystem in your gut, which can support better digestion and overall health. Remember, what matters most is finding an activity you enjoy, as consistency is key to reaping the rewards." -Aware Health Rewards App (From My health, my microbiota)
