Muscle strength linked to healthy gut bacteria, says new study

Muscle strength linked to healthy gut bacteria, says new study

Faecal transplants might be the hot new thing in performance enhancement, at least according to a recent study published in the journal of experimental gerontology (the study of ageing, to you and me).

Scientists working out of the  Nutrition, Exercise Physiology, and Sarcopenia Laboratory at Boston Tuft's University recruited 29 sedentary older (70+) adults and separated them into groups labelled high (HF) and low (LF) functioning according to their Body Mass Index and performance on a short exercise test. 

After establishing the high and low functioning groups, the researchers took fecal samples from all participants to test if differences in the composition of their gut microbiomes – the millions of bacteria in our guts which help digest food, and have previously been linked to everything from gluten intolerance to obesity –  could explain their differences in BMI and physical performance. 

What they found were significant differences in the levels of certain bacteria between the two groups, but that's only half the story. In order to test if these bacteria had a causal effect on the participants BMI and performance (rather than just correlating, or even being a coincidence) the researchers colonised mice with faecal matter from the two groups (that is, they fed it to them). 

These mice were raised in a completely sterile environment, meaning they had no preexisting bacteria in their guts which could skew results.

A month after colonising the mice, the researchers tested their gut microbiomes and grip strength, finding that the mice now had similar differences in their gut microbiomes to the human participants, as well as similar differences in strength. However, the scientists found no difference in body composition.

Michael Lugerston, one of the study's authors, said: “While we were surprised that we didn’t identify a role for the gut microbiome on the maintenance of body composition, with these results we now start to understand the role of gut bacteria on the maintenance of muscle strength...

While this study was short, had a small sample size, and focused exclusively on those over 70, it points to exciting possibilities for maximising performance among strength athletes by tweaking gut bacteria. Though I won't be first in line to be 'colonised' – hopefully, someone comes out with a pill.