A gut feeling - athletes' performance and the microbiome

Wish you could run the Boston Marathon in under 3 hours? The path to a successful marathon performance is usually a painful one and requires both time and the willingness to suffer on an extraordinary scale. But there may be an alternative on the horizon - stay on your couch and train your microbiome instead.

Boston Marathon

Researchers from Harvard Medical School have found that individuals who ran the Boston Marathon differ in their microbiome from us average couch potatoes. Namely, they have a prevalence of a bacterium belonging to the genus Veillonella. Intriguingly,  these bugs metabolize lactic acid, the dreaded enemy of every endurance athlete. When exercising, lactate builds up in your muscles leading to muscle fatigue and consequently a drop in performance. The common wisdom goes that raising your lactate tolerance (or threshold) helps your muscles cope better with high lactate levels, leading to increased performance over longer periods of time. But could lowering lactate levels in your body have the same effect? Veillonella does exactly that by turning lactate into propionate, which in addition has the beneficial effect of boosting exercise capacity.

To test their hypothesis, the researchers turned to mice. They fed mice either a Veillonella atypica strain, isolated from one of the marathon runners, or Lactobacillus bulgaricus, which, unlike Veillonella, does not influence lactate metabolism. Then, it was the mice's job to run the old treadmill until exhaustion. The results were quite impressive - mice given V. atypica were able to run on average 13 percent longer than the control-treated mice.

To corrobate their findings, the researchers turned to shotgun metagenomics. They obtained stool samples from  ultramarathoners and Olympic trial rowers before and after exercising and subjected these to metagenomic sequencing, identifying a group of gene families whose relative abundance changed before and after exercise. These genes encompassed each step of the enriched methylmalonyl-CoA pathway, which degrades lactate into propionate, suggesting that not only is Veillonella enriched after exercise, but so is the metabolic pathway it uses to metabolize lactate.

Taken together, their findings suggest that systemic lactate produced during exercise may cross into the gut where it gets metabolized into propionate by Veillonella, promoting the athlete's performance. Study authors Jonathan Scheiman and George Church have now launched a startup called FitBiomics and are planning to commercialize their findings. Who knows - maybe in a few years' time you'll be able to get up from your couch, gulp down their supplement and travel to the start line in Hopkinton with the sure knowledge that you'll cross the finish line in Boston exactly two and a half hours later...

Nature Medicine Volume 25, pages1104–1109 (2019)