Bacteria enriched in marathon runners

A type of bacteria that is enriched in marathon runners may help improve exercise capacity.skynesher / E+ via Getty Images

Your microbiome is the collection of all the microorganisms—bacteria, fungi, and viruses—that live on your skin and within your body. The microbes in your digestive system have been shown to influence your body’s energy metabolism and nutrition.

To determine whether the bacteria that athletes carry in their gut impact their performance, a team led by Dr. George M. Church at Harvard University and Dr. Aleksandar D. Kostic at the Joslin Diabetes Center compared the gut microbiomes of people who ran the 2015 Boston Marathon with those of sedentary people.

The research was supported in part by NIH’s National Human Genome Research Institute (NHGRI), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), and National Library of Medicine (NLM). Results were published on July 25, 2019, in the Nature Medicine.

The researchers collected fecal samples from 15 marathon runners and 10 people who were sedentary from one week before to one week after the 26.2-mile race. Using DNA sequencing, they found that the amount of a bacterium called Veillonella changed the most before and after the athletes ran the marathon. Non-runners also appeared to have less of these bacteria than runners; however, this finding wasn’t statistically significant.

Veillonella is notable because it can use lactate as a food/energy source. Lactate is produced by the body during exercise. It’s often used as a measure for athletic performance. If your body doesn’t metabolize enough lactate as it’s produced, it can build up in your bloodstream and cause your muscles to feel weak and tired.  

The team tested whether Veillonella could impact exercise performance. They gave a group of mice the Veillonella bacteria taken directly from the marathon runners. They gave another group of mice a different type of bacteria that can’t use lactate. Mice given the Veillonella ran on average 13% longer on a treadmill.

The researchers also showed that lactate injected into the bloodstream of mice crossed into the gut. This result suggests that gut bacteria would be able to access the excess lactate produced by exercise.

In another group of ultramarathon runners and Olympic trial rowers, the researchers found that the activity of Veillonella genes involved in processing lactate increased after exercise.

Finally, the team tested whether propionate, one of the compounds that Veillonella convert lactate into, could account for the exercise-enhancing effects of the bacteria. They found that mice given propionate had run times similar to those given Veillonella.

“Having increased exercise capacity is a strong predictor of overall health and protection against cardiovascular disease, diabetes, and overall longevity,” says Kostic. These findings suggest strategies, such as a probiotic supplement, that might help boost the ability to do meaningful exercise and therefore protect against chronic diseases.

However, more studies are needed to understand how to use this information to alter metabolism to affect performance and health outcomes.

—by Tianna Hicklin, Ph.D.