Specific bacteria in the gut microbiome of elite runners may contribute to enhanced athletic performance, suggests a study published online this week in Nature Medicine.

The human microbiome (the microorganisms that reside within the human body) is known to influence human health. Previous research has associated exercise with changes in the microbiome, but the effects of these changes on athletic performance have remained unknown.

Aleksandar Kostic and colleagues analysed stool samples from 15 Boston Marathon runners and 10 non-runner control subjects for 1 week before the marathon and 1 week after. They report that bacteria of the genus Veillonella became more abundant in the stool of athletes after exercise and that these bacteria had all the genes necessary to consume lactate, a metabolite associated with the fatigue of exercise. These results were validated in an independent cohort of 87 human athletes. In another experiment, the authors isolated a strain of Veillonella from one of the marathon runners and administered it to 16 mice. They found that the mice given the bacteria increased their performance in a laboratory treadmill test by 13%, relative to that of control group.