Bacteria; New research has identified a type of bacteria found in the microbiomes of elite athletes that contributes to improved capacity for exercise. These bacteria, members of the genus Veillonella, are not found in the guts of sedentary people. By taking a closer look at the bacteria, the researchers from Joslin Diabetes Center determined Veillonella metabolizes lactic acid produced by exercise and converts it into propionate, a short chain fatty acid.
Having increased exercise capacity is a strong predictor of overall health and protection against cardiovascular disease, diabetes, and overall longevity, says Aleksandar D. Kostic Ph.D., TITLE., a co-author on the paper. “What we envision is a probiotic supplement that people can take that will increase their ability to do meaningful exercise and therefore protect them against chronic diseases including diabetes.
Bacteria in both cohorts
The work began in 2015 with fecal samples from Boston Marathon runners. Jonathan Scheiman, Ph.D., then a researcher in the lab of George Church, Ph.D., at Harvard Medical School, collected samples during a time span of one week before the Marathon to one week after the Marathon. He also collected samples from sedentary individuals. Dr. Scheiman then brought the samples to Dr. Kostic, who analyzed them to determine the species of bacteria in both cohorts.
One of the things that immediately caught our attention was this single organism, Veillonella, that was clearly enriched in abundance immediately after the marathon in the runners. Veillonella is also at higher abundance in the marathon runners [in general] than it is in sedentary individuals. says Dr. Kostic.
Lactic acid is produced by the muscles during strenuous exercise. The Veillonella bacteria are able to use this exercise by-product as their main food source. Our immediate hypothesis was that it work as a metabolic sink to remove lactate from the system, the idea being that lactate build-up in the muscles creates fatigue, he says.
Organisms in the microbiome
Dr. Kostic and his team return to the lab to figure out; so what be causing the increase in exercise capacity. They ran a metagenomic analysis, meaning they tracked the genetics of all the organisms in the microbiome community, to determine what events were triggered by Veillonella’s metabolism of lactic acid. They note that the enzymes associated with conversion of lactic acid into the short chain fatty acid propionate were at much higher abundance after exercise.
Then the question was maybe it’s not removal of lactic acid; but the generation of propionate, says Dr. Kostic. They did some experiments to introduce propionate into mice; also test whether that was sufficient for this increased running ability phenotype. And it was. The microbiome is such a powerful metabolic engine, says Dr. Kostic. This is one of the first studies to directly show a strong example of symbiosis between microbes and their human host.
It’s very clear. It creates this positive feedback loop. The host is producing something that this particular microbe favors. Then in return, the microbe is creating something that benefits the host, he says. This is a really important example of how the microbiome; which has evolve ways to become this symbiotic presence in the human host.