Exercise May Change Gut Bacteria for More Endurance


    An interesting study showed that after finishing the 26-mile Boston Marathon, runners had changes in the bacteria in their colons that may have helped them to run faster and longer (Nature Medicine, June 24, 2019). Fifteen marathon runners and 10 non-runners provided stool specimens daily for a week before and a week after the marathon. Before the marathon, the runners and non-runners had similar average concentrations of a type of colon bacteria called Veillonella. However, after the marathon, stool cultures from the marathon runners showed increased numbers of Veillonella. Stool samples from 87 other athletes also showed increased Veillonella concentrations after they exercised.

    Next, 16 mice were given Veillonella taken from stool of one runner after the marathon, and 16 mice were given other bacteria. After a few hours, the mice were put on an exercise wheel and they ran to exhaustion. Later, the researchers switched the groups of mice so that Veillonella was given to the mice who had previously been given the placebo bacteria. Mice in both groups ran 13 percent longer after they were given the Veillonella bacteria.

    Other studies show that exercise can change the types of bacteria in your colon (Gut, 2014;63:1913–1920) and that athletes have different concentrations of colon bacteria than non-athletes (Microbiome, 2017;5:98). Accumulating evidence shows that exercise can change colon bacteria to help prevent and treat diseases and prolong lives (Oxid Med Cell Longev, Mar 5, 2017;7). A six-week exercise program helped produce a more healthful distribution of colon bacteria in lean but not in obese individuals (Medicine & Science in Sports & Exercise, April 2018;50(4):747-757).

    How Could Veillonella Bacteria Increase Endurance?
    The limiting factor to how fast a person can run is the time it takes to bring oxygen into muscles. If you can bring oxygen into muscles faster, you will run faster and longer, so anything that will cause you to use less oxygen for the same amount of energy will help you to run faster. You use carbohydrates, fats and protein from the food that you eat for energy. They are then processed to enter a major source of energy through a series of chemical reactions called the Krebs Cycle. If you have enough oxygen, you get plenty of energy to power your muscles and the food products are converted to carbon dioxide and water that you can blow off from your lungs when you breathe out. However, if you are exercising so intensely that you do not have enough oxygen, the chemical reactions slow down and you accumulate very large amounts of lactic acid in muscles to make your muscles acidic and then the lactic acid spills over into your bloodstream to make your blood acidic. The acidity from a buildup of lactic acid causes the terrible muscle burning you feel when you run very fast, and the acidity caused by the accumulation of lactic acid in blood will make you gasp for breath and slow down. Lactic acid is not harmful because as soon as you slow down to catch up on your oxygen debt, the lactic acid is converted to energy and blood levels drop.

    High levels of lactic acid pass to colon cells through the bloodstream. Veillonella are a strain of bacteria that make the enzymes to break down lactic acid to form another chemical called propionate. The authors showed that instilling propionate in the intestines of mice reproduces some of the benefits of the bacteria, Veillonella:
    • increasing treadmill run time to exhaustion, and
    • decreasing levels of common inflammatory markers that are signs of cell damage and slow an athlete down.
    Having lots of Veillonella bacteria in your colon can break down lactic acid to propionate, which may help you to run faster and longer.

    Large amounts of lactic acid can cause cell damage and inflammation, and further tests showed that the mice given Veillonella had lower markers of inflammation and presumably less cell damage. Other studies show that starting people who never exercised on a moderate exercise program increases the number of Firmicutes bacteria in the colon to reduce inflammation associated with heart attacks and certain cancers. Reducing inflammation should also help athletes to recover faster from competitions and intense workouts.

    Stool Transplants Not Recommended
    Entrepreneurs are likely to use the findings of this research to market supplements or even stool transplants as shortcuts to improve athletic performance. Fecal transplants can transmit infections for which there is no available treatment today. At this time, none of the drug testing agencies have dependable tests to show whether an athlete has received fecal transplants.

    My Recommendations
    It is established that exercise helps to prevent disease and prolong lives. Exercise may do this by increasing the proportion of healthful bacteria in your colon; see Exercise Improves Gut Bacteria. This new study and others show that increasing the proportion of healthful bacteria in your colon may also help make you a better athlete. At this time I recommend that you use only exercise and a healthful diet to try to improve the composition of your gut bacteria. Probiotic supplements are questionable because you have no way to tell what is in them, and stool transplants can be dangerous, so I do not recommend them.

    Checked 5/1/23