Home › Blog › Regular Aerobic Exercise May Improve Your Gut Microbiota

The bacteria in your gut is the hottest ticket in medicine right now. Why? We’re just beginning to realize that out-of-whack gut bacteria is responsible for or connected to a large number of disease states. Hence, what’s in your gut may well determine if you’re thin, heavy, or unhealthy. That’s why a recent study that connects better gut bacteria to aerobic exercise is a big deal, as the health benefits of exercise may extend well beyond the heart.

What Is the Gut Microbiota, and Why Is It so Important?

Our gut microbiota (aka gut flora) is the entire colony of bacteria, both good and bad, that lives inside our intestinal tract. While we might think of the intestinal tract as the body’s dumping ground, the truth is, with so much of our immune system housed in our gut, our health depends on the condition of our gut microbiota—if the gut’s not happy, the body’s not happy. Keeping a high population of beneficial bacteria in our gut means it can effectively process and dispose of all the waste we send its way as well as properly function to help keep our body healthy.

Diet is certainly a major player in keeping the gut microbiota healthy. Good gut bacteria flourish on healthy foods, while bad gut bacteria gain their strength through junk foods. Now, a new study establishes a link between exercise and gut bacteria as it credits cardio exercise as another direct link to changing and maintaining our gut microbiota for the better.

How Could Exercise and Gut Bacteria be Related?

The purpose of the new study was to determine if exercise, specifically aerobic exercise, such as running, walking, or swimming, also changes the composition of microbes in the gut. The study consisted of 18 lean and 14 obese male and female subjects, all of whom were sedentary, or generally inactive, prior to the study. Each subject began a supervised exercise program three days per week for a total of six weeks with intensity levels and time increasing throughout the study (topping out at vigorous intensity for 60 minutes each exercise day). Subjects then returned to their sedentary lifestyles for six weeks.

The results? The relationship between exercise and gut bacteria was that short-chain fatty acids, which are produced by the “good” bacteria in the gut, significantly increased in the lean subjects following the six-week exercise period. However, fecal samples obtained following the six-week sedentary period showed that most of these beneficial results in the gut no longer existed. Essentially, the gut reverted back to its condition prior to the study. Researchers concluded that while exercise, separate from diet, does positively alter the function and composition of the gut microbiota, particularly in a lean population, exercise must continue to maintain the gut benefits.

While some gut improvements were found in the obese subjects, researchers want to learn more about why the same significant improvements found in the lean subjects were not realized in the obese group, so more studies are likely to follow.

Problems Associated with an Unhealthy Gut Microbiota

The study above looked at the effect of exercise on the gut without considering diet, and while exercise alone showed positive changes, certainly a healthy diet combined with regular exercise can work hand in hand to keep our gut microbiota at peak performance.

By contrast, an unhealthy gut microbiota can lead to many problems. For example, bad bacteria in the gut may make you more prone to type-2 diabetes, and the diabetes drug metformin may actually work, in part, by altering the gut microbiota. The bacteria in our gut has also been linked to issues in the brain in the past couple of years. One study suggested that the condition of the gut microbiota may be a risk factor for Parkinson’s disease. This was following an earlier study that found that certain fibers in the gut that were also found in the brain nerves in Parkinson’s patients. Interactions between the brain and unhealthy gut microbiota also appear to negatively impact emotion processing. A whole host of issues can result from a leaky gut, which can be caused by too much bad bacteria in the gut microbiota, and even our stem cells may suffer depending on the condition of our gut bacteria.

The upshot? Looks like the benefits of aerobic exercise extend well beyond the heart. I really can’t wait until we see so much published on gut bacteria that we all can use an easy at-home test to see if our guts are happy and if not what to do about it. In the meantime, get out and sweat and breathe hard, as that seems to do the trick as well!

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile