Why athletes should care about their bacterial buddies


— By Casey Jones

When we think about bacteria, thoughts of germs, sniffly noses, and infections may come to mind. But did you know your body is covered in trillions of them? For optimal health and performance, you should think of bacteria as friend, not foe.

The human microbiome is the community of microorganisms — bacteria, viruses, fungi, and more — that share our body space. Our skin, mouth, nose and gastrointestinal tracts are covered in trillions of our micro-sized friends. There are as many bacterial cells in our bodies as there are human cells (about 30 to 40 trillion). Although the total mass of the human microbiome is only around two kilograms, it packs quite an important punch for our health.

The gastrointestinal microbiome, or gut microbiome for short, is of specific concern to health. The bacteria in our gut can generate nutrients from foods that we can’t break down ourselves (1). In the colon, complex carbohydrates are broken down by bacteria into various fats and metabolites that are used elsewhere in the body for energy metabolism. Additionally, the gut microbiome tightly interacts with our body’s immune system, regulating the balance between nasty microbes and those that are beneficial to our bodies.

When our gut microbiome isn’t happy, it goes into a state called dysbiosis. Dysbiotic states can occur through excessive exposure to antibiotics, excess alcohol, or a suboptimal diet. This dysbiotic state of the gut is thought to be the main driver behind disorders like inflammatory bowel disease, and also has links to cardiovascular disease, obesity, and depression. The opposite of having a dysbiotic gut would be having one that is diverse and healthy.

The Athlete Microbiome

A diverse gut is a happy one. Microbial diversity refers to the amount of unique types of bacteria that live in a given microbiome, and those of us with more diverse microbiomes tend to be healthier and disease-free (2).

It so happens that athletes tend to have healthier and more diverse gut microbiomes compared to people that don’t exercise. A study comparing the microbiomes of professional rugby players and sedentary individuals showed that the rugby players had bacteria in their gut that the non-exercisers didn’t. This finding of greater diversity in the athletes also correlated with higher protein consumption and creatine kinase levels, a marker of strenuous exercise in this group (3). In addition, a look at 1,500 people from the American Gut Project showed that moderate exercise causes greater diversity in the microbiome, leading to a healthier gut environment (4).

Given the gut microbiome’s crucial role in metabolism, inflammation and energy production, athletes should take into account several considerations to keep their gut happy.


Some foods contain beneficial bacteria for your gut. They include probiotic yogurt and kefir.

How do I keep my gut healthy?

Eating well, sleeping well, and exercising daily are all clear keys to maintaining optimal health. However there are some specific considerations you should keep in mind for a healthy gut:

  • Foods with prebiotics — fibers that promote the growth of beneficial bacteria in the gut, such as:

    • Beans & Legumes

    • Fruits

    • Whole grains

  • Foods with probiotics — products that contain beneficial bacteria for your gut and increase diversity:

    • Probiotic yogurt

    • Kefir (dairy or coconut)

    • Fermented products like sauerkraut, kimchi, and kombucha

  • Ensure you’re getting proper amounts of fiber in the form of whole grains, fruit, and dark green vegetables like kale and broccoli.

  • Stay hydrated, especially with hot days around the corner!

  • Know when to go to your doctor — you may have a nutritional sensitivity or intolerance if you’re feeling consistent issues with your gut.

The research into the role of the microbiome in athletic performance is still in its infancy. As we learn more, there may be new ways to modulate your gut in the future.

When we make dietary and lifestyle decisions, it’s important to remember that you’re caring for your bacterial buddies in your gut, too.

Casey Jones is a master's in science student at Dalhousie University, where he studies the link between the human microbiome and pediatric Crohn’s disease in Nova Scotians.



  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4815357/

  2. http://www.tandfonline.com/doi/abs/10.4161/gmic.19897

  3. http://gut.bmj.com/content/63/12/1913.long

  4.  http://scholar.colorado.edu/cgi/viewcontent.cgi?article=1154&context=honr_theses