What is the Gut Microbiota and What Does It Do?

To understand how the gut microbiota affects sports performance, we need to know what it is and what it does.  Our intestine is home to a huge and diverse community of bacteria, viruses, and fungi.  These microorganisms are involved in many functions, such as breaking down food, synthesis important vitamins, influence good functioning of the immune system, and even talking to our brain, via what’s called the gut-brain axis.  The gut microbiome can change over time due to factors such as age, diet, lifestyle, medication, and stress.  A healthy gut microbiome is essential for our well-being and can protect us from infections, inflammation, and diseases².

Athletic Performance and Gut Microbiota: A Two-Way Relationship

Can the gut microbiota influence athletic performance such as how well we run, swim, or cycle?

Can exercise change the composition and function of our gut microbiota?  A recent study compared the microbiota of professional athletes to that of more sedentary individuals.  The results revealed significant differences between the two groups, both in terms of composition and functional metabolism¹.  Professional athletes exhibited greater bacterial diversity, with an increase in beneficial species, particularly those involved in the production of butyrate, a short-chain fatty acid crucial for gut health.   Butyrate is an extremely important type of short-chain fatty acid for maintaining gut health⁴.  It plays several beneficial roles, including strengthening our intestinal barrier, regulating inflammation, promoting nutrient absorption from our diet, contributing to the regulation of body weight, and even reducing the risk of certain gut diseases^{5, 6}.

Intense aerobic exercise appears to stimulate the growth of specific bacteria in our gut that produce this substance.  Additionally, a recent systematic review suggests that incorporating specific beneficial bacteria into the diet and using multi-strain probiotic supplements could potentially improve performance in various aspects, including endurance, strength, recovery, and physical conditions like muscle pain and body composition.  However, more research is required to establish conclusive causal evidence, as the current studies vary in their approaches and findings³.

On the other hand, some research has also suggested that excessive and prolonged exercise can cause temporary disruption of the microbiota, but these imbalances are generally reversible with adequate recovery time⁷.

The Gut Microbiota and Sedentary Individuals

Interestingly, these benefits also extend to sedentary individuals.  Although athletes often exhibit more pronounced alterations in their microbiota, studies indicate that regular physical exercise can also benefit the microbiota of sedentary individuals.  Incorporating a moderate exercise routine, such as a daily walk or strength training, can encourage greater microbial diversity within the gut, which could have beneficial effects on overall health.  Additionally, a balanced diet rich in fibre can also promote gut health.  Dietary fibres serve as food for the beneficial bacteria in the microbiota, thus promoting their growth and activity.  By incorporating foods such as fruits, vegetables, whole grains, and legumes into the diet, the necessary nutrients are provided for microbiota to thrive⁵. and reduce processed foods and those high in saturated fats⁷ which can have the opposite impact.

The interdependence between physical performance and the gut microbiota is becoming increasingly evident.  Regular physical exercise and a healthy diet can help promote microbial diversity, strengthening beneficial bacteria which can in turn enhance overall well-being.  Whether it be a professional athlete or someone living a more sedentary lifestyle, nourishing and nurturing the microbiota should be a top priority in terms of health and nutrition.