The gut microbiota is no longer a topic limited to digestive health. Today, it is also being studied for its potential relationship with energy metabolism, inflammation, immunity, recovery, and, consequently, athletic performance.
But does having a certain type of microbiota make an athlete perform better? The answer is not that simple. What science shows is that there is a two way relationship: exercise can influence the gut microbiota, while the microbiota may also influence processes that are important for performance.
Exercise Also Influences the Gut Microbiota
Training does not only create adaptations in the muscles and cardiovascular system. The gut responds to exercise as well.
Regular exercise, especially when combined with an appropriate diet, may promote changes in the composition and diversity of the gut microbiota. On the other hand, very prolonged or high intensity exercise, particularly when combined with insufficient recovery, may increase gastrointestinal stress and affect the intestinal barrier.
This helps explain why nutrition planning is so important for athletes. It is not only about providing energy for training, but also about creating the conditions for the gastrointestinal system to handle the training routine.
The Microbiota Plays a Role in Energy Metabolism
One of the most interesting connections between the microbiota and performance involves the metabolites produced by gut bacteria.
Among them are short chain fatty acids, such as acetate, propionate, and butyrate. These compounds may participate in processes related to energy metabolism, cellular signaling, and inflammatory responses. Evidence suggests that these pathways may influence muscle metabolism and energy efficiency.
This does not mean that certain bacteria can “produce performance.” The relationship is much more complex. The microbiota functions as part of a network involving diet, the gut, metabolism, the immune system, and skeletal muscle.
Gut Health, Immunity, and Recovery
For athletes who train frequently, maintaining good gut function may also be important for sustaining a consistent training routine.
Intense and prolonged exercise can increase physiological stress and, under certain conditions, alter intestinal permeability and inflammatory responses. A balanced gut microbiota may contribute to maintaining the intestinal barrier and regulating immune responses.
In practice, this matters because training well is not only about completing a single session. It is also about recovering well enough to repeat that stimulus week after week.
What About Gastrointestinal Discomfort?
This is where the relationship becomes even more interesting for endurance sports.
Long distance running, cycling, and triathlon can increase the occurrence of symptoms such as nausea, bloating, abdominal cramps, and changes in bowel habits. Intense exercise, reduced gastrointestinal blood flow, heat, and the nutrition strategy used during exercise can all contribute to these symptoms.
The gut microbiota is another piece of this puzzle. Recent studies are investigating whether changes in the microbiome and targeted gut strategies can help reduce gastrointestinal symptoms and improve exercise tolerance.
However, it is important not to turn this evidence into a promise. There is still no single “ideal athlete microbiota” that can be used as a universal formula.
Can Probiotics Improve Performance?
This is one of the most common questions when discussing the gut microbiota and sports.
Some studies involving probiotics have reported positive effects on parameters related to inflammation, gastrointestinal symptoms, and even performance. A systematic review published in 2024 found promising results, but also highlighted that many available studies have methodological limitations and a high risk of bias.
For this reason, probiotics should not be considered a universal ergogenic supplement.
Their effects depend on the specific strain, dose, duration of use, and individual characteristics, as well as the type of sport. More research is needed to understand which strategies actually work and for whom.
So, How Can You Support Your Gut Microbiota for Performance?
Before thinking about a specific supplement, it is worth looking at the fundamentals.
A varied diet that meets the energy demands of training and provides adequate amounts of fiber and plant based foods is one of the main strategies for supporting a healthy gut environment.
It is also important to consider the individual athlete. A nutrition strategy that works well for one person may not work for another, especially when there are major differences in training volume, intensity, sport, and gastrointestinal tolerance.
The gut can also be trained. Gradually exposing the gastrointestinal system to the amounts of carbohydrate and fluids used during prolonged exercise may help athletes improve gastrointestinal tolerance over time.
The Microbiota May Be Another Piece of the Performance Puzzle
The relationship between the microbiota and sports performance is still being explored, but we already know that the gut does not function in isolation.
Exercise, nutrition, the microbiota, metabolism, immunity, and recovery are all connected.
The next step is not to find a “miracle” bacterium capable of increasing performance, but to understand how these interactions can be used in a more individualized way.
For now, the most important message is simple: taking care of your gut is part of taking care of the athlete.
And for those pursuing performance, that means looking beyond what happens during training and considering everything that allows the body to be ready for the next session.
