Microbiome and sport: the gut, the hidden engine of performance.

Our gut hosts nearly 100 trillion microorganisms, ten times more than the number of human cells. Together, these bacteria, yeasts, and archaea form a true metabolic factory: they digest fiber, synthesize vitamins, regulate immunity, and constantly communicate with our brain via the gut–brain axis³.

But their role doesn’t stop there. Recent studies show that athletes’ microbiomes stand out for their diversity and metabolic efficiency: they convert energy substrates more effectively and support endurance⁴. This unique microbial signature comes from a diet rich in fiber, polyphenols, and fermented foods, but also from exercise itself, which stimulates the growth of certain beneficial species⁵.

In 2019, a team at Harvard Medical School identified a fascinating bacterium, Veillonella atypica, found in higher amounts in marathon runners’ microbiomes after a race. This bacterium can convert the lactic acid produced during exercise into propionate, a short-chain fatty acid that muscles can rapidly use as an energy source⁶. In other words, the more we run, the more our microbiome recycles our fatigue into fuel.

This symbiosis perfectly illustrates the concept of ‘microbiotic fuel’: energy produced by our bacteria from our own metabolic waste. This mechanism opens exciting perspectives for sports nutrition and post-exercise recovery⁶ ⁷.

The microbiome also influences muscle function and the bioavailability of essential nutrients: a depleted microbiome can reduce protein synthesis and compromise muscle strength⁸.

For athletes, every training session represents an oxidative and inflammatory stress. A balanced microbiome acts as a shield here: it regulates cytokine production, reduces intestinal permeability, and speeds up muscle recovery⁹.

By contrast, an imbalance (or dysbiosis) can lead to digestive issues, chronic fatigue, and even recurrent upper respiratory tract infections. According to a meta-analysis published in Nutrients, probiotics can reduce the frequency of these infections, thereby improving training continuity¹⁰.

This gut–immunity connection explains why some athletes supplement with specific probiotic strains: Lactobacillus rhamnosus GG and Bifidobacterium longum have been shown to support immune function and limit exercise-induced gastrointestinal disorders¹¹.

Probiotics are living microorganisms capable of rebalancing the gut microbiome. Their benefits go far beyond digestive health: several studies suggest a positive impact on physical performance and recovery¹².

In endurance runners, probiotic supplementation has been associated with improved stamina, a lower perception of effort, and reduced post-exercise muscle soreness¹³. Other research points to better absorption of essential amino acids, supporting muscle repair and rebuilding¹⁴.

However, there is no ‘magic formula.’ The effect depends on the bacterial strain, the duration of use, and the quality of the starting microbiome. The most relevant approach remains a personalized one, combining diet, lifestyle, and targeted supplementation.

At minimiil, we believe that sustainable performance rests on a three-pillar approach: nutrition, movement, and inner balance. To maintain a high-performing microbiome, diet plays a central role.

A diet rich in plant fibers (fruits, vegetables, legumes, whole grains) provides the fuel needed by ‘good’ bacteria that produce short-chain fatty acids. These molecules reduce inflammation, improve insulin sensitivity, and support muscle health⁵.

Fermented foods (minimiil, kefir, kombucha, kimchi, yogurt) naturally deliver a diverse range of probiotic strains. Combined with proper hydration and restorative sleep, they help create an environment for a stable and functional microbiome⁹ ¹⁰.

Finally, exercise itself acts as a microbial modulator: regular, moderate activity promotes beneficial species, while overtraining or chronic stress can deplete gut flora. That’s why we advocate a holistic approach: listen to your body, nourish your microbiome, and train intelligently.

Advances in gut microbiome research are reshaping our understanding of performance. We are moving from a mechanical view of the body to a systemic, complex approach in which humans, their environment, and their bacteria work together to produce optimal effort. It’s not just about adding a probiotic to your routine, but about cultivating a resilient inner ecosystem that can adapt to intensity, stress, and the demands of modern sport.

The future of performance will be intestinal, and perhaps even bacterial!

References

¹ Harvard.edu

² kinesport

³ INRAE

⁴ NCBI

⁵ Gutmicrobiotaforhealth.com

⁶ Harvard.edu

⁷ National Library of Medicine

⁸ INRAE

⁹ National Library of Medicine

¹⁰ National Library of Medicine

¹¹ National Library of Medicine

¹² Gutmicrobiotaforhealth.com