How Probiotics are Reshaping Sports Performance

By Brandy Webb, ND, BSc Scientific Affairs Manager, Probi AB

Diet and lifestyle are well established as major determinants of health; moreover, the link between diet and the gut microbiome is well characterized. More recently, the link between the gut microbiome and exercise has gained recognition by researchers and athletes alike. A recent meta-analysis published in Nutrients by Jarrett, et al. (2025) discusses the science behind how probiotic supplementation may improve exercise parameters like endurance, recovery, and nutrient absorption.

The microbiome-performance link

Probiotics are live microorganisms that, when consumed in adequate amounts, confer health benefits. For athletes, the potential perks are particularly intriguing. Beyond supporting gut health, probiotics may improve protein absorption and increase circulating branched-chain amino acids (BCAAs), essential for muscle repair and energy metabolism. Fermentation of complex carbohydrates by probiotics may help mitigate the inflammatory effects of high-protein diets and support more efficient fatty acid oxidation, especially under exercise conditions. Additionally, during and after exercise, carbohydrate intake helps mitigate release of cortisol and other stress hormones, reducing muscle breakdown and systemic inflammation.

Physical activity is positively associated with relative abundance of short-chain fatty acid-producing bacteria and anti-inflammatory bacteria, as well as microbial richness more generally. Athletes, active individuals, and individuals who engage in exercise interventions show greater levels of Akkermansia, Faecalibacterium, Veillonella and Roseburia. Supplementation with these strains, or others that promote their growth, may have beneficial effects on exercise-related parameters by shifting the microbiome phenotype and associated metabolomic profile.

Probiotic benefits in athletes

The gut microbiome is gaining attention among athletes due to its role in recovery, nutrient absorption and utilization, immune status, GI function, and mental wellbeing. Probiotics offer a novel strategy for optimizing these parameters, and the mechanisms underlying these benefits are multifaceted, as reported by Jarrett, et al.:

Faster recovery: Emerging data suggest that probiotic supplementation may aid recovery from intense exercise by reducing inflammation and muscle damage. Specifically, strains like Lactobacillus paracasei have been shown to lower biomarkers such as creatine kinase, myoglobin, and C-reactive protein (CRP), indicating reduced muscle injury and inflammation. Athletes taking probiotics reported less muscle soreness, better sleep quality, and improved subjective recovery, including in elite populations like rugby players.

Better nutrient absorption: The gut microbiome helps regulate nutrient absorption, which is essential for muscle function and recovery. Probiotics may enhance the bioavailability of key nutrients, particularly branched-chain amino acids (BCAAs) like valine, leucine, and isoleucine that are linked to reduced muscle fatigue and injury. Probiotics may also enhance carbohydrate metabolism and glucose oxidation during exercise, as well as improve iron status when paired with iron supplements. As a key nutrient for oxygen delivery to tissues, iron is particularly relevant for endurance athletes.

Reduced GI distress: Gastrointestinal symptoms like nausea, diarrhea, and bloating are common in athletes, especially during endurance events. These issues are often linked to reduced blood flow to the gut during intense exercise and malabsorption of nutrients like excess carbohydrates. Probiotics may reduce exercise-related GI distress in athletes, likely in part by promoting nitric oxide activity. Studies show that probiotics can significantly reduce GI symptoms in elite cyclists and marathon runners, both at rest and during competition.

Immune defense: Elite athletes in high-intensity sports like cycling, swimming, and rowing face an increased risk of upper respiratory tract illnesses (URTIs), which can lead to significant training and competition time loss. Preventing these illnesses is critical for maintaining performance. Probiotics have been shown to reduce URTI frequency and duration in healthy adults and decrease traveler’s diarrhea, a common issue for traveling athletes. Trials in elite distance runners and university athletes have shown that probiotic supplementation reduces the frequency and severity of URTIs during intensive training or competition periods.

Mental Resilience: Prolonged, high-intensity training and competition can increase anxiety and stress in athletes, negatively affecting performance. Probiotic supplementation has shown anxiolytic effects in the general population, and emerging evidence suggests similar benefits are seen in athletes. Studies in badminton and football players found that probiotics significantly reduced stress and anxiety, enhanced brain wave activity linked to focus and relaxation, and improved sustained attention.

What about Power and Endurance?

Clinical trials suggest that probiotic supplementation can improve oxygen uptake, reduce systemic inflammation, and help maintain energy during prolonged exercise. For example, triathletes who took probiotics for four weeks showed notable improvements in running endurance. Marathon runners experienced enhanced performance after five weeks of supplementation. These gains may be linked to improved vascular function: probiotics appear to increase nitric oxide bioavailability, facilitating better blood flow and oxygen delivery to muscles.

While endurance benefits are better documented, the effects of probiotics on strength and power-based activities remain less clear. High-intensity training can decrease gut microbial diversity, but probiotics may help restore balance and support gut health. Some studies combining probiotics with protein supplements report increased muscle strength and power output in resistance-trained athletes. More research into this area is needed

What’s Next for Probiotics in Sports?

While the data supporting probiotics’ role in endurance and recovery, mental resilience, nutrient uptake, and immune and GI function are promising, more research is needed to clarify their impact on strength and power. The effectiveness of probiotics varies by strain, dosage, supplementation duration, and individual gut microbiome differences.

For athletes and coaches interested in leveraging probiotics, it’s essential to recognize that this is an evolving field. Future studies will help establish standardized protocols tailored to different sports disciplines.

Conclusion

The gut microbiome functions as an integral component of the exercise response, influencing metabolic, immune, and neuroendocrine pathways that underlie performance and adaptation. Probiotics represent a powerful tool with the potential to optimize athletic performance, from boosting endurance and shortening recovery time to supporting immune health and mental well-being. Continued research into the gut-muscle axis and microbiome-host dynamics will be essential to fully harness the microbiome’s potential in exercise science and sports medicine.

About the author:

Brandy Webb, ND, BSc, is a scientific affairs leader specializing in microbiome research and evidence‑based product development in the dietary supplements industry. As Scientific Affairs Manager at Probi AB, part of Symrise AG, she translates complex microbiome science into clear, clinically relevant insights that support innovative formulation and practitioner and consumer education. Her background spans nearly two decades across clinical practice, higher education, and industry roles, including serving as Chief Medical Officer and Scientific Advisory Board Chair for a major practitioner brand and Medical Advisor for a pioneering hormone testing laboratory. Dr. Webb previously held fellow, faculty and residency positions at Bastyr University and founded a naturopathic practice where she provided nutritional guidance to support an active, healthy lifespan. She remains dedicated to advancing personalized, preventative healthcare and microbiome-focused innovation through scientific integrity and education.

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