The intricate relationship between the gut microbiome and athletic performance has garnered significant interest over recent years. The study titled “The Athlete Gut Microbiome and its Relevance to Health and Performance: A Review“,  published in Sports Medicine in 2022, delves into this dynamic interplay, highlighting the bidirectional effects of exercise and the gut microbiome. This article provides an overview and detailed analysis of the study’s findings, followed by practical applications for nutrition coaches.

The Study

The human gut microbiome, comprising approximately 40 trillion microbial cells, plays a crucial role in various bodily functions, including digestion, vitamin metabolism, and immune modulation. The study emphasises the relatively underexplored area of how exercise influences the gut microbiome and vice versa. Key points discussed include:

  1. Differences in Gut Microbiomes:
    • Athletes tend to have a more diverse gut microbiome compared to non-athletes, with higher levels of health-associated bacteria.
  2. Effects of Probiotics and Prebiotics:
    • Specific probiotics and prebiotics can enhance performance metrics, reduce gastrointestinal distress, and lower respiratory infections in athletes.
  3. Exercise-Induced Gastrointestinal Issues:
    • Intense exercise can lead to gut permeability and systemic inflammation, resulting in gastrointestinal and respiratory issues. The gut microbiome’s composition plays a role in these effects.
  4. Role of Microbial Metabolites:
    • Metabolites like short-chain fatty acids (SCFAs) produced by gut bacteria are crucial for energy production, muscle metabolism, and reducing muscle atrophy.
  5. Longitudinal Gut Microbiome Monitoring:
    • Monitoring changes in the gut microbiome over time can provide valuable insights into how lifestyle and diet affect gut health and performance.

The Results

  1. Gut Microbiome Diversity and Athletic Performance:
    • Studies indicate that athletes have a higher alpha diversity in their gut microbiomes, associated with better health outcomes. Increased diversity includes beneficial genera such as Bifidobacterium, Lactobacillus, and Faecalibacterium. This diversity is believed to contribute to improved metabolic functions, reduced inflammation, and enhanced immunity.
  2. Probiotics and Performance Enhancement:
    • Supplementation with specific probiotic strains has shown to positively impact various performance metrics. For instance, Lactobacillus plantarum TWK10 improved muscle mass and endurance in mice. Similarly, Veillonella atypica, which metabolises lactate into propionate, was linked to improved performance in marathon runners. These findings suggest that probiotics can help manage exercise-induced stress and inflammation, thus enhancing recovery and performance.
  3. Managing Gastrointestinal and Respiratory Issues:
    • Intense exercise can lead to gastrointestinal distress and respiratory infections due to increased gut permeability and systemic inflammation. Probiotic supplementation has been shown to mitigate these issues. For example, a blend of probiotics reduced upper respiratory tract infections (URTIs) in marathon runners by 29%. Such interventions can help athletes maintain consistent training schedules without the setback of illness.
  4. Microbial Metabolites and Energy Production:
    • Short-chain fatty acids (SCFAs), particularly butyrate, produced by gut bacteria, play a significant role in gut health and energy metabolism. Higher levels of SCFAs are found in athletes, correlating with improved performance metrics. SCFAs enhance carbohydrate uptake, lipid metabolism, and fatty acid oxidation, crucial for sustained athletic performance.
  5. Longitudinal Monitoring for Optimal Health:
    • The study underscores the importance of longitudinal monitoring of the gut microbiome to understand its dynamic nature. Regular monitoring can identify beneficial shifts or negative perturbations in the gut microbiome, enabling timely dietary or lifestyle interventions to maintain optimal gut health.

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Applications for Nutrition Coaches

As nutrition coaches, we can leverage these insights to optimise our clients’ performance and overall health. Here’s how:

  1. Personalised Nutrition Plans:
    • By understanding individual gut microbiome profiles, nutrition coaches can tailor diets that promote beneficial bacteria. For example, increasing the intake of prebiotic-rich foods like bananas, garlic, and onions can support gut health.
  2. Probiotic Supplementation:
    • Recommending specific probiotic strains known to benefit athletes can help clients reduce inflammation, enhance recovery, and prevent gastrointestinal issues. Strains like Lactobacillus plantarum TWK10 and Veillonella atypica could be considered based on the client’s specific needs.
  3. Managing Exercise-Induced Issues:
    • Coaches can develop strategies to prevent and manage gastrointestinal and respiratory problems related to intense training. This might include recommending probiotics pre-race or post-training to reduce gut permeability and systemic inflammation.
  4. Longitudinal Monitoring:
    • Encourage clients to undergo regular gut microbiome testing to monitor changes over time. This approach helps in making informed adjustments to their diet and training programmes, ensuring sustained gut health and performance.

Practical Tips

Integrating the latest research findings on the gut microbiome and athletic performance into practical applications can significantly benefit athletes and fitness enthusiasts. By adopting strategies that promote gut health, as we we can help clients optimise their performance, recovery, and overall wellbeing. Here are some actionable tips that we can use to support our clients in achieving their fitness and health goals.

  1. Promote Diverse Diets:
    • Encourage clients to consume a varied diet rich in fibers, fruits, vegetables, and fermented foods to naturally boost gut microbiome diversity.
  2. Introduce Probiotic Foods:
    • Recommend incorporating probiotic-rich foods such as yogurt, kefir, sauerkraut, and kimchi into daily meals to enhance gut health.
  3. Prebiotic Integration:
    • Advise on foods high in prebiotics, such as chicory root, asparagus, and leeks, which feed beneficial gut bacteria and promote a healthy microbiome.
  4. Monitor Hydration and Electrolytes:
    • Ensure clients maintain proper hydration and electrolyte balance, especially during intense training, to support gut function and overall health.
  5. Educate on the Gut-Exercise Link:
    • Inform clients about the connection between gut health and exercise performance, emphasising the importance of maintaining a healthy gut for optimal athletic results.
  6. Regular Gut Health Assessments:
    • Suggest periodic gut health assessments to track microbiome changes and make necessary dietary adjustments to maintain a balanced gut flora.

Understanding the relationship between the gut microbiome and athletic performance offers valuable insights for optimising health and performance. As nutrition coaches, we can play a pivotal role by integrating these findings into our practice, providing personalised and evidence-based dietary recommendations to enhance our clients’ athletic potential.


The Athlete Gut Microbiome and its Relevance to Health and Performance: A Review. O’Brien, M. T., O’Sullivan, O., Claesson, M. J., & Cotter, P. D. (2022). Sports Medicine, 52(Suppl 1), S119–S128.Click here to review the full research article.

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