Have you considered how the gut microbiome influences athletic performance? Growing evidence shows the community of microbes in the intestine affects more than digestion — it plays a role in immune regulation, nutrient absorption, inflammation control, and even muscle function. A balanced microbiome can support training adaptations and recovery, while disruptions can undermine performance. Moderate exercise tends to increase microbial diversity, which is generally linked to improved gut barrier integrity and metabolic health. Endurance and resistance training have both been associated with shifts in bacterial populations that can enhance short-chain fatty acid production and nutrient handling. Conversely, excessive training without adequate recovery may reduce diversity and promote inflammation, potentially impairing gains and increasing illness risk. Antibiotics can profoundly alter the microbiome. Athletes may be prescribed antibiotics more frequently due to infections or training-related exposures, and research in animal models suggests that antibiotic treatment during training can blunt muscle adaptation and reduce improvements in aerobic capacity and mitochondrial function. When antibiotic therapy is necessary, targeted strategies to restore microbial balance (dietary fiber, fermented foods, and validated probiotic strains) support recovery of microbiome function. Dietary fibre is a primary substrate for beneficial microbes and is linked to production of metabolites that support gut health and systemic physiology. While carbohydrate guidelines for athletes are well established, fiber recommendations are less explicit. Increasing fiber gradually to around 30 g/day can promote microbial diversity and intestinal barrier function; athletes should time higher-fiber meals away from intense training or competition to minimise gastrointestinal discomfort. Emerging work has even identified specific microbes with potential performance-related effects. For example, investigators isolated Veillonella atypica from endurance athletes and showed, in preclinical models, that the bacterium metabolises lactate into propionate — a compound implicated in improved endurance outcomes. Early human supplementation studies are still inconclusive, highlighting the need for personalised approaches and larger clinical trials before clinical recommendations are made. The International Society of Sports Nutrition (ISSN) summarises current probiotic evidence for athletes: benefits are strain- and dose-dependent, can include improved immune responses and gut barrier function, and may support recovery and nutrient absorption. Products should list genus, species, strain, and CFU at end of shelf life. The ISSN emphasises that athlete-specific microbiota and training regimens can influence response to supplementation. Applying this evidence in practice involves sensible dietary and lifestyle steps: prioritise a varied, fibre-rich diet, include fermented foods where tolerated, be mindful with antibiotic use, and consider strain-specific probiotic interventions when supported by data. For examples of personalised ingredient advice and how microbiome-informed guidance can be implemented, review the InnerBuddies study on personalised ingredient advice: InnerBuddies personalised ingredient study, and for dietary strategies relevant to athletes with digestive sensitivities see The FODMAP diet: a beginner's guide. For an overview of the topic in context, read the full article: [Stronger, Faster, Healthier: The Power of Your Gut in Sports](https://www.innerbuddies.com/blogs/gut-health/stronger-faster-healthier-the-power-of-your-gut-in-sports). Optional resources, such as validated testing or microbiome assessments, may help tailor recommendations: microbiome test. This body of evidence supports a measured, evidence-based approach: nourish microbial diversity through diet and recovery, use antibiotics judiciously, and apply probiotics selectively based on strain-specific data and individual needs.