Abstract
Introduction: Among the various phytochemicals, polyphenols represent a heterogeneous class of compounds with marked antioxidant and anti-inflammatory properties. One of the biggest challenges is to understand the mechanisms of the interrelationship between polyphenols and the human body, also considering the fundamental role played by the gut microbiota in their absorption and bioavailability to improve sports performance. Objective: It was to present the main relationships between polyphenols, gut microbiota, and sports performance. Methods: The PRISMA Platform systematic review rules were followed. The search was carried out from September to October 2024 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 126 articles were found, and 72 articles were evaluated in full, and 61 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 08 studies with a high risk of bias and 26 studies that did not meet GRADE and AMSTAR-2. Most studies showed homogeneity in their results, with X2=75.7%>50%. The Funnel Plot graph showed symmetrical behavior, not suggesting a significant risk of bias in studies with smaller sample sizes. Dietary polyphenols exert several beneficial effects on sports performance, demonstrated in vivo and in human studies. The health-related mechanisms of polyphenols mainly concern the modulation of mitochondrial biogenesis and the stimulation of stress-related enzymes or transcription factors, as well as a nutritional deficiency, which regulates gene expression of essential antioxidant proteins (SOD, Catalase, Glutathione system, etc.). Overall, these mechanisms promote athletic performance by improving cardiometabolic functions, reducing recovery times and post-exercise pain, maintaining a low degree of oxidative stress, and preventing dysregulated inflammatory processes. Therefore, polyphenols are able, through their interaction with the gut microbiota, to favor the proliferation of bacterial genera of great importance for metabolic and cognitive functions, such as Akkermansia, Lactobacilli, and Bifidobacteria. The microbiota, on the other hand, metabolizes polyphenols in the colon to produce small bioactive molecules that exert epigenetic mechanisms on biochemical pathways modulating gene expression.