The athlete gut microbiota: state of the art and practical guidance

The gut microbiota has been proposed to grant the athlete a metabolic advantage that might be key when optimising performance. While a taxonomic core set of microorganisms characterising the athlete's gut microbiota has not been delineated, some compositional features might be associated with improved metabolic efficiency, which appears to be driven by the production of bacterial metabolites, such as short-chain fatty acids. Not only long-term exercise but also dietary patterns associated with high-level sports practice contribute to this microbial environment, yet isolating the impact of individual dietary components is challenging. The present review synthetises the available evidence on the compositional aspects of the athlete's gut microbiota, discusses mechanisms involved in the bidirectional association between exercise and the gut environment, and evaluates the role of athletes' diet in this interplay. Additionally, a practical approach to indicators commonly reported in metagenomic and metabolomic analyses is provided to explore how these insights can translate to support dietary protocols.