Signatures in the gut microbiome of German elite athletes: insights from a matched-subgroup analysis

Elite athletes undergo intense physical training and experience substantial physiological stress, which could affect the composition and function of their gut microbiome. This study compared the gut microbiomes of 148 German junior and senior elite athletes with those of 108 healthy adults to identify taxonomic and functional features associated with elite athletic status. Group comparisons were conducted between healthy adults, senior athletes, and junior athletes, and a matched-subgroup analysis was performed in adults only, controlling for age, sex, body mass index, and dietary pattern. Significant differences in taxonomic composition were observed between athletes and healthy adults. Healthy adults exhibited greater microbial evenness and diversity than junior athletes, whereas senior athletes displayed higher microbial richness. Principal coordinate analysis revealed distinct clustering by athletic status. Linear discriminant analysis effect size identified taxa such as Escherichia-Shigella as being enriched in athletes. Predictive metagenomic profiling (PICRUSt2) indicated differences in microbial functional potential between adult athletes and matched controls, including pathways related to amino acid metabolism, glycolysis, fatty acid β-oxidation, and quinone biosynthesis. Together, these findings demonstrate distinct taxonomic and predicted functional microbiome signatures associated with elite athletic status.IMPORTANCEElite athletic training and lifestyle are associated with the gut microbiome. Our research has revealed distinct microbial structures in elite athletes, characterized by reduced evenness in junior athletes and increased richness in senior athletes, compared to healthy adults. Matched-subgroup analyses confirmed these group-specific differences. The gut microbiomes of athletes were enriched in pathways related to amino acid biosynthesis, glycolysis, fatty acid β-oxidation, and quinone synthesis. These microbiome features may be relevant for metabolic efficiency and resilience to oxidative stress. Combining taxonomic and functional prediction data from a uniquely characterized cohort of junior and senior elite athletes provides novel insight into microbiome signatures associated with sustained physical and psychological stress, with potential implications for performance, recovery, and health.CLINICAL TRIALSThis study is registered with ClinicalTrials.gov as NCT03582020.