RESUMEN

In the present case study, the gut microbiota (GM) profile of a male Elite Mountain Runner (34 years, 171cm, 59 kg, VO2max: 92 mL·min-1 ·kg-1) was analyzed over 5 months competitive period (6 samples). The GM diversity increased through the season coinciding higher levels to the peak performance and shorter and longer race (42 vs. 172 km) produced different phenotypic GM changes. Shorter race promoted the elevation of protective bacteria related to positive benefits (higher production of short-chain fatty acids (SCFAs), lactate resynthesis, mucin degraders). In contrast, longer race promoted an elevation of opportunistic pathogenic bacteria while reducing protective commensal bacteria. The present findings indicate that a higher resilience of the GM after competitions may support rapid recovery from maximal exercise. The GM analyses pre- and post-competition could represent a rapid indicator for the (patho)physiological impact of exercise and provide information on gut health and recovery time needed.