Ultra-Endurance triathlon competition shifts fecal metabolome independent of changes to microbiome composition.

Understanding changes to gut microbiota composition and metabolic output in response to acute exercise may be necessary for understanding the mechanisms mediating the long-term health and performance benefits of exercise. Our primary objective was to characterize acute changes in the fecal microbiome and metabolome following participation in an ultra-endurance (3.9 km swim, 180.2 km bike, 42.2 km run) triathlon. An exploratory aim was to determine associations between athlete-specific factors [race performance (i.e., completion time) and lifetime years of endurance training] with pre-race gut microbiota and metabolite profiles. Stool samples from 12 triathletes (9 males/3 females; 43 ± 14 yr, 23 ± 2 kg/m2) were collected ≤48 h before and the first bowel movement following race completion. Intra- and inter-individual diversity of bacterial species and individual bacterial taxa were unaltered following race completion (P > 0.05). However, significant reductions (P < 0.05) in free and secondary bile acids [deoxycholic acid (DCA), 12-keto-lithocholic acid (12-ketoLCA)] and short-chain fatty acids (butyric and pivalic acids), and significant increases (P < 0.05) in long-chain fatty acids (oleic and palmitoleic acids) were observed. Exploratory analyses revealed several associations between pre-race bacterial taxa and fecal metabolites with race performance and lifetime history of endurance training (P < 0.05). These findings suggest that 1) acute ultra-endurance exercise shifts microbial metabolism independent of changes to community composition and 2) athlete performance level and training history relate to resting-state gut microbial ecology.NEW & NOTEWORTHY This is the first study to characterize acute changes in gut microbial ecology and metabolism following an ultra-endurance triathlon. We demonstrate changes in gut microbial community function, but not structure, as well as several associations between gut microbiome and fecal metabolome characteristics with race completion time and lifetime history of endurance training. These data add to a small but growing body of literature seeking to characterize the acute and chronic effects of exercise on the gut microbial ecosystem.

In Vitro and In Silico Based Approaches to Identify Potential Novel Bacteriocins from the Athlete Gut Microbiome of an Elite Athlete Cohort.

Exercise reduces inflammation, fatigue, and aids overall health. Additionally, physical fitness has been associated with desirable changes in the community composition of the athlete gut microbiome, with health-associated taxa being shown to be increased in active individuals. Here, using a combination of in silico and in vitro methods, we investigate the antimicrobial activity of the athlete gut microbiome. In vitro approaches resulted in the generation of 284 gut isolates with inhibitory activity against Clostridioides difficile and/or Fusobacterium nucleatum, and the most potent isolates were further characterized, and potential bacteriocins were predicted using both MALDI-TOF MS and whole-genome sequencing. Additionally, metagenomic reads from the faecal samples were used to recover 770 Metagenome Assembled Genomes (MAGs), of which 148 were assigned to be high-quality MAGs and screened for the presence of putative bacteriocin gene clusters using BAGEL4 software, with 339 gene clusters of interest being identified. Class I was the most abundant bacteriocin class predicted, accounting for 91.3% of predictions, Class III had a predicted abundance of 7.5%, and Class II was represented by just 1% of all predictions.

The Potential Impact of Probiotics on the Gut Microbiome of Athletes.

There is accumulating evidence that physical fitness influences the gut microbiome and as a result, promotes health. Indeed, exercise-induced alterations in the gut microbiome can influence health parameters crucial to athletic performance, specifically, immune function, lower susceptibility to infection, inflammatory response and tissue repair. Consequently, maintenance of a healthy gut microbiome is essential for an athlete's health, training and performance. This review explores the effect of exercise on the microbiome while also investigating the effect of probiotics on various potential consequences associated with over-training in athletes, as well as their associated health benefits.