contributed by Orla O’Sullivan
Previous studies from our group had demonstrated that elite athletes house a more diverse gut microbiome than non-athlete controls; with the athlete microbiome primed for muscle recovery, energy harvest and protein degradation. These differences in the microbiome cannot be replicated through short-term (8 week) exercise interventions, leading us to hypothesise that it is prolonged exercise, and in turn increased physical fitness, that is important for gut microbiome health. To investigate this, we embarked on a longitudinal, repeated measures “n of 1” case study in which we followed two self-proclaimed ‘couch potatoes’, both with high BMIs, who were undertaking training programs for either a marathon or a triathlon. Over the course of 6 months, we measured their fitness levels, body composition, microbiome and metabolome. As expected, both participants underwent a reduction in BMI and increases in lean body mass and fitness levels. Of particular interest was the observation that both participants had highest gut microbial diversity when they were at peak fitness, and we saw a corresponding drop in microbial diversity when events such as illness and need for medication occurred. At a metabolite level, those metabolites previously identified as being associated with leanness and fitness (e.g. phenylacetlyglutamine) increased as the participants’ fitness level increased. This work is a further step towards understanding the role of the microbiome in fitness and performance, an area that will be of key importance with respect to next-generation approaches to personalised training and nutrition.
This work is the result of a collaboration of APC Microbiome Ireland and Imperial College London and is currently in press in Translation Science and Medicine in Sport.