Fig. 1

Identification of three taxonomic clusters in cyclists. a Dendrogram using the BC dissimilarity index of the top 25 genus-level relative abundance profiles as determined with mWGS sequencing. Genera in the dataset are listed in the key on the left in descending order, with Bacteroides on top as the most abundant organism across all the samples. Included on the dendrogram branches are assigned AU p values. For dendrogram labels, ‘C’ indicates a CAT 1 (amateur) cyclist and ‘P’ depicts a professional cyclist. The color strip marked with the pound sign (#) indicates the average amount of exercise completed each week. b The three principal coordinates of the Jensen-Shannon distances generated from the cyclists’ genus-level relative abundance profiles. Samples are colored by cluster as identified by the partitioning around medoids (PAM) clustering algorithm. Dark blue is cluster one, light blue is cluster two, and black is cluster three. c Cyclists in cluster three overall had a higher number of genera (higher richness) than those in cluster one (p = 0.0112) and cluster two (p = 0.0154). d The Shannon diversity index was significantly higher for cluster three compared to cluster two (p = 0.0004) but was not significantly different than cluster one (p = 0.0534). Statistical significance was determined by the Wilcoxon rank-sum test for each pairwise comparison