Was there any attempt to control for travel, which would, of course, provide diversity in diet and microbes.
Exercise Linked to More Diverse Gut Microbiota, But Diet Likely Plays a Role — Physician’s First Watch
Exercise Linked to More Diverse Gut Microbiota, But Diet Likely Plays a Role
By Amy Orciari Herman
Intense exercise appears to have a beneficial impact on the microbial diversity of the gut, although concurrent dietary extremes are also involved, according to a study of elite athletes in Gut.
Forty professional Irish rugby players were matched to controls based on age, sex, and for half the controls, body mass index. Fecal samples were collected for analysis, and participants filled out food-frequency questionnaires. The diversity of gut microbiota was significantly higher among the athletes than controls. Protein intake was also significantly higher among the athletes, which correlated positively with gut biodiversity.
A commentator says this is "the first report that exercise increases gut microbiota richness/diversity and highlights that exercise is another important factor in the complex relationship among the host, host immunity and the microbiota."