Strange thought has been bumping around my head.
We know there is some relationship between metabolic health and having a diverse gut microbiome.
Seems to me that open water swimmers might have a bit of an advantage there not enjoyed by almost any other type of athlete since we’re exposed to all sorts of great poop in lake water! We all drink a little of that water!
Swimming in Lake Superior probably exposed me to bear, wolf, moose, deer, human, dog, coyote, bobcat, weasels, etc… just to name a few of the larger mammals.