Please make it stop - overselling the microbiome award for rugby, exercise, microbiome stories

Well, I think today's lesson is, many people, including many scientists and science reporters, just do not get that there is a difference between correlation and causation.  I know - this is like beating a dead horse since many write about this issue.  But it just needs to be called out every time until it stops.  And today's fun comes from stories and the original research articles about how exercise supposedly alters the gut microbiome. I was pointed to this just a few minutes ago on Twitter:Seems like more appropriate title would b "rugby players have different diets" http://t.co/nzNsnHCYtA @phylogenomics— Bernat Olle (@bernatolle) June 10, 2014In this Tweet Bernat Olle points to a "news" story in Medpage Today: Exercise Boosts Gut Microbiome Diversity by Kristina Fiore.   Well, so of course I started digging around.  And, not surprisingly, the study that this is based on shows absolutely no causal connection between exercise and the gut microbiome.  The study is in the journal "Gut": Exercise and associated dietary extremes impact on gut microbial diversity.  And here is what they did:They selected subjects - 40 "elite" rugby players.They identified healthy male "controls" with similar age and size and from similar place. Then they collected faecal and blood samples from participants and did surveys about their nutrition and clinical data.Among many measurements, they did 16S sequencing from the fecal samplesThen they did som...
Source: The Tree of Life - Category: Medical Scientists Authors: Source Type: blogs