I dont believe I've had a doctor ignore gut health. Gut Flora is a well known thing, the problem is what works for regulating it properly in different individuals given different diets. I think it's more societally what we consider proper diet is wrong, like all yogurts being just sugar instead of fats.
Gut flora seems to be a case of we know about it but don't really know to how to use it properly and thus reliably. So called probiotics as expected for something that jumps the gun to commercialization from early stages of research tends to have two outcomes - either it does nothing except get excreted or it makes things worse.
There seems to be a history in medicine of a little knowledge being a dangerous thing. Hyperdosing vitamin-C boosts the risk of cancer, megadosing antioxidants doesn't seem to actually help, etc. It brings to mind the period in history in which blood transfusion was known but typing wasn't making the procedures quite risky, and cholesterol being considered just one number.
I think this really depends on where you are. When I first developed post-infectious IBS 15 years ago, I went to quite a few Gastros who knew nothing but: scopes, check for ulcers, tumors, diverticula, etc. - and when it all came back negative they happily declare IBS, pat themselves on the back, and tell me to destress, see a shrink, and not come back. Diet, gut flora, intermittent fasting, FODMAPs, none of those things were mentioned once.
