I don't think Crohn's fits your pattern here. My expertise/bias is that I've had it for about 35 years.
The topic here is controlling body systems based on the chemistry of what's being consumed.
A Crohn's diet has two important factors, which don't really look at the chemicals introduced into the body very much at all. Most important is a purely mechanical component: because scar tissue and adhesions can cause strictures, areas of limited diameter and stretch in the intestines, it's necessary to avoid stuff that might get stuck, like popcorn and other seeds. A second issue, possibly more important but only very poorly understood, is the environment presented to intestinal flora. There's chemistry to that (like carb mix) but, not with respect to the parent organism.
Most people with Chron's disease should avoid spicy food due to chemical irritation and sure the mechanical issues are also important.
However, a nutritionist will suggest a heathy low fiber diet when dealing with a partial obstruction etc. Eggs vs red meat might seem like a simple change, but once a range of dietary restrictions show up a heathy diet becomes a lot more difficult.
Anyway my point was there is a lot of practical diet research out there.
PS: Chrones also frequently causes issues with nutrient absorption and a high protein diet is useful for healing. So, there are some classically nutrition based changes.
The topic here is controlling body systems based on the chemistry of what's being consumed.
A Crohn's diet has two important factors, which don't really look at the chemicals introduced into the body very much at all. Most important is a purely mechanical component: because scar tissue and adhesions can cause strictures, areas of limited diameter and stretch in the intestines, it's necessary to avoid stuff that might get stuck, like popcorn and other seeds. A second issue, possibly more important but only very poorly understood, is the environment presented to intestinal flora. There's chemistry to that (like carb mix) but, not with respect to the parent organism.