Sorry, I didn't want to turn my original post into an essay, but I've already done low FODMAP and various other restricted diets for diagnostic purposes, without any noticeable shift in symptoms. Only bread and sugar seem to be correlated, and not strongly. To me it's a curious symptom rather than the root of the issue.
Have you looked into Mutaflor probiotics? It’s a beneficial E. Coli (seriously) that has research showing it can colonize the gut and clinically improve e.g. IBS symptoms. I’ve personally seen it solve (or significantly mitigate) issues for multiple people.
