i also suffer with the same symptoms like fbo,lg may be fbb and yes my mouth/face swell up after eating certain foods
maybe there is allergy or something, I don't really study this stuff, even though my mouth swell up too I feel that my odor symptom originates from IAS weakness, exacerbated by incomplete evacuation from anismus. I know sometimes conditions like Crohn's disease can effect the whole GI tract, mouth included. There are allergy tests available where they scratch the skin with various common allergens, then check for reactions later.
when you say fbo, lg and fbb...this is fecal odor coming from your sweat and breath? If so this could be a blood borne body odor condition. Maybe think about testing for TMAU, since its the only blood borne body odor condition that is tested for widely at the moment. Most TMAU positive patients have fecal odor, not fish. Possibly because blood borne sulfur compounds as well as TMA. FMO3 deal with sulfides too, but no evidence for this theory.