I also get an explosion of health issues as soon I eat gas producing foods (rice, bread, some foodmaps, sugar, millet now too). I just got the result from my second microbiom dna test and it too showed that I have too much sibo- and methane producing bacteria. However I dont think I have a permanent allergy to specific foods. I just become sensitive to them when I'm bloated. When I'm bloated the gut is leaking substances and those substances cause the issues. When I'm not bloated I can eat milk, cream, protein, egg, small piece of bread. But when I'm bloated I react to all those things.