There are several things that can cause SIBO but the most commun are lack of stomach acid and motility problems. A leaky gut don't favor it either but you can not repair the leaky gut if a bacterial overgrowth is present. I have been taking a lot of supplements to repair the gut an still have severe intestinal issues. The fist time I was close to normal was taking Threelac and Grapefruit-Seed-Extract for almost 6 months. I was Gluten free but later I began to eat it again and everything got worse. I stopped it again around 10 months ago and still I have the problems, so I am not sure it is gluten the cause. I always ate gluten in my life before the hell of Antibiotics I took. I don't have any family member with Celiac or gluten intolerances. Everything was triggered by the f...s Antibiotics . I didn't have any stomach problems before to take them.