To tell you the truth, I have no idea when my odor started. I would smell something funky here and there but never made the connection. The only way I found out the odor was coming from me was when I got a new job and it was during orientation ppl were acting funny around me as if I farted or shat my pants. As for the Antibiotics , I've taking them several times (root canals) and never got any odor. If anything, the Antibiotic Xifaxan helped a little bit, because it decreased flatulence, but I still smelt like garbage. I've also tried probiotics, even spent $100 on VSL 3 and had no success.