Metametrix Labs. I think they're in North Carolina. You have to submit stool samples that are ordered by your health care provider, such as a Naturopath or holistic doc of some sort. I have a naturopath/M.D. in Southern California who does that sort of thing. Not many labs are set up for, or are qualified to do this sort of testing. Metametrix is the only reliable lab I've heard of. Or rather, the only one that can produce reliable results. Good luck!