I’m pretty concerned about probiotics and fecal transplant treatment in Crohn’s disease because of the fact that those patients have antibodies to several species of gut bacteria. Couldn’t the above treatments cause potentially an exacerbation?

Chris Kresser:  That’s a very astute question, and the answer is absolutely yes. I just read a study, I’ll try to dig it up, that suggested that a full 25 percent of patients with IBD and I think, particularly, it may have been particularly Crohn’s, not IBD in general, have an adverse reaction to FMT. I’ve actually, in my second interview with Glenn Taylor from the Taymount Clinic, which you can find in my podcasts, and I asked about that and he said that his experience of now having done thousands of FMTs was concordant with that. He does find that the patients with Crohn’s that it can go either way, especially if they’re in an active flare. I think he doesn’t even allow patients that are in an active Crohn’s flare to come to the clinic for an FMT, but even patients that are in remission there’s a chance of provoking a flare. So I definitely would urge caution for patients with Crohn’s. What’s tricky is that there are a lot of ideas about what causes Crohn’s and of course one of them is that it’s an autoimmune reaction to commensal bacteria, as you mentioned, Dalit. Then of course there is a theory that Crohn’s is caused by Mycobacterium or another infectious process. As is often the case I think it may be multiple etiologies in different patients, and that may explain why some patients get a fecal transplant and they respond well and why other patients get a fecal transplant and they respond poorly.