Chris Kresser: They’re all really good questions, and the answer is we don’t really know. As you probably are aware, the etiology of IBD and Crohn’s is controversial. Some people believe the cause is what I just mentioned. That’s kind of the more conventional view. But there are others that believe it’s caused by infection of Mycobacterium avium subspecies paratuberculosis, or MAP, a mycobacterium. There are people who believe it’s mostly caused by overly sanitary conditions and the absence of certain organisms that have a tuning and regulatory effect, like Necator americanus, human hookworm, things like that. That’s the hygiene hypothesis or the old friends hypothesis. There’s Trevor Marshall and the Marshall folks who believe it’s caused by some kind of chronic infection if not MAP. So there are a lot of ideas out there.
My belief is that Crohn’s and IBD, in general, are multifactorial conditions with several different etiologies in different patients, and this is why you see such a wide variation in responses to different treatments. For example, some patients respond extremely well to steroids in the conventional IBD treatment, whereas other patients don’t respond to those things at all. Some patients respond very well to probiotics, whereas probiotics can cause incredible flare-ups in other patients. Some patients that I know of have done the hookworm therapy and had an almost miraculous recovery and turnaround. Others that I know of have gotten much worse.
By the same token, I just saw a study recently. It was a small sample size, but they were looking at fecal microbiota transplant, or FMT, for Crohn’s disease. Wait a second. I’m confusing studies. So this was a review of studies that have been done so far on FMT for inflammatory bowel disease, and what they found, which is really interesting, was that 25 percent—a full quarter—of patients got worse and had a pretty big flare-up of symptoms with a fecal transplant. I can’t remember the rate of improvement, but it was fairly low, and then there was a group of people who just didn’t really get better or worse. That makes me wonder, is that 25 percent of patients that got worse the subset that is attacking commensal bacteria, and so when you had this huge introduction of commensal bacteria, that really just sent them over the edge and made them a lot of worse? And maybe the ones that got better, maybe they had an infectious cause of Crohn’s. The FMT is excellent at dealing with infections, like C. diff. Maybe those patients got better for that reason.
It’s pretty murky, we don’t really know, but studies overall, when you look at orally taken probiotics, there are definitely some studies showing benefit with both ulcerative colitis and Crohn’s with a number of different products, like VSL #3, for example, or single-strain probiotics like Mutaflor, E. coli Nissle 1917, which we’ve talked about and we’ll talk about in the IBD treatment section. That’s a specific form of E. coli that was isolated back in World War I, and it has been used in Europe, Germany particularly, for many years, decades, and used successfully, and it seems to work pretty well with Crohn’s disease, so that’s one.
Interestingly enough, with Xifaxan, I’ve read some research that suggests that because it doesn’t affect a lot of beneficial bacteria in the colon and only affects the small intestine, it may not matter as much when you take the probiotics, but if you do take them, I think as a precaution it makes sense to just take them away from when you take the Xifaxan. With Xifaxan, it doesn’t tend to matter so much when people take it in terms of full stomach or empty stomach. Some people, a very small number of people, experience GI upset when they take it, but one option would be to take the Xifaxan on an empty stomach three times a day and the probiotics with meals. Or you could take the Xifaxan with meals and just have the patient take the probiotics first thing upon rising and then right before bed. There are some different options there.