What is the 12-week recommendation of Xifaxan in IBD based on?

Chris Kresser:  It’s based on studies showing that 12 weeks of Xifaxan induced remission in active IBD patients. And there are other studies showing that patients that were already in remission, they were separated into two groups. One didn’t receive any care, and the other received Xifaxan for 12 weeks, and the group that received Xifaxan for that period of time had much lower rates of relapse. In a couple of those studies, though, they used a form of Xifaxan that’s not yet available, at least in the US. I’m not sure if it is elsewhere, but it’s an extended release form, so it releases more in the terminal ileum, the final part of the small intestine, which is where a lot of patients with Crohn’s have their disease. But there are some studies showing that even the standard formulation of Xifaxan can be helpful in inducing disease remission or maintaining remission in IBD. The thinking behind that, in terms of mechanisms, is, as I’m sure many of you know, IBD, particularly Crohn’s, is thought to involve an inappropriate autoimmune attack against commensal bacteria. In other words, the body kind of attacks your own beneficial bacteria, the gut microbiome, in the colon or the small intestine. Rifaximin reduces the levels of bacteria in the small intestine, and that may be one reason why it tends to reduce disease and it can be an effective intervention for IBD.