REPORT FROM THE ACTRIMS-ECTRIMS – BOSTON, MA, SEPTEMBER 10-13, 2014 – Several lines of evidence indicate that the gut microbiome plays a role in the pathogenesis of MS. It has been suggested that environmental risk factors, such as diet, vitamin D insufficiency, obesity and smoking, may contribute to alterations in the GI flora that may predispose to autoimmune dysregulation (Joscelyn & Kasper. Mult Scler 2014; epublished July 28, 2014).