As humans, our intestinal tract is colonized by a dense and species-rich community of microorganisms (the gut microbiota) that is of paramount importance to our health. Recent clinical and experimental studies clearly indicate an important role of these communities in the etiology of multiple sclerosis and other autoimmune diseases. Dr. Walter discussed how the gut microbiota is implicated in the pathology of MS and how ‘microbial involvement’ provides explanations for the impact of the environmental risk factors of MS. He presented some of the microbiome-targeted treatment options that are currently discussed and researched in the field. Dr. Jens Walter is an associate professor and Campus Alberta Innovation Program Chair for nutrition, microbes and gastrointestinal health at the University of Alberta. After receiving his doctoral degree from the University of Hohenheim in Germany, he performed postdoctoral research into genetic and metagenomic approaches to study gut microbial ecology at the University of Otago in New Zealand. In 2006, Dr. Walter accepted a tenure track position at the University of Nebraska-Lincoln to work as a molecular microbial ecologist. He received tenure in 2012 before moving to the University of Alberta, Canada in 2014. Dr. Walter’s research focuses on the investigation of ecological and evolutionary processes that shape host-microbial symbioses in the human gut, and the application of these scientific concepts to develop microbiome-targeted nutritional and therapeutic strategies to improve human health.