Alterations of the human gut microbiome in multiple sclerosis

The gut microbiome plays an important role in normal immune function and has been implicated in several autoimmune disorders. Here we use high-throughput 16S rRNA sequencing to investigate the gut microbiome in subjects with multiple sclerosis (MS, n=61) and healthy controls (n=43). Alterations in the gut microbiome in MS include increases in the genera Methanobrevibacter and Akkermansia and decreases in Butyricimonas, and correlate with variations in the expression of genes involved in dendritic cell maturation, interferon signaling and NF-kB signaling pathways in circulating T cells and monocytes. Patients on disease-modifying treatment show increased abundances of the genera Prevotella and Sutterella, and decreased Sarcina, compared to untreated patients. MS patients of a second cohort show elevated breath methane compared to controls, consistent with our observation of increased gut Methanobrevibacter in MS in the first cohort. Further study is required to assess whether the observed alterations in the gut microbiome play a role in, or are a consequence of, MS pathogenesis.