A previous study reported that the supernatant of Faecalibacterium culture, primarily the metabolite butyrate, can maintain Th17/Treg balance and ameliorate colorectal colitis by inhibiting histone deacetylase 1 (HDAC1) (70); this is of significance because Th17/Treg cell imbalance has been implicated in the pathogenesis of most common autoimmune diseases, including MS (71). This evidence concerns the gene HDAC1 and autoimmune disease.