Autoimmunity

Statement of the Problem: In humans, a complex interaction between the host immune system and commensal microbiota is required to maintain gut homeostasis. In this symbiotic relationship, the microbiota provides carbohydrate fermentation and digestion, vitamin synthesis and gut-associated lymphoid tissue development, as well as preventing colonization by pathobionts, whereas the host off ers a niche and nutrients for the survival of the microbiota. However, when this mutualistic relationship is compromised and an altered interaction between immune cells and microorganisms occurs, the gut microbiota may contribute to the autoimmune diseases development. Researchers have made eff orts to clarify the role of the microbiota in autoimmune disease and fi nd new therapeutic approaches to treat immune-mediated diseases. However, the exact mechanisms involved in the gut dysbiosis and breakdown of the gut epithelial barrier are currently unknown. Findings: In our MS study, we observed prevalence of Bacteroidetes phylum,Bacteroides, Flavobacterium and Parabacteroides genera, and Bacteroides vulgatus. Th e Bifi dobacterium and Enterobacter genera, essential for the vitamins B and K synthesis, were found exclusively in control group. Diff erent from other studies, we found no significant diff erences in Firmicutes, Bacteroidetes and Proteobacteria phyla, and Akkermansia, Faecalibacterium and Methanobrevibacter genera in MS patients. No signifi cant differences were found in the plasma concentrations of IL-2, -4, -6,-10, -17A, TNF and IFN-g cytokines. Concerning dietary habits between patients and controls, signifi cant diff erences (P<0.05) were observed in the alcohol consumption, vegetables consumption, fresh fruits, protein consumption, milk and derivatives, carbohydrates, coffee/tea, and spicy food consumption. Conclusion & Signifi cance: We concluded that diet habits play an important role in the microbial community determination in the human intestine. Further studies are necessary to determine the real role of intestinal microbiota in demyelinating diseases of the central nervous system, and whether there is a relationship between intestinal dysbiosis, vitamin defi ciency and the pathophysiology of MS. pathophysiology of MS.