Oral Administration of Probiotic Enterococcus Durans Ameliorates Experimental Autoimmune Encephalomyelitis in Mice

Introduction: Probiotics, including lactobacilli, are known to induce immunomodulatory activity with promising effects in inflammatory diseases. In this study, the potential of Enterococcus durans and three various strains of lactobacilli (lacto-mix), Including L.rhamnosus, L.casei, and L.plantarum for prevention of Experimental Autoimmune Encephalomyelitis (EAE) features were evaluated. Methods: C57BL/6 female mice were inoculated with (MOG35-55) / (CFA) to induce EAE. Different groups (five groups: n = 6 in each group) of animals received saline or probiotics by oral gavage with 200 µl of lactobacilli (1.5 *108 CFU/ml) for 2 week before the immunization and during the test for one month. Results: Histopathological studies showed an increase in infiltration of inflammatory cells and destruction of the myelin membrane in the EAE group but a decrease in the probiotic-treated animals. Pro-inflammatory cytokines (IL-17 and IFN-g) concentration in the supernatant of the brain and spinal cord tissues showed a significant increase in the EAE compared with the normal saline group (p <0.01), while in the spinal cord tissue there was a decrease in IL-17 in those animals treated with the Lacto-mix and Edu + Lacto- mix (p <0.01) and a significant decrease in IFN-g in those animals that received Edu (p <0.05). Western blot analysis of MMP-9 and MBP proteins showed a decrease and increase in treatment and EAE groups, compared to the normal control group respectively. Conclusion: our data suggest that probiotic Enterococcus durans and lacto-mix had a preventive effect against EAE but further studies are needed to clarify the exact mechanisms and their application in preclinical and clinical trials.