Sexual dimorphism in the colonic microbiome and host's transcriptomics profiles of a murine model of multiple sclerosis.

Background: Multiple Sclerosis is a chronic autoimmune disease that attacks the myelin sheath in the central nervous system, with a higher prevalence among female patients. We and others have documented significant changes in microbial taxa in response to the induction of active experimental autoimmune encephalomyelitis (EAE), an MS model. Objective: To evaluate sex as a biological variable in both the host and colonic microenvironment during active EAE. Methods: We conducted colonic transcriptomics and microbiota analysis of colonic fecal content in male and female EAE C57BL/6 J mice and controls at the time of disease induction, pre-onset, and peak disease. Results: Analysis showed significant sex-specific differences in colonic gene expression during EAE. As disease severity increased, the profiles of colon microbiome and transcriptomics became less distinct. Conclusions: Our results suggest early changes in colonic inflammatory pathways, with notable differences between males and females associated with microbiota alterations triggered by disease induction.