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

: 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. To evaluate sex as a biological variable in both the host and colonic microenvironment during active EAE. We conducted colonic transcriptomics and microbiota analysis of colonic fecal content in male and female EAE C57BL/6J mice and controls at the time of disease induction, pre-onset, and peak disease. 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. Our results suggest early changes in colonic inflammatory pathways, with notable differences between males and females associated with microbiota alterations triggered by disease induction.