The Gut Microbiome of Multiple Sclerosis Patients Shows Minimal Sex-Based Differences in Composition

Multiple sclerosis (MS) is a chronic autoimmune and inflammatory disease that impacts approximately 2.8 million people globally. The disease is characterized by immune-mediated damage to the myelin sheaths surrounding neurons in the central nervous system, resulting in debilitating neurodegenerative symptoms that impact the quality of life for the affected. Previous studies have shown that there are differences in the gut microbiome in MS patients compared to healthy controls. Additionally, it has been shown that MS displays sex-based biases in both symptoms and disease course. However, the sex-specific taxonomic and functional differences of the gut microbiome of MS patients remain underexplored. Using previously published 16S rRNA sequencing data from stool samples collected from healthy controls and MS patients in the United States. This study aims to investigate sex-based gut microbiome compositional and functional differences. No broad compositional differences were observed between male and female controls or MS patients, as demonstrated by alpha and beta diversity analyses. However, it was identified that male MS patients retained more healthy taxa compared to female MS patients in their core microbiome, while indicator species analyses revealed no distinct genera across all groups. Differential abundance analysis revealed minimal differences in abundance in all groups. No functional pathway differences were revealed across male and female patients. Altogether, this study suggests that there are minimal sex-based differences between patients, implying that other environmental and lifestyle factors potentially contribute to gut microbiome dysbiosis in MS patients.