Tu188 - Alterations of the Nasal and Oral Microbiota in Multiple Sclerosis

Abstract Text: While changes in the gut microbiota have been identified in multiple sclerosis (MS), little is known about the nasal and oral microbiota, which are important components of the mucosal immune system. The gingival microbiota has been shown to drive systemic inflammation, the pharyngeal microbiota can lead to autoimmune-mediated neurologic diseases, and altered bacterial toxigenic genes in the nasal microbiota have been found in active MS. We investigated nasal, gingival, and oropharyngeal microbiota from MS and healthy control subjects. We profiled the microbial composition using 16S rRNA sequencing and identified site-specific microbiota differences in both the nasal and oral microbiota related to relapsing and progressive MS. We identified several opportunistic bacteria that were associated with disease worsening in MS using linear regression analysis while controlling for confounding factors and subject demographics. Using baseline microbiota samples and clinical outcomes over time, we identified potential beneficial microbes, including D. pigrum and Corynebacterium sp. in the nasal microbiota and Prevotella sp. in the oral microbiota, as well as potential detrimental Streptococcus sp. in the oral microbiota. Taken together, our data suggests that nasal and oral microbiota are altered in MS, are linked to the disease course and provide an avenue to better understand MS pathogenesis and treatment.