To investigate oral microbial profiles and salivary metabolite levels in patients with relapsing–remitting multiple sclerosis (RRMS) compared to healthy controls.
Approach:
Study Design: Cross-sectional case–control study involving 50 adults with RRMS and 50 age-matched healthy controls.
Microbial Analysis: Shotgun metagenomic sequencing of oral swabs to evaluate microbial diversity and composition.
Metabolomic Profiling: Untargeted salivary metabolomic profiling using liquid chromatography–mass spectrometry.
Statistical Analysis: Alpha and beta diversity measures, random forest model for classification accuracy, and correlation networks linking microbial species to metabolites.
Key Findings:
Distinct oral microbial profiles in RRMS patients with reduced salivary hypotaurine.
Lower microbial diversity and significant differences in community composition between RRMS patients and controls.
Reduction in common Gram-positive species and increase in Gram-negative bacteria in RRMS patients.
Metabolomic analysis revealed reduced levels of five salivary metabolites and elevated levels of nine metabolites in RRMS patients.
Random forest model showed moderate accuracy in distinguishing RRMS from controls (67% for controls, 89% for RRMS patients).
A total of 102 microbial species varied in abundance, including 96 bacterial, 5 viral, and 1 fungal species.
Interpretation:
Limitations:
Lack of dental or periodontal assessments limits evaluation of gum disease as a confounder.
Single-center design may restrict generalizability.
