(A) Clinical characteristics of patients are listed in Table A. Patients with RRMS; patients with noninflammatory neurological disease of the CNS (NIND), patients with IND, and HVs; EDSS, median ± IQR, ap < 0.01 NIND vs HV, and RRMS. (B) Levels of anti-Akkermansia muciniphila IgG in sera from patients with RRMS, NIND, IND, and HV. (C) Total IgG concentrations in CSF from patients with RRMS, NIND, and IND. (D) Levels of anti-Escherichia coli IgG in CSF from patients with RRMS, NIND, and IND. (E) Levels of anti-Acinetobacter baumannii IgG in CSF. (F) Levels of anti-Fusobacterium necrophorum IgG in CSF. (G) Levels of anti-Prevotella melaninogenica IgG in CSF. (H) Levels of anti-A muciniphila IgG in CSF. Mean ± standard error. **p < 0.01. (I) Correlation between anti-A muciniphila IgG in CSF from patients with RRMS and EDSS score (Spearman's rank correlation rho = 0.36, p = 0.027). EDSS = Expanded Disability Status Scale; HV = healthy volunteer; IND = inflammatory neurological disease; IQR = interquartile range; NIND = noninflammatory neurological disease; RRMS = relapsing–remitting MS.