Gut bacteria associated with relapse in paediatric-onset MS

A relative abundance of a gut microbiota species within the Blautia genus and its interconnected variants was associated with an elevated risk of relapse in patients with paediatric-onset MS [1]. Blautia stercoris has also been linked to disease activity in other immune-mediated diseases, such as systemic lupus erythematosus.

Commensal gut microbes are known to affect host immune function and may play a role in the pathogenesis of MS. It is largely unknown to what extent gut microbiota may contribute to subsequent disease activity. To investigate this association in paediatric-onset MS patients, stool samples of 53 patients (of whom 38 girls) were collected and analysed using 16S rRNA sequencing in the V4 region. Amplicon sequence variants (ASVs) were identified using the Divisive Amplicon Denoising Algorithm-2. At the time of sample collection, mean age was 15.5 years and disease duration was 1.1 years; 48 used a disease-modifying therapy.

A total of 270 individual ASVs were included in the analyses. Of these, 20 ASVs were nominally significant (P<0.05). An example was Blautia stercoris, the presence of which was associated with higher relapse risk (HR 2.50; 95% CI 1.43-4.37). Higher values of 1 module’s eigengene were significantly associated with higher risk of relapse (HR 1.23; 95% CI 1.02-1.50). In this module, 4 ASVs were individually, nominally associated with higher relapse risk (P<0.05): Blautia massiliensis, Dorea longicatena, Coprococcus comes, and a species in the genus Subdoligranulum. Of 309 MetaCyc pathways, 10 were significantly associated with relapse risk (false discovery rate q<0.2).

1. Horton M, et al. Network analysis identifies gut bacteria associated with multiple sclerosis relapse among pediatric-onset patients. MSVirtual 2020, Abstract LB01.05.