A SPECIFIC microbial ratio in the gut microbiome, characterised by a lower Bifidobacterium to Akkermansia ratio, has been identified as a potential marker for disease severity in multiple sclerosis (MS), offering promise for microbiome-based diagnostics and therapeutic interventions.
Multiple sclerosis is a complex autoimmune disorder affecting the central nervous system, with growing evidence suggesting that gut microbiota dysbiosis plays a role in its pathogenesis. However, the relationship between specific gut bacteria and MS remains poorly understood. Researchers conducted a study to investigate the gut microbiome composition in people with MS (PwMS) compared to healthy controls (HC) and to explore its potential as a diagnostic and therapeutic tool.
Using shotgun metagenomic sequencing, the study profiled stool samples from PwMS and HC, revealing distinct microbial differences. Prevotella copri was enriched in HC, while Blautia species were dominant in PwMS. Experimental autoimmune encephalomyelitis (EAE), an animal model of MS, was used to further explore these findings. Mice administered Blautia wexlerae showed increased gut inflammatory markers and proinflammatory cytokines, alongside a reduced Bifidobacterium to Akkermansia ratio. This lower ratio correlated with greater disease severity post-EAE induction. At the species level, a reduced Bifidobacterium adolescentis to Akkermansia muciniphila (BA:AM) ratio emerged as a consistent marker of disease severity. Validation across human cohorts, including the International Multiple Sclerosis Microbiome Study (iMSMS), confirmed the BA:AM ratio’s relevance as a microbial hallmark in MS.
These findings highlight the potential of the BA:AM ratio as a biomarker for MS diagnosis and prognosis, paving the way for microbiome-based therapeutic strategies. For clinical practice, this research suggests that targeting gut microbiota composition could offer novel avenues for managing MS severity. Future studies should focus on understanding the mechanisms underlying these microbial interactions and developing interventions to restore microbial balance in PwMS. Additionally, longitudinal studies are needed to assess whether modifying the BA:AM ratio could prevent disease progression or improve outcomes.
Katrina Thornber, EMJ
Reference
Ghimire S et al. Specific microbial ratio in the gut microbiome is associated with multiple sclerosis. Proceedings of the National Academy of Sciences. 2025;122(10):e2413953122.
