The gut microbiota in multiple sclerosis varies with disease activity

Area of Science:

• Microbiome research
• Neuroimmunology
• Gastroenterology

Background:

• Multiple sclerosis (MS) is a chronic, immune-mediated neurological disorder impacting young adults.
• The gut microbiota-brain axis is implicated in MS pathogenesis, with altered microbial communities potentially mediating disease.
• Understanding MS gut microbiome characteristics is crucial for elucidating disease etiology.

Purpose of the Study:

• To characterize the gut microbiota in multiple sclerosis (MS) patients.
• To associate gut microbial findings with disease variables and inflammation markers.
• To explore the role of the gut microbiota-brain axis in MS.

Main Methods:

• A case-control study involving 148 MS patients and 148 healthy controls.
• Shotgun sequencing of fecal microbial DNA to analyze bacterial and viral communities.
• Correlation analysis with plasma cytokines, blood cell gene expression, and clinical disease activity.

Main Results:

• 61 bacterial species showed differential abundance between MS cases and controls; 31 were enriched in MS patients.
• Inflammation markers (leukocytes, CRP, IL17A, IL6 gene expression) correlated with MS-related bacterial species.
• In treatment-naïve MS, bacterial richness associated with relapses; specific species like Faecalibacterium prausnitzii and Gordonibacter urolithinfaciens were enriched in non-active MS.
• MS patients exhibited higher viral diversity and abundance of Caudovirales bacteriophages.

Conclusions:

• Significant gut microbiota aberrations in MS are linked to inflammation biomarkers.
• Bacterial richness in treatment-naïve MS correlates with disease activity.
• Enriched symbiotic bacteria in non-active MS producing anti-inflammatory compounds suggest potential therapeutic applications.