Gut microbiome variation is associated to Multiple Sclerosis phenotypic subtypes.

Area of Science:

• Neuroimmunology
• Microbiome Research
• Gastroenterology

Background:

• Multiple sclerosis (MS) is a complex central nervous system inflammatory disease.
• Gut microbiota alterations are observed in MS patients, but findings are inconsistent.
• Understanding these variations is crucial for identifying disease biomarkers.

Purpose of the Study:

• To investigate gut microbiota diversity, enterotypes, and specific taxa in MS patients compared to healthy controls (HC).
• To analyze variations within MS subgroups based on phenotype, disease course, and treatment.
• To explore the relationship between microbial composition and clinical symptoms/disease severity.

Main Methods:

• 16S rRNA gene amplicon sequencing of stool samples from 98 MS patients and 120 HC.
• Analysis of alpha and beta diversity, enterotype profiling, and relative abundance of microbial taxa.
• Controlled for potential confounders and stratified MS subgroups by clinical characteristics.

Main Results:

• Microbial richness was lower in interferon-treated and untreated relapsing-remitting MS during relapse compared to benign and primary progressive MS.
• Enterotypes, specifically Bacteroides 2, were more prevalent in interferon-treated relapsing-remitting MS.
• Lower abundance of Butyricicoccus was observed in primary progressive MS and interferon-treated relapsing-remitting MS, correlating inversely with symptoms and disease severity.

Conclusions:

• Phenotypic subcategorization is essential for consistent MS-microbiome research.
• Gut microbiota composition differs significantly across MS subtypes.
• Microbiome-based biomarkers show potential for assessing MS disease activity and severity.