Gut Microbiota Composition Is Causally Linked to Multiple Sclerosis: A Mendelian Randomization Analysis

Area of Science:

• Microbiome research
• Neuroimmunology
• Human genetics

Background:

• The gut microbiome is increasingly linked to multiple sclerosis (MS) pathophysiology.
• Previous studies are largely correlational, limiting causal inference.
• Mendelian randomization (MR) offers a method to assess causal relationships using genetic variants.

Purpose of the Study:

• To investigate the causal relationship between gut microbiome composition and MS susceptibility.
• To identify specific microbial taxa associated with increased or decreased risk of MS.

Main Methods:

• A two-sample Mendelian randomization analysis was conducted.
• Genetic instruments were derived from large genome-wide association studies (GWASs) of the gut microbiome.
• MS susceptibility data came from a recent large-scale GWAS.

Main Results:

• Several microbial taxa were causally associated with MS risk.
• Increased abundance of Actinobacteria, Bifidobacteriaceae, and Lactobacillus was linked to higher MS risk.
• Prevotella spp., Lachnospiraceae, and Negativibacillus showed a protective effect against MS.

Conclusions:

• The gut microbiome plays a causal role in MS susceptibility.
• Findings reinforce the importance of the microbiome-gut-brain axis in MS etiology.
• This research opens avenues for microbiome-targeted MS prevention strategies.