Causal effects of gut microbiota on multiple sclerosis: A two-sample Mendelian randomization study

Area of Science:

• Microbiome research
• Neuroimmunology
• Genetic epidemiology

Background:

• Observational studies suggest gut microbiota alterations in multiple sclerosis (MS) patients.
• Causal relationships between gut microbiota and MS remain unclear.

Purpose of the Study:

• To assess the causal effects of gut microbiota on multiple sclerosis (MS) using Mendelian randomization (MR).

Main Methods:

• Utilized genetic variants associated with 211 gut microbiota phenotypes from the MiBioGen study as instrumental variables.
• Employed genome-wide association studies (GWAS) data for MS from the International Multiple Sclerosis Genetics Consortium (IMSGC) and FinnGen consortium.
• Conducted sensitivity analyses to assess heterogeneity and pleiotropy.

Main Results:

• Identified seven gut microbiota with potential causal effects on MS from the IMSGC.
• Five specific gut bacteria, including Anaerofilum and Ruminococcus species, showed significant associations with MS in combined analyses.
• Reported odds ratios and confidence intervals for significant associations, such as Anaerofilum id.2053 (OR=1.141, CI: 1.021-1.276) and Ruminiclostridium5 id.11355 (OR=0.724, CI: 0.585-0.895).

Conclusions:

• The Mendelian randomization analysis suggests a potential causal relationship between specific gut microbiota and MS.
• Findings provide a foundation for further mechanistic understanding and clinical research into microbiota-mediated MS.
• Highlights the role of the gut microbiome in MS pathogenesis.