Altered Gut Microbiome in Patients With Dermatomyositis

Area of Science:

• Microbiome research
• Immunology
• Rheumatology

Background:

• Dermatomyositis (DM) is an autoimmune disease with complex pathogenesis.
• The gut microbiome's role in autoimmune diseases is increasingly recognized.
• Understanding microbial alterations in DM may reveal novel therapeutic targets.

Purpose of the Study:

• To compare gut microbial composition between DM patients and healthy controls (HCs).
• To investigate the association between microbial alterations and clinical manifestations of DM, including myositis-specific autoantibodies (MSAs).

Main Methods:

• 16S ribosomal RNA gene sequencing of fecal samples from DM patients and HCs.
• Comparison of microbial diversity and composition.
• Correlation analysis with clinical variables (e.g., physician global damage score, MSAs).
• Predicted metagenomic functional analysis and dietary assessment.

Main Results:

• DM patients exhibited a trend towards lower microbial diversity compared to HCs.
• Lower microbial diversity correlated with higher physician global damage scores in DM patients.
• Patients with interstitial lung disease (ILD)-associated MSAs showed distinct microbial composition and reduced diversity.
• Increased Proteobacteria abundance in ILD-MSA patients was linked to lipopolysaccharide synthesis pathways.

Conclusions:

• DM patients, especially those with ILD-associated MSAs, possess a unique gut microbiome characterized by lower diversity and distinct taxonomic profiles.
• Gut microbiome alterations may play a role in the pathogenesis of DM.
• Further research is warranted to explore the causal links between the gut microbiome and DM pathophysiology.