Altered Gut Microbiome in Patients With Dermatomyositis

Abstract

Objective The study objective was to compare the microbial composition of patients with dermatomyositis (DM) and healthy controls (HCs) and determine whether microbial alterations are associated with clinical manifestations of DM. Methods The 16S ribosomal RNA gene sequencing was performed on fecal samples from patients with DM and HCs. Microbial composition and diversity were compared between subjects with DM and HCs and in association with several DM‐specific clinical variables, including myositis‐specific autoantibodies (MSAs). Differentially abundant microbial taxa and genes associated with clinical characteristics were identified, and functional analysis was performed using predicted metagenomics. Dietary intake was assessed using a 24‐hour dietary recall. Results The fecal microbiome of 36 patients with DM and 26 HCs were analyzed. Patients with DM trended toward lower microbial diversity compared with HCs. The higher physician global damage score was significantly correlated with the lower microbial diversity in patients with DM. Patients with interstitial lung disease (ILD)‐associated MSA (antisynthetase antibody (ab), anti‐melanoma differentiation‐associated protein 5 ab, n = 12) had significant differences in microbial composition and lower microbial diversity compared with HCs. Differential abundance testing demonstrated a unique taxonomic signature in the ILD‐MSA subgroup, and predictive metagenomics identified functional alterations in a number of metabolic pathways. A significant increase in the relative abundance of Proteobacteria was positively correlated with multiple pathways involved in lipopolysaccharide synthesis and transport in the ILD‐MSA group. Conclusion Patients with DM, particularly with ILD‐associated MSAs, have lower microbial diversity and a distinct taxonomic composition compared with HCs. Further studies are needed to validate our findings and elucidate specific pathogenetic mechanisms that link the gut microbiome to clinical and pathological features of DM.

Alternation of Microbiota in Autoimmune Disease

“…Beyond the phylum level, they were also more abundant in Streptococcus, Lachnoclostridium, and Tyzzerella 3 and 4 while less abundant in Bifidobacterium, Christensenellaceae R-7 group and Anaerostipes compared to the health controls. However, the researcher indicated that these differences were not significantly associated with the DM diseases [10]. Overall, the difference observed between DM patients and health control microbiota at the phylum level does indicate some correlation of microbiota dysbiosis and the develop of DM, although the result does not provide a strong support for the difference at the genus level.…”

Microbiome features in bronchoalveolar lavage fluid of patients with idiopathic inflammatory myopathy-related interstitial lung disease

“…Previous research reported that patients with dermatomyositis had lower microbial diversity compared with healthy controls. Results from alpha and beta diversity showed a clear difference in the bacterial richness and community between IIM patients and healthy controls ( 24 ). However, our results were not entirely consistent with some researches.…”

The Immunomodulatory Role of Microbiota in Rheumatic Heart Disease: What Do We Know and What Can We Learn from Other Rheumatic Diseases?

“…The gut microbiome has also been implicated in dermatomyositis (DM), an autoimmune myopathy associated with muscle weakness and skin rashes. DM patients were reported to have lower gut microbial diversity compared with healthy controls [ 81 ], and a subgroup of DM patients with interstitial lung disease (ILD)-associated MSA had decreased abundance of Christensenellaceae and Ruminococcaceae . There are only limited data on the role of the skin microbiota in rheumatoid autoimmune disorders such as SLE, and further studies are warranted to identify and elucidate the function of specific skin microbial species in the cutaneous manifestations of patients with rheumatoid disorders.…”