Exploring gut microbiome dysbiosis in vasculitis in adults: a systematic review

Although studies have confirmed that disruptions in the gut microbiota (dysbiosis) contribute to the development of autoimmune disorders, the precise pathways through which the gut microbiota influences the onset and progression of vasculitis remain largely unknown. In recent years, research has increasingly concentrated on assessing the contribution of the gut microbiota to vasculitis. This systematic study sought to assess the dominant gut microbiota profiles in vasculitis patients and compare them to those of healthy individuals.

The Cochrane methodology was used to design and conduct the present systematic review. Relevant articles published up to May 2025 were searched and collected from four electronic databases: PubMed, Scopus, Medline, and Web of Science. The keywords used in the search included "vasculitis," "Takayasu arteritis," "giant cell arteritis," "polyarteritis nodosa," "microscopic polyangiitis," "granulomatosis with polyangiitis," "eosinophilic granulomatosis with polyangiitis," "cryoglobulinemic vasculitis," "IgA vasculitis," "variable vessel vasculitis," "Behçet's disease," and "Cogan's syndrome" alongside phrases like "gut microbiome," "gut microbiota," and "gut flora."

Overall, 12 publications were included in the analysis. Three addressed individuals with Takayasu arteritis (TAK), three investigated ANCA-associated vasculitis (AAV), another three examined Behçet's disease (BD), while one study each pertained to IgA vasculitis (IgAV), Kawasaki disease (KD), and a nonspecific form of vasculitis. The majority of these works observed variations in both α-diversity and β-diversity, as well as in the diversity and richness of the gut microbiota. Additionally, the structure of the microbial communities differed markedly between those with vasculitis and healthy individuals. Notably, Bacteroidetes, Firmicutes, and Proteobacteria-the dominant bacterial phyla in the human gastrointestinal tract-were frequently diminished in affected patients.

The occurrence of intestinal microbial imbalance in individuals diagnosed with vasculitis has been validated. As observed in various other autoimmune conditions, the gut microbiota of vasculitis patients is chiefly comprised Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria. Disruptions in the microbial ecosystem-mainly typified by diminished diversity and population density-may play a role in triggering and advancing the disease.

This review was not registered.