There are no published data concerning dysbiosis in small vessel vasculitides, although it has been demonstrated that gut dysbiosis in glomerulonephritis mice models (with a prevalence of Escherichia coli or Citrobacter rodentium) may locally expand Th17 lymphocytes, which could then migrate to the kidney through a chemokine pathway involving C-C motif chemokine ligand 20 (CCL20) and C-C motif chemokine receptor 6 (CCR6) [56]. The gene discussed is CCL20; the disease is glomerulonephritis.