Gut microbiota dysbiosis in childhood vasculitis: a perspective comparative study

Kawasaki disease (KD) and Henoch-Schonlein Purpura (HSP) are the most frequent vasculitis in childhood. A multifactorial mechanism has been hypothesized for both with an abnormal immune response in genetically predisposed children. The gut microbiota (GM) alterations might trigger the hyperimmune reaction. Our aim was to explore the GM in KD and compare it with the GM of HSP and febrile children. Children diagnosed with KD, HSP and non-KD febrile illness (F) were enrolled. GM was profiled by 16S rRNA gene-based next-generation sequencing and compared with profiles of healthy age- and sex-matched children. Results: We enrolled 13 KD, 10 HSP and 12 F children. Their GM significantly differed from controls, with an overall reduction in the relative abundance of beneficial taxa belonging to Ruminococcaceae and Lachnospiraceae families. Potential KD and HSP signatures were identified, including greater amounts of Eggerthella in the former, and [Eubacterium] in the latter. This is the first study analysing GM in a mostly Caucasian cohort of KD and HSP children. KD patients have an unbalanced GM profile, distinct from that of HSP and F children, with an increase in potential pro-inflammatory pathogens, suggesting intestinal inflammation. These data could open up new opportunities for childhood vasculitis treatment.