The association of gut microbiota with responsiveness to initial high-dose intravenous immunoglobulin therapy in Kawasaki disease

Variations in gut microbiota may contribute to the pathogenesis and treatment response in Kawasaki disease (KD), but their role remains unclear. We analyzed fecal samples from 25 children with acute-phase KD and 9 age-matched healthy controls, none of whom had received antibiotics or steroids within two months of sampling. The gut microbiota was examined using 16S rRNA amplicon sequencing. Among the KD patients, 8 were refractory to initial intravenous immunoglobulin (IVIG) therapy. Although α-diversity tended to be lower in KD patients compared to healthy controls, no significant difference was observed. Similarly, α-diversity did not differ significantly between IVIG responders and non-responders. However, comparison of bacterial composition within the KD group revealed that Peptostreptococcaceae was significantly more abundant in IVIG non-responders ( P  = 0.02). At the genus level, Peptostreptococcus and Intestinibacter were also more prevalent in the non-responder group. These findings suggest that specific gut microbiota, rather than overall diversity, may be associated with IVIG treatment resistance in KD. Peptostreptococcaceae was relatively abundant in KD patients who did not respond to initial IVIG therapy. Responsiveness to IVIG therapy in KD may be associated with variations in the gut microbiota.