Tsuji S, et al. - This study was designed to test the hypothesis that dysbiosis involving decreased butyric acid-producing gut microbiota leads to defective induction and differentiation of peripherally induced regulatory T cells (Tregs), resulting in idiopathic nephrotic syndrome (INS) relapse. Gut microbiota dysbiosis was exhibited by pediatric relapsing INS patients. Notably, a decreased proportion of butyric acid-producing bacteria and lower fecal butyric acid quantities, concomitant with reduced circulatory Tregs, were the reported characteristics of this gut microbiota dysbiosis in this patient population.