Fecal microbiota transplantation induces remission of infantile allergic colitis through gut microbiota re-establishment

AIM: To investigate the impact of fecal microbiota transplantation (FMT) treatment on allergic colitis (AC) and gut microbiota (GM). METHODS: We selected a total of 19 AC infants, who suffered from severe diarrhea/hematochezia, did not relieve completely after routine therapy or cannot adhere to the therapy, and were free from organ congenital malformations and other contraindications for FMT. Qualified donor-derived stools were collected and injected to the AC infants via a rectal tube. Clinical outcomes and follow-up observations were noted. Stools were collected from ten AC infants before and after FMT, and GM composition was assessed for infants and donors using 16S rDNA sequencing analysis. RESULTS: After FMT treatment, AC symptoms in 17 infants were relieved within 2 d, and no relapse was observed in the next 15 mo. Clinical improvement was also detected in the other two AC infants who were lost to follow-up. During follow-up, one AC infant suffered from mild eczema and recovered shortly after hormone therapy. Based on the 16S rDNA analysis in ten AC infants, most of them (n = 6) had greater GM diversity after FMT. As a result, Proteobacteria decreased (n = 6) and Firmicutes increased (n = 10) in post-FMT AC infants. Moreover, Firmicutes accounted for the greatest proportion of GM in the patients. At the genus level, Bacteroides (n = 6), Escherichia (n = 8), and Lactobacillus (n = 4) were enriched in some AC infants after FMT treatment, but the relative abundances of Clostridium (n = 5), Veillonella (n = 7), Streptococcus (n = 6), and Klebsiella (n = 8) decreased dramatically. CONCLUSION: FMT is a safe and effective method for treating pediatric patients with AC and restoring GM balance.