Fecal microbiota transplantation relieves abdominal bloating in children with functional gastrointestinal disorders via modulating the gut microbiome and metabolome

Objective: To evaluate the efficacy and safety of fecal microbiota transplantation (FMT) in functional gastrointestinal disorders (FGIDs) in children with abdominal bloating and changes in their gut microbiome and metabolome. Methods: Twelve pediatric FGID patients with predominant abdominal bloating who underwent FMT were enrolled in the study. Fourteen healthy controls and four stool donors were included for analysis. Clinical responses were assessed at 8 weeks after FMT. Fecal bacterial composition was determined by 16S rRNA gene sequencing. The fecal metabolome was measured by targeted metabolomics analysis. Results: Median age of the 12 children with FGIDs was 6 years, and nine were boys. Abdominal bloating was relieved in all patients by FMT at 8 weeks. Meanwhile, FMT significantly improved abdominal pain and diarrhea. The a diversity was significantly lower in the FGID patients, while the fecal microbial community (beta diversity) separated from that of healthy control (HCs). The relative abundances of multiple bacterial genera were significantly changed in the feces of the pediatric FGID patients. The levels of several short-chain fatty acids were lower, and lactic acid level was higher in FGID patients than in HCs. Altered bacterial composition was correlated with changes in the fecal metabolite profile and clinical symptoms in FGID patients. FMT modulated fecal microbiome and metabolome in FGID children toward a healthy state. Conclusions: FMT relieves abdominal bloating and modulates fecal microbiome and metabolome toward a healthy state in children with FGIDs. FMT may provide an alternative therapy for children with FGIDs and abdominal bloating.