Restoring Microbial Balance: Clinical Applications, Challenges, and Future Directions of Fecal Microbiota...

Fecal microbiota transplantation (FMT) has emerged as a microbiota-directed therapeutic strategy with established efficacy in recurrent Clostridioides difficile infection (rCDI) and expanding investigational applications in pediatric medicine. Given the central role of the gut microbiota in immune maturation, metabolic homeostasis, and colonization resistance-particularly during early life-restoring microbial diversity represents a biologically plausible intervention for disorders characterized by dysbiosis. This narrative review critically examines current evidence regarding the indications, efficacy, safety, and practical considerations of FMT in pediatric populations. A structured literature search was conducted across PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Library from inception through December 2025. Eligible studies included randomized controlled trials, observational studies, systematic reviews, meta-analyses, and guideline statements addressing pediatric FMT. RCDI remains the primary and best-supported indication, with reported success rates exceeding 80% after a single FMT and approaching 90% with repeat procedures. Evidence for other indications-including inflammatory bowel disease (IBD), malignancy-associated CDI, transplant recipients, multidrug-resistant organism (MDRO) decolonization, neurodevelopmental disorders, allergic colitis, and functional gastrointestinal disorders-remains limited and heterogeneous. While short-term remission rates in pediatric ulcerative colitis appear promising, data derive largely from small, non-standardized studies, and long-term efficacy and safety remain insufficiently defined. FMT usage in immunocompromised children, particularly oncology and transplant populations, is controversial due to limited pediatric-specific evidence and theoretical risks. Substantial variability in donor screening, preparation methods, dosing, and administration routes further limits standardization. Currently, FMT should be considered established therapy for pediatric rCDI, whereas other applications require well-designed, multicenter trials with long-term follow-up to clarify safety and clinical benefit.