Microbiota-nutrition sequential therapy for refractory radiation proctitis: A case report

Figure 7 Schematic illustrating synergistic mechanisms of faecal microbiota transplantation plus immunomodulatory enteral nutrition against radiation enteritis. Faecal microbiota transplantation remodels gut microbiota to enrich beneficial Ruminococcus, Bacteroides, Faecalibacterium, reduce pathogenic Escherichia-Shigella and Enterobacter, and boost intestinal short-chain fatty acid (SCFA) levels. EPA, DHA, glutamine, arginine and nucleotides exert multi-target protection. SCFAs combined with these nutrients strengthen tight junctions, suppress NF-κB-driven inflammation, activate GPCR signaling to mitigate intestinal fibrosis, and enhance mucosal immunity via elevated gut-associated lymphoid tissue activity and secretory IgA secretion. Combined therapy relieves abdominal pain, diarrhea and hematochezia, and restores intact intestinal mucosa. GALT: Gut-associated lymphoid tissue; sIgA: Secretory IgA.