Fecal microbiota transplantation for Crohn's disease-like intestinal lesions arising after allogeneic stem cell transplantation.

Several cases of inflammatory bowel disease (or similar gastrointestinal lesions) arising after allogeneic hematopoietic stem cell transplantation have been reported, but the effect of intestinal dysbiosis on development of these lesions remains unclear. We performed fecal microbiota transplantation (FMT) and 16S rRNA microbiome analysis in a patient who developed Crohn's disease-like lesions after allogeneic transplantation. A 62-year-old woman underwent haploidentical stem cell transplantation from her daughter to treat double-hit lymphoma relapsed after chimeric antigen receptor T-cell therapy, and achieved remission without developing acute graft-versus-host disease. Eight months later, she developed Crohn's disease-like intestinal lesions after cytomegalovirus enteritis. Her condition did not improve with the conventional treatment, so she underwent FMT from her daughter as part of a clinical trial. Diarrhea gradually improved, and follow-up endoscopy 4 months after the FMT showed ulcer healing and scarring. The 16S rRNA analysis revealed a reduction in the relative abundance of the Enterococcus genus after FMT, suggesting that dysbiosis may have contributed to lesion development. The patient is currently on a regular diet, with no symptom recurrence, and the primary disease remains in remission. Although this outcome suggests that FMT is effective, careful patient selection is required to reduce the risk of FMT-associated sepsis.