The role of fecal microbiota transplantation in the treatment of acute graft-versus-host disease.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is one of the most important methods for treating a wide range of hematologic malignancies and bone marrow failure diseases. However, graft-versus-host disease (GVHD), a major complication associated with this method, can seriously affect the survival and quality of life of patients. Acute GVHD (aGVHD) occurs within 100 days after transplantation, and gastrointestinal aGVHD (GI-aGVHD) is one of the leading causes of nonrecurrent death after allo-HSCT. In recent years, fecal microbiota transplantation (FMT) has been attempted as an emerging treatment method for various diseases, including aGVHD after HSCT. Studies have shown encouraging preliminary clinical results after the application of FMT in aGVHD, particularly steroid-resistant aGVHD. Additionally, several studies have demonstrated that the gut microbiota plays an important immunomodulatory role in the pathogenesis of GVHD. Consensus guidelines recommend FMT as a secondary option for the treatment of aGVHD. This article aims to review FMT treatment for GI-aGVHD after allo-HSCT.