The Potential of targeting the gut microbiota to improve allogeneic haematopoietic stem cell transplantation outcomes, focusing on graft-versus-host diseases.
Summary
Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is the treatment of choice for many
haematological malignancies and benign diseases. Outcomes of allo-HSCT have improved over the
years; however, there is still a high rate of transplant-related mortality, with graft-versus-host disease
(GVHD) as one of the key contributors. Currently, there is an unmet need for biomarkers and new
therapeutic strategies to treat GVHD. In allo-HSCT, the preparative regimen and prophylactic
antibiotics may cause significant changes to the gut microbiota and the gut. The resulting dysbiosis and
gut injury has been linked to the occurrence of GVHD and other major complications. This highlights
the possible function of the microbiota as a biomarker and microbiota modulation as an interventional
strategy. Microbiota modulation strategies can be prophylactic and therapeutic with the goal to
prevent or treat dysbiosis, respectively. Prophylactic strategies include enteral nutrition, anaerobicsparing antibiotics, prebiotics, probiotics, postbiotics, and faecal microbiota transplantation (FMT).
Therapeutic strategies include FMT and lactoferrin. In this review, we outline our current
understanding of how microbiota can be used as a biomarker and microbiota modulation can be used
as a prophylactic or therapeutic strategy to improve GVHD outcomes following allo-HSCT.