Visual abstract| Pooled allogeneic faecal microbiota therapy for steroid resistant GI-aGvHD

Severe gastrointestinal acute graft versus host disease (GI-aGvHD) is a serious complication that can occur after allogeneic hematopoietic cell transplantation (allo-HCT). Gut dysbiosis and a loss of bacterial diversity in the intestinal microbiome post-transplantation is thought to be an important factor in the development of the condition.

Fecal microbiota transplant is currently under investigation for the treatment of GI-aGvHD, with several pilot studies highlighting encouraging data. While the issue of donor sourcing remains a problem for fecal microbiota transplantation, one potential solution has been the development of a standardized fecal microbiota transplant product, MaaT013. This new form of microbiota therapy has previously been reported on the GvHD Hub.

Recently, Malard et al. performed the multicenter, single arm phase II HERACLES study (NCT03359980) investigating the safety and efficacy of MaaT013 in patients diagnosed with steroid-refractory GI-aGvHD. Here, we summarize the key results.