Golob JL, et al. - In view of the risk for death from graft-versus-host disease (GVHD) in association with low bacterial diversity in the stool microbiota early after transplant, researchers here sought for the specific species associated with GVHD risk. In this study, it was observed that the stool microbiota around the time of neutrophil recovery post-hematopoietic cell transplantation was predictive of subsequent development of severe acute GVHD.