Xylose versus Bacteroides in graft-versus-host.

In a recent Cell paper, Hayase et al. define a mechanistic link between a carbapenem antibiotic and graft-versus-host disease (GVHD) following hematopoietic cell transplantation. Bacteroidesthetaiotaomicron was observed to induce degradation of colonic mucus, an effect that was reversed by treatment with xylose, which served as a prebiotic to reduce mortality.