Prebiotics decrease the cumulative incidence of aGVHD. (A) The cumulative incidence of all grades of aGVHD was significantly lower in the prebiotics group than in the historical control group. (B) The cumulative incidence of grades 2 to 4 aGVHD was significantly lower in the prebiotics group than in the historical control group. (C) The cumulative incidence of grades 3 and 4 aGVHD tended to be lower in the prebiotics group than in the historical control group although the difference was not significant. (D-E) The cumulative incidence of all-stage skin aGVHD, and stage 3 and higher aGVHD was significantly lower in the prebiotics group than in the historical control group. (F-G) The cumulative incidence of the gut and lower gut aGVHD tended to be lower in the prebiotics group than in the historical control group, although the difference was not significant. (H) The cumulative incidence of the liver aGVHD did not differ between the prebiotics and historical control groups.