Allo B6 were co-housed with B6 at ratio of Allo B6: B6 = 1:1 from day 14 after BMT (A). Data are from three independent experiments. (B-F) Stool from Allo B6 co-housed with B6 for 2weeks, B6 co-housed with Allo B6 for 2weeks, Allo B6 not co-housed, and B6 were analyzed by 16S rRNA gene sequencing. (B) Inverse Simpson alpha diversity index were shown. (Allo B6 not co-housed: N=6, Allo B6 co-housed with B6: N=4, B6 co-housed with Allo B6: N=5, B6: N=4). (C) PCoA were shown (Allo B6 not co-housed: N=9, Allo B6 co-housed with B6: N=6, B6 co-housed with Allo B6: N=5, B6: N=7). Microbiome composition (D) and taxa differentially abundant by LEfSe analysis (E & F) are shown. Survival rate (G), body weight change (H), and clinical GVHD score (I) of BMT recipients were shown. (Allo B6 were co-housed with B6: N=18, Allo B6 not co-housed: N=6). The horizontal line in box (B) represents the median with the box bounding the interquartile range. The ends of the whisker lines represent the minimum and maximum values. One-way ANOVA analysis with Tukey post hoc test (B), log-rank test (G), and two-tailed Mann-Whitney test (I) was used to determine (mean ± s.e.m.). *P < 0.05.