The curative effects of simvastatin and HFD mitigating radiation toxicity base on gut microbiota composition pattern. FMT was performed to male (or female) mice using fecal pellets from female (or male) mice for 14 d. Before 7 Gy TBI exposure, the fecal pellets of recipients were collected and assessed measured by 16S rRNA high‐throughput sequencing. A,B) The observed species number A) and Chao1 diversity index B) of enteric bacteria in male recipients was measured. Significant differences are indicated: Wilcoxon rank sum test. n = 5 per group. C,D) The observed species number C) and Chao1 diversity index D) of enteric bacteria in female recipients was measured. Significant differences are indicated: Wilcoxon rank sum test. n = 5 per group. E,G) PCoA were used to examined the alteration of intestinal bacteria taxonomic pattern from male E) and female G) recipients. n = 5 per group. F,H) The β diversity of enteric bacteria was compared by weighted unifrac analysis. Significant differences are indicated: Wilcoxon rank sum test. n = 5 per group. I,J) Kaplan–Meier analysis I) and body weight measurement J) of male recipients after 7 Gy TBI, n = 18 per group; *P < 0.05, **P < 0.01 by Student's t‐test between simvastatin‐treated group and control. K,L) Kaplan–Meier analysis K) and body weight measurement L) of female recipients after 7 Gy TBI, n = 18 per group.