Fig. 5

IPA preserves irradiation-shifted enteric bacterial composition at day 12 after TAI. a, b The observed species number and Chao1 diversity index of intestinal bacteria was examined by 16S rRNA high-throughput sequencing after 12 days of TAI exposure. Significant differences are indicated: Wilcoxon rank sum test. n = 6 per group. c, d PCoA and NMDS were used to measure the shift in intestinal bacterial composition profile after irradiation at day 12. e The β diversity of intestinal bacteria was compared by the weighted unifrac analysis. Significant differences are indicated: Wilcoxon rank sum test. n = 6 per group. f The alteration of intestinal bacterial patterns at the genus level was assessed by 16S rRNA sequencing, n = 6 per group. The heat map is color-based on row Z-scores. The mice with the highest and lowest bacterial level are in red and blue, respectively. g The abundances of most varied strain bacteria was assessed using 16S high-throughput sequencing after irradiation at day 12. Statistically significant differences are indicated: Wilcoxon rank sum test, n = 6 per group. h Linear discriminant analysis (LDA) effect size (LEfSe) results represented significantly different in abundance of gut bacteria between TAI and IPA groups and indicated the effect size of each differentially abundant bacterial taxon in the small intestine after irradiation at day 12, n = 6 per group. Significant differences are indicated: Wilcoxon rank sum test. i The content of IPA in fecal was examined by ELISA. Mean ± SEM. Significant differences between each two cohorts are indicated: *P < 0.05 and ***P < 0.005; Student’s t test, n = 8 per group. j, k Photographs (j) and length (k) of dissected colon from IPA gavage mice with or without antibiotics (ABX) treatment, the colon tissues were obtained at day 21 after 12 Gy TAI. Mean ± SEM. Significant differences are indicated: Student’s t test, n = 6 per group. l The morphology of the small intestine was shown by H&E (× 100 magnification; scale bar: 100 μm) and PAS (× 1000 magnification; scale bar: 50 μm) staining. The small intestine tissues were obtained at day 21 after 12 Gy TAI. The arrows point to the goblet cells