Fig. 4

Epithelial proliferation induced by inulin diet is dependent on gut microbiota. A 16S rRNA gene sequencing of the C57BL/6 colon microbiota showing changes in beta diversity on inulin diet group. Expressed by UniFrac PCoA analysis (n = 6). PERMANOVA test (R² = 0.1879, p = 0.012). B Heatmap of relative abundance taxa of bacteria in the different diets (n = 6), scale in log10. C Experimental model scheme with germ-free mice and two dietary groups. D Quantification of colon length normalized by mice weight (n = 6–7). Data pooled from 2 independent experiments. E Quantification of colon crypt depth (left) and number of EdU-positive cells per crypt (right) in germ-free mice (n = 4–7), the latter analyzed by Mann–Whitney test. Data pooled from 2 independent experiments. F Quantification of the levels of SCFAs in the colon fecal luminal content assessed by GC–MS (n = 5–10). Data pooled from 2 independent experiments. Results analyzed by two-way ANOVA. In all graphs, each point represents an individual animal. Unless otherwise stated, results were analyzed by Student’s t-test. *p < 0.05, **p < 0.01, ****p < 0.0001, and ns = not significant