Fig. 4

Fecal microbial transplantation reproduces fiber sensitivity status and drives individualized colitis susceptibility. A–F Upon arrival, germ-free WT mice undergo fecal microbial transplantation with fecal suspension from donor 1 (fibers-resistant) or donor 2 (fibers-sensitive) (N = 15 mice per donor). After 7 days of microbiota stabilization, mice were subsequently divided into three experimental groups and exposed to either cellulose- (grey), inulin- (purple), or psyllium- (green) supplemented diets for 25 days (N = 5 mice per experimental group). On day 19 and for 6 days, Dextran sulfate sodium was added to the drinking water (2.5% w/v) to induce intestinal inflammation. A Following euthanasia, colon lengths were measured. B, C Colonic sections were subjected to hematoxylin and eosin staining, and histological scoring of inflammation was performed (B). Representative images are presented in C. Bar = 100 μm. D, E Colonic sections were stained for CD68 monocyte marker, and 15 crypts were randomly selected per animal in order to determine the number of CD68 + cells per crypt (D). Representative images are presented in E. Bar = 400 μm. F Colonic mRNAs were extracted, and q-RT-PCR was used to evaluate the TNF-α pro-inflammatory cytokine expression level reported. Data are presented as relative values compared to the cellulose-treated group, defined as 1. Data are the means ± S.E.M, with individual data points being represented (N = 3). Significance was determined using a one-way ANOVA followed by Tukey’s multiple comparison test and significant differences were recorded as follows: *p < 0.05, ***p < 0.001, and ****p < 0.0001