a–d, Dietary emulsifiers did not affect mucus and mucus-related genes expression in wild-type mice. Wild-type (WT) mice were exposed to drinking water containing CMC or P80 (1.0%) for 12 weeks. a–c, mRNA expression analysis by qRT–PCR of Muc2 (a), Tff3 (b) and Klf4 (c) genes in the colonic mucosa. Points are from individual mice, bar represent the mean ± s.e.m., (n = 9). d, Colons were stained using periodic acid–Schiff stains. Scale bar, 200 μm. Pictures are representative of 10 biological replicates. e–j, Dietary emulsifiers alter microbiota localization, composition and pro-inflammatory potential in Tlr5^−/− mice. Tlr5^−/− mice were exposed to drinking water containing CMC or P80 (1.0%) for 12 weeks. e–g, Confocal microscopy analysis of microbiota localization: MUC2, green; actin, purple; bacteria, red; and DNA, blue. Scale bar, 20 μm. Pictures are representative of five biological replicates. h, Distances of closest bacteria to intestinal epithelial cells (IEC) per condition over five high-powered fields per mouse. i, j, PCR-based quantification of total bacterial load (i) and bacterial load adhered to colonic mucosa (j). Data are the means ± s.e.m., n = 5. Significance was determined using one-way ANOVA corrected for multiple comparisons with a Sidak test; P < 0.05 compared to water-treated group. k, l, Dietary emulsifiers do not modify total bacterial load in wild-type and Il10^−/− mice. Wild-type and Il10^−/− mice were exposed to drinking water containing CMC or P80 (1.0%) for 12 weeks. Total bacterial load in stool of wild-type (k) and Il10^−/− (l) mice. Points are from individual mice. Data are geometric means with 95% confidence interval (n = 5 for k except n = 4 for CMC- and P80-treated groups; for l, n = 8, 4 and 6 for water-, CMC- and P80-treated groups, respectively).