Effects of early dietary intervention with a fermentable fibre on colonic microbiota activity and mucin gene expression in newly weaned rats

Colonic microbiota composition and metabolic processes were investigated after modifying the diet immediately post-weaning in rats. Three-week old Sprague–Dawley rats were fed cellulose or inulin diet for 0 day (d), 7 d or 14 d. Real-time PCR quantification showed significantly higher colonic Bifidobacterium spp. in rats fed inulin on d7 and d14. Inulin was effective in increasing the total bacteria, Bacteroides-Prevotella-Porphyromonas group and Faecalibacterium prausnitzii, while decreasing Lactobacillus spp. Higher concentrations of short-chain fatty acids (SCFAs: acetic, butyric and propionic acids), lactic acid and succinic acid were observed in inulin-fed rats. Inulin ingestion altered colonic mucin (MUC)-3 gene expression, and increased the colon crypt depth with more goblet cells per crypt. Significant positive correlations between SCFAs concentrations and MUC3 expression were observed. Dietary supplementation with inulin altered microbiota composition, and their fermentation end-products may have aided in modifying mucin gene expression and morphology in the colon of young rats.

► Inulin was susceptible to colonic microbial fermentation in young rats.
► Proliferation of colonic Bifidobacterium spp. occurred 7 and 14 days after inulin consumption.
► SCFAs concentrations and MUC3 gene expression were positively correlated.