Soluble Dextrin Fibers Alter the Intestinal Microbiota and Reduce Proinflammatory Cytokine Secretion in Male IL-10-Deficient Mice

Background: Prebiotic fibers stimulate the growth and activity of the gut microbiota. Interleukin 10-deficient (IL-10(-/-)) mice develop a colitis that is influenced by the gut microbial composition.

Objective: The purpose of this study was to determine the effect of prebiotic fibers on the intestinal microbiota and immune function in IL-10(-/-) mice.

Methods: At 4 wk of age, male IL-10(-/-) mice (n = 8/group) were randomly assigned to 5 diets: unpurified diet with cellulose (4%; control), corn-derived hydroxypropylated new resistant starch (NRS) (2% NRS + 2% cellulose), soluble fiber dextrin from tapioca (SFD-t) (4%), soluble fiber dextrin from corn (SFD-c) (4%), or soluble corn fiber (4%) for 12 wk. Growth, small intestinal permeability, histologic injury, intestinal cytokine secretion, and microbiota composition by 16S ribosomal RNA pyrosequencing of stool were measured. ANOVA and principal component analysis were applied to assess the fibers' effects.

Results: There were no significant differences in mouse growth, intestinal weight, length, or gut permeability over the 12 wk feeding period. Mice fed dextrin-based diets secreted 47-88% less colonic IL-1β, tumor necrosis factor α, and IL-23 (SFD-t diet) and IL-12 heterodimer p70, IL-6, and chemokine ligand 1 (CXCL1) (SFD-c diet) (P < 0.05) than did the control group, whereas NRS-fed mice secreted 55-77% less IL-6 and CXCL1 (P < 0.05). Both SFD-t- and SFD-c-fed mice had a 70-75% lower abundance of Lactobacillaceae than control mice. The SFD-t diet group had a lower enterocyte injury score (P < 0.04) than did control mice, and this was associated with increased abundance of butyrate producers, including Incertae sedis XIV, Lachnospiraceae, and Ruminococcaceae (P < 0.001).

Conclusions: These results demonstrate that soluble prebiotic fibers selectively stimulate the growth of a distinctive gut microbiota in IL-10(-/-) mice. SFD-t induced the growth of butyrate-producing microbes and was effective in reducing proinflammatory cytokine secretion and enterocyte injury in this mouse model of colitis.