Figure 1.

Inulin fiber diet activates ILC2^INFLAM and exacerbates intestinal damage and inflammation. (A) Heatmap showing differential gene expression of colonic ILC2s in mice fed the control or inulin fiber diet for 2 wk (n = 2 mice). (B) Frequency of IL-5–expressing, IL-13–expressing, or AREG-expressing KLRG1⁺ ILC2s in colonic lamina propria, determined by intracellular cytokine staining (n = 3 mice). Flow cytometry plots were gated from CD45⁺Lin⁻CD90.2⁺CD127⁺ cells. (C) Representative flow cytometry plots and frequency of CD11b⁺SiglecF⁺ eosinophils in the CD45⁺ population (n = 4 mice). (D) Representative immunofluorescence staining showing Siglec-F⁺ eosinophils in the colons. Scale bar = 50 μm. (E and F) Disease and recovery of DSS-treated control diet– and inulin fiber diet–fed mice were monitored by daily weight loss (E) and DAI (F). Mice were fed control or inulin fiber diet from 2 wk prior to the DSS challenge to the endpoint of the experiment (n = 5 mice). (G) Representative H&E staining of distal colons at the endpoint of the DSS experiment. Scale bar = 500 μm. Graph shows histological scores (n = 3–5 mice). (H) Representative flow cytometry plots and frequency of CD11b⁺SiglecF⁺ eosinophils in the CD45⁺ population (n = 3–5 mice). (I) Frequency of IL-5–expressing, IL-13–expressing, or AREG-expressing KLRG1⁺ ILC2s in colonic lamina propria, determined by intracellular cytokine staining (n = 4 mice). Data are representative of three (C and E–G) or two (B, D, H, and I) independent experiments. Data are means ± SEM. Statistics were calculated by unpaired two-tailed t test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, ns, not significant.