Table 1.
Diet composition.
Table 2.
Disease activity index1.
Figure 1.
Changes in DAI score and colon weight per length.
(A) DAI was calculated by the sum of three clinical scores (stool consistency, rectal bleeding, and weight loss) during the DSS treatment period. Significant differences comparing scores to values on day 0 (before DSS treatment) were determined by Dunnett’s multiple comparison test (**P<0.01, ***P<0.001). (B) Colon weight per length with or without DSS treatment. Two-way ANOVA P values for the colon weight per length (diet and treatment) were 0.0047 for diet, <0.0001 for treatment, and 0.0053 for the interaction between diet and treatment. No significant difference was observed for strain. Significant differences between the untreated group and the 2% DSS-treated group were determined by an unpaired two-tailed Student’s t-test (**P<0.01, ***P<0.001). Values are expressed as means ± SEM (n = 5–7).
Figure 2.
MPO activity and histological appearance.
(A) MPO activity in the distal colon on day 7. Significant differences in activity between rats with or without DSS treatment were determined by an unpaired two-tailed Student’s t-test (*P<0.05, **P<0.01). Two-way ANOVA P values for MPO activity (diet and treatment) were <0.0001 for treatment. No significant difference was observed for treatment and the interaction between diet and treatment. Values are expressed as means ± SEM (n = 5–7). (B) Hematoxylin and eosin staining in a distal colonic section fixed with formalin. The scale bar represents 500 µm.
Figure 3.
Inflammatory cytokine expression in distal colonic mucosa.
The mRNA expression of IL-1β (A) and IFN-γ (B) was evaluated in the distal colon of rats with or without DSS treatment using a TaqMan gene expression assay. GAPDH was used as the internal control. Significant differences between rats with or without DSS treatment were determined by a median test (*P<0.05). Two-way ANOVA P values for IL-1β (A) and IFN-γ mRNA expression (diet and treatment) were 0.0042 and 0.0087 for treatment, respectively. No significant difference was observed for treatment and the interaction between diet and treatment. Values are expressed as means ± SEM (n = 6).
Table 3.
Cecal content weight, pH of cecal contents, and total SCFAs in cecal content of rats fed the control, S-IMO, L-IMO, or Dex diet.
Figure 4.
Concentrations of organic acids in cecal content.
Organic acids (succinic, lactic, acetic, propionic, iso-butyric, n-butyric, iso-valeric and n-valeric acids) were measured via HPLC in the homogenates of cecal contents of (A) untreated or (B) DSS-treated rats. Significant differences in each organic acid were determined by Dunnett’s multiple comparison test (**P<0.01, ***P<0.001). Values are expressed as means ± SEM (n = 6).
Figure 5.
Concentrations of GLP-1 and GLP-2 in ileal and colonic mucosa.
Active GLP-1 concentrations in the mucosa of (A) the terminal ileum and (B) the proximal colon were measured using a GLP-1 ELISA kit. Total GLP-2 concentrations in the mucosa of (C) the terminal ileum and (D) the proximal colon of rats treated with DSS were measured using a GLP-2 ELISA kit. Significant differences were determined by Dunnett’s multiple comparison test (*P<0.05, **P<0.01). Values are expressed as means ± SEM (n = 5–6).
Figure 6.
(A) Representative dot plots of phenotypes in PBL expressing CD8α and CD161 molecules in rats fed the control diet. (B) The percentage of CD8+ CD161−, CD8−CD161+, and CD8+CD161+ cells in the CD45+ cell populations. Significant differences between rats with or without DSS treatment were determined by an unpaired two-tailed Student’s t-test (*P<0.05, ***P<0.001). Values are expressed as means ± SEM (n = 3–5).