Figure 1. Evaluation of the animal model. (A) Body weight following an injection of STZ in the control and treatment groups. (B) Glucose tolerance test results in the two groups at 18 w. (C) Fasting serum insulin level in the two groups at 18 w. (D) Serum VF levels in the two groups at 18 w. (E) Immunohistochemical staining of VF in the colon muscle layers in the two groups at 8 w. Left panel: Representative image; right panel: Quantitative analysis. Low magnification, 200×, scale bar = 100 μm; high magnification, 400×, scale bar = 50 μm. *P < 0.05, **P < 0.01, ***P < 0.001, control group n = 10, T2DM group n = 8.