Pig bile powder maintains blood glucose homeostasis by promoting glucagon-like peptide-1 secretion via inhibiting farnesoid X receptor

Figure 5 Long-term feeding of bile powder prevented blood glucose disorders. A: Schematic diagram. Mice were randomly divided into two groups (n = 5 per group). All of the mice were fed a high-fat diet (HFD) for 6 weeks and were injected with streptozotocin (STZ) (50 mg/kg, intravenous) to induce blood glucose disorder. An HFD was continued for an additional 6 weeks. Mice in the bile powder group were treated with bile powder (75 mg/kg/day, intragastric gavage) for 12 weeks, and those in the HFD + STZ group were treated with the vehicle; B: Oral glucose tolerance test after 12 weeks of treatment; C: The area under the curve of the oral glucose tolerance test after 12 weeks of treatment; D: Insulin tolerance test after 12 weeks; E: The area under the curve of the insulin tolerance test after 12 weeks of treatment; F: Serum glucagon-like peptide-1 levels; G: Relative expression of farnesoid X receptor and fibroblast growth factor 15 gene expression in the ileum. Data are shown as mean ± SEM. P < 0.05. ns: Not significant (P > 0.05) compared between groups. Statistical analysis was performed using the Student’s t-test. HFD: High-fat diet; STZ: Streptozotocin; BP: Bile powder; OGTT: Oral glucose tolerance test; ITT: Insulin tolerance test; AUC: Area under the curve; GLP-1: Glucagon-like peptide-1; RT-PCR: Real-time polymerase chain reaction.