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

Figure 1 Bile powder improved blood glucose in a diabetic mouse model. A: Schematic diagram. 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. Mice continued a HFD for an additional 6 weeks. The mice were randomly divided into four groups (n = 5 per group) and treated with different doses of bile powder (BP): The HFD + STZ group (control group); The low-dose BP group (25 mg/kg/day, intragastric gavage); The medium-dose BP group (50 mg/kg/day, intragastric gavage); The high-dose BP group (75 mg/kg/day, intragastric gavage). The oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were performed after 30 days and 45 days of BP administration; B: OGTT after 30 days of BP treatment; C: Area under the curve (AUC) of the OGTT after 30 days of BP treatment; D: OGTT after 45 days of BP treatment; E: AUC of the OGTT after 45 days of BP treatment; F: ITT after 45 days of BP treatment; G: AUC of the ITT after 45 days of BP treatment; H: Serum glucagon-like peptide-1 levels in the HFD + STZ group and the high-dose BP group after 45 days of treatment. Data are shown as mean ± SEM. ns: Not significant (P > 0.05) compared between groups. Statistical analysis was performed using the Student’s t-test. ^aP < 0.05. ¹High-fat diet + streptozotocin vs low-dose bile powder. ²High-fat diet + streptozotocin vs medium-dose bile powder. ³High-fat diet + streptozotocin vs high-dose bile powder. 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.