Altered glucose and insulin tolerance by supplementing the diet with green tea. (A) Plasma glucose and (B) insulin concentrations in an oral glucose tolerance test performed at week 8. Mean values and SEM for 11 mice in each group. (C) Plasma glucose expressed as % of basal after an intraperitoneal injection of insulin at week 15. Mean values and SEM for 9–11 mice in each group. No differences were detected between any of the four groups. The areas under the curves (AUC) are shown in the insets (D) HOMA-IR index at week 22. The index was calculated by multiplying fasting glucose (mM) and fasting insulin (μU/ml) divided by 22.5. Ctrl = high fat control diet (HFD), Lp = HFD + L. plantarum in the drinking water, GT = HFD supplemented with 4% green tea powder, Lp + GT = HFD supplemented with 4% green tea powder and L. plantarum in the drinking water. Data are means ± SEM for 9–11 mice/group. *p < 0.05, **p < 0.01, ***p < 0.001.