Cyp7a1-tg mice showed improved insulin sensitivity and glucose homeostasis. Female mice were fed either a chow or Western diet for 4 months. (A) Fasting serum glucose and (B) fasting serum insulin were determined. (C) GTT. (D) ITT. (E,F) Hepatic mRNA expression in mice fasted overnight. Results are expressed as means and standard errors (n =6–12). *Statistical significance (P < 0.05) versus WT mice on a chow diet; **statistically significant difference (P < 0.05) versus HFD-fed WT mice. Abbreviations: GTT, glucose tolerance test; ITT, insulin tolerance test; Tg, transgenic; WT, wild-type.