CYP8B1 and diabetes mellitus: These changes were associated with a relative deficiency of 12α-hydroxylated bile salts and in expression of Cyp8b1. In diabetes, the impaired insulin response led to dysfunctional Foxo1, which drives bile salt synthesis towards 12α-hydroxylated bile salts, leading to an abnormally hydrophilic bile salt pool affecting cholesterol and triglyceride metabolism.