How is cholesterol soluble in human bile?

Cholesterol is not directly soluble in human bile. Instead, it is solubilized by bile salts. Bile salts are amphipathic molecules, meaning that they have both hydrophilic (water-loving) and hydrophobic (water-hating) regions. The hydrophobic regions of bile salts interact with the hydrophobic cholesterol molecules, while the hydrophilic regions interact with the water molecules in bile. This forms a micelle, which is a spherical aggregate of cholesterol molecules surrounded by bile salts. Micelles allow cholesterol to be transported in the aqueous environment of bile.