How do hydrochloric acids and bile salts help digest food?

hydrochloric acids (found in the stomach) helps to denature the protein due to the low pH of hydrochloric acid. When the proteins are denatures, the molecule falls apart, thus it is digested. Bile salts emulsify the food. Emulsify is the same thing as breaking it down, but scientist use the word "emulsify" specifically to refer to the breakdown by bile salts.