Bile salts emulsify fats by coating them so that they do not group together and exit the body as waste. This makes it easier for the small intestine to digest and absorb fats.
Fat is difficult for the body to digest in its natural form. Fat is water repellent, whereas the enzyme responsible for fat digestion, lipase, is water soluble. Because it is water soluble, it cannot access the insides of fat particles to digest them.
Emulsification is the body's process of breaking down fats into smaller parts and making them easier to digest. Bile salts play a crucial role in this process. The liver uses cholesterol to produce bile salts, which are further regulated by bacterial flora in the liver. They are responsible for helping the body break down and absorb fats and fat-soluble nutrients.
When fat moves through the small intestine, it breaks up into small droplets. This is an important part of the emulsification process, but it cannot help process fats on its own. Fat droplets tend to regroup once the fat is broken up, which makes it difficult for lipase to process it. Bile salts work with another type of bile molecule called phospholipids to coat the droplets so that they do not regroup. The lipase can then digest the fat.