Bile, informally known as stomach acid, chemically breaks down food early on in the digestive process.
Explanation:
Chewing is the first step in the process of digestion (assuming we are talking about humans and other animals with a similar digestive system) where the food is mechanically/physically broken down.
At the same time, saliva breaks down the food chemically (hence why leaving a simple carb such as bread in your mouth causes it to dissolve over time)
Once you swallow, muscles in the esophagus push the broken-down food to the stomach, where more chemical digestion takes place as a result of bile.
