The role of the acid in our stomach is to mainly dissolve the large chunks of food and create an acidic medium to activate various digestive enzymes.

In the acidic medium, the enzyme pepsinogen is activated and then converted to pepsin, which is a protein-digesting enzyme that helps in the digestion of proteins and can also kill the bacteria present in the stomach that enters along with food.

The enzyme pepsin requires HCl to get activated in the presence of HCl. The acid will break down the food more easily and helps in absorbing nutrients and easy digestion of food.