What is the role of hydrochloric acid in the human body?

Acids play a very important role in the human body as well. The stomach produces hydrochloric acid ($\mathrm{HCl}$) which is useful for the digestion of food. During indigestion, too much aid is produced which causes pain in the stomach and is often termed acidity.

Hence, the major role of hydrochloric acid is the digestion of food in the human body.