Stomach acid plays a major role in regulating the immune system as it is critical in killing toxic parasites and bacteria that come along with food, thereby maintaining the gut health which would otherwise lead to bloating, diarrhoea etc. The acid is known to activate the pepsin enzyme which is required for the digestion of protein. This acid is regarded to signal the pancreas to synthesize the digestive enzymes and juices to disintegrate it furthermore.
The hydrochloric acid found in the stomach facilitates the process of digestion by disintegrating complex large food molecules to simpler molecules. The acid activates the pepsinogen enzyme required to digest proteins. When there is no hydrochloric acid in the stomach, the iron absorption process is hindered as iron is essential in the solution for absorption. The stomach is prompted to produce acid when food is consumed for the production of the gastrin hormone. Hence, the acid lowers the pH level in the stomach, switching off the gastrin production which otherwise would lead to hypergastrinemia.