Gastric acid helps digest food we eat, control propagation of viruses. The body secretes 0.5 liter of it, which is the size of 500ml bottle for every meal. When you’re hungry, its acidity becomes very strong that it can even melt metals!!!

But if the acid could melt metals, how does the stomach membrane remain unhurt? It’s because when the acid is secreted, simultaneously it secretes viscous liquid to make a protection of the surface. The viscous liquid is alkalinity, which neutralize the acid!

Makes sense!