Question

What kills bacteria in our food in the mouth and stomach ?

Answer 1

Hint: The bacteria present and taken in by food are killed by the acidic pH of the oral cavity (mouth) and stomach. Saliva is a transparent liquid produced by a number of glands in the mouth. Saliva is an essential component of good health. Water makes up the majority of it. Saliva, on the other hand, contains critical nutrients that your body requires to digest food and maintain your teeth healthy.

Complete answer:
Saliva forms a thin layer on teeth that protects them from infection, while antimicrobial chemicals in saliva kill disease-causing bacteria. Saliva washes away little particles of food that feed the germs that cause tooth decay as it flows around the mouth.
In our mouth, the enzyme lysozyme destroys germs in food, and in the stomach, HCl (hydrochloric acid) from gastric juice kills bacteria. Your stomach stores food for a limited amount of time. This enables you to eat a huge meal quickly and digest it over a long period of time. When your stomach is full, it can store about one litre of chewed food. Food that has been swallowed is driven down your throat and into your stomach.
Sphincters are two circular muscles that keep food contained in your stomach. As soon as food enters your stomach, your stomach lining releases enzymes that start breaking down proteins in the food. Your stomach lining also secretes hydrochloric acid, this provides the optimal environment for protein-digesting enzymes to function.
Hydrochloric acid is a powerful bacteria-killer that protects your body from dangerous microorganisms that can enter your body through food. By secreting sticky, neutralising mucus that clings to the stomach walls, your stomach protects itself from being digested by its own enzymes or burned by the corrosive hydrochloric acid.

Note:
Saliva contains a variety of electrolytes and organic compounds that help to keep local pH levels stable, promoting remineralization. Saliva contains buffers and neutralising agents, such as sodium bicarbonate and phosphates, as well as other salivary components. Furthermore, a salivary protein known as sialin has the ability to elevate salivary pH to neutral values.