Antibiotic,antiseptic etc..
stomach acid
Cooler temperatures help preserve foods, higher temperatures kill the bacteria and prepare the foods so they can be eaten.
In some cases, with vegetables and fruits, it isn't always necessary to cook the food, as many of them can be eaten raw. Meats should be cooked to kill any bacteria and help prevent food borne illness.
Food is cooked to kill bacteria as it is canned; the cans then keep out any new bacteria.
Boil it.
Its to kill any germs or bacteria found in raw foods. Of course, some foods dont have those bacteria, so they can be eaten raw.
Normally fruit essence is a food for bacteria. Acidic fruit, such as citrus, or vinegars, can kill some bacteria.
Some foods do not need to be cooked fully, for example, tomatoes can be eaten raw or cooked - or anywhere in between. Other food, such as chicken, must be cooked completely to kill any bacteria in the flesh. The bacteria can cause food poisoning, salmonella or even e-coli.
Dettol
Bacteria in our digestive tract help break down food so that we can assimilate it. Bacteria in the soil help break down soil nutrients so that plants can assimilate it. Bacteria in milk help turn milk into cheese. (That's all I've got right now.)
they help kill bad bacteria in your body
Well there are lots of helpful, symbiotic bacteria in your saliva that help kill lots of harmful bacteria and viruses; so in a way, yes.
It creates an acidic environment which many bacteria cannot tolerate.