Is there dna in your food? how do you know?

YES,THERE IS DNA IN OUR FOODS.
All living organisms both plants and animals have DNA in their nucleus. Humans eat both plants and animals materials in their food, thus, the foods eaten by humans have DNA in their cells. DNA is a thread like structure that is made up of nucleic acid and is found in all living cells. It is the basis of inheritance in both plants and animals. During cell division, the DNA replicate in order to pass inheritable traits to the newly formed cells.

To kill bacteria from our body especially from stomach

He used pea plants to study the patterns of heredity.