Every living thing eats bacteria. It is found on and in plants and animals; therefore, any animal that eats plants or animals is eating bacteria. From single-cell organisms such as paramecium and all the way up the food chain to human beings, living things eat bacteria.
Bacteria is eaten by many types of shellfish, worms and mammals. There are literally millions of animals that eat bacteria as a regular part of their diet. Bacteria is found in common foods that people eat, such as yogurt and cheese. Bacteria is vital to the function of many species' digestive systems, as it helps break down foods such as plants.