Some bacteria cause diseases, including food poisoning, meningitis and scarlet fever. Inside the body, these bacteria reproduce quickly. They produce poisons that make you feel ill.
Among the people that need to know about bacteria are chefs. Anyone who cooks needs to know how to prevent bacteria spreading in their kitchens, to ensure all the food they produce is safe to eat.
Not all bacteria are harmful. For example, yoghurt and cheese makers use bacteria to make their products. Bacteria like intestinal flora can be helpful to our bodies whereas E.coli can be harmful and cause disease.
More importantly, there are millions of bacteria in your digestive system. Having the right mix of bacteria here is vital. Gut bacteria help to digest food. They also help to prevent diabetes, obesity, and some types of cancer.