What are four ways bacteria can be helpful to humans?

Though some bacterias cause disease and illness in humans, the majority are harmless. Some bacterias are used to aid digestion, used in preparation of certain foods, used to battle infections or used by industry.

Bacteria in the intestinal tract helps the body to digest food. The production of several foods, such as cheeses, sausage and sauerkraut, depend upon bacteria or fermenting bacteria in order to reach their finished states. Harmless bacteria is used to treat some bacterial infections in the human body by interfering with the colonization of the harmful bacteria. Hydrocarbon-oxidizing bacterias aid in the decomposition of petroleum, and they are used by industry when cleaning oil spills.