The executive branch is responsible for implementing the laws that are created by the legislative branch (the Senate and House of Representatives). The head of the executive branch is the President of the United States. His role includes acting as the Commander-in-Chief of the Armed Forces.
There are many kinds of bacteria, some which cause deadly diseases and some which are helpful to man. Those which are harmful cause diseases in man, animals, and plants. They can cause food to spoil, even poisoning people who eat them. But there are a great many bacteria that man and nature use in helpful ways. For example, bacteria play an important role in making buttermilk, sauerkraut, cheese, and vinegar by causing a chemical change called fermentation. Bacteria also attack dead plants and animals, and break them down into nourishment for the soil. Bacteria are even used to purify water in sewer treatment plants!
The idea that bacteria are beneficial can be tough to understand. We take antibiotics to kill harmful bacterial infections and use antibacterial soaps and lotions more than ever. The wrong bacteria in the wrong place can cause problems, but the right bacteria in the right place can have benefits. This is where probiotics come in. Probiotics are live microorganisms that may be able to help prevent and treat some illnesses.