How Antibiotics Work…
There are 17 different classes of antibiotics; however, each class works in a similar manner. Every antibiotic is either a general ("broad-spectrum") or specific ("focused") antibiotic. A broad-spectrum antibiotic is designed to eliminate a variety of similar bacteria. A focused antibiotic targets only one or two specific bacteria. If you did not receive a test prior to your being prescribed an antibiotic, you would've been prescribed a broad-spectrum antibiotic; nearly all prescribed antibiotics are broad-spectrum.
Notice that antibiotics target BACTERIA. Bacteria are cells in themselves. Our body is made up of many cells. Cells are individual units within the body that are separated from other cells by a shell, as it were. The shells of bacteria are different from the shells of the cells in our body. Therefore, your immune system can seek out and identify what is not part of the body.
An antibiotic can do the same thing. When a person takes an antibiotic, it looks for the shells that have a certain identifier; it then destroys those cells by, in essence, cutting a hole in the bacteria's shell. The cell dies, hence the bacteria dies.
Unfortunately, broad-spectrum antibiotics do not know the difference between good bacteria and those causing an infection. Our bodies contain bacteria that are necessary for food digestion, vitamin and mineral absorption, and mucous membrane nourishing. When an antibiotic is working, it will destroy these bacteria as well.