In the area of medicine, bacteria are important in both positive and negative ways. When things are balanced, bacteria live in and on humans without causing illness, and in fact contribute to the health of humans. However, on occasion, bacteria can cause serious illnesses in humans. In this case, bacteria contribute to our economy in a very big way, doctors, hospitals, drug companies, insurance companies, and so on. All of these are big business! (We'll talk about all this in a future activity.)
Bacteria can be altered genetically to produce important substances in the treatment of various illnesses. They can be used to: