Have you ever had a tooth ache or strep throat? Bacteria have a bad reputation because they usually make us sick. Can they ever help us?

"They are as unrelated to human beings as living things can be, but bacteria are essential to human life and life on planet Earth. Although they are notorious for their role in causing human diseases, from tooth decay to the Black Plague, there are beneficial species that are essential to good health" (Davidson 2007).

[Davidson, Michael. "Bacteria Cell Structure." Molecular Expressions: Cell Biology and Microscopy--Structure and Function of Cells and Viruses. Florida State University, 2007. <http://micro.magnet.fsu.edu/cells/bacteriacell.html>.]