Back to bacteria. In the last column, we talked about “germs,” a.k.a. pathogenic (disease-causing) bacteria. But all bugs aren’t bad. As long as we need carbon and nitrogen, digestion of food, and protection from diseases, we need bacteria.

In the soil, bacteria decompose organic matter and cycle elements such as carbon and nitrogen. Plants and animals can’t create some needed nitrogen compounds, but bacteria assist in turning atmospheric nitrogen into ammonium, or nitrates. These forms of nitrogen are essential for plant life, and plants are a staple of our diets. Where would vegetarians be without bacteria?

Outside and inside our bodies, we benefit from bacteria. In the digestive system, they break down our food, providing essential nutrition. Also, they help our immune system. Exposure to bacteria, both benign and harmful, stimulates the production of antibodies that can respond to disease.

And, we have a bunch of bacteria in us, and on us! In a recent study, it was determined that 10,000 species of bacteria live in or on healthy people (almost 200 separate species live on the skin). It was also found that nearly everyone has low levels of harmful types of bacteria. In most cases, these simply coexist with microbes. For example, many people have Staphylococcus aureus on their skin, which causes no harm unless they get into the tissue through a cut or abrasion and give rise to a “staph” infection.

So, antibacterial soaps may kill 99.99% of germs, but we wouldn’t want that to be the case all over. While some types are indeed harmful, good bacteria play an important role in our overall health and well-being.

C.P.S. (Curious Postscript): “A wise old owl sat on an oak; the more he saw, the less he spoke; the less he spoke, the more he heard; why aren’t we all like that wise old bird?” — Edward Hersey Richards

Curious about something? Send your questions to Dr. Jerry D. Wilson, College of Science and Mathematics, Lander University, Greenwood, SC 29649, or email Selected questions will appear in the Curiosity Corner. For Curiosity Corner background, go to