Pity the poor bacterium, the Rodney Dangerfield of the unicellular world. It eats our trash, makes soil fertile, turns the food we swallow into useful vitamins, and yet it gets no respect. Most people, when you get right down to it, are just plain bacteria bigots. They want to run all 2,000-plus species of bacteria out of town just because of a few ornery germs that can harm us.

And now, it seems, our pursuit of a bacteria-free world is making us sick. Got antibacterial soap? It could be doing you more harm than good.

A study published this month in Chest (trust me, it's a medical journal) finds that antibiotic exposure during infancy is associated with asthma. This follows a string of studies from the past few years, such as those from the Immune Tolerance Network, revealing that early exposure to harmful bacteria builds a healthy immune system. Kids exposed to endotoxin-releasing bacteria, for example, are less likely to be allergic to dogs and cats.

These docs have a sense of humor, too. They call this the Pigpen Effect, after the Peanut's character with his protective cloud of dirt. It's a dirty little secret the antibacterial soap people don't want you to know about.

The rising incidence of asthma and allergies in the developed (cleaner) world, doctors say, could be tied to the relatively sterile environments our children live in compared to a generation ago. Children not exposed to harmful bacteria, or conversely, given antibiotics to kill bacteria, do not receive the germ workout required to make antibodies. More specifically, they do not develop T-helper cells, which fight foreign cellular invaders and minimize allergies.

Unfortunately the American consumer is at war with all bacteria. According to the Soap and Detergent Association (too bad its acronym couldn't spell SUD), more than three-quarters of liquid soap and more than a quarter of bar soaps on supermarket shelves contain triclosan, an antibiotic that kills most bacteria, both good and bad.

Ridding ourselves of bacteria is a hopeless endeavor. Bacteria outnumber human cells in your body 10 to 1. This is a good thing. The entire digestive tract is lined with bacteria, from top to, uh, bottom. These bacteria work with the body's own chemicals in breaking down food, converting it to useful vitamins and minerals, and making sure the intestinal walls can absorb the nutrients for the bloodstream to circulate. Without these bacteria, we could not digest food. Babies, born relatively bacteria-free, are extremely limited in what they can eat.

Human skin contains many species of harmless bacteria. Their presence prevents harmful bacteria, what we commonly call germs, from gaining a foothold on your skin. Numerous studies show that antibacterial soap is no more effective than ordinary soap in cleaning your hands. Either kind lifts off germ-laden dirt. But antibacterial soap kills helpful bacteria on the skin, freeing up valuable real estate so that harmful bacteria can move in later.

The marketing of antibacterial products during flu and cold season is a scam, because colds and flu are caused by viruses, not bacteria. Most bacterial infections in the United States are food-borne: salmonella, listeria, and E. coli. We cannot wash food in triclosan. Apparently we tolerate feces in our food supply yet reach for an antibacterial wipe to clean some jelly off the counter. It's enough to make you sick.

Christopher Wanjek is the author of the books “Bad Medicine” and “Food At Work.” Got a question about Bad Medicine? Email Wanjek. If it’s really bad, he just might answer it in a future column. Bad Medicine appears each Tuesday on LIveScience.

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