Durham, N.C. — One in every 20 people in the United States develops auto-immune diseases, such as Type 1 diabetes or multiple sclerosis. One in every 10 people develop nasal and sinus allergies.

Why are these problems so prevalent? Duke researchers are using wild rats to find out.

As a boy, Dr. Bill Parker, a Duke surgical sciences researcher, used to trap rats on a farm. His experience has came in handy as wild rats at a recycling facility are being used to learn more about auto-immune diseases.

“Basically, we hope that the rats can't read, or if they can, they don't know what a study is,” Parker said.

Wild rats are different from lab rats, Parker said. Lab rats are born and bred in hygienic environments. The immune system of a wild rat constantly has to fight parasites, much like the human body does.

“When you take these things away, your immune system basically has nothing to do,” Parker said.

Parker said that may be why people develop auto-immune diseases – because the immune system is bored.

“It might be a pollen grain, or it might be a molecule that your own body produces, which would give you an auto-immune disease,” Parker said.

Researchers used fluorescent tags on the cells of wild rats to study their immune systems.

“You only see shifts like this in our laboratory animals when they're getting some sort of auto-immune disease, experimentally induced,” Parker said.

Parker hopes the research will lead to more studies and better treatments for auto-immune diseases.

Parker based part of his research on a 2004 study at the University of Iowa. Researchers there found that when patients with inflammatory-bowel disease were exposed to specially prepared worm eggs, it helped relieve symptoms and control the disease.