THURSDAY, Aug. 24 (HealthDay News) -- U.S. researchers have discovered an intestinal protein that defends the organ against microbial invaders.

The finding offers new insight into how the intestine fights off pathogens, says a team from the University of Texas Southwestern Medical Center, and could lead to treatments for inflammatory bowel disease and intestinal infections.

"We found that when the gut lining comes into contact with bacteria, it produces a protein that binds to sugars that are part of the bacterial outer surface. Once bound, these proteins quickly destroy their bacterial targets. They're killer proteins with a sweet tooth," study senior author Dr. Lora Hooper, assistant professor of immunology, said in a prepared statement.

The researchers used mice raised inside plastic sterile bubbles. Because the mice had never been in contact with microbes in the outside world, they did not have the bacteria that normally colonize the gut.

During the study, the mice were exposed to different types of gut bacteria and the researchers observed how the epithelial cells lining the rodents' intestines responded to these invaders.

This protein is called RegIIIgamma in mice and HIP/PAP in humans. The protein may help create an "electric fence" that protects the intestinal surface against invading bacteria, Hooper explained.

The study appears in the Aug. 25 issue of Science.

People with inflammatory bowel disease, which can cause painful ulcers and bloody diarrhea, have elevated levels of HIP/PAP production.