Protein balances 'good' and 'bad' bacteria in gut

A protein -- SIGIRR -- produced by the cells that line the intestines helps keep the "good" and "bad" in balance, researchers in Canada say. Bruce Vallance, an associate professor in the University of British Columbia's Department of Pediatrics and a scientist at the Child & Family Research Institute at BC Children's Hospital, said SIGIRR suppresses the cells' immune response to bacteria. "We expected that when SIGIRR was removed, our intestines would trigger a stronger immune response to a gut infection, affording us more protection against the infection," Vallance said in a statement. "Instead, the stronger immune response also killed the resident bacteria in our gut." The researchers found gut flora -- microorganisms that live in our digestive tract -- literally compete for living space and nutrients with some invading bacterial pathogens. "Without our gut flora, bad bacteria that are more resistant to our immune system can rapidly take over and wreak havoc, causing infection or even Inflammatory Bowel Disease," Vallance said. By dampening the body's immune response to allow the good bacteria to take up residence in the gut, SIGIRR maintains the delicate balance that keeps the gut healthy, Vallance said. "Maintaining a healthy gut flora by limiting antibiotic use or even taking probiotics yogurt -- found in may be important in fortifying this important defense barrier in our intestines," he said. The study was published in the journal PLOS Pathogens.