The gut may need bacteria to provide a little bit of oxidative stress to stay healthy, new research suggests. Probiotic bacteria promote healing of the intestinal lining in mice by inducing the production of reactive oxygen species, researchers at Emory University School of Medicine have shown. The results, published online on May 9, 2011, in PNAS, demonstrate a mechanism by which bacterial cultures in foods such as yogurt and kimchi have beneficial effects on intestinal health. The insights gained could also guide doctors to improved treatments for intestinal diseases, such as necrotizing enterocolitis in premature babies or intestinal injury in critically ill adults. The laboratories of Dr. Andrew Neish and Dr. Asma Nusrat, both professors of pathology and laboratory medicine, teamed up for the study. The paper’s co-first authors are postdoctoral fellow Dr. Philip Swanson and associate research professor Dr. Amrita Kumar. “It’s been known for years that probiotic bacteria can have these kinds of helpful effects, but it wasn’t really clear how this worked,” Dr. Neish says. “We’ve identified one example, among many, of how certain kinds of bacteria have specific biochemical functions in the body.” Recent research has shown that the bacteria in our intestines influence our metabolism and immune systems. For example, an imbalance in the proportions of harmful and beneficial bacteria seems to over-activate immune cells in the intestines, driving inflammatory bowel disease. Intestinal epithelial cells, the cells that line the intestine, live in close contact with bacteria and normally form a barrier that keeps bacteria away from other organs. They can repair small gaps in the barrier, which breaks down in intestinal diseases, by migrating into the gaps.Login Or Register To Read Full Story