A molecule made by gut bacteria may be useful for treating inflammatory bowel disease, according to a new study (Mazmanian SK et al. Nature. 2008;453: 620-624). Scientists at the California Institute of Technology in Pasadena and Harvard Medical School in Boston discovered that a sugar called polysaccharide A, or PSA, produced by the symbiotic gut bacterium Bacteroides fragilis, protects mice from developing a disorder similar to Crohn disease and ulcerative colitis that occurs following exposure to the pathogenic bacterium Helicobacter hepaticus.
Hampton T. Microbes Ward Off Bowel Disease. JAMA. 2008;300(1):33. doi:10.1001/jama.300.1.33-a