Emulsifier may be key to treating ulcers.

Until the 1980s, scientists believed that bacteria could not survive in the stomach's acidic environment. Then they discovered that Heliocobacter pylori thrived in its mucus layer. As a result of that finding, stomach ulcers, once attributed to stress and high levels of stomach acid, now are considered infectious diseases, treatable with antibiotics.

In 1992, David Cave, associate professor of medicine at Tufts University and chief of gastroenterology at St. Elizabeth's Medical Center, Boston, asked Anne Kane, who directs the Intestinal Microbiology Core of the Digestive Disease Center at New England Medical Center, to provide him with large batches of H. pylori for his research into an acid-reducing protein generated by the bacteria. Kane was able to produce the bacteria easily in small batches, but the organism failed to multiply in big-batch fermenters. The bacteria is microaerophilic, meaning it needs some oxygen to grow, but not too much. At first, Kane thought her problem had to do with the oxygen mix. Eventually, she narrowed it down to an anti-foam agent routinely added to large-batch bacterial cultures to reduce bubbles.

"I thought it was the simethicone - the chemical in the anti-foam agent that dampens bubbles." She wanted to See if she was right by exposing the bacteria to pure simethicone, but couldn't because it is not soluble without an emulsifier. Kane needed to eliminate the emulsifier as a potential factor, so she took her investigation to the...