Enzyme May Aid People With Celiac Disease

(HealthDay News) -- A diagnosis of celiac disease currently means a lifetime of watching what you eat -- making sure that no gluten, a product found in many commonly eaten foods, ever passes your lips.
But that dietary restriction may soon come to an end. According to researchers in the Netherlands, an enzyme originally developed for commercial food processing -- AN-PEP -- may be able to break down gluten in the stomach before it reaches the small intestine. That's important, because the small intestine is where celiac disease originates.
"There is a realistic chance that this enzyme can be used to develop an alternative treatment for celiac disease," said the study's lead author, Frits Konig, professor of immunology at Leiden University Medical Center.
"It is very difficult to predict if such an enzyme-based treatment would actually be preferred over a gluten-free diet, but at the very least, it would provide patients with the option to occasionally follow a normal diet -- for example, when going out or during other social occasions, times when a gluten-free diet is certainly bothersome," he said.
Konig and his colleagues reported their findings in the online journal American Journal of Physiology - Gastrointestinal and Liver Physiology.
Celiac disease affects about 1 percent of people in the United States and Europe, according to Konig. It's an autoimmune disease that occurs when the body mistakenly sees gluten molecules as foreign invaders that need to be destroyed. Along with destroying gluten molecules, parts of the small intestine are destroyed during the immune system response. Eventually, it becomes difficult for the small intestine to properly absorb nutrients from food, which can cause anemia and vitamin deficiencies.
Currently, the only effective treatment is to avoid gluten altogether. While this may not sound difficult, Konig pointed out how hard it really is to do. "Gluten is a common protein found in wheat and related cereals like barley and rye. This means many common food products, like bread, breakfast cereals, pasta, cookies, etc., are forbidden," Konig said. "Moreover, gluten is often used as an additive in the food industry, so, many products that are not normally associated with wheat may contain gluten," he added.
The Netherlands researchers aren't the only ones studying enzymes as a treatment for celiac disease. Earlier this week, researchers at Stanford University announced they had also discovered an enzyme -- EP-B2 -- that can help prevent the inflammatory immune system response that occurs when gluten is consumed.
Both the enzymes used in the Dutch study and the California study have only been tested in cultures, not in humans. There is no animal model for celiac disease, so treatments can't be studied in animals, either. Konig said that, in the acidic environment of the stomach, he believes the enzyme used in the Stanford research wouldn't survive. The AN-PEP enzyme, however, should work well in the stomach, he said.
"AN-PEP is very efficient and completely breaks down gluten proteins into fragments that are so small that they can no longer cause inflammation in the intestine," Konig said. "This we have also demonstrated by using white blood cells from patients that respond to gluten and cause inflammation in the intestine. These cells no longer respond to gluten when it has been treated with the AN-PEP enzyme," Konig added.
AN-PEP is derived from Aspergillus niger, a common fungus, according to Konig. Because Aspergillus niger is already used in commercial food processing, he said he doesn't expect there to be side effects from the treatment.
Konig said the next step is to conduct human trials.
Dr. Roshini Rajapaksa, a gastroenterologist at New York University Medical Center, is enthusiastic about the Dutch findings. "This could be a huge advancement in terms of treating a very common disease, and it will help a lot of people who are suffering or are dramatically changing their lifestyle," she said.
Rajapaksa had a word of caution, however. "Right now, we're dealing with chemicals in test tubes, so we don't know about any potential side effects. All sorts of things occur in the human body, though it doesn't look like there's any reason this shouldn't work," she said.

More information
To learn more about celiac disease, visit the Celiac Disease Foundation.