Prolyl Endoprotease Enzyme May Allow Patients with Celiac Disease to Safely Eat Gluten on Occasion

Celiac.com 05/23/2007 - The results of a study recently published in the journal Gut suggest that the enzyme prolyl endoprotease from Aspergillus niger (AN-PEP) taken along with meals might allow patients with celiac disease to safely consume gluten on occasion.

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The negative effects of celiac disease are due in large part to an immune response to gluten.

Because proline-rich gluten proteins resist the digestive enzymes of the gastro-intestinal tract, they are very likely suspects in the generation of this immune response.

A team of doctors in the Netherlands set out to assess the abilities of a post-proline cutting enzyme, prolyl endoprotease from Aspergillus niger (AN-PEP) in breaking down gluten. The research team was made up of doctors Cristina Mitea (1), Robert Havenaar (2), Jan Wouter Drijfhout (1), Luppo Edens (3), Liesbeth Dekking (1)* and Frits Koning (1).

The study was not performed on actual celiac patients, but used a dynamic system that mimics the human gastrointestinal tract (TIM system). Using the TIM system, the team performed two experiments. The first used the TIM-system to process a slice of bread with and without the presence of AN-PEP. The second experiment used the TIM-system to process standard fast food items, again both with and without the presence of AN-PEP.

Samples of the digesting food were taken from the TIM systems stomach, duodenum, jejunum and ileum compartments from zero to four hours after the beginning of the experiment. These samples were evaluated for levels of immunogenic peptides from gliadins and glutenins by monoclonal antibody based competition assays, Western blot analysis and proliferation T-cell assays.

Results of both experiments showed that AN-PEP broke down gluten in the stomach so effectively that almost no gluten reached the duodenum compartment. Because these results show that AN-PEP is capable of speeding the breakdown of gluten in a gastrointestinal system that closely mimics live digestion, the team concluded that AN-PEP might offer celiac patients an opportunity to stray from their strict gluten free diets from time to time.

Participating Institutions:
1 Dept of Immunohematology and Blood Transfusion,
Leiden University Medical Center, Leiden, Netherlands.
2 TNO Quality of Life, Zeist, Netherlands
3 DSM Food Specialties, Delft, Netherlands

Gut. Published Online First: 9 May 2007. doi:10.1136/gut.2006.111609