Gastrointestinal Support BioCore DPP IV Helps Digest Gluten & Cereal Grains A Dietary Supplement Vegetarian - Vegan Probiotics/Enzymes/Digestive Family Owned Since 1968 GMP Quality AssuredGluten Digest, with BioCore DPP IV, is a comprehensive enzyme blend formulated to promote the complete digestion of cereal grains. DPP IV (Dipeptidylpeptidase IV) is a unique enzyme with specific activity against the characteristic proline bonds found in cereal grain proteins. Gluten Digest also includes proteases and amylases that address other protein and carbohydrate components that commonly co-occur in these foods.