Influence of dietary components on Aspergillus niger prolyl endoprotease mediated gluten degradation

Food Chem. 2015 May 1;174:440-5. doi: 10.1016/j.foodchem.2014.11.053. Epub 2014 Nov 14.


Celiac disease (CD) is caused by intolerance to gluten. Oral supplementation with enzymes like Aspergillus niger propyl-endoprotease (AN-PEP), which can hydrolyse gluten, has been proposed to prevent the harmful effects of ingestion of gluten. The influence of meal composition on AN-PEP activity was investigated using an in vitro model that simulates stomach-like conditions. AN-PEP optimal dosage was 20 proline protease units (PPU)/g gluten. The addition of a carbonated drink strongly enhanced AN-PEP activity because of its acidifying effect. While fat did not affect gluten degradation by AN-PEP, the presence of food proteins slowed down gluten detoxification. Moreover, raw gluten was degraded more efficiently by AN-PEP than baked gluten. We conclude that the meal composition influences the amount of AN-PEP needed for gluten elimination. Therefore, AN-PEP should not be used to replace a gluten free diet, but rather to support digestion of occasional and/or inadvertent gluten consumption.

Keywords: Diet; Endoprotease; Gluten; Oral supplementation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus niger / enzymology*
  • Celiac Disease / therapy
  • Diet, Gluten-Free
  • Dietary Fats / metabolism
  • Dietary Proteins / metabolism
  • Digestion
  • Glutens / metabolism*
  • Serine Endopeptidases / metabolism*


  • Dietary Fats
  • Dietary Proteins
  • Glutens
  • Serine Endopeptidases