A new enzyme, originally developed for commercial food processing, turns out to also quickly and nearly-completely break down whole gluten molecules as well as the T cell stimulatory peptides that cause coeliac disease a digestive disease with no current effective treatment other than avoiding wheat, barley or rye products.
In addition, the enzyme operates best in just the kind of physiological environment found in the human stomach and works 60 times faster than an earlier promising enzyme, which was not effective in acidic conditions and was inactivated by pepsin both of which are found in the stomach.
According to Frits Koning, lead researcher at the Leiden University Medical Center, in the Netherlands, where the latest research was conducted: “On the basis of our results, there now is a realistic chance that oral supplementation with an enzyme can ensure gluten degradation in the stomach before reaching the small intestine, where it causes problems for people with coeliac disease.”
The new prolyl endoprotease (PEP) that was studied is derived from Aspergillus niger (AN), a common fungus. Strains of A. niger are used in industrial production of citric and gluconic acid as well as producing several food grade enzymes.
Because there are no animal models of coeliac disease, the in vivo efficacy of AN-PEP for gluten detoxification will ultimately have to be addressed in clinical studies involving coeliac patients. AN- PEP appears to be a prime candidate for such clinical trials, the study report concluded.
I promise to keep you fully updated as soon as the results of these clinical trials become available.
Coeliac disease: A disease of many paradoxes
Coeliac disease is a gut disorder which can strike at any age. It is thought to affect one in 100 people in the UK.
It is caused by gluten, a protein that is found in wheat, and other similar proteins that are found in rye and barley. In some people these proteins cause damage to the tiny projections – or villi – that line the small intestine.
Villi play a significant role in the digestion process. However, when damaged they become inflamed.
This renders them unable to absorb food properly, and can lead to diarrhoea and malnutrition.
Currently the only way to elude the disease symptoms is by avoiding wheat, barley and rye products. It sounds easy, but gluten especially is widespread in Western diets, Koning says. Gluten is often used as a food additive because it adds protein content inexpensively and also gives dough its elasticity and stickiness, which helps in manufacturing. For instance, Koning says: Coeliac patients can eat crisps, but not if they have added paprika or other spices because theyre glued to the crisp with gluten.
Coeliac disease: AN-PEP outstrips earlier enzyme by 60-fold
Earlier attempts at finding non-human proteases for gluten detoxification (first proposed in the late
1950s) focused on prolyl oligopeptidases (POP), most notably FM-POP, which was able to break down gluten sequences in the laboratory.
However FM-POP’s optimal operating pH is between 7 and 8, so it didn’t work well in the more acidic stomach pH that goes down to 2 at one stage. A combination of pH 2 and pepsin ‘immediately inactivated FM-POP,’ the paper said.
AN-PEP, on the other hand, is active from pH 2-8, with optimum effect around pH 4. The combination of pH 2 and pepsin didn’t affect AN-PEP activity.
‘An effective enzymatic treatment for coeliac diseases requires destroying all or at least the vast majority of gluten derived T cell stimulatory sequences,’ the report said. The key to this is to break the large gluten molecules (large peptides and intact proteins) into smaller pieces before they leave the stomach. Because food stays in the stomach one to four hours, speed of protein degradation is also important. Mass spectrometry comparisons showed that ‘degradation of gluten peptides by AN-PEP was on average [about 4 minutes, or] 60 times faster than degradation by FM-POP,’ the paper reported.
AN-PEP has several additional commercial advantages, the paper said: ‘The enzyme is extremely stable and can be produced at acceptable cost at food grade quality in an industry setting.’
‘Highly efficient gluten degradation with a newly identified prolyl endoprotease: implications for celiac disease,’ is in the online American Journal of Physiology and Liver Physiology, published by The American Physiological Society. Research was by Dariusz Stepniak, Liesbeth Spaenij-Dekking, Cristina Mitea, Martine Moester, Arnoud de Ru, Renee Baak- Pablo, Peter van Veelen and Frits Koning of Leiden University Medical Center, the Netherlands, and Luppo Edens of DSM Food Specialties, Delft.