The finding raises the possibility that patients with coeliac disease could take an oral supplement that would allow them to eat wheat, barley and rye without triggering any symptoms.
The enzyme prolyl endonuclease is derived from the Aspergillus niger fungus and was first identified by the food industry. It was found to degrade proteins by breaking them down at the amino acid, proline. Gluten consists of around 20 per cent proline; this meant that it could be used to degrade gluten.
Finding an enzyme able to break gluten down before it leaves the stomach has proved difficult. Other enzymes that showed promise were inactivated by acidic pH or digested by pepsin.
However, prolyl endonuclease can break down gluten even at pH2 and it can resist digestion with pepsin.
Although it has yet to be tested in vivo, the researchers hope an oral dose of the enzyme could be used to break down gluten before it reaches the small intestine and induces an inflammatory T-cell response.
Lead researcher Dr Frits Koning, from the Leiden University Medical Center in the Netherlands, said: 'There is now 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.'
He added that clinical trials into prolyl endonuclease for coeliac disease could begin within a year.