Enzyme Supplement Protects Gluten-sensitive Patients

Damian McNamara

May 19, 2017

CHICAGO — The prolyl endoprotease enzyme derived from Aspergillus niger might help people with a gluten sensitivity who unintentionally consume wheat or other grains avoid troublesome gastrointestinal symptoms, a small study suggests.

The enzyme, known as AN-PEP and marketed as Tolerase G by DSM in the United States, "actually works," said lead investigator Julia König, PhD, from Örebro University in Sweden. "There are a lot of enzymes on the market, but this functions in the stomach where the pH is acidic. Often enzymes don't work in this environment."

However, "you cannot use this enzyme to treat or prevent celiac disease," she cautioned here at Digestive Disease Week (DDW) 2017. A gluten-free diet is the only treatment, she said.

In a previous study Dr König was involved in, researchers demonstrated that AN-PEP breaks down gluten after an intragastrically infused liquid meal in healthy volunteers (Aliment Pharmacol Ther. 2015;42:273-285).

In their current randomized placebo-controlled crossover study, Dr König and her colleagues assessed the ability of AN-PEP to degrade gluten after a normal meal in people with gluten sensitivity.

The 18 participants self-reported gluten sensitivity and there was no confirmation of celiac disease.

On three separate visits, investigators collected gastric and duodenal aspirates with a multilumen nasoduodenal-feeding catheter. Participants then consumed a porridge containing gluten, approximately 0.5 g, in the form of two crumbled wheat cookies. They also consumed two tablets, containing AN-PEP (either 160,000 PPi or 80,000 PPi) or placebo.

Investigators collected stomach and duodenal aspirates over the course of 3 hours.

Gluten concentrations in the stomach and in the duodenum were significantly lower in both the high- and low-dose AN-PEP groups than in the placebo group.

Table. Mean Gluten Concentrations After Gluten Consumption

Aspirates (mg × min/mL) High-Dose AN-PEP Low-Dose AN-PEP Placebo P Value
Stomach 31 31 218 .001
Duodenum 12 8 65 .015


Gluten was degraded by 81% in the high-dose group and by 87% in the low-dose group before the meal reached the small intestine.

Dr König was asked during a press briefing whether participants were able to discern a difference in symptoms between the three treatment groups.

"We did not find a difference, but it was quite an invasive procedure," she replied. "We placed an NG tube through the nose and they were fasting overnight, so they already had GI symptoms due to that, in addition to the gluten they consumed, which was very little."

An advantage of the AN-PEP enzyme is that it works in the acidic environment of the stomach, which is not true for all enzymes, she explained.

We are not suggesting they can gorge on a whole bowl of pasta or pizza.

Despite the promise shown in this study, the enzyme is meant only for the unintentional consumption of gluten. "We are not suggesting they can gorge on a whole bowl of pasta or pizza. Even a small amount of gluten can cause harm in these patients," Dr König pointed out.

Enzyme Seems to Work Quickly

"The researchers showed that they can reduce the amount of gluten in the stomach substantially, and it seems to work fairly quickly," said Joseph Murray, MD, from the Mayo Clinic in Rochester, Minnesota.

"This is proof that it can degrade gluten in the stomach. That has not been done before," he told Medscape Medical News. However, it might not be useful as a rescue strategy, he pointed out.

"You have to take it right away. Many people who accidentally ingest gluten only realize that hours later, when they develop symptoms, at which point the food has probably already passed through the stomach," he explained.

The US Food and Drug Administration does not review the safety or efficacy of dietary supplements, and AN-PEP falls into that category, Dr Murray added. "But is it likely to cause harm? I kind of doubt it."

The researchers are planning a follow-up study to compare the effects of AN-PEP on specific symptoms in people with gluten sensitivity, Dr König reported.

Dr König and Dr Murray have disclosed no relevant financial relationships.

Digestive Disease Week (DDW) 2017: Abstract Su1137. Presented May 7, 2017.

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