These options are still years from commercial availability, but early results have been encouraging, according to a review of the drug pipeline in Gastroenterology Report.

“Based on data on ClinicalTrials.gov, there are two investigational products we are aware of which may enter large confirmatory trials in the not too distant future,” said lead author Dr. Klaus Gottlieb, senior medical director of the immunology and internal medicine department for Quintiles, a company that provides bio-pharmaceutical development services and consulting in Durham, North Carolina.

“One of them is an enzyme that splits the molecule in wheat that causes celiac disease, gluten, into smaller harmless products and another one promises to make the gut less leaky and thus prevent potentially toxic substances (from) reaching deeper layers where they may cause inflammation,” Gottlieb said.

Two million Americans and 3.5 million Europeans have celiac disease, although more than half in the U.S. are not diagnosed, the authors say.

People with the disorder must avoid eating gluten, a protein in wheat, rye and barley. If people with celiac disease consume foods that contain those grains, their immune response leads to intestinal damage, malnutrition and other problems.

Several new therapies have shown promise in human trials, appearing at least somewhat effective. None have yet entered safety trials, the final step before Food and Drug Administration approval and commercial availability.

It’s still hard to say when one of these options will reach the market, but if all goes well it could happen in three to five years, said Gottlieb.

For one potential oral therapy, patients take a mixture of two enzymes that split the gluten molecule into smaller harmless products. In a trial of adults with celiac disease, those taking this drug had no change in their intestinal biopsies after eating gluten, while those taking a placebo did have evidence of injury to the intestinal lining.

However, symptoms were similar in both groups.

Three daily doses of another drug, designed to control an inflammatory process in the intestines, did appear to reduce diarrhea, indigestion and abdominal pain symptoms in one trial.

Several others in earlier stages of development are aimed at suppressing the immune response to gluten and preventing intestinal inflammation.

Before the drugs are approved, it’s hard to say if they will allow people with celiac disease to eat gluten in small amounts, large amounts, or without restriction, Gottlieb said.

“If they eat a lot of gluten, they may still have some symptoms and perhaps other long-term health consequences,” he said. Some may be best to take right before eating gluten and others might be more effective when taken on a regular schedule.