Do "gluten-digesting" pills work?

"Helps digest gluten and carbs," reads the label of me+my Gluten Assist. Really?

“Gluten is a really tough plant protein,” notes Daniel Leffler, director of clinical research at the Celiac Center at Beth Israel Deaconess Medical Center in Boston. “A variety of enzymes in the stomach are responsible for chopping up proteins, but they don’t work on gluten.”

That allows long fragments of undigested gluten to leave the stomach and enter the small intestine. Most people can tolerate those fragments. But not those with celiac disease.

Celiac disease: a lifetime of avoiding gluten

“Their immune system mistakes gluten for a dangerous foreign protein, and attacks it the way it would attack bacteria or a virus,” explains Leffler. “That damages the intestine, and causes abdominal pain and diarrhea and so on.”

The only option for people with celiac: a lifetime of avoiding gluten...if they can.

“We think that a lot of people with celiac disease never fully heal,” says Leffler. “It’s not that they aren’t doing their very best to be as gluten-free as can be. It’s just that there’s no such thing as being completely gluten-free in our environment because foods, particularly restaurant foods, are often contaminated by small amounts of gluten.”

Enjoy gluten with the help of a pill?

Researchers are looking for an enzyme that can break down the small amounts of gluten that people with celiac disease are inevitably exposed to. “While it has to be able to snip gluten in a test tube,” says Leffler, “it also has to digest gluten in the stomach in the presence of acid and other foods. And it has to digest gluten quickly, before it can leave the stomach and enter the small intestine. It’s a very high bar.”

High, indeed. In an industry-funded study, five “gluten-digesting” supplements—they went unnamed—couldn’t even pass the test-tube snip test.

What about brands that add Tolerase G, an enzyme that seemed promising in test tubes and in people without celiac disease? The only study in people with celiac was useless because study participants had no symptoms after taking either Tolerase G or a placebo.

Of course, weak evidence hasn’t stopped supplements from using names—like Gluten Assist, Gluten Cutter, Gluten Rid, Gluten Digest, GlutnGo, Gluten Block, or Gluten Free-er—that sound like they help.

“I worry that they provide a false sense of security,” says Leffler. “People who take them may think they can be less careful with their diet, and that can do significant harm in the long run.”

But Leffler, who is working with a company on a new enzyme, is optimistic. “The idea makes so much sense therapeutically,” he notes. “The right enzyme and the right formulation could be effective.”

Just don’t expect to find that right enzyme and right formulation on your drugstore shelves anytime soon.

The bottom line

“There’s no good evidence that the currently available enzymes can protect people with celiac disease from even small amounts of gluten,” says Leffler.

Photo: thodonal/stock.com.