Are probiotic supplements safe for people with celiac disease?

Probiotics

Many people with celiac disease take probiotic supplements to alleviate or prevent symptoms. Probiotics contain bacteria to promote a healthy digestive system and are generally considered safe, but this week researchers from Columbia University presented preliminary findings from a small study showing that more than half of the top-selling probiotic supplements contained some gluten, including ones that were labeled as gluten-free.

Columbia’s Peter Green, who presented the data at the Digestive Disease Week conference in Washington, DC, told the New York Times that he was baffled as to why these supplements contained any gluten at all:

“The question is: Why are companies putting wheat or barley or rye in probiotic supplements?” Dr. Green said. “People use these natural products in an attempt to be healthy. Yet it’s a very poorly regulated industry. Can anyone trust a gluten-free label?”

Probiotics supplements and foods are sold in many forms, from pills to yogurt and granola bars. Last November, we spoke to Stefano Guandalini, MD, Section Chief of Pediatric Gastroenterology, Hepatology, and Nutrition and Medical Director of the Celiac Disease Center at the University of Chicago, about these supplements. He said that while there still isn’t a lot of data available, a few strains of bacteria have been shown to help patients with various gastrointestinal issues. But given these new findings about gluten, are they safe for someone with celiac disease?

Stefano Guandalini, MD

In an email, Guandalini cautioned not to read too much into preliminary data from the new study. He pointed out that only 2 of the 15 probiotics labeled as gluten-free contained more than 20 parts per million (ppm) of the protein, which is the FDA’s cutoff for the designation. Any product with less than 20 ppm is considered safe to eat for someone with celiac.

“The standard of 20 ppm makes a lot of sense when it comes to foods, because people may ingest them in large amounts (i.e. several ounces, or maybe even up to one pound per day),” he wrote.

For supplements though, even in the worst-case example from the study that contained 100 ppm of gluten, Guandalini says a person with celiac would have to ingest quite a bit to pose a risk.

For example, he wrote, the minimal level of possible risk to a person with celiac is about 10 milligrams of gluten per day. For the supplements that contained 100 ppm of gluten, someone would need to take more than 100 grams to reach this amount. Since the pills typically weigh 50 milligrams to 1 gram, they’d have to take nearly 100 probiotic pills a day to be in danger.

“To me it’s unthinkable that you could ingest enough of them to cause any damage,” Guandalini said.

He said he still believes the FDA should apply the same gluten-free labeling standard to these supplements as they do for food, and that as long as they contain less than the allowed 20 ppm, they are still safe for consumers.

“Gluten presence is quite pervasive, so it does not come as a surprise,” that many of the products contained gluten, he wrote, but, “In spite of all the noise about this issue, I still believe that making sure the manufacturers adhere to the ‘Gluten-free’ standard set by the FDA when labeling is enough.”

About Matt Wood (491 Articles)
Matt Wood is a senior science writer for the University of Chicago Medicine and editor of the Science Life blog.
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