Researchers from the Celiac Disease Center at Columbia University Medical Center have found that a number of well-known probiotic supplements available on the market contain traces of gluten despite being labeled as gluten-free.

Celiac Disease Center director Dr. Peter Green and his colleagues tested 22 high-selling probiotics and discovered that around 55 percent of them had gluten.

Probiotics are supplementary pills that contain what are considered "good bacteria," and they are generally viewed to be beneficial in keeping a healthy digestive system.

"We see a lot of patients [with celiac] and we have a lot of patients who have it and don't feel better," Green said. "We found previously that about 25 percent of celiac patients use supplements or non-traditional medical products, and probiotics were the largest and most frequently consumed. Those people [who used probiotics] had more symptoms compared to people who weren't taking these supplements."

According to the U.S. Food and Drug Administration (FDA), for a product to be gluten-free, it must contain less than 20 parts per million of the substance.

In their study, the researchers found that majority of the probiotics tested contained only small traces of gluten. However, around 18 percent of the products still contained high amounts of the substance to even be considered gluten-free.

Green said that the results of their study suggest that probiotics with labels claiming that they are gluten-free cannot be trusted. He explained that being certain of the gluten content of supplements is very important, especially for people who suffer from celiac disease.

People diagnosed with celiac disease show an immune reaction to gluten, which can damage their intestines. This is the reason why these individuals try to avoid eating gluten. The researchers noted that people with the condition take dietary supplements such as probiotics.

A previous study conducted by the Celiac Disease Center revealed that patients with celiac disease who regularly took supplements had a higher chance of manifesting symptoms of the disease compared with those who did not take supplements.

Green and his team, however, are still uncertain whether the traces of gluten they detected in the probiotics could pose a risk to the health of people with celiac disease.

The findings of the Celiac Disease Center's study will be presented during the Digestive and Disease Week meeting in Washington, D.C. scheduled this week.

Photo: Ryan Snyder | Flickr