Sometimes one food fallacy can conflict with another, and so you must choose - if you like paying over 240 percent more for a gluten-free label and 200 percent more for a probiotics label, you may have to pick between them. 

How can yogurt contain wheat, rye, and barley? Why does anyone believe those health claims about probiotics? These are all valid questions. Labels are no reassurance, more than half of 22 probiotic products recently tested were labeled gluten-free yet still had gluten. Two probiotics had so much gluten they might present a danger to celiac patients, according to an analysis performed by investigators at the Celiac Disease Center at Columbia University Medical Center (CUMC). Tests on 22 top-selling probiotics revealed that 12 of them had detectable gluten.

The investigators used liquid chromatography-mass spectrometry, a sensitive detection technology, to quantify gluten content. Most of the probiotics that tested positive for gluten contained less than 20 parts per million of the protein which is still gluten-free by Food and Drug Administration (FDA) standards, the same way 'organic' food can have 50 synthetic ingredients and still be called organic. However, four of the brands (18% of the total) contained in excess of that amount. 

"We have been following reports in the scientific literature and news media on inaccurate labeling of nutritional supplements, and it appears that labels claiming a product is gluten-free are not to be trusted, at least when it comes to probiotics," said Dr. Peter Green, professor of medicine and director of the Celiac Disease Center, "This is a potential hazard for our patients, and we are concerned." 

"Many patients with celiac disease take dietary supplements, and probiotics are particularly popular," said Dr. Samantha Nazareth, a gastroenterologist at CUMC and the first author of the study. "We have previously reported that celiac patients who use dietary supplements have more symptoms than non-users, so we decided to test the probiotics for gluten contamination." 

Patients with celiac disease only develop intestinal damage when consuming more than 10 milligrams of gluten daily, and it is unlikely that contaminated probiotics can lead to that amount unless patients are ingesting mega-doses, but most of the gluten-free market is people who just want it to be gluten-free. 75 percent of non-celiacs who claim to be gluten sensitive show no sensitivity in tests but they are paying double so they deserve accuracy in the products they are buying whether it is a nocebo or not. 

"Why is there any gluten in these products? Why should the consumer pay any attention to gluten-free labeling on such products?" asks Dr. Benjamin Lebwohl, assistant professor of medicine and epidemiology at the Celiac Disease Center and a co-author of the study. "And given the great consumer interest in probiotics, will regulatory bodies take action to protect the public?"

"Widespread Contamination of Probiotics with Gluten, Detected by Liquid Chromatography-Mass Spectrometry," will be presented by Dr. Samantha Nazareth tomorrow at Digestive and Disease Week (DDW) in Washington DC. Top image credit: brownpau, CC BY-SA