Is There Gluten in Your Probiotics?
An interview with study author Peter Green, MD, director of The Celiac Disease Center at Columbia University
A small study presented earlier this month at the annual Digestive Diseases Week meeting reports there may be trace amounts of gluten in some probiotics. A lot of people with celiac disease and gluten sensitivity take probiotic supplements for digestive health. In this study, researchers sampled 22 popular probiotic brands, including 15 that were labeled gluten-free. Half of them contained detectable amounts of gluten, with two brands containing more than 20 parts per million (ppm) of gluten, the threshold set by FDA for gluten-free labeling.
The study, which doesn’t give supplement brand names, introduces troubling questions about the gluten content in probiotics. What’s our take on this? While study results can be considered preliminary until published, a take-home message for consumers is this: Consult with your doctor about the probiotic you’re taking and call the manufacturer help line to learn more about what’s in that pill. In the meantime, we’re digging further into this issue. Look for more email updates, info posted on our Facebook page and important details in the pages of Gluten Free & More.
Here GF&M’s health editor, Christine Boyd, interviews the study author, celiac expert Peter H.R. Green, MD, director of The Celiac Disease Center at Columbia University.
GF&M: What prompted your probiotic study?
Dr. Green: Previously we’d done a study that showed about 20 percent of individuals with celiac disease use dietary supplements, mostly probiotics and fish oil. Those who were using probiotics reported more symptoms than those who didn’t use them. Why more symptoms were reported wasn’t clear -- we didn’t ask in the questionnaire if they were taking probiotics due to the symptoms or otherwise. Then an article came out in the New York Times that showed supplements have a high rate of not having in them what’s on the label and being contaminated with rice, wheat and noxious herbs. So we decided to investigate probiotics for gluten contamination.
GF&M: What did you find?
Dr. Green: We purchased 22 popular probiotics from Amazon.com and drug stores. We had gluten content analyzed by a process called mass spectometry. Half had gluten in them. The bulk of them had gluten levels less than 20 parts per million (ppm), which the FDA says is safe for food. Four probiotics had more than 20 ppm and two of these were labeled gluten-free. It didn’t matter what the price was either. Basically, among 22 probiotics, about 13 percent had more than tolerable gluten levels and others had some gluten below the 20 ppm level.
GF&M: How big is the health risk to celiacs from this gluten-contamination?
Dr. Green: We know from follow-up endoscopies that 30 to 40 percent of celiac individuals don’t heal. This could be because of little bits of gluten they’re getting. We know there’s an individual sensitivity to gluten that we can’t predict. Generally we think 20 ppm – which is not much gluten at all—is tolerated by most celiacs. But studies have shown far less gluten can cause problems for some individuals with celiac disease. We can’t predict where you may fall. Our advice is to be as strict as you possibly can.
GF&M: Should celiacs stop taking their probiotics?
Dr. Green: Typically I don’t advise anyone to take probiotics or other dietary supplements. The exception is multivitamins. We will advise patients to take a gluten-free labeled multivitamin. However, our next study is going to investigate gluten levels in multivitamins.
GF&M: Is there any way to be sure a probiotic is gluten-free?
Dr. Green: Unfortunately, I don’t think so. Our study showed even products labeled gluten-free can have gluten in them.
GF&M: Can you share the names of the probiotics that contained gluten?
Dr. Green: We only tested 22 probiotic brands. We don’t know if there’s variability in gluten content from batch to batch. Some say there’s variability in the actual viability of microorganisms from batch to batch. We were purely interested in why patients aren’t feeling better. Our study shows there are little bits of gluten in many probiotics. And maybe that’s why some people still don’t feel better.
GF&M: Are you going to report the mislabeled probiotics to FDA?
Dr. Green: Our job is to do the research. Patients and consumers have to push for a better regulated industry. In general, dietary supplements are a poorly regulated industry. This issue extends into gluten-free food labeling, too. Recently there was a paper* from Idaho that looked at gluten contamination in foods and found 5 of 8 gluten-free breakfast cereals had more than 20 ppm of gluten. This was published after the labeling rule went into effect. In Canada, gluten-free food is tested for the presence of gluten.
GF&M: This is scary news for celiac individuals. Is there any guidance you can offer?
Dr. Green: There are very small amounts of gluten that a gluten-free individual is exposed to every day. Trace amounts of gluten contamination in a probiotic probably isn’t harmful for most celiacs. But how many probiotic capsules are they taking each day? The amount can add up.
In our study, we’ve demonstrated that people have to be aware. Probiotics aren’t indicated for celiac disease. If patients want to take them, they should discuss it with their doctor. To me, our study also emphasizes that celiac individuals need to be followed by a doctor who’s really interested in celiac disease, whether at a celiac center or by an expert gastroenterologist in the community.
According to the National Center for Complementary and Integrative Health, probiotics are live microorganisms (e.g., bacteria) that are either the same as or similar to microorganisms found naturally in the human body and may be beneficial to health. More information on probiotics can be found at nccih.nih.gov.
*Lee HJ et al. Gluten contamination in foods labeled as "gluten free" in the United States. J Food Prot. 2014 Oct;77(10):1830-3. Tricia Thompson, MS, RD of Gluten Free Watchdog has examined this paper and found its analytical methods flawed. Specifically, researchers used the competitive R5 ELISA test, which is indicated for measuring gluten content in hydrolyzed and fermented foods (e.g., beer, soy sauce, etc.) The foods tested in this study—breakfast cereal, pasta, tortillas—don’t appear to be hydrolyzed or fermented. As a result, findings may be inaccurate. Please read more here.