By Amy Ratner, Beyond Celiac Medical and Science News Analyst
For the first time, celiac disease patients and others who follow the gluten-free diet will be able to test whether they’ve consumed gluten using at-home urine and stool tests.
Gluten Detective tests detect fragments of the immunogenic gluten protein, called GIP, harmful to those who have celiac disease. They are being sold online by Glutenostics, the distributor of the tests in the United States and Canada.
Gluten detection levels
The urine test detects 500 milligrams of gluten or more – a significant amount starting with the equivalent of about 2 bites of gluten-containing bread – up to 24 hours after consumption. The test works best when done the morning after gluten exposure is suspected, using a first-morning urine sample.
The test is most useful for: those who are new to the gluten-free diet and are more likely to make bigger mistakes; those who’ve eaten at a restaurant and suspect a gluten-containing food was served instead of a gluten-free item; and parents who suspect their children might have eaten a gluten-containing food.
Its shorter window of detection makes it the better of the two tests to pinpoint the source of gluten and is useful for suspicion of gluten exposure from the night before.
Although more cumbersome to take, the stool test is more sensitive and will give a positive result if 50 milligrams or more – starting with the equivalent of a crumb of bread – is detected. The test most effectively picks up gluten consumed two to four days before it’s administered.
The stool test is designed to detect inadvertent consumption of small amounts of gluten, typically the kind that can occur when a gluten-free food has had cross-contact with a gluten-containing food. This could include gluten-free menu items that have been cross-contaminated during preparation or gluten-free products that have been exposed to gluten when manufactured or packaged.
Since the stool test can detect a lower level of gluten, it’s better for monitoring chronic smaller amounts of gluten exposure.
Gluten immunogenic peptides (GIP) - Fragments of gluten proteins that are resistant to gastrointestinal digestion and trigger symptoms and intestinal damage in those who have celiac disease and perhaps symptoms in those who have gluten sensitivity.
The tests are greater than 96 percent specific for gluten fragments, according to Glutenostics. The urine test is more than 90 percent reliable within its respective time window and limit of detection, while the stool test is more than 95 percent, the company reports on its website.
An exciting new tool
“This one-of-a-kind technology will empower people to take control of their gluten-free life and improve adherence to the diet through scientifically informed decision-making,” said David Winternheimer, Ph.D., CEO of Glutenostics. People with celiac disease who feel “alone and lost on an island” when the gluten-free diet isn’t totally working now have a product they can use to help manage the condition, he noted.
“This is one of the more exciting things to come out for celiac disease,” said Jocelyn Silvester, M.D., director of research of the Celiac Disease Program at Boston Children’s Hospital and a scientist who has used the tests in celiac disease studies. “It is already revolutionizing clinical trials and now it gives celiac disease patients the first opportunity to document ingested gluten exposure.”
“We haven’t had an objective way to measure gluten exposure,” said Daniel Leffler, M.D., director of research at the Celiac Center at Beth Israel Deaconess Medical Center, and a medical director at Takeda Pharmaceuticals. “This gives us a potentially powerful tool to understand the patient who is doing well and why and the patient who is not doing well and why.”
How the test works
To take a test, you collect a small sample of stool or urine, mix it with a solution and use a test strip similar to a pregnancy test to get a positive or negative result. The tests come with all the supplies you need, in kits of two urine tests, two stool tests or one of each test. The kits cost $45 plus shipping, and the company is currently offered a 25 percent off coupon on its website for first-time customers. Results are ready in 10 to 15 minutes.
A positive result from the urine test requires more gluten than the 50 milligrams considered a safe cutoff for those who have celiac disease, so the company recommends that those who have celiac disease follow-up a negative urine test result with the more sensitive stool test.
Winternheimer said that in general the stool test is more likely to be used by those who have celiac disease and are accustomed to avoiding bigger transgressions, but want to know whether they are consuming a small, but still harmful amount of gluten. This could include someone who was careful about a meal eaten in a restaurant but still gets symptoms or asymptomatic celiac disease patients who can’t tell when they have been exposed to a small amount of gluten. Research has shown that even those who don’t have symptoms often have intestinal damage related to inadvertently eating gluten.
The stool test is 10 times more sensitive than the urine test. Gluten peptide fragments travel through the digestive system and linger there longer. Consequently, more fragments are excreted in the stool, making them easier to detect.
The stool test reacts to the accumulation of all fragments from gluten consumed two to four days before the test is taken, so users might not be able to determine the exact source strictly based on the test. But they can use other information, including a review of anything unusual in their diet over the time period covered by the test, to begin to figure it out.
The stool test can also be weekly or periodically to monitor whether you are regularly consuming small amounts of gluten.
Research results showed that the current version of the urine test could most accurately detect 500 milligrams of gluten or more within 24 hours. Francisco Leon, M.D., Ph.D., a founder of Glutenostics and partner in Biomedal, said the company is working to develop a second- generation urine test, which would have the sensitivity of the stool test and still be easy to use. Meanwhile, the level detected by the current test is clinically significant, Silvester said.
Development of that second generation of urine test will be an important step, Leffler said, because stool testing can be a significant barrier for patients. “It’s inconvenient and unpleasant and realistically people don’t like to do it,” he said. But he noted that evolution of testing is normal, and the fact that Glutenostics has proven that urine testing is feasible when researchers did not originally expect gluten to be found in urine indicates a more sensitive urine test is likely to be developed.
Silvester and other researchers at Boston Children’s Hospital are about to launch a study that will examine how the urine and stool tests can fit into the management of celiac disease. “One of the things we hope to find out is how to work (the tests) into the way doctors look after patients and how patients look after themselves,” Silvester said.
Biomedal, the company that developed the test being distributed by Glutenositics, offers the at-home urine and stool tests in Europe under the brand name Gluten Detect.
What to do with results
The urine and stool tests are not taken until after you have potentially eaten gluten, so they don’t give you upfront information that can prevent you from eating a gluten-containing food. But they provide evidence of whether you’ve eaten gluten or not – something that’s previously always been a guessing game.
You can then use the results to avoid a repeat exposure in the future. The Glutenostics website gives consumers advice on how they can use the test results. For example, those who are strictly following a gluten-free diet but get a positive stool test result and have ongoing symptoms for an unknown reason are advised to cut back to only naturally gluten-free, unprocessed foods and then slowly introduce highe- risk processed items while keeping a food diary and continuing to test for gluten.
Glutenostics originally intended to sell the tests in stores, but that would have resulted in a higher price, and the company decided to make them available online only, at least at the start, Winternheimer said. Online-only sales through the website will also enable the company to keep in direct contact with consumers, answering their questions and getting feedback on how well the products are working, he noted.
Plans for the launch of a test that would give the amount of gluten detected instead of just a positive or negative result, primarily aimed for use in physicians’ offices, have been delayed and won’t be a part of the initial launch. A quantitative test is currently being used for research only.
The tests that forms the basis of Gluten Detective have been studied in a number of clinical trials, primarily in Europe.
Gluten Detective is not approved under the Food and Drug Administration’s Food Drug and Cosmetic Act and cannot make a medical claim related to the treatment of celiac disease or any other condition. The tests can only claim to detect gluten consumed, fragments of which are found in the stool or urine of everyone, but only trigger an autoimmune response in those who have celiac disease.
FDA approval of the tests would require clinical trials conducted in the United States, which would have delayed the launch of Gluten Detective for several years. Glutenostics is running additional trials in the United States and could seek FDA approval in the future.
“This is a scientifically sound and validated product,” Winternheimer said. “We don’t want it to be seen as something gimmicky that does not work.”
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