What you need to know about taking a gluten intolerance test

Welcome to GlutenIntoleranceTest.com. We offer information about non-celiac gluten sensitivity and the options for gluten intolerance testing. Since you are visiting this site, you or someone you know most likely experiences an adverse reaction to eating wheat or other grains that contain gluten. While your body may already be telling you that it doesn’t react well to gluten, it’s important to know whether the body reacts in a harmful way to gluten. A gluten intolerance test can help you determine whether gluten causes a temporary, inconvenient reaction, or if it actually disrupts the immune system, thus presenting a more serious threat to your health.

There are different health problems associated with gluten intolerance. Finding out which, if any, apply to you is the first step in designing a diet that is optimal for your health.

gluten intolerance test tube

A small stool sample is all that is needed for a laboratory to conduct a gluten intolerance test.

There are different reasons why some people react negatively to gluten-containing products:

  • People with celiacs disease have an an “auto-immune disease”. Their bodies create an antibody called anti-gliadin, when they eat gluten. This antibody is a reaction to gliadin, which is a component of gluten. People who react to gliadin with antibodies are considered “gluten intolerant” which is synonymous with celiac disease.
  • People can also react allergicly to glutenin, another component of gluten. Gliadin allergy means you may have a “wheat or gluten allergy.”
  • Gluten sensitivity means that people have had a negative result to a gluten intolerance test, but still feel better on a gluten free diet. Either they are affected by something in wheat other than gliadin, or possibly the test was not performed or interpreted correctly.
  • There are also people who have a negative reaction to starchy products in general. These people may be under the impression they are specifically intolerant of gluten, when in fact over consumption of starches and sugars in general is to blame.

Clearly there are a variety of subtle differences separating gluten intolerance / celiac disease, gluten and wheat allergy, gluten sensitivity and starch intolerance. It isn’t always evident which (or any) of these conditions are present. For that reason, taking the right gluten intolerance test is the best place to start.

Why take a gluten intolerance test?

To determine whether or not you are gluten intolerant, have a gliadin or glutenin allergy or have celiac desease, you can take a gluten intolerance test. It is important to know exactly what, if anything, you are up against. Celiacs disease is a serious condition, but goes undiagnosed in most cases. Gaining access to the right gluten intolerance test is an essential step in identifying undiagnosed celiac cases. Gluten intolerance can be annoying – tons of foods cannot be enjoyed without having to pay a price. That price varies per person. Some may simply become a bit drowsy, while others might experience more severe irritation. In general, however, a gluten intolerance is easy to manage. There are many great gluten free alternatives, and it seems more and more gluten free products are being offered.
Celiac disease on the other hand, is very serious. Diagnosing celiac disease can help prevent a plethora of complications, including brain damage. In fact, it is important that a lot more people take a gluten intolerance test because gluten is so rarely diagnosed. Gluten intolerance is the most undiagnosed disorder in the US! Only one out of every eighty people with gluten intolerance has actually been diagnosed. To say that the known cases of gluten intolerance represent only the tip of the iceberg would be an understatement. A gluten intolerance test can finally reveal the cause of years of discomfort, exhaustion and poor health.

How accurate is a gluten intolerance test?

The truth is, a gluten intolerance test is less accurate than one would hope. It gets a bit technical, but here is the breakdown:

  • about one in one hundred people have gluten intolerance (people with irritable bowel syndrome much more frequently)
  • the gluten intolerance test has a specificity of 98%

What 98 % specificity means, is that 98% of all positive results are accurate. 2% of positive results are false positives. Since only 1% of the population tests positive, there are 2 false positive results for every real one. In other words, the specificity of the test is 98%, yet only 33% of positive results are truly positive. Keep in mind, this is the case with a random sample. People with IBS are gluten intolerant up to 4% of the time. So for people with IBS, about 6 of one hundred will have a positive gluten intolerance test result. 4 (66%) will have an accurate positive result. This is a bit better, but clearly there is some uncertainty regarding taking a gluten intolerance test. Kind of confusing? Absolutely. Unfortunately some companies are taking advantage of the confusing formula used to determine test accuracy, and are presenting their products as more accurate than they really are. What does specificity really tell you about a product? Nothing. More information is needed: How frequent are positive results? If a test is positive 50% of the time, and is 98% specific, 4% of positive results will be false positive. When the test is only positive 1% of the time, those false positive results 2% of the time become much more relevant.

Is there a gluten intolerance test to diagnose celiac disease with?

gluten intolerance test icebergThe answer is simple: no. There are no gluten intolerance test kits that diagnose celiacs disease. This is an important point, and should be made very clear. There are tests on the market that claim to be able to detect celiac disease. This is not true, these tests merely measure anti-gliadin. In other words, the tests determine gluten intolerance, but not celiac disease. Even a medical laboratory cannot measure celiac disease from a stool or blood sample. If there was a test for celiac disease, that would be wonderful. It simply isnt the case though. The fact that it is so difficult to diagnose celiac disease is the reason so few cases are ever diagnosed. Sadly this causes very serious health problems for those who are never diagnosed, and continue to eat gluten throughout their life.

So how is celiac disease diagnosed then?

Celiac disease can only be comfirmed with endoscopy. This means an instrument is fed through the mouth into the small intestine. Here a tissue sample is collected for analysis. The tissue is examined to determine if it is damaged in a way that is characteristic of celiac disease. If there was a simple test for celiac disease, it would be a blessing – however science has not yet produced an accurate test. It is unpleasant and invasive to have an instrument inserted through the mouth, and intestinal tissue removed. The nature of this exam is one of the reasons celiac disease goes undiagnosed in so many cases. So whats the point of taking a gluten intolerance test, you may be wondering? A gluten intolerance test can first and foremost help establish whether gluten is a problem. Once it has been determined that gluten is in fact triggering a response from the body, then it makes sense to undergo endoscopy. In other words, a gluten intolerance test can help make a selection of people who need endoscopy to determine whether celiac disease is present. With a negative gluten intolerance test result, it is immediately clear endoscopy is not needed, and there is no chance of celiac disease.

Gliadin the phantom “pathogen”

When someone is gluten intolerant, their body perceives Gliadin, a component of the gluten protein, as a harmful pathogen. Basically, the body confuses Gliadin for a harmful bacteria, and tries to attack it. Of course gluten isn’t a pathogen – it isn’t even alive. So the body ends up fighting an endless, pointless battle against a phantom opponent.

This battle may not have a real opponent, but it does have a real victim: the human body. Especially in the case of celiac disease, there are a plethora of real, and sometimes very serious, health risks. For people with gluten intolerance, the result is often constant fatigue and cold and flu like symptoms. When people are sick, the symptoms are often caused by the immune response of the body itself – not by the source of the illness. Gluten intolerance is often confused with celiac disease, or thought of as an allergy. In fact it isn’t an allergy at all, but an auto immune response.

The body makes a distinctlty different antibody in response to gluten than it does with other allergies. For example, with a peanut allergy, the body makes IgE antibodies – the same is true of almost all allergies – even wheat allergy, which is so easy to confuse with gluten intolerance, triggers an IgE antibody response. Gluten intolerance triggers an IgA response. IgA responses are normally reserved for bacteria. So in other words, the body mistakes gluten for a bacteria, and reacts accordingly. One type of gluten intolerance test involves testing a stool sample, to determine the presence of Iga in the stool. Atni-tissue-transglutaminase is the specific Iga response that is tested for. Gluten is a protein, and one of the components in gluten is gliadin. The body makes enzymes to break down gliadin, which can be found in the stool.

Intestinal Parasites

Visit www.parasiet.com to learn about how intestinal parasites can cause IBS symptoms.

Non Celiac Gluten sensitivity (NCGS)

Some people are sensitive to gluten, but do not have celiac disease or wheat allergy. If you’ve taken a gluten intolerance test or been tested for celiac disease, and had a negative test result, you still may suffer from gluten sensitivity, also called Non Celiac Gluten Sensitivity (NCGS).

Doctors and researchers agree that there are people who have been shown to not have celiac disease or wheat allergy by a qualified medical specialist, but who nevertheless respond well to a gluten-free diet. In this case, the cause might be gluten sensitivity.

NCGS symptoms

People with gluten sensitivity have symptoms that resemble both celiac disease, and irritable bowel syndrome (IBS). IBS symptoms include abdominal pain, bloating, diarrhea or constipation. People with NCGS often experience these symptoms in addition to symptoms like headaches, migraines, feeling groggy, chronic fatigue, joint and muscle pain, and a tingling feeling in the arms, hands, legs and feet.

Gluten sensitivity test

NCGS can only show through a strict diet, and must be guided by a physician or dietician. Testing for NCGS goes as followed: For the first 6 weeks a strict gluten-free diet is followed, after which gluten is once again eaten. The physician or dietician then compares the symptoms experienced during both phases.

Studies are currently being conducted worldwide to find out what the exact cause of gluten sensitivity is, and to try to develop a diagnostic method. It is possible that the symptoms may in fact not be due to the protein gluten, for example, but to a different protein or a different substance present in wheat and other gluten containing grains. Some doctors and researchers specializing in NCGS have attempted to develop criteria, with which to diagnose NCGS: the so called Salerno criteria. These criteria are still not fully applicable in practice.


It may also be that the diagnosis of celiac disease wasn’t complete, and the possibility was not eliminated properly. In some cases, the biopsies from people who were tested and shown not to have celiac disease, may have been incorrectly handled or misinterpreted and despite the negative test, it still could be celiac disease.

In truth, we still do not know exactly what gluten sensitivity is. Hopefully this will become clear in the future with more research. If in doubt, we advize to first consult your doctor, and take a gluten intolerance test to exclude the diagnosis of celiac disease and wheat allergy. If the results of these gluten intolerance tests are negative, a gluten free test diet can be administered by a qualified medical specialist.

Talking to a doctor about taking a gluten intolerance test

If you think the symptoms you are experiencing indicate celiac disease, discuss this with your doctor. Unfortunately, this is not always easy. Celiac disease is relatively unknown, and it’s possible that your doctor may not know much about testing for gluten intolerance. The trouble involved in finally obtaining a gluten intolerance diagnosis, is something most people who have went through the process do not look back on fondly. One reason is that the symptoms of celiac are rather vague, and also correspond with other disorders. So it is not entirely the fault of your doctor, if he or she does not immediately think of celiac disease.

The doctor can determine whether there are antibodies to gluten in the blood, with a simple blood test. If that is the case, then the probability of celiac disease is large. However, it also happens often that no antibodies are found in the blood test, but that does not mean that celiac disease should be ruled out. If there you have symptoms that fit celiac disease, or have a close relative with celiac disease, then further testing is advised.

blood testing

With the standard blood test it is checked whether antibodies against tissue transglutaminase (tTGA) are present. tTGA is based on the presence of IgA antibodies. However, some people with celiac disease have an IgA deficiency. This is a congenital condition, in which the immune substance IgA is either lacking or missing. People with IgA deficiency need an additional gluten intolerance test,  based on IgG antibodies.

If antibodies are found in the blood, or if there are other important reasons to suspect celiac disease, such as persistent intestinal problems, your doctor should refer you to a gastroenterologist or pediatrician for an intestinal biopsy.

intestinal biopsy

healthy intestinal villi

This is what healthy intestinal villi should look like. Villi greatly increase the total surface area of the small intestine. People with celiac disease who eat gluten eventually suffer from atrophy of the villi. This reduces the intestines ability to absorb nutrients, eventually leading to health problems related to malnourishment.

An intestinal biopsy is one of the gluten intolerance tests used to diagnose celiac disease. A biopsy of the intestines means that a small tissue sample is collected from the small intestine, to determine if the tissue has been affected by gluten. To take a biopsy, the doctor inserts a thin, flexible tube through the mouth, into the small intestine. With a tiny pair of pliers attached to the end of the tube, a small pieces of the intestine wall is cut out. This sample is then examined in a lab, under a a microscope. If the intestinal villi appear to be lacking, or to be damaged, this qualifies as a positive diagnosis of celiac disease.

Anaesthesia in intestinal biopsy

An intestinal biopsy is relatively quick procedure. While it should not hurt, it’s also not very nice. It is possible to get anaesthesia, or the throat can be sprayed with a light anaesthetic liquid spray. For children, there is the option of going under completely.

Discuss with your doctor whether or not, and what type of anesthesia you want for yourself or for your child. Your doctor can discuss the pros and cons of a specific anaesthetic with you, so you can make an informed decision. It’s best to discuss this well before the biopsy, so the hospital can take it into account when planning the gluten intolerance test procedure.

If you find it difficult to make a decision, you may be able to find an association for people with celiac disease to get in contact with, who have experience with undergoing an intestinal biopsy.