In some respects testing for gluten sensitivity is relatively easy. But like everything else in healthcare, there are all kinds of exceptions and challenges.
The best way to test for reactions to gluten is with antibodies. Antibodies are produced by the immune system to fight things like viruses and bacteria, but you do not normally produce antibodies against food, because you don’t want to be fighting your food. But when you are producing antibodies against food that is a problem and a message from your immune system that something is wrong.
One of the oldest and easiest to access tests for gluten sensitivity has been blood tests for anti-gliadin IgA and IgG antibodies. Gliadin is a component of gluten. Twenty years ago doctors would run these all the time. I have no idea why, since 99% of them didn’t pay any attention to the results if the tests for celiac disease were negative, meaning that you didn’t have celiac disease.
But fortunately for me these tests were run, and you could readily tell if someone was reacting to gluten when you saw IgA or IgG anti-gliadin antibodies in the blood. If it was positive, then I knew that there was a gluten sensitivity.
However, this isn’t the only way to test for gluten sensitivity, and it also isn’t guaranteed to pick up all types of gluten sensitivity.
You can also test for antibody reactions to wheat, and spelt, and rye, and barley, as well as gluten, not just gliadin. These IgG and IgA antibody tests will also usually pick up gluten reactions, and can pick up a gluten reaction that isn’t specific to gliadin. That’s very helpful, because it happens quite a bit.
But sometimes all of these blood tests will be negative, and you’ll still have a gluten sensitivity. Blood is not the only place where you can find antibodies. Antibodies also show up in stool. And these antibodies can be positive even when your blood tests are negative. So we like to look there too, because many times I’ve seen where the only positive test for gliadin antibodies was in the stool test.
But that’s not all. It gets even more interesting. You can react to things in wheat other than gluten. Say what? Yes, there are a lot of other components in wheat than gluten. No one talks about them, but they are just as important. And you can just as easily react to them as you can to gluten.
So you can, for example, have positive antibodies to wheat, but not to gluten or gliadin. I’ve seen this happen many times.
Then are also reactions to things like the germ of the wheat, or what we usually call wheat germ. You might think of wheat germ as a product, which it is, but remember it’s also a part of wheat. This is another important food reaction that can cause all of the same symptoms but is not a gluten reaction.
That’s a summary of how to test for gluten sensitivity, and a bit about testing for wheat reactions as well. And keep in mind, if you’ve tested positive and removed gluten but not gotten any better or all better, then there is a lot more going on than just a gluten reaction. And that’s what we help people figure out at the IBS Treatment Center.
Do you think you could have a non-celiac gluten sensitivity?
Dr. Wangen is the founder and medical director of the IBS Treatment Center, the award winning author of two books, and a nationally recognized speaker on digestive disorders. He has been on ABC, NBC, and Fox as well as public radio, and was named one of Seattle’s Top Doctors by Seattle Magazine.