Different types of testing for gluten sensitivity exist, including genetic testing, intestinal biopsy evaluation, and antibody testing. As we have discussed, an immune reaction to gluten does not have to involve either the gut or specific genotypes, as many people develop neurological disorders instead. Therefore, it is not necessary to perform an intestinal biopsy or gene testing to evaluate gluten sensitivity.
Stool testing for gluten sensitivity has little evidence in the literature, so I do not use it or
endorse it at this point. Most doctors screen for gluten sensitivity using blood tests, but saliva
tests have shown great promise in terms of their reliability.
Blood testing for gluten sensitivity involves placing samples of your blood in a dish of gluten
proteins and seeing whether antibodies develop, an indication gluten activates your immune
cells and you have gluten sensitivity.
The problems and solutions with gluten sensitivity testing
Testing for gluten sensitivity is much more complex than most people and the standard health
care model realize. This is because people can react to a number of different portions of the
gluten protein. Most labs only test for antibodies to a portion of gluten called “alpha gliadin,”
which, thanks to current research, we now know is extremely limited and produces many
clinically negative results. If you have symptoms that suggest a gluten sensitivity but your
gluten test came back negative, you may want to get tested again with a more thorough
evaluation using the information below.
Gliadin
Gluten is made of a sticky portion called “glutenin” and a protein portion called “gliadin.” Gliadin
is further broken down into alpha, omega, and gamma gliadins. Most labs only test for alpha
gliadin antibodies, which are most commonly associated with celiac disease. Even worse, they do
not report this limitation in test results. The reports usually state “gliadin” antibody, but do not
specify it is alpha gliadin. The result often comes back negative, doctors tell patients they can eat
gluten, and patient health further deteriorates. When the patient finally tests for the other
branches of gluten, the results show severe gluten sensitivity. I have seen this happen many
times.
Glutenin
Glutenin, the sticky portion, makes up 47 percent of the total protein content of wheat and is
responsible for the strength and elasticity of wheat dough. Most labs do not test for glutenin
sensitivity because it was believed glutenin is not immune reactive. However, this has been
disproven. Many people have severe reactions to glutenin but show normal results on the basic
gliadin antibody test.
Deamidated gluten
As I mentioned earlier, deamidation is an acid or enzymatic treatment used by the food
processing industry to make wheat water soluble so it mixes easily with other foods, and
deamidated gliadin has been shown to trigger a severe immune response in people. Many
people will never test positive on a conventional gliadin antibody test but will have profound
immune reactions to deamidated gliadin. If you suffer from impaired brain function, testing for
deamidated gluten is critical.
Lectins
Many people who react to wheat do not react to the gluten portion of wheat. Instead, they react
to the lectin portion. Lectins are substances that bind sugars and carbohydrates together. In
wheat, they are called wheat germ agglutinin (WGA).
The highest concentration of WGA is found in whole wheat or sprouted wheat. WGA can pass
through the blood-brain barrier and attach to the myelin sheath, the protective coating on
nerves. This can inhibit nerve growth factor, a chemical critical for neuron growth and health.
Many people never test positive for gluten antibodies but have a WGA sensitivity. For these
people eating lectins may cause a severe inflammatory response and destroy neurons.
Opioids
Lastly, people may react to gluten opioids, which is different from a reaction to gliadin, glutenin,
or WGA. An immune response to opioids takes place in the nervous system and can be
measured by antibodies to gluteomorphin and prodynorphin. Gluteomorphin is an opioid peptide
formed during the digestion of gluten. Prodynorphin is an opioid that is the basic building block
of endorphins.
If a person has elevated antibodies to these compounds, gluten may cause a neurological
reaction. The most difficult thing about an opioid sensitivity is that going gluten-free can cause
severe withdrawal symptoms, including depression, mood swings, or abnormal bowel activity. It
is similar to withdrawal from opioid drugs such as heroin. If this occurs the person must hang in
there for a couple of weeks on a strict gluten-free diet and deal with the withdrawal symptoms
until they’ve kicked the gluten addiction.
Transglutaminase
The last issue to cover with gluten sensitivity testing is transglutaminase, which I introduced
earlier. Positive transglutaminase antibodies indicate gluten triggers autoimmunity.
There are three major transglutaminases: TG2, TG3, and TG6.
TG2 is found in the intestinal tract and elevated TG2 antibodies indicate villous atrophy
(destruction of the tiny finger-like projections in the small intestine that absorb food) and
destruction of the intestinal lining.
TG3 is found in the skin and is associated with skin outbreaks triggered by gluten, such as
dermatitis herpetiformis.
TG6 is associated with neurological destruction triggered by gluten.
Labs today only test for antibodies to TG2, the intestinal transglutaminase. They also list the test
results as “transglutaminase” and never specify it is only TG2. If you have neurological issues
possibly stemming from gluten, you also need to evaluate TG6.
Also, it’s important to test additionally for transglutaminase bound to gliadin or the test may miss
transglutaminase antibodies, possibly resulting in a clinically negative result. Most labs only test
for transglutaminase not bound to gliadin.
You can now see how flawed and limited gluten testing is today and why so many people
continue to suffer despite a negative celiac test. The most common tests my patients have done
before they come to my office are an isolated alpha gliadin and TG2. As you now know, this is
not nearly enough information, as many people have severe immune reactions to other types of
gluten or may produce antibodies to a different transglutaminase enzyme.
In summary, a complete gluten antibody screen should include:
- alpha gliadin
- omega gliadin
- gamma gliadin
- deamidated gliadin
- wheat germ agglutinin (WGA)
- gluteomorphin
- prodynorphin
- transglutaminase-2 (TG2)
- transglutaminase-3 (TG3)
- transglutaminase-6 (TG6)
This is the panel I use for my patients, and it has revealed countless misdiagnosed issues of
gluten sensitivity. This panel is only available through Cyrex Labs (cyrexlabs.com), and it is called
the Wheat/Gluten Proteome Sensitivity and Autoimmunity Panel.
If the test shows you are gluten sensitive you should avoid gluten at all costs. If you have positive
reactions to any of the transglutaminases, it means you have an autoimmune reaction and
should consider further screening for antibodies to neurological tissue if you suffer from brain
decline.
To learn more, download my free guide Gluten and the Brain.
