Understanding my digestive health: Celiac disease, wheat allergy and non-celiac gluten sensitivity

23 February 2023

Gluten-related disorders can affect your overall health, but there are important differences between them.

Celiac disease is an autoimmune disorder that causes genetically susceptible individuals to react to gluten—a protein found in wheat, barley and rye. Individuals with an allergy to wheat have a different type of immune reaction to wheat proteins. For those with a non-celiac gluten sensitivity, consumption of gluten can cause discomfort and other symptoms, although the causes are not yet clearly identified. Even though the three conditions are quite different, they may be confused because they can all result in some overlapping symptoms after consuming gluten. 

Celiac disease and consuming gluten

When you have celiac disease and ingest gluten, your immune system views the gluten as an invader. The autoimmune response, damages intestinal “villi” (tiny projections) which absorb essential nutrients—and this damage can lead to malnourishment and several other health issues tied to gut health.

Celiac disease affects people differently; there are actually more than 200 known celiac disease symptoms which may occur in the digestive system or other parts of the body. Here are some common symptoms you may experience if you have celiac disease:

  • Diarrhea
  • Abdominal pain, bloating and gas
  • Weight loss
  • Fatigue
  • Skin rash

Celiac disease affects nearly 1 in every 100 people worldwide; however over 80% of celiac patients are undiagnosed.

Left untreated, celiac disease can lead to serious health complications down the road. That’s why it’s important to understand the differences between celiac disease, wheat allergy and non-celiac gluten sensitivity. While they can all can cause discomfort, they have different potential consequences.

How wheat allergy and non-celiac gluten sensitivity are different from celiac disease

Though wheat allergy and non-celiac gluten sensitivity could be associated with symptoms similar to celiac disease, these three conditions each result from a distinct disease process. The IgA and IgG antibodies used to screen for celiac disease are different from the IgE antibodies use to test for wheat allergy. Someone with a non-celiac gluten sensitivity will not test positive for celiac or wheat allergy. Ultimately, only the trigger is the same for these three conditions: consuming and ingesting some or all forms of gluten.

If you test negative for celiac disease and wheat allergy, you could still have non-celiac gluten sensitivity.

The range of gluten-related disorders cause discomfort and bring about challenges. Luckily there are tests to properly evaluate for celiac disease and wheat allergy.

Testing for celiac disease and wheat allergy

There are two steps to finding out if you have celiac disease: screening and diagnosis. A simple blood test can measure your tissue transglutaminase IgA antibody (tTG-IgA). If this initial screening test is positive, your physician can help you with confirmation of the diagnosis and guide you with the assistance of a dietician in pursuing the only treatment available: switching to a gluten-free diet.

Furthermore, your healthcare provider can counsel you regarding any vitamins and/or dietary supplements that may benefit you given celiac disease can cause nutritional deficiencies. If your celiac screening result is normal but you still feel that gluten is contributing to your digestive discomfort, Labcorp OnDemand offers food allergy testing to help you further investigate your body’s response to consuming wheat and other common food allergens.

You should always consult with a physician experienced with celiac disease to ensure proper diagnosis.

If you’re an adult wondering if you should get tested for celiac disease, doctors recommend the following individuals should receive testing:

  • Anyone with symptoms suggestive of celiac disease
  • Anyone with a first-degree relative who has celiac disease (namely parents, children and siblings)
  • Anyone who has an associated autoimmune disorder or other condition, namely Type 1 diabetes mellitus, thyroid disease, liver disease, Down syndrome, Turner syndrome, Williams syndrome and selective immunoglobulin A (IgA) deficiency.

You can purchase a blood test, such as Labcorp OnDemand’s test, which measures:

  • Total IgA: IgA is a class of antibody that is found throughout your body, especially in the GI tract and is involved in many of your immune responses. Knowing your total IgA is helpful for interpreting your celiac-specific antibody results.
  • tTG-IgA: This test detects IgA antibodies to tissue transglutaminase (tTG). In celiac disease, the immune response leads to IgA antibodies against tTG.
  • tTG-IgG: This test detects IgG antibodies to tTG, and will be performed if your IgA level is below normal. In celiac disease, the immune response often leads to IgG antibodies against tTG.
  • DGP-IgG: This test measures IgG antibodies to deamidated gliadin peptide (DGP) and will be performed if your IgA level is below normal. Gliadin is a major component of gluten. In celiac disease, the immune response often leads to antibodies against DGP.

Ultimately, screening for celiac will help you find out whether or not you may have celiac disease, which could prompt you to make specific dietary changes to improve your overall health if recommended by your healthcare provider. If you suspect you have celiac disease but your screening test results are normal, it may prompt you to consider other possible conditions such as food allergy or non-celiac gluten sensitivity. Keep in mind that celiac disease can develop at any age in people who are genetically predisposed, so you should consider retesting in the future if your concerns persist. Take charge of your health if you think you may have gluten-related disorders—you and your provider can easily order a celiac antibody test and a food allergy test today from the lab providers trust most.