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Gluten sensitivity, or non-celiac gluten sensitivity (NCGS), is a genuine condition that falls under the umbrella term “gluten intolerance.”

This article covers the various types of gluten intolerance, including NCGS.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Gluten is perhaps one of the most controversial and misunderstood food compounds. Although often seen as a single protein, gluten encompasses a number of proteins called prolamins.

Prolamins are present in wheat, rye, barley, and a cross between wheat and rye known as triticale.

Although there are many prolamins present in these grains, gliadin and glutenin are the main prolamins in wheat.

These proteins are resistant to complete digestion by digestive enzymes that reside in the gastrointestinal (GI) tract.

This is because enzymes that the pancreas, stomach, and brush border of the intestinal tract produce are unable to fully break down proteins that have a high content of proline residue. Proline is an amino acid — the building block of protein — that is present in gluten.

Incomplete digestion of these proteins allows large units of amino acids called peptides to cross over through the wall of the small intestine.

These fragments cross the intestinal barrier and travel to other parts of the body, where they can trigger an inflammatory immune response in susceptible individuals.

It is important to note that gluten proteins are exceptionally resistant to digestion in all people, not just in people who have celiac disease, which is an autoimmune condition.

“Gluten intolerance” is an umbrella term that refers to three major types of gluten-related conditions. Below, we look at each in turn.

Celiac disease

Celiac disease is perhaps the most well-known gluten-related medical condition. It is an autoimmune disease that involves the immune system reacting to gluten proteins.

When people with celiac disease eat gluten, it leads to damage in the small intestine and causes a wide range of symptoms, including diarrhea, abdominal pain, and bloating.

Prolonged gluten exposure in people with celiac disease can lead to decreased bone mineral density, significant weight loss, iron deficiency anemia, seizures, muscle weakness, and other serious symptoms.

Prevalence varies around the world, with some countries experiencing higher rates than others.

Experts estimate that the condition currently affects around 1–2% of the population in the United States and is more common in females.

Celiac disease is also more common in people who have other autoimmune conditions, including type 1 diabetes.

Experts believe that the condition is due to both genetic and environmental factors. Doctors usually recommend that people with celiac disease follow a strict gluten-free diet.

Wheat allergy

According to research, people with a wheat allergy have an allergic reaction to proteins present in wheat. This type of allergy is much more common in children, although it can also affect adults.

Wheat allergy can produce severe symptoms, including anaphylaxis, which is an allergic reaction that can be life threatening.

Although both celiac disease and wheat allergy are serious conditions, the mechanisms involved in either of them differ.

For example, unlike celiac disease, wheat allergy can be immunoglobulin E (IgE) mediated. This means that wheat-specific IgE antibodies bind to wheat, thereby triggering the release of inflammatory compounds, including histamine.

IgE-mediated immune responses are immediate and can be life threatening. A response can also stem from wheat inhalation — for instance, when baking with wheat flour.


Some people experience reactions to gluten even though they do not have celiac disease or an allergy to wheat. Experts refer to this type of gluten intolerance as NCGS.

According to a 2019 review, NCGS is much more common than celiac disease and may impact up to 13% of the population.

Like celiac disease, NCGS is more common in females.

People with NCGS experience GI symptoms that include bloating, gas, and diarrhea, as well as non-GI symptoms, such as fatigue, anxiety, and headaches. These symptoms often improve on a gluten-free diet.

Experts believe there is a link between NCGS symptoms and an immune response, although there is still some controversy surrounding the precise cause. NCGS is more common in people with autoimmune diseases.

Some scientists suggest that other components of wheat, not just gluten, may cause or contribute to NCGS. There is still much to learn about NCGS, and scientists continue their efforts to better understand this condition.

If a person experiences the symptoms listed above after consuming gluten, a doctor must rule out celiac disease and wheat allergy before they can diagnose NCGS.

There are currently no tests that can help diagnose NCGS, which is why the condition remains a diagnosis of exclusion.

Following a diagnosis of NCGS, an individual should avoid gluten by following a gluten-free diet.

Gluten sensitivity, or NCGS, is a type of gluten intolerance.

Celiac disease and wheat allergy are other gluten-related conditions, but they differ from NCGS in many ways.

If a person has symptoms such as diarrhea, bloating, or headaches after consuming gluten, they should consult a doctor about tests for gluten intolerance.