Symptoms of Gluten Sensitivity

Medically reviewed by Jay N. Yepuri, MD, MS

The symptoms of gluten sensitivity, otherwise known as non-celiac gluten sensitivity (NGCS), are often indistinguishable from celiac disease (CD. Both are triggered by exposure to gluten (a protein found in wheat and other grains like rye and barley), and both can cause gastrointestinal (GI) symptoms like stomach pain, bloating

However, with gluten sensitivity, symptoms tend to develop faster and people are far more likely to develop extraintestinal (non-GI) symptoms like fatigue, headaches, and "brain fog."

This article looks at the symptoms, causes, diagnosis, and treatment of non-celiac gluten sensitivity and explains how it differs from celiac disease.

Gluten Sensitivity vs. Celiac Disease

Non-celiac gluten sensitivity, as per its name, is an abnormal sensitivity to gluten that is not associated with celiac disease.

With CD, symptoms are caused by an autoimmune reaction to gluten. What this means is that the body will respond to gluten by releasing immune proteins, called autoantibodies, that inappropriately target and attack the lining of the small intestine with inflammation.

With NCGC, gluten appears to cause direct damage to intestinal tissues in the absence of a known autoimmune response.

NGCS is poorly understood, but studies have shown that gluten can be cytotoxic (toxic to cells) in some people. Other studies suggest that gluten might trigger an innate immune response similar to what would happen with a local infection, causing inflammation as gluten passes through the gut.

How They Differ

NGCS differs from CD in a few key ways.

Because gluten directly affects the lining of the intestines in people with NGCS, it generally causes symptoms within minutes to hours. By contrast, the autoimmune response triggered by CD can develop gradually rather than abruptly, sometimes causing symptoms days or weeks later.

Another way that NGCS differs is that it is more likely to cause extraintestinal symptoms. Because inflammation is triggered when gluten comes into contact with intestinal tissues, it is more generalized and can "spill over" beyond the intestines, reaching muscles, joints, and the brain.

By contrast, the autoimmune response with CD is more targeted. The autoantibodies released by the immune system are essentially "programmed" to attack tiny, finger-like projections in the intestinal lining called villi. Because of this, symptoms are predominantly gastrointestinal.

Symptoms of Gluten Sensitivity

NCGS can cause both gastrointestinal and extraintestinal symptoms, although some people may only experience GI symptoms while others may only experience non-GI symptoms.

Gastrointestinal

Digestive problems are common with non-celiac gluten sensitivity. These symptoms tend to develop soon after eating gluten and can mimic those of irritable bowel syndrome (IBS).

Studies suggest the most common GI symptoms of NGCS (by the percentage of people affected) are:

Extraintestinal Symptoms

Symptoms outside of the GI tract are more common with gluten sensitivity than with CD. These are categorized as being neurological (related to the nervous system) or systemic (related to the body as a whole).

The most common extraintestinal symptoms of NGCS (by the percentage of people affected) are:

Gluten Sensitivity in Children

It is difficult to know how many children are affected by NGCS because the symptoms are hard to differentiate from functional gastrointestinal disorders (FGDs) like IBS. Some studies suggest that the rate of IBS among children in the United States hovers between 1.2% and 2.9%.

Children thought to have gluten sensitivity may, in fact, have a wheat, rye, or barley allergy. Cereal grain allergy is common in children and is usually outgrown with age.

In children diagnosed with NGCS, GI symptoms predominate, while extraintestinal symptoms are rare. A 2019 study in the Journal of Pediatrics reported that the most common symptoms in children were abdominal pain, bloating, rash, and diarrhea or loose stools.

Diagnosis of Gluten Sensitivity

Due to the lack of understanding about the disease or how it causes illness, there are no lab tests or imaging studies that can diagnose NGCS. The diagnosis is primarily based on the testing and exclusion of all other possible causes.

Chief among these are:

• Celiac disease: Diagnosed with blood tests that can detect celiac autoantibodies and a biopsy of the small intestines to check for villous atrophy (the erosion of villi)

• Wheat allergy: Diagnosed with an allergy blood test, a skin prick test (applying a tiny amount of wheat protein under the skin), or a patch test (applying wheat protein against the skin).
  

Other tests may be ordered to rule out other suspected causes.

If CD and wheat allergy are excluded, your healthcare provider may recommend eating a gluten-free diet for 6 weeks, followed by the reintroduction of gluten for one week. A 30% improvement in symptoms with the diet and a 30% increase in symptoms with the reintroduction of gluten is considered by some to be diagnostic of NGCS.

The healthcare provider will take into account other "clues" that NGCS is involved, including the rapid onset of symptoms after eating gluten and extraintestinal symptoms.

How Gluten Sensitivity Is Treated

The elimination of gluten from the diet is the primary treatment of NGCS. Experimentation may be needed to determine how much, if any, gluten you can eat before symptoms develop.

The grains not allowed on a gluten-free diet include:

• Wheat

• Wheat varietals like durum, graham, bulgur, farro, farina, semolina kamut, and spelt

• Barley

• Rye

• Triticale (a hybrid of rye and wheat)

• Malt

The grains allowed on a gluten-free diet include:

• Quinoa

• Brown rice

• Wild rice

• Sorghum

• Tapioca

• Millet

• Amaranth

• Oats
  

Related: Where to Find Gluten-Free Food

Summary

Gluten sensitivity, otherwise known as non-celiac gluten sensitivity (NGCS), is a functional gastrointestinal disorder that has many of the same symptoms as celiac disease (CD). Even so, symptoms of NGCS develop within minutes to hours of eating gluten, while symptoms of CD can occur days or even weeks after.

While NGCS and CD can both cause gastrointestinal symptoms like stomach pain, bloating, nausea, and diarrhea, NGCS is more likely to cause extraintestinal symptoms like headaches, fatigue, joint and muscle pain, and "brain fog."

If positively diagnosed, NGCS is treated with a gluten-free diet.

Read Next: Best Gluten-Free Meal Delivery Services