Gluten intolerance is when the body cannot digest gluten well or has difficulty processing it. Gluten is a protein found in foods such as wheat, rye, and barley.
This condition can cause symptoms such as diarrhea, abdominal pain and bloating, and excess gas. It is also known as non-celiac gluten sensitivity.
Gluten intolerance has no cure, so gluten needs to be completely removed from the diet for symptoms to improve. Celiac disease, by contrast, is an autoimmune condition that causes inflammation and damage to the small intestine when gluten is consumed.
Common symptoms
The main symptoms of gluten intolerance are:
-
Diarrhea or constipation
-
Fatigue
-
Abdominal bloating
-
Excess gas
-
Headache
-
Nausea
-
Fatigue that gets worse after eating foods that contain gluten
In some cases, a person with gluten intolerance may also have mental confusion, malaise, slowed thinking, lactose intolerance, fibromyalgia, dermatitis, joint pain, and depression.
Gluten intolerance symptoms may appear within hours or days after eating foods that contain this protein.
How to test for gluten intolerance
Gluten intolerance is diagnosed by a gastroenterologist or primary care provider based on the person’s symptoms and health history.
To confirm the diagnosis, the provider may also order tests to help rule out celiac disease. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), blood tests and biopsies of the small intestine are typically used to diagnose or rule out the condition.
In addition, the provider may recommend a gluten-free diet to see whether the symptoms improve.
Possible causes
The cause of gluten intolerance is not completely understood. However, some studies show that wheat may damage the lining of the intestine in some people, making it easier for bacteria to enter the bloodstream or liver and trigger inflammation.
Other studies suggest that some people may not be sensitive to gluten itself, but rather to a type of carbohydrate found in many foods that is not fully digested and ferments in the gut, triggering symptoms.
Celiac disease vs gluten intolerance
Celiac disease is an autoimmune condition in which eating foods with gluten triggers an immune response that causes inflammation and damage to the small intestine. Symptoms may appear soon after eating gluten or develop gradually over several hours or days.
Gluten intolerance, on the other hand, refers to difficulty digesting gluten. Symptoms usually appear hours or even days after eating gluten, do not involve inflammation or autoimmune reactions, and any intestinal changes typically improve once gluten is removed from the diet.
Treatment options
Because there is no cure, treatment for gluten intolerance focuses on removing gluten from the diet. This means avoiding wheat, rye, barley, and malt, which are commonly found in foods such as pizza, bread, cookies, and cake.
People with gluten intolerance can eat foods such as corn, tapioca, cassava, and other starches like rice and potatoes. According to the NIDDK, these foods are naturally free of gluten.
A doctor or dietitian may also recommend probiotics, which are beneficial bacteria that help balance the gut microbiota and may ease symptoms such as bloating, gas, diarrhea, and constipation.