What Gluten Does to the Body?

Jan 09, 2024

What Gluten Does to the Body?

Gluten, a mixture of seed storage proteins found in wheat, barley, rye, and oats, has become popular in recent years due to its connection with various health issues. The proteins that make gluten vary depending on their source; some are more reactive within the human digestive tract than others. This article will delve into the details of gluten sensitivity disorders, specifically celiac disease, wheat allergy, and non-celiac gluten sensitivity, to help understand the facts and dispel common misconceptions.

What is Gluten?

Gluten is a combination of proteins, specifically seed storage proteins, found in grains such as wheat, barley, rye, and oats. Gluten makes up about 85 to 90% of the protein in wheat and is a complex mixture of multiple distinct but related proteins, mainly gliadin and glutenin. The specific proteins that constitute gluten vary depending on the grain source and interact differently within the human digestive system. Wheat gluten proteins are the most reactive and clinically relevant, making them the focus of this article. The grains are the primary sources of gluten, so they are important to understanding gluten intolerance or sensitivity. Gluten intolerance or sensitivity is when the body has difficulty digesting gluten, leading to various symptoms such as digestive issues, skin rashes, and brain fog. Symptoms can vary widely, but some common ones include bloating, gas, diarrhea, constipation, and fatigue.

Gluten Intake

Gluten intake can cause inflammation in the gut and brain, leading to brain fog, a feeling of mental confusion or lack of clarity. Gluten can also affect nutrient absorption by damaging the lining of the small intestine, leading to deficiencies in vitamins and minerals such as iron and calcium. Common digestive issues related to gluten intolerance or sensitivity includes bloating, gas, diarrhea, constipation, and abdominal pain. Common skin rashes related to gluten intolerance, or sensitivity includes dermatitis herpetiformis and eczema. Removing gluten from your diet may help with joint pain in some individuals with gluten intolerance or sensitivity, as it can reduce inflammation in the body.

Gluten Digestion

Digestion of gluten begins in the mouth, where saliva breaks down the starch in the dough but not the gluten proteins themselves. The stomach then mechanically and chemically digests the food using hydrochloric acid and the protease enzyme pepsin. Contrary to popular belief, the stomach can break down gluten, but not completely. Pepsin breaks gluten into seed storage proteins gliadin and glutanin, which are then sent to the small intestine.

The partially digested food, called chyme, is released from the stomach into the small intestine through the pyloric sphincter. In the small intestine's duodenum, proteases from the pancreas and the intestinal lining attempt to further break down gliadin and glutanin. However, they can only create amino acid fragments that are too large to be absorbed properly, leading to potential issues.

Gluten Sensitivity

Common gluten intolerance or sensitivity symptoms include digestive issues, skin rashes, brain fog, joint pain, and fatigue. An accurate diagnosis can be obtained through blood tests, a gluten-free diet, and a gluten challenge. Health risks associated with gluten consumption for those with gluten intolerance or sensitivity include malnutrition, autoimmune disorders, and an increased risk of certain cancers. However, eliminating gluten from your diet includes improved digestion, increased energy, and better overall health.

Gluten Sensitivity Disorders

Celiac Disease

Celiac disease is an autoimmune disease to gluten is called celiac disease. Celiac can damage the small intestine. Some people who don't have celiac disease still seem to feel sick after eating foods that contain gluten, affecting around 1% of the global population. In individuals with celiac disease, gliadin fragments invade the intestinal tissue, triggering an autoimmune response that attracts white blood cells and causes inflammation. The resulting inflammation and atrophy of the intestinal tissue can lead to weight loss, diarrhea, short stature, osteoporosis, and other complications.

Gluten-sensitive enteropathy is another term for celiac disease, an autoimmune disorder related to gluten intolerance or sensitivity. Blood tests that diagnose gluten intolerance or sensitivity include the anti-tissue transglutaminase (tTG) and anti-endomysial antibody (EMA) tests. Eating healthier while avoiding gluten can be done by incorporating a variety of whole foods such as fruits, vegetables, and lean proteins.

The Role of Genetics in Celiac Disease

A genetic predisposition plays a significant role in the development of celiac disease. Individuals with the disease have a different version of a gene that causes white blood cells to attack gliadin fragments. Interestingly, 30-40% of the global population carries this genetic variant, but only 1% develops celiac disease, suggesting that environmental factors also play a part.

Environmental Factors and Celiac Disease

Determining the environmental factors that contribute to celiac disease is challenging. Researchers have hypothesized that the timing of introducing gluten into a child's diet and breastfeeding could play a role, but the jury is still out. The gut microbiota and its byproducts could also be involved in developing the disease.

 People with gluten sensitivity experience gastrointestinal distress – ranging from diarrhea, gas, and bloating to constipation and irritable bowel symptoms – when they eat gluten. (People with celiac disease, on the other hand, may experience these symptoms, or may have no symptoms at all.)

Diagnosing Celiac Disease

Celiac disease is diagnosed through a serology test that detects antibodies attacking the gliadin protein, followed by an endoscopic duodenum biopsy to examine the intestinal wall.

Wheat Allergy

A gluten allergy, or wheat allergy, is an immune reaction to wheat proteins, including gluten. It differs from gluten intolerance or sensitivity because it is an allergic response rather than a digestive issue. Dermatitis herpetiformis is a skin condition related to gluten intolerance or sensitivity. It is a chronic autoimmune disorder that causes itchy bumps or blisters on the skin. Gluten exposure occurs when someone with gluten intolerance or sensitivity consumes foods that contain gluten, leading to adverse reactions such as digestive issues or skin rashes.

Wheat allergy, which affects about 1% or less of the population, involves multiple wheat proteins. Upon consumption, antibodies bind to the proteins, initiating a white blood cell immunologic reaction that can sometimes lead to anaphylaxis, a severe and potentially fatal allergic reaction.

Non-Celiac Gluten Sensitivity

Non-celiac gluten sensitivity (NCGS) is a controversial and poorly understood condition. It is characterized by gastrointestinal and extraintestinal symptoms similar to celiac disease and wheat allergy but without specific immunological markers or allergic responses. The prevalence of NCGS is difficult to pinpoint, with estimates ranging from 0.6% to 6% of the population.

Differences between Celiac Disease, Wheat Allergy, and Non-Celiac Gluten Sensitivity

Immunological Responses 

Celiac disease and wheat allergy are both immune-mediated conditions but involve different mechanisms. Celiac disease is an autoimmune disorder where the body's immune system attacks its tissues, while wheat allergy is an immunoglobulin E (IgE)-mediated allergic response to specific proteins in wheat.

NCGS, on the other hand, does not involve a clear immunological response, making it difficult to diagnose and study. Some researchers propose that NCGS is not a specific condition but a collection of symptoms caused by other factors, such as FODMAPs (fermentable oligo-, di-, monosaccharides, and polyols) or other components of wheat.


While celiac disease, wheat allergy, and NCGS share some common symptoms, they also exhibit distinct differences. Celiac disease typically presents gastrointestinal symptoms, such as diarrhea, abdominal pain, bloating, and extraintestinal manifestations like anemia, osteoporosis, and short stature.

Wheat allergy symptoms can range from mild (hives, itching, and swelling) to severe (anaphylaxis). Additionally, wheat allergy can cause respiratory symptoms, such as wheezing and difficulty breathing, which are not typically seen in celiac disease or NCGS.

NCGS symptoms resemble celiac disease but are generally less severe and do not result in intestinal damage. Furthermore, unlike celiac disease, NCGS has no genetic predisposition and no definitive diagnostic test.

Treatment and Management of Gluten Sensitivity Disorders

Gluten-Free Diet

A strict gluten-free diet is the primary treatment for celiac disease, wheat allergy, and NCGS. This diet eliminates all gluten sources, including wheat, barley, rye, and oats. It is essential for individuals with these conditions to carefully read food labels and be aware of potential sources of gluten contamination.

Fortunately, many foods are naturally gluten-free, including fruits, vegetables, meats, fish, eggs, and most dairy products. Gluten-containing foods to avoid include bread, pasta, cereal, beer, and baked goods made with wheat, barley, or rye. Eliminating gluten from your diet can improve your digestive health by reducing inflammation in the gut and improving nutrient absorption. Avoiding gluten can benefit those with autoimmune disorders or poor nutrient absorption by reducing inflammation and allowing the body to better absorb nutrients from food.

Nutritional Considerations

Gluten-free alternatives can be nutritionally adequate if it is well-balanced and includes a variety of foods. However, eliminating gluten-containing grains can lead to deficiencies in certain nutrients, such as fiber, iron, calcium, and B vitamins. Individuals following a gluten-free diet should consider incorporating gluten-free whole grains, such as quinoa, brown rice, and millet, and consuming fortified gluten-free products to ensure proper nutrient intake.

 Psychological and Social Support

Living with a gluten sensitivity disorder can be challenging, requiring constant vigilance and dietary restrictions. Psychological and social support from friends, family, and healthcare professionals can help individuals cope with challenges and maintain a high quality of life.

Bottom Line

Gluten sensitivity disorders, including celiac disease, wheat allergy, and non-celiac gluten sensitivity, are complex and multifaceted. People with certain medical conditions have very good reasons to avoid gluten, the gluey, chewy protein found in wheat, kamut, spelt, rye, barley, triticale, and malt. Understanding these disorders' differences and underlying mechanisms can help healthcare professionals provide better diagnosis, treatment, and support for affected individuals. People with gluten sensitivity disorders can maintain their health and well-being by following a well-balanced gluten-free diet and seeking psychological and social support.