Gluten is a structural protein naturally found in certain cereal grains. The term "gluten" usually refers to the combination of prolamin and glutelin proteins that naturally occurs in many cereal grains and that can trigger celiac disease. The types of grains that contain gluten include all species of wheat, as well as barley, rye, and some cultivars of oat. Cross hybrids of any of these grains also contain gluten. Gluten makes up 75–85% of the total protein in bread wheat. Baked goods made of bread become fluffy and stretchy because of gluten.
Coeliac disease or celiac disease is a long-term autoimmune disorder, primarily affecting the small intestine, where individuals develop intolerance to gluten, present in foods such as wheat, rye and barley. Classic symptoms include gastrointestinal problems such as chronic diarrhoea, abdominal distention, malabsorption, loss of appetite, and among children failure to grow normally. This often begins between six months and two years of age. Non-classic symptoms are more common, especially in people older than two years. There may be mild or absent gastrointestinal symptoms, a wide number of symptoms involving any part of the body, or no obvious symptoms. Coeliac disease was first described in childhood; however, it may develop at any age. It is associated with other autoimmune diseases, such as Type 1 diabetes mellitus and Hashimoto's thyroiditis, among others.
Irritable bowel syndrome (IBS) is a "disorder of gut-brain interaction" characterized by a group of symptoms that commonly include abdominal pain, abdominal bloating and changes in the consistency of bowel movements. These symptoms may occur over a long time, sometimes for years. IBS can negatively affect quality of life and may result in missed school or work or reduced productivity at work. Disorders such as anxiety, major depression, and chronic fatigue syndrome are common among people with IBS.
A gluten-free diet (GFD) is a nutritional plan that strictly excludes gluten, which is a mixture of prolamin proteins found in wheat, as well as barley, rye, and oats. The inclusion of oats in a gluten-free diet remains controversial, and may depend on the oat cultivar and the frequent cross-contamination with other gluten-containing cereals.
Gliadin is a class of proteins present in wheat and several other cereals within the grass genus Triticum. Gliadins, which are a component of gluten, are essential for giving bread the ability to rise properly during baking. Gliadins and glutenins are the two main components of the gluten fraction of the wheat seed. This gluten is found in products such as wheat flour. Gluten is split about evenly between the gliadins and glutenins, although there are variations found in different sources.
Intestinal permeability is a term describing the control of material passing from inside the gastrointestinal tract through the cells lining the gut wall, into the rest of the body. The intestine normally exhibits some permeability, which allows nutrients to pass through the gut, while also maintaining a barrier function to keep potentially harmful substances from leaving the intestine and migrating to the body more widely. In a healthy human intestine, small particles can migrate through tight junction claudin pore pathways, and particles up to 10–15 Å can transit through the paracellular space uptake route. There is some evidence abnormally increased intestinal permeability may play a role in some chronic diseases and inflammatory conditions. The most well understood condition with observed increased intestinal permeability is celiac disease.
The specific carbohydrate diet (SCD) is a restrictive diet originally created to manage celiac disease; it limits the use of complex carbohydrates. Monosaccharides are allowed, and various foods including fish, aged cheese and honey are included. Prohibited foods include cereal grains, potatoes and lactose-containing dairy products. It is a gluten-free diet since no grains are permitted.
Zonulin: A Protein with Implications for Gut Health and Disease
Gluten-related disorders is the term for the diseases triggered by gluten, including celiac disease (CD), non-celiac gluten sensitivity (NCGS), gluten ataxia, dermatitis herpetiformis (DH) and wheat allergy. The umbrella category has also been referred to as gluten intolerance, though a multi-disciplinary physician-led study, based in part on the 2011 International Coeliac Disease Symposium, concluded that the use of this term should be avoided due to a lack of specificity.
The immunochemistry of Triticeae glutens is important in several inflammatory diseases. It can be subdivided into innate responses, class II mediated presentation, class I mediated stimulation of killer cells, and antibody recognition. The responses to gluten proteins and polypeptide regions differs according to the type of gluten sensitivity. The response is also dependent on the genetic makeup of the human leukocyte antigen genes. In gluten sensitive enteropathy, there are four types of recognition, innate immunity, HLA-DQ, and antibody recognition of gliadin and transglutaminase. With idiopathic gluten sensitivity only antibody recognition to gliadin has been resolved. In wheat allergy, the response pathways are mediated through IgE against other wheat proteins and other forms of gliadin.
FODMAPs or fermentable oligosaccharides, disaccharides, monosaccharides, and polyols are short-chain carbohydrates that are poorly absorbed in the small intestine and ferment in the colon. They include short-chain oligosaccharide polymers of fructose (fructans) and galactooligosaccharides, disaccharides (lactose), monosaccharides (fructose), and sugar alcohols (polyols), such as sorbitol, mannitol, xylitol, and maltitol. Most FODMAPs are naturally present in food and the human diet, but the polyols may be added artificially in commercially prepared foods and beverages.
Sidney Valentine Haas, M.D. (1870–1964) was a U.S. pediatrician whose research determined a dietary means of combating celiac disease.
Pediatric gastroenterology developed as a sub-specialty of pediatrics and gastroenterology. It is concerned with treating the gastrointestinal tract, liver and pancreas of children from infancy until age eighteen. The principal diseases it is concerned with are acute diarrhea, persistent vomiting, gastritis, and problems with the development of the gastric tract.
Non-celiac gluten sensitivity (NCGS) or gluten sensitivity is a controversial disorder which can cause both gastrointestinal and other problems.
Detlef Schuppan is a German biochemist and physician. He focuses on the diagnosis and treatment of coeliac disease and wheat sensitivity, fibrotic liver diseases and the immunology of chronic diseases and cancer. He is the director of the Institute of Translational Immunology and a professor of internal medicine, gastroenterology, and hepatology at the Medical Center of the Johannes Gutenberg University of Mainz in Germany. He directs the outpatient clinic for coeliac disease and small intestinal diseases. He is also a professor of medicine and a senior visiting scientist at Harvard Medical School.
The gluten challenge test is a medical test in which gluten-containing foods are consumed and (re-)occurrence of symptoms is observed afterwards to determine whether and how much a person reacts to these foods. The test may be performed in people with suspected gluten-related disorders in very specific occasions and under medical supervision, for example in people who had started a gluten-free diet without performing duodenal biopsy.
Larazotide is a synthetic eight amino acid peptide that functions as a tight junction regulator and reverses leaky junctions to their normally closed state. It is being studied in people with celiac disease.
The intestinal mucosal barrier, also referred to as intestinal barrier, refers to the property of the intestinal mucosa that ensures adequate containment of undesirable luminal contents within the intestine while preserving the ability to absorb nutrients. The separation it provides between the body and the gut prevents the uncontrolled translocation of luminal contents into the body proper. Its role in protecting the mucosal tissues and circulatory system from exposure to pro-inflammatory molecules, such as microorganisms, toxins, and antigens is vital for the maintenance of health and well-being. Intestinal mucosal barrier dysfunction has been implicated in numerous health conditions such as: food allergies, microbial infections, irritable bowel syndrome, inflammatory bowel disease, celiac disease, metabolic syndrome, non-alcoholic fatty liver disease, diabetes, and septic shock.
Carlo Catassi is an Italian gastroenterologist, epidemiologist, and researcher. He is known for international studies on the epidemiology of celiac disease. Currently, he is Head of the Department of Pediatrics at the Università Politecnica delle Marche, Ancona, Italy, and Visiting Scientist at Massachusetts General Hospital in Boston, Massachusetts, United States. From 2013-2016, he served as President of the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP). His research had included contributions to understanding the clinical spectrum of celiac disease and other gluten-related disorders.
Ludvig M. Sollid is a Norwegian physician-scientist whose laboratory has made discoveries in the pathogenesis of HLA associated human disorders, most notably celiac disease. He is currently a Professor of Medicine (immunology) at the University of Oslo and a Senior Consultant at Oslo University Hospital.
