Glutens: Prolamins in the endosperm of SEEDS from the Triticeae tribe which includes species of WHEAT; BARLEY; and RYE.Celiac Disease: A malabsorption syndrome that is precipitated by the ingestion of foods containing GLUTEN, such as wheat, rye, and barley. It is characterized by INFLAMMATION of the SMALL INTESTINE, loss of MICROVILLI structure, failed INTESTINAL ABSORPTION, and MALNUTRITION.Diet, Gluten-Free: A diet which is devoid of GLUTENS from WHEAT; BARLEY; RYE; and other wheat-related varieties. The diet is designed to reduce exposure to those proteins in gluten that trigger INFLAMMATION of the small intestinal mucosa in patients with CELIAC DISEASE.Dermatitis Herpetiformis: Rare, chronic, papulo-vesicular disease characterized by an intensely pruritic eruption consisting of various combinations of symmetrical, erythematous, papular, vesicular, or bullous lesions. The disease is strongly associated with the presence of HLA-B8 and HLA-DR3 antigens. A variety of different autoantibodies has been detected in small numbers in patients with dermatitis herpetiformis.Gliadin: Simple protein, one of the prolamines, derived from the gluten of wheat, rye, etc. May be separated into 4 discrete electrophoretic fractions. It is the toxic factor associated with CELIAC DISEASE.Jejunum: The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum.Diet: Regular course of eating and drinking adopted by a person or animal.Reticulin: A scleroprotein fibril consisting mostly of type III collagen. Reticulin fibrils are extremely thin, with a diameter of between 0.5 and 2 um. They are involved in maintaining the structural integrity in a variety of organs.Intestinal Mucosa: Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.Transglutaminases: Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.Immunoglobulin A: Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.Duodenum: The shortest and widest portion of the SMALL INTESTINE adjacent to the PYLORUS of the STOMACH. It is named for having the length equal to about the width of 12 fingers.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Diet, Reducing: A diet designed to cause an individual to lose weight.Animal Feed: Foodstuff used especially for domestic and laboratory animals, or livestock.Triticum: A plant genus of the family POACEAE that is the source of EDIBLE GRAIN. A hybrid with rye (SECALE CEREALE) is called TRITICALE. The seed is ground into FLOUR and used to make BREAD, and is the source of WHEAT GERM AGGLUTININS.Dietary Proteins: Proteins obtained from foods. They are the main source of the ESSENTIAL AMINO ACIDS.Diet Therapy: By adjusting the quantity and quality of food intake to improve health status of an individual. This term does not include the methods of food intake (NUTRITIONAL SUPPORT).Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.Diet, High-Fat: Consumption of excessive DIETARY FATS.Wheat Hypersensitivity: Allergic reaction to wheat that is triggered by the immune system.Diet, Fat-Restricted: A diet that contains limited amounts of fat with less than 30% of calories from all fats and less than 10% from saturated fat. Such a diet is used in control of HYPERLIPIDEMIAS. (From Bondy et al, Metabolic Control and Disease, 8th ed, pp468-70; Dorland, 27th ed)HLA-DQ Antigens: A group of the D-related HLA antigens found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.Digestion: The process of breakdown of food for metabolism and use by the body.Diet, Protein-Restricted: A diet that contains limited amounts of protein. It is prescribed in some cases to slow the progression of renal failure. (From Segen, Dictionary of Modern Medicine, 1992)Flour: Ground up seed of WHEAT.Animal Nutritional Physiological Phenomena: Nutritional physiology of animals.