Gastrointestinal Tract: Generally refers to the digestive structures stretching from the MOUTH to ANUS, but does not include the accessory glandular organs (LIVER; BILIARY TRACT; PANCREAS).Digestive System: A group of organs stretching from the MOUTH to the ANUS, serving to breakdown foods, assimilate nutrients, and eliminate waste. In humans, the digestive system includes the GASTROINTESTINAL TRACT and the accessory glands (LIVER; BILIARY TRACT; PANCREAS).Digestive System Physiological Phenomena: Properties and processes of the DIGESTIVE SYSTEM as a whole or of any of its parts.Upper Gastrointestinal Tract: The segment of GASTROINTESTINAL TRACT that includes the ESOPHAGUS; the STOMACH; and the DUODENUM.Gastrointestinal Neoplasms: Tumors or cancer of the GASTROINTESTINAL TRACT, from the MOUTH to the ANAL CANAL.Gastrointestinal Diseases: Diseases in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.Lower Gastrointestinal Tract: The segment of GASTROINTESTINAL TRACT that includes the small intestine below the DUODENUM, and the LARGE INTESTINE.Stomach: An organ of digestion situated in the left upper quadrant of the abdomen between the termination of the ESOPHAGUS and the beginning of the DUODENUM.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.Urinary Tract Infections: Inflammatory responses of the epithelium of the URINARY TRACT to microbial invasions. They are often bacterial infections with associated BACTERIURIA and PYURIA.Intestines: The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.Intestine, Small: The portion of the GASTROINTESTINAL TRACT between the PYLORUS of the STOMACH and the ILEOCECAL VALVE of the LARGE INTESTINE. It is divisible into three portions: the DUODENUM, the JEJUNUM, and the ILEUM.Colon: The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.Urinary Tract: The duct which coveys URINE from the pelvis of the KIDNEY through the URETERS, BLADDER, and URETHRA.Cecum: The blind sac or outpouching area of the LARGE INTESTINE that is below the entrance of the SMALL INTESTINE. It has a worm-like extension, the vermiform APPENDIX.Intestine, Large: A segment of the LOWER GASTROINTESTINAL TRACT that includes the CECUM; the COLON; and the RECTUM.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.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Enteric Nervous System: Two ganglionated neural plexuses in the gut wall which form one of the three major divisions of the autonomic nervous system. The enteric nervous system innervates the gastrointestinal tract, the pancreas, and the gallbladder. It contains sensory neurons, interneurons, and motor neurons. Thus the circuitry can autonomously sense the tension and the chemical environment in the gut and regulate blood vessel tone, motility, secretions, and fluid transport. The system is itself governed by the central nervous system and receives both parasympathetic and sympathetic innervation. (From Kandel, Schwartz, and Jessel, Principles of Neural Science, 3d ed, p766)Germ-Free Life: Animals not contaminated by or associated with any foreign organisms.Gastrointestinal Motility: The motor activity of the GASTROINTESTINAL TRACT.Gastric Mucosa: Lining of the STOMACH, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. The surface cells produce MUCUS that protects the stomach from attack by digestive acid and enzymes. When the epithelium invaginates into the LAMINA PROPRIA at various region of the stomach (CARDIA; GASTRIC FUNDUS; and PYLORUS), different tubular gastric glands are formed. These glands consist of cells that secrete mucus, enzymes, HYDROCHLORIC ACID, or hormones.Intestinal Absorption: Uptake of substances through the lining of the INTESTINES.Gastrointestinal Contents: The contents included in all or any segment of the GASTROINTESTINAL TRACT.Ileum: The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.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.Lactobacillus: A genus of gram-positive, microaerophilic, rod-shaped bacteria occurring widely in nature. Its species are also part of the many normal flora of the mouth, intestinal tract, and vagina of many mammals, including humans. Pathogenicity from this genus is rare.Pyramidal Tracts: Fibers that arise from cells within the cerebral cortex, pass through the medullary pyramid, and descend in the spinal cord. Many authorities say the pyramidal tracts include both the corticospinal and corticobulbar tracts.Gastrointestinal Hemorrhage: Bleeding in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.Endoscopy, Gastrointestinal: Endoscopic examination, therapy or surgery of the gastrointestinal tract.Probiotics: Live microbial DIETARY SUPPLEMENTS which beneficially affect the host animal by improving its intestinal microbial balance. Antibiotics and other related compounds are not included in this definition. In humans, lactobacilli are commonly used as probiotics, either as single species or in mixed culture with other bacteria. Other genera that have been used are bifidobacteria and streptococci. (J. Nutr. 1995;125:1401-12)Gastrointestinal Transit: Passage of food (sometimes in the form of a test meal) through the gastrointestinal tract as measured in minutes or hours. The rate of passage through the intestine is an indicator of small bowel function.Esophagus: The muscular membranous segment between the PHARYNX and the STOMACH in the UPPER GASTROINTESTINAL TRACT.Administration, Oral: The giving of drugs, chemicals, or other substances by mouth.Gastrointestinal Stromal Tumors: All tumors in the GASTROINTESTINAL TRACT arising from mesenchymal cells (MESODERM) except those of smooth muscle cells (LEIOMYOMA) or Schwann cells (SCHWANNOMA).Digestion: The process of breakdown of food for metabolism and use by the body.Lactobacillus reuteri: A species of gram-positive, rod-shaped LACTIC ACID bacteria found naturally in the human intestinal flora and BREAST MILK.Enteroendocrine Cells: Cells found throughout the lining of the GASTROINTESTINAL TRACT that contain and secrete regulatory PEPTIDE HORMONES and/or BIOGENIC AMINES.Inflammatory Bowel Diseases: Chronic, non-specific inflammation of the GASTROINTESTINAL TRACT. Etiology may be genetic or environmental. This term includes CROHN DISEASE and ULCERATIVE COLITIS.Metagenome: A collective genome representative of the many organisms, primarily microorganisms, existing in a community.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Bifidobacterium: A rod-shaped, gram-positive, non-acid-fast, non-spore-forming, non-motile bacterium that is a genus of the family Bifidobacteriaceae, order Bifidobacteriales, class ACTINOBACTERIA. It inhabits the intestines and feces of humans as well as the human vagina.Stomach Diseases: Pathological processes involving the STOMACH.Gastrointestinal Hormones: HORMONES secreted by the gastrointestinal mucosa that affect the timing or the quality of secretion of digestive enzymes, and regulate the motor activity of the digestive system organs.Animal Feed: Foodstuff used especially for domestic and laboratory animals, or livestock.Foreign Bodies: Inanimate objects that become enclosed in the body.Enteritis: Inflammation of any segment of the SMALL INTESTINE.Gastric Emptying: The evacuation of food from the stomach into the duodenum.Digestive System Diseases: Diseases in any part of the GASTROINTESTINAL TRACT or the accessory organs (LIVER; BILIARY TRACT; PANCREAS).Intestinal Diseases: Pathological processes in any segment of the INTESTINE from DUODENUM to RECTUM.Colony Count, Microbial: Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Intubation, Gastrointestinal: The insertion of a tube into the stomach, intestines, or other portion of the gastrointestinal tract to allow for the passage of food products, etc.Bacteria: One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.Digestive System Surgical Procedures: Surgery performed on the digestive system or its parts.Stomach Neoplasms: Tumors or cancer of the STOMACH.Digestive System Neoplasms: Tumors or cancer of the DIGESTIVE SYSTEM.Endoscopes, Gastrointestinal: Instruments for the visual examination of the interior of the gastrointestinal tract.Rectum: The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.Intestinal Neoplasms: Tumors or cancer of the INTESTINES.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Crop, Avian: A thin-walled distention of the alimentary tract protruding just outside the body cavity in the distal end of the neck (esophagus), used for the temporary storage of food and water.Duodenal Neoplasms: Tumors or cancer of the DUODENUM.Digestive System Abnormalities: Congenital structural abnormalities of the DIGESTIVE SYSTEM.Intestinal Perforation: Opening or penetration through the wall of the INTESTINES.Biliary Tract: The BILE DUCTS and the GALLBLADDER.Respiratory System: The tubular and cavernous organs and structures, by means of which pulmonary ventilation and gas exchange between ambient air and the blood are brought about.Fatty Acids, Volatile: Short-chain fatty acids of up to six carbon atoms in length. They are the major end products of microbial fermentation in the ruminant digestive tract and have also been implicated in the causation of neurological diseases in humans.Esophageal Diseases: Pathological processes in the ESOPHAGUS.Endoscopy: Procedures of applying ENDOSCOPES for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. transluminal, to examine or perform surgery on the interior parts of the body.Intestinal Polyps: Discrete abnormal tissue masses that protrude into the lumen of the INTESTINE. A polyp is attached to the intestinal wall either by a stalk, pedunculus, or by a broad base.Urogenital System: All the organs involved in reproduction and the formation and release of URINE. It includes the kidneys, ureters, BLADDER; URETHRA, and the organs of reproduction - ovaries, UTERUS; FALLOPIAN TUBES; VAGINA; and CLITORIS in women and the testes; SEMINAL VESICLES; PROSTATE; seminal ducts; and PENIS in men.Carcinoid Tumor: A usually small, slow-growing neoplasm composed of islands of rounded, oxyphilic, or spindle-shaped cells of medium size, with moderately small vesicular nuclei, and covered by intact mucosa with a yellow cut surface. The tumor can occur anywhere in the gastrointestinal tract (and in the lungs and other sites); approximately 90% arise in the appendix. It is now established that these tumors are of neuroendocrine origin and derive from a primitive stem cell. (From Stedman, 25th ed & Holland et al., Cancer Medicine, 3d ed, p1182)Immunity, Mucosal: Nonsusceptibility to the pathogenic effects of foreign microorganisms or antigenic substances as a result of antibody secretions of the mucous membranes. Mucosal epithelia in the gastrointestinal, respiratory, and reproductive tracts produce a form of IgA (IMMUNOGLOBULIN A, SECRETORY) that serves to protect these ports of entry into the body.Genitalia, Female: The female reproductive organs. The external organs include the VULVA; BARTHOLIN'S GLANDS; and CLITORIS. The internal organs include the VAGINA; UTERUS; OVARY; and FALLOPIAN TUBES.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Mucins: High molecular weight mucoproteins that protect the surface of EPITHELIAL CELLS by providing a barrier to particulate matter and microorganisms. Membrane-anchored mucins may have additional roles concerned with protein interactions at the cell surface.Biological Availability: The extent to which the active ingredient of a drug dosage form becomes available at the site of drug action or in a biological medium believed to reflect accessibility to a site of action.Crohn Disease: A chronic transmural inflammation that may involve any part of the DIGESTIVE TRACT from MOUTH to ANUS, mostly found in the ILEUM, the CECUM, and the COLON. In Crohn disease, the inflammation, extending through the intestinal wall from the MUCOSA to the serosa, is characteristically asymmetric and segmental. Epithelioid GRANULOMAS may be seen in some patients.Caco-2 Cells: Human colonic ADENOCARCINOMA cells that are able to express differentiation features characteristic of mature intestinal cells, such as ENTEROCYTES. These cells are valuable in vitro tools for studies related to intestinal cell function and differentiation.Myenteric Plexus: One of two ganglionated neural networks which together form the ENTERIC NERVOUS SYSTEM. The myenteric (Auerbach's) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. (From FASEB J 1989;3:127-38)Lactobacillus plantarum: A species of rod-shaped, LACTIC ACID bacteria used in PROBIOTICS and SILAGE production.Intestinal Obstruction: Any impairment, arrest, or reversal of the normal flow of INTESTINAL CONTENTS toward the ANAL CANAL.Prebiotics: Non-digestible food ingredients mostly of a carbohydrate base that improve human health by selectively stimulating the growth and/or activity of existing BACTERIA in the COLON.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Biliary Tract Diseases: Diseases in any part of the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Colonic Diseases: Pathological processes in the COLON region of the large intestine (INTESTINE, LARGE).Diet: Regular course of eating and drinking adopted by a person or animal.Interstitial Cells of Cajal: c-Kit positive cells related to SMOOTH MUSCLE CELLS that are intercalated between the autonomic nerves and the effector smooth muscle cells of the GASTROINTESTINAL TRACT. Different phenotypic classes play roles as pacemakers, mediators of neural inputs, and mechanosensors.Proto-Oncogene Proteins c-kit: A protein-tyrosine kinase receptor that is specific for STEM CELL FACTOR. This interaction is crucial for the development of hematopoietic, gonadal, and pigment stem cells. Genetic mutations that disrupt the expression of PROTO-ONCOGENE PROTEINS C-KIT are associated with PIEBALDISM, while overexpression or constitutive activation of the c-kit protein-tyrosine kinase is associated with tumorigenesis.Organ Specificity: Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.Mucous Membrane: An EPITHELIUM with MUCUS-secreting cells, such as GOBLET CELLS. It forms the lining of many body cavities, such as the DIGESTIVE TRACT, the RESPIRATORY TRACT, and the reproductive tract. Mucosa, rich in blood and lymph vessels, comprises an inner epithelium, a middle layer (lamina propria) of loose CONNECTIVE TISSUE, and an outer layer (muscularis mucosae) of SMOOTH MUSCLE CELLS that separates the mucosa from submucosa.Colonic Neoplasms: Tumors or cancer of the COLON.Abdominal Pain: Sensation of discomfort, distress, or agony in the abdominal region.Endoscopy, Digestive System: Endoscopic examination, therapy or surgery of the digestive tract.Escherichia coli Infections: Infections with bacteria of the species ESCHERICHIA COLI.Duodenal Diseases: Pathological conditions in the DUODENUM region of the small intestine (INTESTINE, SMALL).Mesentery: A layer of the peritoneum which attaches the abdominal viscera to the ABDOMINAL WALL and conveys their blood vessels and nerves.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Animal Nutritional Physiological Phenomena: Nutritional physiology of animals.Stomach, AvianEpithelial Cells: Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.Diarrhea: An increased liquidity or decreased consistency of FECES, such as running stool. Fecal consistency is related to the ratio of water-holding capacity of insoluble solids to total water, rather than the amount of water present. Diarrhea is not hyperdefecation or increased fecal weight.Pancreas: A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.Lactobacillus acidophilus: A species of gram-positive, rod-shaped bacteria isolated from the intestinal tract of humans and animals, the human mouth, and vagina. This organism produces the fermented product, acidophilus milk.Caustics: Strong alkaline chemicals that destroy soft body tissues resulting in a deep, penetrating type of burn, in contrast to corrosives, that result in a more superficial type of damage via chemical means or inflammation. Caustics are usually hydroxides of light metals. SODIUM HYDROXIDE and potassium hydroxide are the most widely used caustic agents in industry. Medically, they have been used externally to remove diseased or dead tissues and destroy warts and small tumors. The accidental ingestion of products (household and industrial) containing caustic ingredients results in thousands of injuries per year.Epithelium: One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.Gastrointestinal Agents: Drugs used for their effects on the gastrointestinal system, as to control gastric acidity, regulate gastrointestinal motility and water flow, and improve digestion.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Tablets, Enteric-Coated: Tablets coated with material that delays release of the medication until after they leave the stomach. (Dorland, 28th ed)Duodenitis: Inflammation of the DUODENUM section of the small intestine (INTESTINE, SMALL). Erosive duodenitis may cause bleeding in the UPPER GI TRACT and PEPTIC ULCER.Mice, Inbred C57BLGastroenterology: A subspecialty of internal medicine concerned with the study of the physiology and diseases of the digestive system and related structures (esophagus, liver, gallbladder, and pancreas).Eating: The consumption of edible substances.Muscle, Smooth: Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Bacterial Adhesion: Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.Colitis: Inflammation of the COLON section of the large intestine (INTESTINE, LARGE), usually with symptoms such as DIARRHEA (often with blood and mucus), ABDOMINAL PAIN, and FEVER.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Bezoars: Concretions of swallowed hair, fruit or vegetable fibers, or similar substances found in the alimentary canal.Ileal Diseases: Pathological development in the ILEUM including the ILEOCECAL VALVE.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Antibiosis: A natural association between organisms that is detrimental to at least one of them. This often refers to the production of chemicals by one microorganism that is harmful to another.Ileus: A condition caused by the lack of intestinal PERISTALSIS or INTESTINAL MOTILITY without any mechanical obstruction. This interference of the flow of INTESTINAL CONTENTS often leads to INTESTINAL OBSTRUCTION. Ileus may be classified into postoperative, inflammatory, metabolic, neurogenic, and drug-induced.Gastric Fundus: The superior portion of the body of the stomach above the level of the cardiac notch.Adenocarcinoma: A malignant epithelial tumor with a glandular organization.Dietary Fiber: The remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.Absorption: The physical or physiological processes by which substances, tissue, cells, etc. take up or take in other substances or energy.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Lactobacillus rhamnosus: A species of gram-positive, rod-shaped bacteria used in PROBIOTICS.Stomach Ulcer: Ulceration of the GASTRIC MUCOSA due to contact with GASTRIC JUICE. It is often associated with HELICOBACTER PYLORI infection or consumption of nonsteroidal anti-inflammatory drugs (NSAIDS).Esophageal Neoplasms: Tumors or cancer of the ESOPHAGUS.Vagus Nerve: The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Fermentation: Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.Visceral Afferents: The sensory fibers innervating the viscera.Mice, Inbred BALB CRats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Rumen: The first stomach of ruminants. It lies on the left side of the body, occupying the whole of the left side of the abdomen and even stretching across the median plane of the body to the right side. It is capacious, divided into an upper and a lower sac, each of which has a blind sac at its posterior extremity. The rumen is lined by mucous membrane containing no digestive glands, but mucus-secreting glands are present in large numbers. Coarse, partially chewed food is stored and churned in the rumen until the animal finds circumstances convenient for rumination. When this occurs, little balls of food are regurgitated through the esophagus into the mouth, and are subjected to a second more thorough mastication, swallowed, and passed on into other parts of the compound stomach. (From Black's Veterinary Dictionary, 17th ed)Reproductive Tract Infections: Infections of the genital tract in females or males. They can be caused by endogenous, iatrogenic, or sexually transmitted organisms.Peutz-Jeghers Syndrome: A hereditary disease caused by autosomal dominant mutations involving CHROMOSOME 19. It is characterized by the presence of INTESTINAL POLYPS, consistently in the JEJUNUM, and mucocutaneous pigmentation with MELANIN spots of the lips, buccal MUCOSA, and digits.Intestinal Pseudo-Obstruction: A type of ILEUS, a functional not mechanical obstruction of the INTESTINES. This syndrome is caused by a large number of disorders involving the smooth muscles (MUSCLE, SMOOTH) or the NERVOUS SYSTEM.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Pyloric Antrum: The region between the sharp indentation at the lower third of the STOMACH (incisura angularis) and the junction of the PYLORUS with the DUODENUM. Pyloric antral glands contain mucus-secreting cells and gastrin-secreting endocrine cells (G CELLS).Cholecystokinin: A peptide, of about 33 amino acids, secreted by the upper INTESTINAL MUCOSA and also found in the central nervous system. It causes gallbladder contraction, release of pancreatic exocrine (or digestive) enzymes, and affects other gastrointestinal functions. Cholecystokinin may be the mediator of satiety.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Enterocytes: Absorptive cells in the lining of the INTESTINAL MUCOSA. They are differentiated EPITHELIAL CELLS with apical MICROVILLI facing the intestinal lumen. Enterocytes are more abundant in the SMALL INTESTINE than in the LARGE INTESTINE. Their microvilli greatly increase the luminal surface area of the cell by 14- to 40 fold.Bifidobacteriales Infections: Infections with BACTERIA of the order Bifidobacteriales. This includes infections in the genera BIFIDOBACTERIUM and GARDNERELLA, in the family Bifidobacteriaceae.Colon, Sigmoid: A segment of the COLON between the RECTUM and the descending colon.Ileostomy: Surgical creation of an external opening into the ILEUM for fecal diversion or drainage. This replacement for the RECTUM is usually created in patients with severe INFLAMMATORY BOWEL DISEASES. Loop (continent) or tube (incontinent) procedures are most often employed.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Ruminants: A suborder of the order ARTIODACTYLA whose members have the distinguishing feature of a four-chambered stomach, including the capacious RUMEN. Horns or antlers are usually present, at least in males.Endocrine Glands: Ductless glands that secrete HORMONES directly into the BLOOD CIRCULATION. These hormones influence the METABOLISM and other functions of cells in the body.Peptic Ulcer: Ulcer that occurs in the regions of the GASTROINTESTINAL TRACT which come into contact with GASTRIC JUICE containing PEPSIN and GASTRIC ACID. It occurs when there are defects in the MUCOSA barrier. The common forms of peptic ulcers are associated with HELICOBACTER PYLORI and the consumption of nonsteroidal anti-inflammatory drugs (NSAIDS).Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Bacterial Physiological Phenomena: Physiological processes and properties of BACTERIA.Cloaca: A dilated cavity extended caudally from the hindgut. In adult birds, reptiles, amphibians, and many fishes but few mammals, cloaca is a common chamber into which the digestive, urinary and reproductive tracts discharge their contents. In most mammals, cloaca gives rise to LARGE INTESTINE; URINARY BLADDER; and GENITALIA.Gastric Fistula: Abnormal passage communicating with the STOMACH.Gastrins: A family of gastrointestinal peptide hormones that excite the secretion of GASTRIC JUICE. They may also occur in the central nervous system where they are presumed to be neurotransmitters.Hyraxes: Any of certain small mammals of the order Hyracoidea.Intestinal Polyposis: The growth of INTESTINAL POLYPS. Growth processes include neoplastic (ADENOMA and CARCINOMA) and non-neoplastic (hyperplastic, mucosal, inflammatory, and other polyps).Barium Sulfate: A compound used as an x-ray contrast medium that occurs in nature as the mineral barite. It is also used in various manufacturing applications and mixed into heavy concrete to serve as a radiation shield.Microbiota: The full collection of microbes (bacteria, fungi, virus, etc.) that naturally exist within a particular biological niche such as an organism, soil, a body of water, etc.Jejunal Neoplasms: Tumors or cancer in the JEJUNUM region of the small intestine (INTESTINE, SMALL).Gastroscopy: Endoscopic examination, therapy or surgery of the interior of the stomach.Peptide YY: A 36-amino acid peptide produced by the L cells of the distal small intestine and colon. Peptide YY inhibits gastric and pancreatic secretion.Polyps: Discrete abnormal tissue masses that protrude into the lumen of the DIGESTIVE TRACT or the RESPIRATORY TRACT. Polyps can be spheroidal, hemispheroidal, or irregular mound-shaped structures attached to the MUCOUS MEMBRANE of the lumen wall either by a stalk, pedunculus, or by a broad base.Endosonography: Ultrasonography of internal organs using an ultrasound transducer sometimes mounted on a fiberoptic endoscope. In endosonography the transducer converts electronic signals into acoustic pulses or continuous waves and acts also as a receiver to detect reflected pulses from within the organ. An audiovisual-electronic interface converts the detected or processed echo signals, which pass through the electronics of the instrument, into a form that the technologist can evaluate. The procedure should not be confused with ENDOSCOPY which employs a special instrument called an endoscope. The "endo-" of endosonography refers to the examination of tissue within hollow organs, with reference to the usual ultrasonography procedure which is performed externally or transcutaneously.Gastritis: Inflammation of the GASTRIC MUCOSA, a lesion observed in a number of unrelated disorders.Malacoplakia: The formation of soft patches on the mucous membrane of a hollow organ, such as the urogenital tract or digestive tract.Peyer's Patches: Lymphoid tissue on the mucosa of the small intestine.Anti-Inflammatory Agents, Non-Steroidal: Anti-inflammatory agents that are non-steroidal in nature. In addition to anti-inflammatory actions, they have analgesic, antipyretic, and platelet-inhibitory actions.They act by blocking the synthesis of prostaglandins by inhibiting cyclooxygenase, which converts arachidonic acid to cyclic endoperoxides, precursors of prostaglandins. Inhibition of prostaglandin synthesis accounts for their analgesic, antipyretic, and platelet-inhibitory actions; other mechanisms may contribute to their anti-inflammatory effects.Diagnostic Techniques, Digestive System: Methods and procedures for the diagnosis of diseases or dysfunction of the digestive system or its organs or demonstration of their physiological processes.Yogurt: A slightly acid milk food produced by fermentation due to the combined action of Lactobacillus acidophilus and Streptococcus thermophilus.Food: Any substances taken in by the body that provide nourishment.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Gastric Juice: The liquid secretion of the stomach mucosa consisting of hydrochloric acid (GASTRIC ACID); PEPSINOGENS; INTRINSIC FACTOR; GASTRIN; MUCUS; and the bicarbonate ion (BICARBONATES). (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p651)Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Squalus acanthias: A species of shark in the family SQUALIDAE, used for its oil (SQUALENE) and as fish meal. It also figures heavily in biological research, especially with reference to its RECTAL GLAND in studies of WATER-ELECTROLYTE BALANCE.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Galectin 4: A galectin found in the small and large intestine and the stomach. It occurs as a homodimer with two 36-kDa subunits and is localized to sites of cell adhesion where it may play role in assembly of ADHERENS JUNCTIONS.Neuroendocrine Tumors: Tumors whose cells possess secretory granules and originate from the neuroectoderm, i.e., the cells of the ectoblast or epiblast that program the neuroendocrine system. Common properties across most neuroendocrine tumors include ectopic hormone production (often via APUD CELLS), the presence of tumor-associated antigens, and isozyme composition.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Histocytochemistry: Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.Meckel Diverticulum: A congenital abnormality characterized by the outpouching or sac formation in the ILEUM. It is a remnant of the embryonic YOLK SAC in which the VITELLINE DUCT failed to close.Random Allocation: A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.Protein-Losing Enteropathies: Pathological conditions in the INTESTINES that are characterized by the gastrointestinal loss of serum proteins, including SERUM ALBUMIN; IMMUNOGLOBULINS; and at times LYMPHOCYTES. Severe condition can result in HYPOGAMMAGLOBULINEMIA or LYMPHOPENIA. Protein-losing enteropathies are associated with a number of diseases including INTESTINAL LYMPHANGIECTASIS; WHIPPLE'S DISEASE; and NEOPLASMS of the SMALL INTESTINE.Colonoscopy: Endoscopic examination, therapy or surgery of the luminal surface of the colon.Gastroenteritis: INFLAMMATION of any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM. Causes of gastroenteritis are many including genetic, infection, HYPERSENSITIVITY, drug effects, and CANCER.Eosinophilia: Abnormal increase of EOSINOPHILS in the blood, tissues or organs.Irritable Bowel Syndrome: A disorder with chronic or recurrent colonic symptoms without a clearcut etiology. This condition is characterized by chronic or recurrent ABDOMINAL PAIN, bloating, MUCUS in FECES, and an erratic disturbance of DEFECATION.Milk, HumanMouth: The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.