Achlorhydria
Encyclopedia
Achlorhydria or hypochlorhydria refers to states where the production of gastric acid
in the stomach
is absent or low, respectively. It is associated with various other medical problems.
, and impairs protein digestion by inhibiting the activation of the enzyme pepsin
, whose activation is dependent upon a low gastric pH. Furthermore, low acid levels in the stomach are linked with bacterial overgrowth
(as the stomach does not kill microbes normally present in food), which can manifest as diarrhea
or decreased absorption
of nutrients or vitamins. Risk of particular infections, such as Vibrio vulnificus
(commonly from seafood) is increased. Even without bacterial overgrowth, low stomach acid can lead to nutritional deficiencies through malabsorption of basic electrolytes (magnesium
, zinc
, etc.) and vitamins (including vitamin C
, vitamin K
, and the B complex of vitamins). Such deficiencies may be involved in the development of a wide range of pathologies, from fairly benign neuromuscular issues to life-threatening diseases. A person with achlorhydria can suffer from stomach pains caused by the digestion of food that is not properly broken down by gastric acid.
stimulation. High gastrin
levels are often detected.
) or TMG (trimethylglycine
), which are sweet-tasting and non-acidic. Unlike TMG/DMG, betaine HCL includes chloride
, which breaks down into hydrochloric acid in the stomach, facilitating a lower pH and improving the breakdown of food. Betaine HCL is typically sold as a preparation containing pepsin
, a digestive enzyme.
In addition to taking steps to lower the pH of the stomach, supplementation with minerals and vitamin
s such as vitamin B12
(which is poorly absorbed in achlorhydria/hypochlorhydria due to the absence of intrinsic factor
) is usually recommended to compensate for malabsorption of nutrients. Foods with high microbial loads (including dairy products that intentionally contain microbes such as penicillin
) are usually avoided. Because the acidity of the stomach is a primary defense against infection of the gastrointestinal tract, antifungals, probiotic
s, and antibiotic
s may be needed to treat recurring infections.
Gastric acid
Gastric acid is a digestive fluid, formed in the stomach. It has a pH of 1 to 2 and is composed of hydrochloric acid , and large quantities of potassium chloride and sodium chloride...
in the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
is absent or low, respectively. It is associated with various other medical problems.
Signs and symptoms
The decreased acid level itself can cause symptoms similar to gastroesophageal reflux diseaseGastroesophageal reflux disease
Gastroesophageal reflux disease , gastro-oesophageal reflux disease , gastric reflux disease, or acid reflux disease is chronic symptoms or mucosal damage caused by stomach acid coming up from the stomach into the esophagus...
, and impairs protein digestion by inhibiting the activation of the enzyme pepsin
Pepsin
Pepsin is an enzyme whose precursor form is released by the chief cells in the stomach and that degrades food proteins into peptides. It was discovered in 1836 by Theodor Schwann who also coined its name from the Greek word pepsis, meaning digestion...
, whose activation is dependent upon a low gastric pH. Furthermore, low acid levels in the stomach are linked with bacterial overgrowth
Small bowel bacterial overgrowth syndrome
Small bowel bacterial overgrowth syndrome , or small intestinal bacterial overgrowth , also termed bacterial overgrowth; is a disorder of excessive bacterial growth in the small intestine. Unlike the colon , which is rich with bacteria, the small bowel usually has less than 104 organisms per...
(as the stomach does not kill microbes normally present in food), which can manifest as diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
or decreased absorption
Malabsorption
Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal tract.Impairment can be of single or multiple nutrients depending on the abnormality...
of nutrients or vitamins. Risk of particular infections, such as Vibrio vulnificus
Vibrio vulnificus
Vibrio vulnificus is a species of Gram-negative, motile, curved, rod-shaped bacteria of the Vibrio Genus. It was first reported by Hollis et al. in 1976. It was subsequently given the name Beneckea vulnifica by Reichelt et al. in 1976 , and finally Vibrio vulnificus by Farmer in 1979...
(commonly from seafood) is increased. Even without bacterial overgrowth, low stomach acid can lead to nutritional deficiencies through malabsorption of basic electrolytes (magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
, zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, etc.) and vitamins (including vitamin C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...
, vitamin K
Vitamin K
Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...
, and the B complex of vitamins). Such deficiencies may be involved in the development of a wide range of pathologies, from fairly benign neuromuscular issues to life-threatening diseases. A person with achlorhydria can suffer from stomach pains caused by the digestion of food that is not properly broken down by gastric acid.
Causes
- The slowing of the body's basal metabolic rate associated with hypothyroidismHypothyroidismHypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...
- Autoimmune disorders where there is antibodyAntibodyAn antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
production against parietal cellParietal cellParietal cells, or oxyntic cells, are the stomach epithelium cells that secrete gastric acid and intrinsic factor.Acetylcholine and gastrin . The histamine receptors act by increasing intracellular cAMP, whereas the muscarinic and gastrin receptors increase intracellular Ca2+ levels...
s which normally produce gastric acid. - The use of antacids or drugs that decrease gastric acid production (such as H2-receptor antagonistH2-receptor antagonistThe H2 receptor antagonists are a class of drugs used to block the action of histamine on parietal cells in the stomach, decreasing the production of acid by these cells. H2 antagonists are used in the treatment of dyspepsia, although they have been surpassed in popularity by the more effective ...
s) or transport (such as proton pump inhibitorProton pump inhibitorProton-pump inhibitors are a group of drugs whose main action is a pronounced and long-lasting reduction of gastric acid production. They are the most potent inhibitors of acid secretion available today. The group followed and has largely superseded another group of pharmaceuticals with similar...
s). - A symptom of rare diseaseRare diseaseA rare disease, also referred to as an orphan disease, is any disease that affects a small percentage of the population.Most rare diseases are genetic, and thus are present throughout the person's entire life, even if symptoms do not immediately appear...
s such as mucolipidosisMucolipidosisMucolipidosis is a group of inherited metabolic disorders that affect the body's ability to carry out the normal turnover of various materials within cells....
(type IV). - A symptom of Helicobacter pyloriHelicobacter pyloriHelicobacter pylori , previously named Campylobacter pyloridis, is a Gram-negative, microaerophilic bacterium found in the stomach. It was identified in 1982 by Barry Marshall and Robin Warren, who found that it was present in patients with chronic gastritis and gastric ulcers, conditions that were...
infection which neutralizes and decreases secretion of gastric acidGastric acidGastric acid is a digestive fluid, formed in the stomach. It has a pH of 1 to 2 and is composed of hydrochloric acid , and large quantities of potassium chloride and sodium chloride...
to aid its survival in the stomach. - A symptom of pernicious anemiaPernicious anemiaPernicious anemia is one of many types of the larger family of megaloblastic anemias...
, atrophic gastritisAtrophic gastritisAtrophic gastritis is a process of chronic inflammation of the stomach mucosa, leading to loss of gastric glandular cells and their eventual replacement by intestinal and fibrous tissues...
or of stomach cancerStomach cancerGastric cancer, commonly referred to as stomach cancer, can develop in any part of the stomach and may spread throughout the stomach and to other organs; particularly the esophagus, lungs, lymph nodes, and the liver...
. - Radiation therapyRadiation therapyRadiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
involving the stomach. - Gastric Bypass procedures such a Duodenal Switch and RNY, where the largest acid producing parts of the stomach are either removed, or blinded.
- VIPomaVIPomaA VIPoma is a rare endocrine tumor, usually originating in the pancreas, that produces vasoactive intestinal peptide ....
s (vasoactive intestinal peptides) and somatostatinomaSomatostatinomaSomatostatinoma is a tumor of the delta cells of the endocrine pancreas that produces somatostatin.It is associated with diabetes mellitus and abnormal glucose tolerance.Triad of : Mild Diabetes mellitus, Steatorrhoea, Gall stones...
s are both islet cell tumors of the pancreas.
Diagnosis
90% of all patients with achlorhydria have detectable antibodies against the H+/K+ ATP-ase proton pump. The diagnosis is made if the gastric pH remains high (>4.0) despite maximum pentagastrinPentagastrin
Pentagastrin is a synthetic polypeptide that has effects like gastrin when given parenterally. It stimulates the secretion of gastric acid, pepsin, and intrinsic factor, and has been used as a diagnostic aid as the pentagastrin-stimulated calcitonin test.Pentagastrin binds to the cholecystokinin-B...
stimulation. High gastrin
Gastrin
In humans, gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the antrum of the stomach, duodenum, and the pancreas...
levels are often detected.
Treatment
Treatment focuses on addressing the underlying cause of symptoms. Many health practitioners recommend meal-time supplementation with betaine hydrochloride (also known as betaine HCL) to increase gastric acidity and allow for proper digestion. Betaine HCL should not be confused with betaine in the form of DMG (dimethylglycineDimethylglycine
Dimethylglycine is a derivative of the amino acid glycine with the structural formula 2NCH2COOH. It can be found in beans and liver. It can be formed from trimethylglycine upon the loss of one of its methyl groups...
) or TMG (trimethylglycine
Trimethylglycine
Trimethylglycine is an organic compound that occurs in plants as either glycine betaine or a choline-containing glycine betaine compound. Trimethylglycine was the first betaine discovered by science; originally it was simply called betaine because, in the 19th century, it was discovered in sugar...
), which are sweet-tasting and non-acidic. Unlike TMG/DMG, betaine HCL includes chloride
Chloride
The chloride ion is formed when the element chlorine, a halogen, picks up one electron to form an anion Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. The chloride ion, and its salts such as sodium chloride, are very soluble in water...
, which breaks down into hydrochloric acid in the stomach, facilitating a lower pH and improving the breakdown of food. Betaine HCL is typically sold as a preparation containing pepsin
Pepsin
Pepsin is an enzyme whose precursor form is released by the chief cells in the stomach and that degrades food proteins into peptides. It was discovered in 1836 by Theodor Schwann who also coined its name from the Greek word pepsis, meaning digestion...
, a digestive enzyme.
In addition to taking steps to lower the pH of the stomach, supplementation with minerals and vitamin
Vitamin
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...
s such as vitamin B12
Vitamin B12
Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...
(which is poorly absorbed in achlorhydria/hypochlorhydria due to the absence of intrinsic factor
Intrinsic factor
Intrinsic factor also known as gastric intrinsic factor is a glycoprotein produced by the parietal cells of the stomach. It is necessary for the absorption of vitamin B12 later on in the small intestine...
) is usually recommended to compensate for malabsorption of nutrients. Foods with high microbial loads (including dairy products that intentionally contain microbes such as penicillin
Penicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
) are usually avoided. Because the acidity of the stomach is a primary defense against infection of the gastrointestinal tract, antifungals, probiotic
Probiotic
Probiotics are live microorganisms thought to be beneficial to the host organism. According to the currently adopted definition by FAO/WHO, probiotics are: "Live microorganisms which when administered in adequate amounts confer a health benefit on the host"...
s, and antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s may be needed to treat recurring infections.
Prognosis
Little is known on the prognosis of achlorhydria, although there have been reports of an increased risk of gastric cancer.See also
- HyperchlorhydriaHyperchlorhydriaHyperchlorhydria refers to the state in the stomach where gastric acid levels are higher than the normal range. In humans, the normal pH is around 1 to 3, which varies throughout the day. The highest basal secretion levels are in the late evening . Hyperchlorhydria is usually defined as having a...
- IsopropamideIsopropamideIsopropamide is a long-acting anticholinergic drug. It is used in the treatment of peptic ulcers and other gastrointestinal disorders involving hyperacidity and hypermotility. Chemically, it contains a quaternary ammonium group. It is most often provided as an iodide salt, but is also available as...
- Fundic gland polyposisFundic gland polyposisFundic gland polyposis is a medical syndrome where the fundus of the stomach develops many polyps. The condition has been described both in patients with polyposis conditions of the colon , and in patients in whom it occurs sporadically.-Clinical presentation:Most patients with fundic gland...