Gastric and intestinal pH balance

Gastric and intestinal pH balance refers to the tightly regulated acid–base environment of the stomach and intestines. In the stomach, highly acidic gastric juice (pH 1–3) is produced by parietal cells via the H,K-ATPase proton pump and is buffered by bicarbonate secreted by other cells[4]. Acid secretion is dynamically regulated in response to food intake and is controlled by neuroendocrine mediators including gastrin (stimulates acid when pH is high), histamine, acetylcholine, and somatostatin (inhibits acid secretion when pH is low)[1][2][3][4][5]. In the small and large intestines, pH is modulated by continued secretion of bicarbonate (from the pancreas and gut epithelial cells), fermentation by microbiota, and absorption of metabolic products. pH regulation is crucial for the activation of digestive enzymes, protection against pathogens, and proper nutrient absorption. Abnormalities in pH balance underlie many gastrointestinal diseases, and are the target of several classes of drugs, but pH balance itself is not a molecule, receptor, or defined molecular entity[2][3][4][5].

Other names

Gastric pH regulationIntestinal pH regulationGastrointestinal acid-base balance

Inhibition of H,K-ATPase to reduce acid secretion (e.g., omeprazole). Blockade of histamine H2 receptors to reduce acid secretion. Neutralization of gastric acid by chemical buffers (antacids). Suppression of gastrin and stimulation of somatostatin for acid inhibition.