Gastric hydrogen ion (H+)

Gastric hydrogen ions, commonly referred to as gastric acid, are positively charged ions secreted by the parietal cells of the stomach into the gastric lumen via the H+/K+-ATPase pump [1]. These ions are fundamental to the digestive process, as they maintain a highly acidic environment (pH 1.0–3.0) necessary for the denaturation of dietary proteins and the conversion of pepsinogen into the active proteolytic enzyme pepsin [2]. Beyond digestion, the high concentration of hydrogen ions serves as a critical innate immune barrier by neutralizing ingested pathogens [1]. Pathologically, the overproduction or reflux of these ions into the esophagus can cause mucosal damage, leading to conditions such as gastroesophageal reflux disease (GERD) and peptic ulcers [3]. Therapeutic strategies targeting these ions include direct neutralization by antacids, which are basic compounds that react with H+ to form water and salts, thereby rapidly reducing acidity [4]. Additionally, pharmacological inhibition of the secretion of these ions is achieved through proton pump inhibitors (PPIs) and H2-receptor antagonists, which are mainstay treatments for acid-related disorders [5].

Other names

Gastric acidStomach acidGastric protonsHydronium ionGastric H+

Direct chemical neutralization of hydrogen ions in the gastric lumen to increase pH.