Gastric hydrochloric acid and luminal gastric contents

Gastric hydrochloric acid and luminal gastric contents represent the chemical and enzymatic environment of the stomach, primarily characterized by a low pH (1.5 to 3.5) maintained by parietal cell secretion of hydrochloric acid (HCl). This acidic environment is vital for the activation of pepsinogen into the proteolytic enzyme pepsin, the denaturation of dietary proteins, and the elimination of ingested pathogens (StatPearls, 2023). However, when the protective mucosal barrier is overwhelmed or when these contents reflux into the esophagus, they contribute to the pathogenesis of gastroesophageal reflux disease (GERD), gastritis, and peptic ulcer disease (NIH, 2022). Unlike systemic pharmacological agents that inhibit acid production by targeting receptors or enzymes, certain therapeutic classes target the luminal contents directly. Antacids act by chemically neutralizing HCl to increase gastric pH, thereby reducing mucosal irritation and pepsin activity, while alginates react with the acid to form a physical, pH-neutral barrier or raft that floats on top of the gastric contents to prevent reflux (NCBI, 2022).

Other names

Gastric acidStomach acidGastric juiceLuminal gastric acidHydrochloric acid

Chemical neutralization of hydrochloric acid to increase gastric pH and the formation of a physical barrier (raft) to prevent reflux of luminal contents.