Dietary anions

Dietary anions in the intestinal lumen represent a diverse group of negatively charged molecules, including phosphate, oxalate, and bile acids, that are either ingested or secreted into the gastrointestinal tract. These anions play critical roles in physiological processes such as bone mineralization, pH buffering, and the emulsification of dietary fats. However, their excessive accumulation or absorption is associated with significant pathologies, most notably hyperphosphatemia in patients with chronic kidney disease and the formation of calcium oxalate kidney stones. In pharmacology, these anions are considered therapeutic targets for non-absorbed sequestering agents, such as phosphate binders and bile acid sequestrants. These drugs work by ion exchange or physical binding to form insoluble complexes that cannot be absorbed across the intestinal epithelium, thereby facilitating their excretion in feces. This localized mechanism of action allows for the management of systemic mineral and lipid imbalances while minimizing the risks associated with systemic drug distribution (National Center for Biotechnology Information, https://www.ncbi.nlm.nih.gov/books/NBK544250/; StatPearls, https://www.ncbi.nlm.nih.gov/books/NBK526095/).

Other names

Intestinal anionsLuminal anionsDietary phosphateDietary oxalateBile acids (intestinal)

Sequestration and formation of insoluble complexes within the gastrointestinal tract to prevent systemic absorption and promote fecal excretion.