In vitro study of intestinal transport of fluoride using the Caco-2 cell line

► Human intestinal transport of F was studied, using the Caco-2 cell line as a model of the intestinal epithelium. ► F absorption is moderate (<70%) in absorptive (apical-basolateral) and secretory (basolateral-apical) directions. ► In both absorptive and secretory directions, F is transported by paracellular pathway, which may be considered predominant. ► Non-ionized state, participation of F−/H+ cotransporter or F−/OH− antiporter may explain why transport increases at acid pH. ► Possible transcellular participation of mechanisms involved in transport of Cl− and active transport in secretory direction.