Fatty acids alter monolayer integrity, paracellular transport, and iron uptake and transport in Caco-2 cells.

The Caco-2 cell line was used as a model to determine if the type of fatty acid, unsaturated versus saturated, differentially altered the uptake and transport of iron in the human intestine and if the changes were the result of alterations in monolayer integrity and paracellular transport. Cells were cultured in either a lower-iron or normal-iron medium and incubated with a bovine serum albumin control, linoleate, oleate, palmatate, or stearate. Oleate, palmatate, and stearate enhanced (p < 0.05) iron uptake in cells grown in lower iron. The fatty acid effect on iron uptake by cells grown in normal iron was not as pronounced. Iron transport was not affected (p > 0.05) by an interaction between the type of medium (iron concentration) and the type of fatty acid. Iron transport was enhanced (p < 0.05) with palmatate and stearate. Various indicators of monolayer integrity and paracellular transport were also affected by the fatty acids, thus impacting iron uptake and transport. These results indicate that oleate, palmatate, and stearic can enhance iron uptake and transport; however, this enhancement may be the result of alterations in the integrity of the intestine.