Iron Supplements Containing 299v Increase Ferric Iron and Up-regulate the Ferric Reductase DCYTB in Human Caco-2/HT29 MTX Co-Cultures.

Several human interventions have indicated that 299v ( 299v) increases intestinal iron absorption. The aim of the present study was to investigate possible effects of 299v on the mechanisms of iron absorption on the cellular level. We have previously shown that lactic fermentation of vegetables increased iron absorption in humans. It was revealed that the level of ferric iron [Fe (H₂O)₅] was increased after fermentation. Therefore, we used voltammetry to measure the oxidation state of iron in simulated gastrointestinal digested oat and mango drinks and capsule meals containing 299v. We also exposed human intestinal co-cultures of enterocytes and goblet cells (Caco-2/HT29 MTX) to the supplements in order to study the effect on proteins possibly involved (MUC5AC, DCYTB, DMT1, and ferritin). We detected an increase in ferric iron in the digested meals and drinks containing 299v. In the intestinal cell model, we observed that the ferric reductase DCYTB increased in the presence of 299v, while the production of mucin (MUC5AC) decreased independently of 299v. In conclusion, the data suggest that the effect of 299v on iron metabolism is mediated through driving the Fe/DCYTB axis.