Whole Wheat Flour Components Intervention Against Lead Toxicity: Impacts on Metal Bioavailability and Protection of the Intestinal Epithelial Barrier

Abstract

Consumption of whole wheat flour promotes lead excretion, yet the functional components reducing lead bioavailability and their protective mechanisms remain unclear. To identify these components and to validate whether their mechanism is related to protection of the intestinal barrier, this study established an in vitro model combining gastrointestinal simulated digestion, colonic fermentation, and Caco‐2 intestinal epithelial cells. Results showed that dietary fiber and polyphenols are the key active components that synergistically reduce the bioavailability of lead to 3.90%. They exert a protective effect by maintaining intestinal barrier integrity, as evidenced by an increase in transepithelial electrical resistance of 22.66% and a reduction in cell monolayer permeability of 6.91% after 24 h compared to the lead group. Furthermore, they can alleviate oxidative stress, upregulate the expression of tight junction proteins, and improve intestinal barrier integrity to reduce lead absorption, thus providing a theoretical basis for dietary intervention in heavy metal exposure.