Assessment and Comparison of Bioavailability of Cadmium in Different Foods Using In Vitro, In Cellulo, and In Vivo Models

Cadmium (Cd) is a potential carcinogen and can easily trigger human renal and hepatic dysfunction. Ingestion of Cd-contaminated food is considered the principal way of human exposure to Cd. Bioavailability evaluation has been utilized to assess human health risk, while the correlation of the in cellulo and in vivo Cd bioavailability in foods is not clear. In this study, the bioavailability of Cd in food samples (pork kidney, indica, and lettuce) were primarily evaluated and compared in vitro, in cellulo, and in vivo mouse models. The linear regression analysis demonstrated the bioavailability of Cd in cellulo Caco2 cells model, and the in vivo mouse model exhibited a strong correlation coefficient (R2 = 0.95). In contrast, the simplified in vitro bioaccessibility evaluation displays a poor prediction to simulate the digestion process of Cd in cellulo (R2 = 0.65) or in vivo (R2 = 0.74), as it neglects the effects of food matrices (moisture, starch, and fat) on the transportation rate of gastrointestinal. These findings suggested that simplified in vitro bioaccessibility evaluation is not considered suitable to precisely predict the bioavailability of Cd, while the Caco2 cells model might be a promising Cd bioavailability assessment model to predict human exposure to Cd from food intake.