Influence of Dietary Lipid Type on the Bioavailability of DDT and Its Metabolites in Soil: Mechanisms and Health Implications.

ABSTRACT

The impact of dietary lipid type on DDTr (DDT and its metabolites) relative bioavailability (RBA) in soil was investigated using an in vivo mouse model and in vitro assays. Three different lipids were long chain triglycerides (LCT), medium chain triglycerides (MCT), and short chain triglycerides (SCT). DDTr-RBA markedly (p < 0.05) increased from 51.3 ± 10.8% (control) to 94.6 ± 15.9% (10% w/w LCT) and 112 ± 20.8% (20% LCT) in LCT amended treatments. A significant increase in DDTr-RBA (92.2 ± 9.84%, p < 0.05) was also observed when mice were administered diets containing 20% MCT; however, no influence on DDTr-RBA was observed for SCT amended diets. Mechanism exploration showed that LCT and MCT enhanced DDTr solubilization by a factor of 7.31-9.59 compared to controls as a consequence of micelle formation which promoted DDTr mobilization from soil. LCT significantly enhanced DDTr intestinal absorption via increasing synthesis and secretion of apolipoprotein B 48 (32.2 ± 2.08 mg/L), compared to MCT (22.1 ± 1.32 mg/L) and SCT (15.5 ± 2.03 mg/L) treated Caco-2 cells. Mouse gut microflora analysis highlighted that LCT and MCT may increase intestinal permeability by regulating abundance of Lactobacillus, which may influence the absorption of DDTr.