Bioavailability of lead in contaminated soils elevated with high carbohydrate, protein, and fat diets via influences on gut microbiota and intestinal barrier function.

Accidental ingestion of lead (Pb) contaminated soil will interact with different types of foods in the gastrointestinal tract. To determine the effects of food composition on soil Pb oral bioavailability, a mouse bioassay was conducted to evaluate the relative bioavailability (RBA) of Pb with high-fat, high-protein, high-carbohydrate, and high-dietary fiber diets. Results indicated that high-fat diet most effectively enhanced Pb-RBA (91.4% for soil A and 89.7% for soil B, respectively), while high-dietary fiber reduced it. Compared with the basal diet group, high-carbohydrate, high-fat, and high-protein diets combined with Pb caused oxidative damage, intestinal inflammation, and the positive cells rate of the intestine increased significantly (1.18-4.23 fold). However, high-dietary fiber diet reduced oxidative damage in mice, significantly reduced the rate of intestinal positive cells, and protected intestinal barrier function. These findings indicate that high-fat diet poses the highest health risks when associated with Pb exposure, followed by high-carbohydrate and high-protein diets, while increased dietary fiber intake shows potential for reducing such Pb exposure risks.