High-Dietary Fiber Diet Reduces Arsenic Oral Bioavailability and Health Risk from Soils by Regulating Gut Microbiota...

Unlike conventional energy-intensive physical/chemical soil remediation, dietary regulation of As oral bioavailability represents a cost-effective, sustainable downstream intervention in environmental risk management and control. However, how distinct dietary structures regulate As bioavailability remains unelucidated, hindering a holistic understanding of corresponding exposure and health risks. To address this, a mouse bioassay was conducted to evaluate the relative bioavailability (RBA) of As in two soils with four typical diet structures (high-fat, high-protein, high-carbohydrate, and high-dietary fiber diets). The results showed that although the four diets promoted the gastrointestinal As dissolution by 1.1-1.7-fold, the high-dietary fiber diet decreased As-RBA by 9.49-13.2% and lowered the health risk by 0.50-0.70-fold, which was more effective than high-protein and high-carbohydrate diets. The decrease was associated with lower intestinal permeability, which correlated with a significant increase in the relative abundance of Roseburia and Lachnospiraceae, and a decrease in the apoptosis rate of mouse intestinal epithelial cells. In contrast, a high-fat diet increased As-RBA by 8.72-11.9% and raised the health risk by 1.33-1.38-fold, which was associated with a significant proliferation of Dubosiella and a significant inhibition of Roseburia. This study shows that a high-dietary fiber diet is associated with reduced As exposure and potential health risks, in parallel with favorable changes in gut microbiota, oxidative status, and intestinal permeability.