Differential influence of molybdenum disulfide at the nanometer and micron scales in the intestinal metabolome and microbiome of mice

Abstract

The molybdenum disulfide nanomaterial (nano-MoS₂) is receiving increasing amounts of attention due to its special physicochemical characteristics. However, little is known about the influence of the different sizes of MoS₂ on the intestinal metabolome and microbiome. In this study, C57BL/6 mice were exposed to nano-MoS₂ and MoS₂ micromaterials (micro-MoS₂) via food premixed with 15 and 150 mg MoS₂ per kg food for 90 days. The results showed that nano-MoS₂ and micro-MoS₂ exposure induced Mo accumulation in mouse organs, especially in the small intestine (SI) and large intestine (LI). Nano-MoS₂ had a higher bioavailability and caused greater intestinal inflammation than micro-MoS₂. Metabolome analyses showed that both types of MoS₂ exposure changed the metabolic profiles of the intestine and intestinal microbiota. Ten and eight significantly altered microbial-host cometabolites were found in the SI and LI, respectively, and these were primarily involved in amino acid and carbohydrate metabolism. Additionally, both types of MoS₂ exposure obviously changed the intestinal microbiota, especially in the LI. Correlation analysis suggests that micro-MoS₂ could alter the intestinal metabolic profiles by changing the microbial community, but nano-MoS₂ could cause similar effects by changing the microbial community and direct intestine toxicity. This study provides insights into the toxicity and health risks of nano-MoS₂ and micro-MoS₂ introduced by oral exposure.