Microplastic-Induced Gut Microbiome and Metabolic Disruption in Sprague-Dawley Rats

Abstract

Toxic effects of exposure to microplastics (MPs) on living organisms and humans have attracted a global concern. However, most previous studies exposed animals to only one type of MP (mainly polystyrene) to assess the health risk of MPs for animals. Therefore, we conducted a laboratory gavage experiment on rats based on the types and concentration of MPs to which humans are exposed in their daily life. The purpose of this study is to use Sprague-Dawley (SD) rat models to assess the potential health risks in mammals from co-exposure to various MPs. In the present study, SD rats were exposed to 12 mg/kg bw/day mixed-MPs (containing 10 types of MPs) for 42 days, and then examined the alteration of gut microbes and metabolites. The results showed that 6 gut microbes at the family level (f_Muribaculaceae, f_Oscillospiraceae, f_Bacteroidaceae, f_Neisseriaceae, f_Prevotellaceae, and f_Veillonellaceae) were significantly perturbed (t-test, p < 0.05) in rats after MP exposure. MP intervention also significantly regulated 47 metabolites and 4 metabolic pathways (citrate cycle; D-glutamine and D-glutamate metabolism; glyoxylate and dicarboxylate metabolism; alanine, aspartate, and glutamate metabolism) in SD rat serum. These findings contribute to assessing the health risks of various MP co-exposure in mammals in the actual environment and provide a novel insight into the toxicity mechanism of MPs.