Related Experiment Video
Updated: Jul 20, 2026
Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain
Published on: January 4, 2018
Polystyrene microplastic exposure induces insulin resistance in mice via dysbacteriosis and pro-inflammation
Dingjie Huang1, Ying Zhang2, Jianglan Long2
1Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China; Beijing Institute of Clinical Pharmacy, Beijing 100050, China; Beijing Key Laboratory for Evaluation of Rational Drug Use, Beijing 100038, China.
Abstract:
Microplastics (MPs) as emerging contaminants have become a global environmental problem. However, studies on the effects of MPs on metabolic diseases remain limited. Here, we evaluated the effects of polystyrene (PS), one of the most prominent types of MPs, on insulin sensitivity in mice fed with normal chow diet (NCD) or high-fat diet (HFD), and explained the underlying mechanisms. Mice fed with NCD or HFD both showed insulin resistance (IR) after PS exposure accompanied by increased plasma lipopolysaccharide and pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin-1β. Exposure to PS also resulted in a significant decrease in the richness and diversity of gut microbiota, particularly an increase in the relative abundance of Gram-negative bacteria such as Prevotellaceae and Enterobacteriaceae. Additionally, PS with a small particle size (5 μm) accumulated in the liver, kidneys and blood vessels of mice. Further analyses showed inhibition of the insulin signaling pathway in the liver of PS exposed mice, such as inhibition of IRS1 and decreased expression of PI3K. Hence, the mechanism of PS exposure to induce IR in mice might be mediated through regulating gut microbiota and PS accumulation in tissues, stimulating inflammation and inhibiting the insulin signaling pathway. In conclusion, PS might be a potential environmental contaminant that causes metabolic diseases associated with IR.
Insights
Polystyrene microplastics (MPs) exposure induced insulin resistance in mice by altering gut bacteria and causing inflammation. This suggests MPs may be environmental contaminants linked to metabolic diseases.
Area of Science:
- Environmental Science
- Toxicology
- Metabolic Diseases
Background:
- Microplastics (MPs) are emerging contaminants with widespread environmental presence.
- Limited research exists on the impact of MPs on metabolic diseases, particularly insulin resistance.
Purpose of the Study:
- To investigate the effects of polystyrene microplastics (PS MPs) on insulin sensitivity in mice.
- To elucidate the underlying mechanisms by which PS MPs induce insulin resistance.
Main Methods:
- Mice were fed either a normal chow diet (NCD) or a high-fat diet (HFD) and exposed to PS MPs.
- Evaluated insulin resistance, plasma lipopolysaccharide, pro-inflammatory cytokines, gut microbiota composition, and PS accumulation in tissues.
- Analyzed the insulin signaling pathway in liver tissues.
Main Results:
- PS MP exposure led to insulin resistance in both NCD and HFD groups.
- Increased plasma lipopolysaccharide and pro-inflammatory cytokines (TNF-α, IL-1β) were observed.
- Gut microbiota diversity decreased, with an increase in Gram-negative bacteria.
- Small-sized PS MPs (5 μm) accumulated in liver, kidneys, and blood vessels.
- Insulin signaling pathway (IRS1, PI3K) was inhibited in the liver.
Conclusions:
- PS MP exposure induces insulin resistance potentially through gut microbiota dysregulation, tissue accumulation, inflammation, and impaired insulin signaling.
- Polystyrene microplastics may act as environmental contaminants contributing to metabolic diseases associated with insulin resistance.
Related Concept Videos
01:28Microbial Bioremediation of Plastics
01:18Dysbiosis of the Gut Microbiota
01:21Microbiota Modulation by Antibiotics