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Updated: Jun 26, 2026
Quantitative Polymerase Chain Reaction-based Analyses of Murine Intestinal Microbiota After Oral Antibiotic Treatment
Published on: November 17, 2018
Oral exposure to high concentrations of polystyrene microplastics alters the intestinal environment and metabolic
Yuka Hasegawa1, Takuro Okamura1, Yuriko Ono1
1Department of Endocrinology and Metabolism, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Introduction:
Oral exposure to microplastics (MPs) is a global health concern. In our previous study, MPs induced glucose intolerance and non-alcoholic fatty liver disease (NAFLD) under a high-fat diet-induced leaky gut syndrome (LGS). This study aims to evaluate the effects of high concentrations of MP on lipid metabolism under normal dietary conditions and to assess the changes in the intestinal tract resulting from MP exposure.
Methods:
C57BL6/J mice were fed a normal diet (ND) without polystyrene MPs (PS-MPs) or with PS-MPs (1000 µg/L or 5000 µg/L) for six weeks. Subsequently, intestinal permeability, gut microbiota, and metabolite levels in the serum, feces, and liver were determined.
Results:
Mice fed the ND showed no increase in intestinal permeability in either group. However, high MPs concentrations led to increased serum lipid levels and exacerbated fatty liver function. Oral exposure to MPs did not affect the number of innate lymphoid cells or short-chain fatty acids in the intestine. However, it increased the number of natural killer cells, altered the gut microbiota, induced inflammation, and modulated the expression of genes related to nutrient transport in the intestine. The severity of intestinal disturbance tended to worsen with dose.
Discussion:
Despite the absence of LGS, high concentrations of MPs induced dyslipidemia and NAFLD. Oral exposure to MPs triggered intestinal inflammation via natural killer cells, altered the gut microbiota, and modulated nutrient metabolism. Our study highlights the need for environmental measures to reduce oral MPs exposure in the future.
Insights
High concentrations of microplastics (MPs) cause dyslipidemia and fatty liver disease even without leaky gut syndrome. MPs disrupt gut microbiota and induce intestinal inflammation, underscoring the need to reduce environmental exposure.
Area of Science:
- Environmental Health
- Toxicology
- Gastroenterology
Background:
- Oral exposure to microplastics (MPs) is a growing global health concern.
- Previous research linked MPs to glucose intolerance and non-alcoholic fatty liver disease (NAFLD) under specific dietary conditions.
- The impact of high MP concentrations on lipid metabolism and the intestinal tract under normal diets requires further investigation.
Purpose of the Study:
- To evaluate the effects of high concentrations of MPs on lipid metabolism in mice on a normal diet.
- To assess MP-induced changes in the intestinal tract, including permeability, gut microbiota, and inflammation.
- To determine if MPs cause NAFLD and dyslipidemia independent of leaky gut syndrome.
Main Methods:
- C57BL6/J mice were fed a normal diet with or without polystyrene MPs (PS-MPs) at high concentrations (1000 µg/L or 5000 µg/L) for six weeks.
- Intestinal permeability, gut microbiota composition, and serum, fecal, and liver metabolite levels were analyzed.
- Changes in immune cell populations and gene expression related to nutrient transport were also assessed.
Main Results:
- High MP concentrations increased serum lipid levels and exacerbated fatty liver function, despite no increase in intestinal permeability.
- MP exposure altered gut microbiota, induced intestinal inflammation mediated by natural killer cells, and modulated nutrient transport gene expression.
- The severity of intestinal disturbances correlated with MP dose.
Conclusions:
- High-dose oral microplastic exposure can induce dyslipidemia and NAFLD even in the absence of leaky gut syndrome.
- Microplastics trigger intestinal inflammation and alter gut microbiota, impacting nutrient metabolism.
- Reducing environmental microplastic exposure is crucial to mitigate adverse health effects.
