Intestinal permeability and gene expression after polyethylene and polyamide microplastic ingestion in Wistar rats

Area of Science:

• Environmental Science
• Toxicology
• Gastroenterology

Background:

• Microplastics are widespread environmental contaminants.
• Human and mammalian health effects of microplastic ingestion are largely unknown.
• Understanding microplastic uptake and effects in mammals is crucial.

Purpose of the Study:

• To investigate the effects of oral microplastic (polyamide and polyethylene) ingestion in rats.
• To assess impacts on duodenal permeability and tight junction protein expression.
• To quantify microplastic levels in rat feces.

Main Methods:

• Rats were fed diets containing 0.1% microplastics (polyamide, polyethylene, or mixture) for 5 weeks.
• Duodenal permeability was measured using an Ussing chamber.
• Gene and protein expression of tight junction proteins (occludin, zonula occludens protein 1) were analyzed in gut tissue and plasma.
• Microplastics were quantified in feces using pyrolysis-gas chromatography/mass spectrometry.

Main Results:

• Microplastic ingestion led to increased duodenal permeability.
• Occludin gene expression was elevated in polyethylene-exposed rats.
• Zonula occludens protein 1 levels in the gut were higher in microplastic-exposed groups.
• No significant changes were observed in zonula occludens protein 1 plasma levels or occludin protein concentrations.

Conclusions:

• Short-term oral exposure to 0.1% microplastics had limited effects on duodenal permeability and tight junction protein gene expression.
• The study provides insights into the physiological responses of rats to microplastic ingestion.
• Further investigation into chronic exposure and diverse microplastic types is warranted.