Intestinal Microplastic Retention Reshapes Gut Microbial Ecology through Surface-Associated Colonization and Additive...

Area of Science:

• Environmental Science
• Microbiology
• Toxicology

Background:

• Microplastics (MPs) pose risks to the human gut microbiota, but interaction mechanisms are unclear.
• Understanding MP-microbiota interactions is crucial for assessing gut health impacts.

Purpose of the Study:

• To investigate how retained poly(ethylene terephthalate) MPs affect gut microbial communities.
• To elucidate the mechanisms of MP-microbiota interactions in a simulated gut environment.

Main Methods:

• Utilized the Simulator of the Human Intestinal Microbial Ecosystem (SHIME), a host-free in vitro model.
• Compared poly(ethylene terephthalate) MPs with additive-eluted MPs and silica particles (SiO2).
• Analyzed microbial community composition, surface properties, and network interactions.

Main Results:

• MPs exhibited greater surface roughness and hydrophobicity, promoting colonization by specific taxa.
• MP retention led to spatial redistribution of microbes and displacement of keystone taxa.
• Leachable additives independently altered microbial composition and predicted functional pathways, including xenobiotic degradation.

Conclusions:

• Retained MPs condition gut microbial ecosystems through surface interactions and additive leaching.
• MP-associated microbial perturbations are significant for gut health and require consideration in exposure assessments.
• This study provides mechanistic insights into microplastic impacts on the human gut microbiome.