"Microplastic Toxicity in the Body Varies with Gut Bacteria": Seoul National University Research Team Finds [Reading Science]

Potential for Toxicity Mitigation Using Native Probiotics
Proposal for New Assessment Criteria

New research has found that the effects of microplastics on the human body may not depend solely on the size or properties of the particles, but can also vary according to the types of bacteria present in the gut. The study even suggests the possibility of using specific microorganisms to reduce toxicity, leading to analysis that risk assessments and response strategies for microplastics may change as a result.

On March 19, Professor Kim Younghoon and his research team from the Department of Agricultural Biotechnology at Seoul National University's College of Agriculture and Life Sciences announced that they had demonstrated how microplastic toxicity can vary significantly depending on interactions with gut bacteria. The results were published in the international journal of microbial ecology, The ISME Journal.

Mechanism of Microplastic Toxicity Regulation Pathway by Plastic-Degrading Bacteria. Provided by the research team

"The Same Microplastics Act Differently": Toxicity Changes Depending on Bacterial Strains

Using experiments with Caenorhabditis elegans, the research team found that host responses differed dramatically when polystyrene microplastics were co-exposed with two types of plastic-degrading bacteria.

When the LG3 strain (Enterobacter hormaechei), which has a tendency to enhance microplastic toxicity, was introduced, there was greater intestinal accumulation of microplastics, increased oxidative stress, and more pronounced physiological damage. In contrast, when the SCGB1 strain (Bacillus amyloliquefaciens), which acts to mitigate microplastic toxicity, was introduced, these toxic responses were alleviated.

Even under the same conditions, the amount of microplastics accumulated in the gut was found to be higher in the LG3 group compared to the SCGB1 group.

"Toxicity Mitigation via Probiotics": A New Potential Response Strategy

The research team also confirmed that these differences were not merely coincidental, but stemmed from "strain-specific interactions" between bacteria and microplastics.

The LG3 strain strongly binds to microplastics, forming biofilms and enhancing toxicity. In contrast, the SCGB1 strain induces protective host responses through metabolic products such as isobutyrate and isovalerate.

Comparison of Microplastic Accumulation Levels According to Yeast Strains. Provided by Research Team

Notably, the SCGB1 strain is a native Bacillus strain isolated from Cheonggukjang, suggesting the potential for its use as a probiotic to mitigate microplastic toxicity.

The research team explained that their findings highlight the need to consider not only particle characteristics but also the gut microbiome environment when assessing the risks of microplastics. They emphasized the significance of this study in opening up the possibility for "microbiome-based response strategies" that use specific microorganisms to reduce toxicity.

Professor Kim Younghoon commented, "The fact that a strain derived from a traditional fermented food showed the potential to mitigate microplastic toxicity holds both scientific and industrial value. In the future, we expect this to lead to the verification of its applicability to humans and the development of related technologies."

This content was produced with the assistance of AI translation services.