The pervasive presence of microplastics into the environment has become a significant global concern. Not only do they pollute oceans and soils, but scientists have also confirmed that they may adversely affect crop growth and human health. After recently publishing findings on the impact of nanoplastics on hydroponic vegetable growth in the Journal of Hazardous Materials, Assistant Professor Bao-Hong Lee and his team at the Department of Horticultural Sciences, NCYU, have published new findings in the world-leading journal Nature Communications in June, demonstrating a novel mechanism by which nanoplastics compromise gut health.
The team uncovered a novel molecular mechanism showing how microplastics indirectly affect health. Nanoplastics change the composition of extracellular vesicles (EVs) released by bacteria or host cells. These changes can affect crop growth, the human intestinal barrier, and microbial balance. Both studies have received significant international attention. The latest paper published in Nature Communications was selected as a highlight article, underscoring its significance within the global scientific community.
Professor Lee’s team has long investigated the role of EVs in inter-kingdom communication. Their initial study found that polystyrene nanoplastics, while not directly toxic to lettuce, promote the proliferation of specific bacteria in hydroponic systems. The EVs released by these bacteria suppress the plant’s antioxidant defenses and growth pathways, ultimately causing lettuce wilting and death.
In their latest study, the team further focused on gut health and discovered that nanoplastics are not inert particles passively entering the intestines. Instead, they actively disrupt communication between host and bacteria by interfering with EVs and modulating microRNA (miRNA) expression. The findings confirm that nanoplastics reduce gut barrier protein expression in mice and disrupt gut microbiota balance, promoting the overgrowth of bacterial strains linked to intestinal disorders. By hijacking the delicate dialogue between bacteria and host, nanoplastics disrupt the gut microenvironment – weakening the intestinal barrier, impairing immune responses, and reshaping the structure of the microbial community. Notably, this research opens new therapeutic possibilities. Targeting specific EV-derived miRNAs or modulating their biogenesis may lead to the development of future strategies to restore gut homeostasis disrupted by environmental pollutants. This opens up a new molecular strategy: focusing on restoring microbiota-host communication rather than simply removing pollutants.
These two studies are the first to systematically demonstrate that nanoplastics can indirectly harm a wide range of organisms – both plants and animals – by disrupting EVs produced by microbes or host cells. In an era where pollution has become a “microscopic threat,” these findings serve as a wake-up call for urgent action across scientific, medical, and environmental sectors to mitigate the profound effects of nanoplastics on human health.
Assistant Professor Lee emphasized, “These two studies show that the hazards of nanoplastics extend beyond environmental pollution; they can affect organismal health through subtle interference with cellular communication. Whether in crops or humans, nanoplastics may pose hidden health risks via EV-mediated pathways, warranting serious attention. Our research explores the role of EVs in host–microbe interactions, elucidating how they regulate gut microbiota and host health. This novel and important field opens promising avenues for developing microbial EV-based therapeutic targets.”
As EV-related innovations continue to grow globally, Assistant Professor Lee’s team calls for increased national investment in EV research and applications, so that Taiwan can join the global trend and strengthen its international visibility and leadership in the field.
Photo 1: NCYU Assistant Professor Bao-Hong Lee (third from left) and Associate Professor Wei-Hsuan Hsu of National Cheng Kung University, along with their research teams, received the 2024 Future Tech Award from Taiwan’s National Science and Technology Council for their collaborative research on the functions of microbial EVs.