A bacterium commonly found in kimchi may help trap tiny plastic particles in the gut and assist in their removal from the body, according to a recent study by the World Institute of Kimchi, a government-funded research institute in South Korea. The study, led by researchers Se Hee Lee and Tae Woong Whon, focused on a specific lactic acid bacterium, Leuconostoc mesenteroides CBA3656, which is naturally present in kimchi. The scientists tested how well this bacterium could bind to polystyrene nanoplastics (PS-NPs), which are extremely small plastic particles—less than one-thousandth of a millimeter in size—formed when larger plastics break down. Nanoplastics are a growing concern because they can enter the human body through food and water. Once inside, their tiny size allows them to pass through the intestinal wall and accumulate in organs such as the kidneys and brain. However, current methods to reduce their buildup in the body are still in early stages of development. Researchers are exploring biological solutions, such as using bacteria, to address this issue. In the lab, the kimchi-derived strain L. mesenteroides CBA3656 showed an impressive ability to bind to nanoplastics, achieving an 87% adsorption rate. This was slightly higher than a reference strain, Latilactobacillus sakei CBA3608, which had an 85% rate. However, when tested under conditions simulating the human gut, the performance of the two strains diverged significantly. The reference strain's adsorption rate dropped to just 3%, while L. mesenteroides CBA3656 maintained a strong 57% binding capacity. This suggests that the kimchi-derived strain is more effective at binding nanoplastics in environments that resemble the human digestive system. In experiments with germ-free mice, the researchers found that mice given L. mesenteroides CBA3656 excreted more than twice as much nanoplastics in their feces compared to a control group that did not receive the probiotic. This indicates that the bacteria may help move nanoplastics through the digestive tract and out of the body. The study highlights a potential new role for lactic acid bacteria, traditionally known for their use in food fermentation, in addressing environmental pollutants. The findings offer a novel approach to reducing nanoplastic accumulation in the gut. Dr. Sehee Lee, the lead researcher, emphasized the dual challenge of plastic pollution, stating that it is not only an environmental issue but also a growing public health concern. She noted that microorganisms from traditional fermented foods like kimchi may offer innovative biological solutions to this emerging problem.