Researchers in South Korea have uncovered a novel health benefit associated with traditional fermented foods, discovering that a specific lactic acid bacterium isolated from kimchi can significantly aid in the removal of nanoplastics from the human body. The groundbreaking findings reveal that the microorganism is capable of binding to ultrafine plastic particles within the intestine, paving the way for potential biological strategies to combat the growing public health challenge posed by environmental micro- and nanoplastics.
The discovery was announced by the World Institute of Kimchi, a prominent government-funded research institute operating under the Ministry of Science and ICT. Led by President Hae Choon Chang, the institute has been spearheading investigations into the diverse functional properties of kimchi-associated microbes, moving beyond their traditional roles in flavor formation and food preservation to explore their broader interactions with human health and environmental pollutants.
Nanoplastics have become an escalating global concern in recent years, defined broadly as ultrafine plastic particles measuring less than 1 micrometer, or one-thousandth of a millimeter, in diameter. These microscopic fragments are continuously generated through the physical, chemical, and biological degradation of larger plastic debris accumulating across terrestrial and aquatic ecosystems. As plastics weather in the environment, they break down into increasingly smaller particles that eventually infiltrate natural water systems, agricultural soils, and the food chain.
Consequently, humans are regularly exposed to nanoplastics through routine consumption of food and drinking water. Due to their extraordinarily minute scale, these particles possess physical characteristics that allow them to bypass standard physiological filtration mechanisms. Researchers note that nanoplastics are capable of crossing the delicate intestinal barrier, entering the bloodstream, and ultimately accumulating in vital internal organs, including the kidneys and the brain.
Despite mounting alarms from the scientific and medical communities regarding the systemic risks posed by these tissue-accumulating particles, effective biological strategies to reduce nanoplastic retention within the human gastrointestinal tract remain in their absolute infancy. Until now, medical science has had few tools to address the silent influx of micro- and nanoplastics into the human body, leaving a critical gap in preventative health research.
To investigate potential biological interventions, a dedicated research team led by Drs. Se Hee Lee and Tae Woong Whon at the World Institute of Kimchi focused their attention on the adsorption capacities of beneficial microorganisms traditionally found in fermented foods. Specifically, the team examined Leuconostoc mesenteroides CBA3656, a specialized lactic acid bacterium naturally derived from kimchi, evaluating its interaction with polystyrene nanoplastics, which are among the most common synthetic polymer particles found in environmental samples.
During initial evaluations conducted under standard, controlled laboratory conditions, the kimchi-derived strain CBA3656 demonstrated a remarkably high adsorption efficiency of 87 percent. This performance was found to be directly comparable to, and slightly higher than, a commonly studied reference strain, Latilactobacillus sakei CBA3608, which exhibited an adsorption rate of 85 percent under identical baseline parameters.
However, the true test of any potential probiotic strain lies in its ability to survive and function within the hostile and dynamic environment of the human digestive system. A notable and critical divergence in performance was observed when the researchers subjected the strains to simulated human intestinal conditions, which feature complex enzymatic activity, fluctuating pH levels, and competing biological compounds.
Under these challenging simulated physiological conditions, the adsorption rate of the reference strain Latilactobacillus sakei CBA3608 plummeted drastically down to just 3 percent, rendering it virtually ineffective in a real-world biological scenario. In stark contrast, the kimchi-derived strain Leuconostoc mesenteroides CBA3656 demonstrated exceptional resilience, maintaining a substantially higher adsorption level of 57 percent. These compelling results strongly indicated that the specialized kimchi strain possesses the structural and chemical stability required to bind nanoplastics effectively, even within the complex chemical environment of the human intestinal tract.
To validate these in vitro discoveries within a living biological system, the research team advanced their investigations by conducting rigorous animal experiments utilizing a germ-free mouse model. The controlled environment of the germ-free model allowed scientists to isolate the specific interactions between the administered probiotic strain and the ingested polystyrene nanoplastics without interference from a pre-existing complex gut microbiome.
When compared against a control group of subjects that did not receive the probiotic supplementation, both male and female mice that were actively administered strain CBA3656 exhibited a striking more-than-twofold increase in the quantity of nanoplastics detected within their feces. This quantitative leap in excreted synthetic particles strongly suggests that the probiotic microorganism actively contributes to the enhanced clearance and elimination of nanoplastics by securely binding to them as they travel through the gastrointestinal tract, thereby preventing their absorption and subsequent systemic distribution.
The implications of this study extend well beyond simple dietary supplementation, providing robust scientific evidence that lactic acid bacteria originating from kimchi are capable of actively interacting with environmental micropollutants in ways previously unimagined. By expanding our understanding of how traditional fermented food microflora operate inside a mammalian host, the findings offer entirely new theoretical insights into potential biological mechanisms designed to mitigate the steady accumulation of synthetic polymers within the human body.
Reflecting on the broader significance of the study, Dr. Sehee Lee, the lead researcher spearheading the project, emphasized the intersection between ecological degradation and human well-being. Plastic pollution is increasingly recognized not only as an environmental issue but also as a public health concern, she noted, pointing out that modern populations are exposed to synthetic particles in ways that previous generations never faced.
Our findings suggest that microorganisms derived from traditional fermented foods could represent a completely new biological approach to address this emerging challenge, Dr. Lee explained, outlining the vision for future research initiatives. She added that the research team intends to continue expanding the scientific value and application of kimchi microbial resources, ensuring that these indigenous strains contribute meaningfully to both public health safeguards and innovative environmental solutions.