Kimchi-derived bacteria may help remove nanoplastics from the gut. Digest
Tiny plastic particles are now found in food, water, and even inside the human body, raising concerns about how they affect health. In a new study, scientists explored whether food-derived bacteria could help capture nanoplastics and promote their removal from the body.
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The researchers examined two lactic acid bacteria isolated from kimchi: Leuconostoc mesenteroides CBA3656 and Latilactobacillus sakei CBA3608. They exposed these bacteria to polystyrene nanoplastics (extremely small plastic particles under 1 micrometer in size) and measured how effectively the bacteria could bind and remove these particles under different laboratory conditions. They also evaluated Leuconostoc mesenteroides in germ-free mice, allowing the researchers to isolate the direct interaction between the bacteria and nanoplastics without interference from other microbes.
- Under typical laboratory conditions, including neutral pH and body temperature, both strains rapidly captured nanoplastics, but Leuconostoc mesenteroides reached near-maximum performance within about 30 minutes, while Latilactobacillus sakei took about 60 minutes.
- At higher plastic concentrations, Leuconostoc mesenteroides maintained strong performance, while Latilactobacillus sakei showed a sharp drop in efficiency.
- Across a wide range of pH levels and temperatures, both strains remained effective, although Latilactobacillus sakei performed slightly better under extreme acidity and heat.
- Microscopy images showed that nanoplastics attached to the outside of bacterial cells rather than entering them.
- In simulated intestinal fluid, Leuconostoc mesenteroides retained substantial binding ability, while Latilactobacillus sakei lost most of its effectiveness, indicating greater suitability under conditions found in the human body.
- Germ-free mice given Leuconostoc mesenteroides excreted more nanoplastics in their feces than untreated controls, suggesting reduced absorption in the gut.
The experiments show that these bacteria bind nanoplastics to their surfaces, suggesting that the particles remain intact rather than being broken down. This is relevant because degradation may not promote elimination, as smaller fragments or byproducts could still be absorbed, whereas intact particles attached to the bacteria are more likely to pass through the gut and be excreted.
Treated mice excreted more nanoplastics in their feces, but nanoplastic levels in internal organs were not measured, so it remains unclear how tissue exposure differed between treated and untreated mice. Because the mice were germ-free and lacked a normal gut microbiome, it is also uncertain whether the bacteria would be as effective in a typical gut with many other microbes present. However, if confirmed in human clinical trials, specific probiotic supplements or simply eating kimchi and other fermented foods could help protect against the harmful effects of nanoplastics. In this clip, I outline the steps I take to limit microplastic exposure and discuss methods that may support the elimination of microplastics and their associated chemicals.