Tiny plastic particles can enter your body through food and drinking water and end up everywhere.
Finding ways to help move them out has become an important research challenge — and scientists have found a promising candidate in an unexpected food.
Kimchi is a traditional Korean dish made from fermented vegetables, usually cabbage. Even if you’ve never tried it, one of its bacteria may give you a reason to pay attention.
Researchers found that this bacterium could grab onto nanoplastics under conditions resembling the human intestine.
That raises an intriguing possibility: Could bacteria from fermented foods help capture tiny plastic particles in the gut and carry them out of the body?
Quick answer
A specific bacterium isolated from kimchi bound polystyrene nanoplastics in laboratory tests. In mice, those receiving the bacteria excreted more than twice as much nanoplastic as those that didn’t. These findings suggest a potential way to capture plastic particles in the intestine and promote their removal. Human studies are needed to determine whether the strain produces the same effect in people.
Why nanoplastics are getting attention
Microplastics are tiny plastic particles; nanoplastics are their even smaller counterparts. Some researchers also use “microplastics” as an umbrella term covering both.
Nanoplastics typically measure less than 1 micrometer—one-thousandth of a millimeter. They can form as larger pieces of plastic break down and enter the body through food and water.
Scientists are increasingly studying what happens after these particles reach the digestive tract. Their extremely small size allows them to interact with the intestinal lining, and experimental research indicates that some can cross biological barriers.
A systematic review of 30 laboratory studies using human gastrointestinal cells and related models found effects including oxidative stress, inflammation and mitochondrial dysfunction. Smaller particles consistently showed greater cellular uptake and biological effects, although these effects mainly occurred at high concentrations.
That research helps explain the concern, but it doesn’t establish what everyday exposure does to human health over time. A 2022 World Health Organization report identified substantial research gaps, and scientists continue working to understand which exposures pose the greatest risks.
Finding ways to limit how long these particles remain in the digestive tract is therefore an important research goal.
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How a kimchi bacterium traps nanoplastics
Researchers at South Korea’s World Institute of Kimchi focused on Leuconostoc mesenteroides CBA3656, a lactic acid bacterium isolated from kimchi.
They tested whether polystyrene nanoplastics could attach to the bacterium’s surface—a process called adsorption.
Under standard laboratory conditions, CBA3656 had an adsorption efficiency of about 87 percent. That was similar to a comparison strain, Latilactobacillus sakei CBA3608, which reached about 85 percent.
But the more revealing test simulated conditions inside the human intestine.
There, the comparison bacterium’s ability to bind the particles dropped dramatically, to about 3 percent. CBA3656 maintained an adsorption rate of about 57 percent.
That difference matters. A bacterium that captures plastic in a laboratory solution needs to retain that ability under intestinal conditions to be useful in the gut. This particular strain did.
These percentages describe binding under the tested conditions—not the percentage of plastic removed from an entire body.
What happened when researchers tested the bacteria in mice?
The researchers then tested CBA3656 in germ-free mice, which are raised without the normal community of microorganisms that live in the digestive tract.
Both male and female mice receiving the strain had more than twice as much nanoplastic detected in their feces as control mice that did not receive it.
That provides evidence that the bacterium can do more than bind plastic in a test tube. In the mouse intestine, it helped promote excretion of the particles.
The findings, published in Bioresource Technology, identify this strain as a promising candidate for further research into capturing and removing nanoplastics.
Why the gut could hold part of the answer
The gut is one of the body’s first points of contact with substances we swallow. It is also home to the gut microbiome, whose microorganisms influence digestion, immune function and other aspects of health.
This study approaches the plastic problem from an intriguing direction: Could food-derived bacteria help capture particles passing through the intestine?
The proposed mechanism is physical binding. Components of the bacterium’s surface provide places where nanoplastics can attach. Once bound, the particles may travel with intestinal contents and leave the body in feces.
The research points toward a possible way to promote elimination in the gut. It does not establish that the bacteria can retrieve plastic already lodged in other organs.
This isn’t the first time, scientists have look at processes in the gut to help eliminate pollutants. In another study, “Humanized” mice, whose intestines had been cleared of existing microbes and replaced with nine kinds of microbes that live in human guts, had more PFAS excreted in their poop than microbe-free mice.
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Should you eat more kimchi?
Kimchi has supplied researchers with a promising bacterial strain. The next challenge is determining whether it works in a gut containing a normal microbial community—and ultimately in people.
Researchers also need to establish whether increased excretion translates into less plastic retention and measurable health benefits.
Meanwhile, there are other reasons to consider giving kimchi a try.
In a small human trial using kimchi powders, researchers found changes that supported stronger immune cell function.
Another study involving 90 overweight adults found that taking freeze-dried kimchi capsules for three months helped decrease body fat and reduce triglycerides.
If you’re curious, start with a small serving alongside a familiar meal. Its tangy flavor can work in a sandwich, salad or rice bowl.
Kimchi can be spicy and may not suit everyone’s taste. Yogurt, kefir, miso and sauerkraut offer other ways to enjoy fermented foods, although this study did not demonstrate that those foods remove nanoplastics.
The plastic-trapping discovery gives scientists a compelling reason to look more closely at kimchi’s bacteria—and readers another reason to take an interest in this fermented food.
Sources:
Efficient biosorption of nanoplastics by food-derived lactic acid bacterium — Bioresource Technology
This popular fermented food may help flush nanoplastics from the body — ScienceDaily
Kimchi-Derived Probiotic Found to Promote Binding and Excretion of Intestinal Nanoplastics — National Research Council of Science & Technology, via Newswise
Dietary and inhalation exposure to nano- and microplastic particles and potential implications for human health — World Health Organization
Effect of microplastics and nanoplastics in gastrointestinal tract on gut health: A systematic review — Malaysian Journal of Pathology
FAQ: Your questions answered about kimchi and nanoplastics
Both are small plastic particles, but nanoplastics are smaller—typically less than 1 micrometer, or one-thousandth of a millimeter. Some researchers use “microplastics” as an umbrella term that includes nanoplastics.
Eating kimchi has not been shown to remove nanoplastics in people. Researchers tested a specific bacterium isolated from kimchi, which bound nanoplastics in laboratory experiments and increased their excretion in germ-free mice.
Polystyrene nanoplastics attached to the bacterium’s surface through a process called adsorption. The strain retained substantial binding ability under simulated intestinal conditions and helped promote the particles’ elimination in mice.
Kimchi is a traditional Korean food made from fermented vegetables, most commonly cabbage. It has a tangy flavor and is often spicy. You can eat it as a side dish or add a small serving to a sandwich, salad or rice bowl.
This study did not establish that other fermented foods remove nanoplastics. Yogurt, kefir, miso and sauerkraut are other fermented-food options, but their effects should not be assumed to match those of the specific bacterial strain tested.
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