Microplastics are tiny fragments of plastic less than 5 millimeters long that form as larger plastics break down. They are now found in soil, water, the air we breathe, and even inside living creatures. Evidence shows these particles can cross barriers in the lung and intestine, reach the bloodstream, and deposit in organs including reproductive tissues, placenta, and brain. Early clinical findings link microplastics to immune changes, reproductive effects, and cardiovascular risks, though many human studies still have small sample sizes and imperfect exposure measurements.
Researchers have detected microplastics across the human body in saliva, blood, sputum, breast milk, liver, kidneys, spleen, brain, and even inside bone. One long-running archive of soil samples shows a sharp rise in plastic traces beginning in the mid-20th century as plastic use exploded. Consumption appears to be rising and varies by region, with studies suggesting a several-fold increase since 1990. In bottled beverages, a single liter can contain tens of thousands of particles, and newer testing found that some drinks in glass bottles can contain five to fifty times more microplastics than the same drinks in plastic or cans because plastic-coated caps shed tiny fragments.
Common pathways into the body include food, bottled and packaged drinks, and inhaled indoor and outdoor air. Heating liquids in plastic or dipping plastic-sealed tea bags in hot water can release additional particles. Researchers are now running “human challenge” studies that mimic everyday exposures to measure how many particles enter the blood after something as ordinary as a cup of tea or a microwaved meal.
Microplastics can compromise the blood-brain barrier in animal models, reduce antioxidant defenses, and damage proteins that support learning and memory. One study found lower levels of a key antioxidant enzyme and higher levels of a cell-damage marker after exposure. Researchers also discovered microplastics in carotid artery plaques; people with plastics lodged there had a 4.5-fold higher risk of stroke, heart attack, or death over about three years. Scientists have identified plastics in human brains, with up to ten times higher levels in those who had dementia. Experts caution that plastics likely act alongside other stressors by amplifying chronic inflammation and oxidative stress, potentially accelerating aging, vascular dysfunction, and disease progression.
The new idea: probiotics that bind and escort plastics out
A January 2025 paper in Frontiers in Microbiology screened 784 bacterial strains for their ability to adsorb 0.1-micrometer polystyrene particles. Two stood out:
- Lacticaseibacillus paracasei DT66 with a 71.4% adsorption rate
- Lactiplantibacillus plantarum DT88 with a 79.8% adsorption rate
Under the microscope, these bacteria became coated with plastic particles and formed clumps. In mice, the strains increased microplastic excretion by 34% and cut residual particles in the intestine by up to 67%. The DT88 strain also reduced gut inflammation, bringing pro-inflammatory cytokines back toward normal levels.
How these probiotics appear to work
- Physical binding: Cell surfaces and extracellular polymers on these bacteria latch onto plastic particles, creating bacteria-plastic aggregates.
- Enhanced elimination: The larger clumps move through the gut more quickly and are excreted more efficiently.
- Inflammation control: DT88, in particular, mitigated plastic-induced inflammatory changes in the intestine.
- Possible motility support: In mice, butyrate increased after probiotic use, suggesting a role for gut motility in moving aggregates along.
What you can buy today
The exact strains DT66 and DT88 are not commercially available yet. However, their parent species are common in foods and supplements:
- Fermented foods:
- Kefir and yogurt often include Lactobacillus plantarum, Lacticaseibacillus paracasei (sometimes labeled L. paracasei), and L. reuteri.
- Fermented vegetables like traditional kimchi or sauerkraut frequently contain L. plantarum.
- Supplements:
- L. plantarum is widely sold, typically from about 500 million to 20 billion CFU per day.
- L. paracasei appears in many blends, commonly up to about 2 billion CFU.
- L. reuteri products are well studied for gut colonization and have been shown to break down plastic-related chemicals such as BPA, although they were not tested here for direct microplastic removal.
What benefits you might reasonably expect
Based on animal data and in-vitro work, related strains may help:
- Bind ingested microplastics in the gut
- Increase elimination of particles in stool
- Reduce local intestinal inflammation associated with microplastic exposure
These effects are strain-specific, and human studies are still limited. Think of potential microplastic support as an added bonus on top of the established gut and immune benefits of these probiotics.
Scientists describe the accumulating findings as concerning but still evolving. One group that found microplastics in human brains reported being “shocked” by the levels in dementia cases. Cardiovascular researchers linked plastics in artery plaques to markedly higher clinical risk over time. Reviews in leading medical journals emphasize that methods for exposure measurement and human risk assessment must mature, but animal and cell data generally support the early clinical signals.
Practical ways to support a probiotic strategy
A combined approach makes sense while the science advances:
- Include fermented foods like kefir, yogurt, and fermented vegetables that provide L. plantarum, L. paracasei, and L. reuteri.
- Consider probiotic supplements containing these species from reputable brands, recognizing that results vary by strain.
- Reduce exposure where possible: prefer glass or metal food storage when heating, avoid microwaving in plastic, choose loose-leaf tea over plastic-sealed bags, use water and air filtration, and be mindful that some glass-bottled drinks can carry extra microplastics due to cap coatings. Simple manufacturing steps like cap cleaning have been shown to lower contamination.
Bottom line
Microplastics are pervasive and can reach sensitive organs. Emerging research suggests that select probiotic strains can bind these particles in the gut, boost elimination, and calm inflammation. While we wait for human trials and commercial access to the top performers, regularly consuming foods and supplements rich in L. plantarum, L. paracasei, and L. reuteri offers a practical, low-risk path that may provide both gut-health benefits and a measure of microplastic defense.
This article is informational and not medical advice.
