- Microplastics — tiny particles in the air, water, and soil — are increasingly found in drinking water and food supplies around the world.
- The effects of microplastics on humans have been studied and found to affect the composition and diversity of gut microbiomes.
- Researchers in China found that boiling hard tap water can produce calcium carbonate, which form crystallized encapsulations around microplastics that could be scraped or removed by pouring the water through a coffee filter.
- This technique removed up to 90% of the microplastics in samples of hard water and up to 25% of the microplastics in soft water.
Microplastics — tiny particles in the air, water, and soil — are an unfortunate byproduct of the globalized economy in a time that some researchers have defined as the
Defined by the United States National Oceanic and Atmospheric Administration (NOAA), the United Nations Environment Program (UNEP), and the European Chemicals Agency as particles under 5 millimeters (mm) long and insoluble in water, microplastics are increasingly prevalent in the Earth’s oceans, atmosphere, drinking water, and food supplies.
Some studies have examined the effects that microplastics have on the human gut microbiome. In 2022, researchers published a study in the journal
While there are some water filtration systems that can reduce the number of microplastics in municipal drinking water supplies, a new study in the journal Environmental Science & Technology Letters suggests that boiling and filtering water — using the same methods and materials that one might use to make tea or coffee — could reduce 90% of free-floating nano- and microplastics (NMPs).
Researchers took samples of hard tap water from Guangzhou, China, and added different levels of NMPs to different samples, then boiled each sample for five minutes.
They found that crystalline structures of calcium carbonate — which occurs when boiling hard tap water since it is full of minerals — encapsulated the particles of MNPs.
Prof. Eddy Zeng, one of the study authors, said that these particles could build up over time and be scrubbed away; by pouring the rest of the water into a coffee filter, any remaining encrusted MNPs could be removed.
These methods showed that more encapsulation was visible in hard water, with 90% of MNPs removed from a sample that had 300 milligrams (mg) of calcium carbonate per liter. Soft water samples with less than 60 mg of calcium carbonate per liter showed a 25% reduction in MNPs through boiling.
Dr. Vincent Young, MD, Ph.D., professor of internal medicine and microbiology and immunology at the University of Michigan, who was not involved in the study, told Medical News Today that while studies have been conducted to establish the scope and effects of exposure to microplastics, nothing concrete has yet been established.
“There are multiple papers that suggest that the gut microbiome changes upon exposure to microplastics,” Dr. Young said. “That being said, it isn’t clear if these changes have a direct effect on human health. It should be noted that many things can alter the microbiome in the short run, again with unclear effects on human health.”
Melanie Murphy Richter, a registered dietitian nutritionist and the director of communications for Prolon, who was not involved in the study, told MNT that human gut development has changed as broader access to drinking water has evolved.
“The cells within our gut change every 3 days. That means that our gut composition will adapt and change in a matter of weeks (sometimes months) in favor of what we are exposed to most often,” Richter said.
“With the change in water supply, our gut composition has invariably changed. In fact,
certain research shows that people in the U.S. and U.K. have distinct gut microbiome signatures directly related to the source and amount of drinking water. Andother research shows that there is still quite a bit of ‘dark matter’ when it comes to identifying the hundreds of species and types of microbes that have been found in tap water.”
“Sanitation — which is a good thing, don’t get me wrong — has changed our microbiome. This is part of the so-called hygiene hypothesis,” Dr. Young said.
“This has greatly lowered the burden of infectious diseases, but might be linked to the rise of conditions such as asthma, inflammatory bowel disease and other conditions characterized by altered immune responses due to lower exposure to pathogens,” he noted.
Richter cited a number of long-term effects of chronic exposure to microplastics, like digestive disorders, endocrine disruption, obesity, cardiovascular disease, and neurodegenerative disorders. She added that these medical conditions as a result of microplastic exposure often fall on people living on the economic or racial margins of society.
“Microplastic exposure and consumption disproportionately affect low-income communities and Indigenous communities due to social, economic and environmental factors. For instance, these communities tend to be situated near industrial facilities, landfills, waste incinerators or other sources of plastic pollution which can increase their exposure to microplastics in air, water, soil and food,” Richter said.
“Additionally, these communities typically don’t have the same access to clean drinking water or less polluted foods. Their lack of access to these nutritious foods and cleaner waters could exacerbate their risk of exposure,” she pointed out.
Any level of pre- or probiotic supplements can help regulate a healthy gut microbiome. Fermented foods like yogurt, sauerkraut, pickles, or kimchi can also be part of a good probiotic digestive regimen.
Richter added that fiber in foods like onions, asparagus, bananas, or buckwheat are prebiotics that feed the “good bacteria” that exist in the gut, and suggested that omega-3s in flaxseeds, walnuts, and mackerel can reduce inflammation.
Polyphenols in green tea, berries, or leafy greens can also fight against damage from microplastic consumption, she said, as can items like “binders.”
“Binders like activated charcoal, bentonite clay, or zeolite clay may help to bind to certain toxins and remove them from the body. Research on the efficacy of binders is still in its early stages but shows promise,” Richter said. “It’s important to remember not to take binders when you eat food, however, to avoid essential nutrients being removed from your body. Also, I recommend taking them with a big glass of water.”