Microplastics shown to alter the gut health of certain seabirds
New research from McGill University, Canada, has found that microplastics can cause significant changes in the gut microbiome of seabirds, raising fears that microplastics could have a similar effect on humans.
Microplastics are small plastic particles less than 5 mm in length. They have been shown to be present everywhere on the planet – in the air, water, soil and foods – thanks to our prolonged and widespread overuse and mismanagement of plastic. We don’t know exactly how much we consume, but estimates range from five grams a week – the approximate weight of a credit card – down to a tiny fraction of that. The concern is that tiny fragments, smaller than a single bacterium, can penetrate human cells and pass from the gut to the bloodstream where their impact on health is unknown but is unlikely to be beneficial.
Scientists from McGill studied two seabird species, the northern fulmar (Fulmarus glacialis) and the Cory’s shearwater (Calonectris borealis). These birds live mainly on the high seas and feed on marine mollusks, crustaceans, and fish. Their study found evidence that microplastics in the digestive tract of these seabirds increased the number of pathogens and antibiotic-resistant microbes present, while simultaneously decreasing the beneficial bacteria found in the gut.
Cory’s shearwater
Julia Baak, from McGill University, explains why these changes are so alarming. “The gut microbiome encompasses all the microbes in the gastrointestinal tract, which help control the digestion of food, immune system, central nervous system, and other bodily processes. It’s a key indicator of health and well-being.”
The study warns that humans may experience similar impacts from ingesting plastic: “Our findings reflect the circumstances of animals in the wild. Since humans also uptake microplastics from the environment and through food, this study should act as a warning for us.”
According to the study’s authors, most research examining the impact of microplastics on the microbiome are done in laboratories using high concentrations of microplastics not typically found in nature. Studying animals in the wild presenting with typical levels of microplastic ingestion reveals that changes in the microbiome can occur at lower concentrations than previously thought.
Despite studies like this one, our understanding of the impact of microplastics ingestion in both animals and humans is poor. More research is needed and fortunately funding for this type of study is increasing. Meantime, if you are concerned about the potential health risks of ingesting microplastics, you can follow these simple steps to reduce your exposure:
- Eat fresh, unpackaged foods
- Avoid heating food in plastic
- Ditch the plastic water bottle
- Filter your water before drinking
- Wear natural fiber clothes
