The researchers believe that this phenomenon could also occur in humans.
Scientists have long known that seabirds ingest microplastics by mistaking them for food. And according to a study published Monday, March 27 in the journal Nature Ecology & Evolution, this waste not only clogs or passes through the stomach, but also upsets the balance of the entire digestive system.
Examining the digestive tracts of two Atlantic seabird species, the northern fulmar and the armored shearwater, the researchers found that the tiny plastic particles were messing up their microbiome – a complex group of microorganisms including good and bad bacteria. Basically, the more microplastics the bird ingests, the more stomach bacteria, mostly beneficial, decrease while potentially pathogens multiply.
Possible consequences for humans
Microplastics, which result from the breakdown of plastic products in the environment, are found all over the world, from the deepest ocean trenches to the top of Mount Everest and in most animal food chains. In humans, traces have been found in blood, breast milk and placenta.
The study confirms previous findings that prolonged intake of microplastics causes what is known as gut dysbiosis, an imbalance between healthy bacteria and harmful bacteria in the digestive tract. Its effects can be far-reaching as many species including humans, like birds, have an important microbiome in their digestive systems. “It’s a whole symbiosis that takes place in both birds and humans,” said Gloria Fackelmann from the University of Ulm (Germany), lead author of the study.
The study’s authors hope their findings in seabirds will lead to related studies in humans. “If this artificial substance (plastic) can change our microbiome, I think that should give people food for thought,” said Gloria Fackelmann.