Katharina Buczek
Just a handful of studies have specifically analyzed the impact that plastics have on the microbiome. And most of these research efforts have been experimental mouse models.
That’s why for this study, the team hoped to look at real-life examples.
Fackelmann and her colleagues decided to examine seabirds from Portugal and Canada. They collected 27 northern fulmars, as well as 58 Cory’s shearwaters. The latter group had died following collisions with buildings.
Afterward, the team took samples from two ends of each animal’s intestinal tract. First, the proventriculus, and then, the cloaca. The goal was to determine what the microbiome looked like at each end.
Additionally, the researchers flushed out each bird’s gastrointestinal tract in order to count the individual pieces of plastic ingested. They also weighed the total amount found in the gut of every animal.
It was discovered that the birds with more microplastic pieces in their guts also had more microbiome diversity.
While a range of gut microbe varieties has typically been thought of as a good thing, though, that is not always true– especially if the introduced bacteria are harmful.
So, the team analyzed the microbiomes to figure out if the introduced microbes were considered “good” or “bad.” To do this, they looked up each individual microbe type to narrow down exactly what each one does.
This analysis revealed that birds with more plastic in their guts also had more microbes known to break down plastic.
On top of that, there were more microbes known to be antibiotic resistant and more with disease-causing potential.
Now, Fackelmann and her team did not assess the overall health of the seabirds– meaning they were unsure whether or not the microbes were making the animals sick.
