To find out if the bacteria introduced could be “good” or “bad,” Fackelmann and her colleagues analyzed microbial populations and looked up each bacterium in the database to Find out what they do. They found that the more plastic, the more bacteria decomposed the plastic. There are also many bacteria known to be resistant to antibiotics, and many more capable of causing disease.
Fackelmann and her colleagues didn’t assess the health of the birds, so they don’t know if these bacteria could make them unwell. “But if you’re accumulating pathogens and antibiotic-resistant bacteria in your digestive system, that’s obviously not good,” says Wagner.
Research published in the journal Nature Ecology and Evolution shows that the levels of plastic present in the environment are sufficient to affect an animal’s microbiome, Fackelmann said. The next step, she said, is to find out what this means for their health and the health of other animals, including humans.
“When I read [the study], I was thinking about the whales we found stranded with kilograms of plastic debris found in their bellies,” Wagner said. “It could be quite similar to what birds have in their digestive systems, so it would be interesting if this happened in whales, dolphins, [and other marine animals] also.”
We still don’t know if the amount of plastic humans ingest is enough to form our microbiome. Richard Thompson, professor of marine biology at the University of Plymouth in the UK, says humans absorb far less plastic than seabirds. The amount of plastic that enters our bodies also depends on where we live and work. For example, people who work in textile factories will have higher exposure levels than people who work outdoors.
And we don’t know the consequences of ingesting bacteria that cling to microplastics that enter our bodies. Thompson points out that humans have been exposed to a lot of disease-causing bacteria that aren’t found on plastic. For example, we might worry that tiny bits of plastic might catch nasty bugs in the sewage and that they might somehow get into our bodies. But sewage spills regularly contaminate beaches and direct drinking water.
It’s likely that plastic-degrading bacteria will also take up residence in our guts. It is difficult to know how—or whether—this will affect us. Bacteria can evolve rapidly, and they can exchange genes with neighboring bugs. “Are we going to evolve to eat plastic? My answer is probably no,” said Fackelmann. But the possibility that our gut will become home to more bacteria that can break down plastic is “not out of the question,” she said.
It is also possible that plastic pollution will affect us indirectly. The introduction of many pathogenic bacteria into birds and other animals can cause disease outbreaks, and one of the bacteria the team found correlated with the plastic in the bird’s intestines that is thought to be infectious from animals. to people. Wagner thinks it’s unlikely that bacteria that seabirds pick up from floating plastic could cause epidemics in humans. “But the more we mess with natural systems, the higher the chance of infection from animals to humans. [a disease jumping from animals to humans]he added.
Given the prevalence of microplastics, studies like this are needed to help us understand how plastic pollution affects living organisms, including humans, the researchers say.
“We basically plasticized the globe,” says Wagner. “Everyone is exposed to microplastics and the chemicals in plastic—it’s only a matter of time until we figure out what impact it has on our microbiome. And I can’t see any argument for why ingesting plastic is beneficial.”