Nanoplastics in Human Bodies Can Make Antibiotics Less Effective, Study Finds

A new study has revealed that nanoplastics present in the human body can interact with pharmaceutical drugs, including antibiotics, making them less effective and even increasing the risk of antibiotic resistance.

Researchers looked at how the common antibiotic tetracycline, often used for respiratory tract, skin or intestinal bacterial infections, interacted with four types of nanoplastics in the body: polyethylene (PE), polypropylene (PP), polystyrene (PS) and nylon 6,6 (N66).

The team used simulations and in vitro experiments to study the interactions between the antibiotic and the different forms of nanoplastics.

They found that when the nanoplastics are present the tetracycline’s absorption changed, making it less successful as an antibiotic. In the presence of PS specifically, the antibiotic experienced a drop in biological activity. The scientists published their findings in the journal Scientific Reports.

“The binding was particularly strong with nylon,” Dr. Lukas Kenner, professor at Medical University of Vienna and co-author of the study, said in a statement. Further, Kenner noted the dangers of nanoplastic presence indoors compared to outdoors and how that could affect antibiotic effectiveness. “The micro- and nanoplastic load is around five times higher there than outdoors. Nylon is one of the reasons for this: it is released from textiles and enters the body via respiration, for example.”

As Plastic Pollution Coalition reported, a separate study from 2022 found that nanoplastics were able to enter the blood and organs of animals. While nanoplastic ingestion and inhalation is difficult to quantify because of how small these particles are, scientists have estimated that humans consume about 5 grams of microplastics per day, Reuters reported. Nanoplastics are about 1 to 1,000 nanometers in size, while microplastics are about 5 millimeters or smaller.

In addition to revealing how plastic particles were decreasing biological activity in antibiotics, the researchers found that the nanoplastics caused changes in how the drug moved through the body, potentially causing it to go to unintended areas. They are also concerned that by moving antibiotics away from target treatment areas, the nanoplastics could also increase antibiotic resistance, making bacteria less susceptible to treatment.

“Our finding that the local concentration of antibiotics on the surface of the nanoplastic particles can increase is particularly worrying,” Kenner said. “At a time when antibiotic resistance is becoming an ever greater threat worldwide, such interactions must be taken into account.”