Researchers, whose findings appear in the journal Environmental Microbiome, began by conducting a pilot study with honey bees in New York's Brooklyn neighborhood, before expanding their research to four other cities (Melbourne, Sydney, Tokyo and Venice).

The goal was to better understand the microbiome of cities, i.e. all the microorganisms (bacteria, fungi, viruses...) that are present there.

They postulated that these insects, which can travel more than a mile around their hive in the city, could be valuable for collecting these urban microorganisms, avoiding entrusting this laborious task to humans.

"This method is more suitable for the scale of urban spaces than other sampling methods, for example by swab," Elizabeth Hénaff, of New York University, co-author of the study, told AFP.

The scientists actually found various genetic information, different depending on the city, in the debris accumulated in the hives.

"The interest of studying the urban microbiome is that the environmental microbiome is very important for human development and health," says Elizabeth Hénaff.

The study refers to other research that increasingly tends to prove that our well-being depends on our interactions with bacteria and fungi.

The researchers were able to find traces of a pathogen that is transmitted from cats to humans, suggesting that it would be theoretically possible to use bees as a "potential" means of monitoring certain diseases.

But the authors temper this aspect of their discovery. "Our interest is rather to be able to characterize the +healthy+ microbiome of urban areas, given that the majority of microbes are beneficial or even essential for human health," insists Elizabeth Hénaff.

"It opens us up to the broader idea that it's possible to detect pathogens" in this way, Kevin Slavin, an independent researcher and co-author of the study, concluded at a press conference.

But he also doesn't rely on bees – whose activity is particularly marked by the seasons – for this, suggesting that other species close to humans could perhaps one day do this work.

© 2023 AFP