The impact of air pollution on British bumble bees extends beyond humanity.

Recent research from the University of Leicester, UK, has determined that air pollution affects the complex network of microbes that are all around us. Bee populations are also declining around the world, so Lister’s team is looking into whether these two factors are related. The researchers are now looking at the effects of air pollution on the bee’s gut microbiome, which is a community of beneficial bacteria vital to keeping bees healthy.

The team is looking at how air pollution affects bees’ beneficial gut bacteria and microbiome composition, and the subsequent impact on bees’ health. Dr Hannah Sampson, first author of the study, explains, “We know that pollution is a huge problem globally and we know that bee declines seem to be increasing over the past few years. They are probably related, as bees are constantly exposed to these particulate pollutants in the air.”

Bumblebees have a delicate gut microbiome that has co-evolved with bee species over millions of years. The balance of bacteria in the bee gut microbiome is vital to maintaining bee health, and any disruption to this microbiome can pose a risk not only to bee health but to pollination and global food security. Snodgrassella alvi is a beneficial member of the bee’s gut microbiome; It colonizes the large intestine of bees in a structure called biofilm. Biofilm is a protective matrix that promotes bacterial colonization on surfaces (such as dental plaque). S. alvi is particularly important, as it is one of the primary colonizers of the bee gut microbiome.

Dr Sampson, who is part of an air pollution bacteria team led by Professor Morrissey at the University of Leicester, grew S. alvi bacteria in laboratory conditions and exposed them to black carbon air pollution. It found that exposure to black carbon altered the behavior of S. alvi and the structure and formation of the bacteria’s biofilms. This is concerning, as any disruption of this could have indirect effects on the overall composition and function of the bee gut microbiome.

The researchers also looked at the effects of black carbon pollution on live bumblebees. They took samples from the bees before and after exposure and measured the abundance of bacteria in their guts to see any differences. The researchers found that there was a significant change in the abundance of two types of bacteria that are beneficial and vital to the health of the bees’ gut microbiome.

While Dr. Sampson urges caution in deducing that air pollution directly contributes to bee population declines from this preliminary study, she is clear on the importance of understanding this interaction in order to know how to better protect our planet.

“More research needs to be done because air pollution has a much bigger impact than we think. Air pollution affects microbial communities. Changes in these important communities could have adverse effects on a lot of different ecosystems that affect bees and also directly affect humans, she notes.