Popular Weed Killer May Disrupt Bee Gut Bacteria, Increase Death Risk

The world's mostly widely used herbicide, glyphosate, may also be expediting the loss of bees around the globe, according to a new report. Glyphosate is used to kill weeds and is the active ingredient in Monsanto's Roundup, a product widely used in the United States. A newly published study reveals evidence that the same ingredient may also be harming bees in a way that contributes to declining bee populations.

The study was published in the Proceedings of the National Academy of Sciences and indicates that glyphosate may not be as harmless to living creatures as previously thought. The herbicide works by disrupting an enzyme found in both plants and microorganisms. That latter point is important due to the way the ingredient was found to harm bees: by impacting their gut bacteria.

During their research, scientists found that honey bees exposed to the same levels of glyphosate found in crops experienced a significant and negative impact to their gut bacteria. One particularly important gut bacteria species, Snodgrassella alvi, helps protect bees against pathogens, among other things.

Of importance, the bees exposed to glyphosate were found to be more likely to die when faced with a pathogen than others bees with properly functioning gut bacteria. Eight days after exposing the bees, only one-tenth of them remained alive versus half of the healthy bees. It's important to note that bee population losses can't be pinned exclusively to glyphosate, but rather the study indicates that herbicide use may be a contributing factor to an overall larger problem.

The study follows a report published by EWG in August that highlighted the presence of glyphosate in commonly consumed food products, including oatmeal and granola.