AUSTIN, TEXAS — Monsanto is being accused of killing off bees around the world, reports NPR.

Bees are being exposed to glyphosate, an ingredient in weed killer, according to a new study published in Proceedings of the National Academy of Sciences

Scientists painted the bees' backs with colored dots to track them, and found that glyphosate significantly decreased the amount of healthy gut bacteria in honey bees.

This could increase the chance of bees receiving infections or even dying because of harmful bacteria.

They believe glyphosate may be contributing to "colony collapse disorder," a phenomenon when bee colonies are wiped out.

Scientists encouraged the public to avoid spraying using weed killers that contain glyphosate when they are spraying their flowers.

The researchers involved say better guidelines are needed to regulate use of glyphosate in order to protect bees.

In a statement, Monsanto denied the accusations and claims "no large-scale study has ever found a link between glyphosate and honey bee health issues."