Roundup Exposure May Damage Gut Microbiome: Study

The findings of a new study highlight new concerns about the potential side effects of Roundup exposure, indicating that the active ingredient in the weedkiller, glyphosate, may interfere with microorganisms in the gut, increasing the risk of gastrointestinal disorders and other health problems.

Researchers from across Europe, working with King’s College London, released a study this month in the journal BioRxiv, which publishes research before it is peer-review.

The findings indicate that rat studies have shown that glyphosate can cause an imbalance in the microbiome through its main mechanisms of action.

Glyphosate kills weeds and other plants by inhibiting enzymes in a biochemical process known as the shikimate pathway. Although Monsanto has maintained that the weedkiller is safe, since humans and animals do not use the shikimate pathway in their own biological processes, the findings of this study raise questions about this conclusion.

While humans and animals may not have the shikimate pathway, many of the microorganisms in their guts do, and can be negatively affected by Roundup exposure.

Researchers tested different formulations of Roundup at levels previously assumed to have no side effect. They used either pure glyphosate or a formulation of Roundup approved in Europe known as MON 52276, giving them to respectively to groups of female rats at levels representing the acceptable daily intake levels set in Europe and the U.S.

The results indicate glyphosate inhibited the enzymes in certain microorganisms, while others had their levels significantly increased. The researchers saw more pronounced effects with the formulation, often resulting in effects not seen in the rat group given just glyphosate alone.

“This revealed the first biomarker of glyphosate effects on rat gut microbiome,” the researchers noted. “Although more studies will be needed to ascertain if there are health implications arising from glyphosate inhibition of the shikimate pathway in the gut microbiome, our findings can be used in environmental epidemiological studies to understand if glyphosate can have biological effects in human populations.”

In the United States, Bayer and its Monsanto subsidiary face about 43,000 Roundup lawsuits brought by farmers, agricultural works and consumers nationwide, each raising similar allegations that users developed non-Hodgkins lymphoma or other forms of cancer after repeated exposure to the glyphosate-based weedkiller.

While Bayer continues to maintain that glyphosate is safe, following high-profile losses in the first three cases to go to trial, where juries awarded massive damages to individuals diagnosed with cancer following exposure to glyphosate, pressure is mounting on the company to reach Roundup settlements for glyphosate cancer claims, with a number of additional cases being prepared for trial.