For years, there has been an argument by anti-GMO campaigners that the popular herbicide glyphosate and its use in GMO crops and agriculture has detrimental effects on our environment, animal feed, as well as the human body, specifically our gut microbiome. Monsanto, the company producing the weed-killer RoundUp has continuously stated their product is the safest herbicide ever manufactured but that doesn’t define it as being totally safe.

It seems the EPA, as well as others in the scientific community is agreeing with Monsanto as the EPA raised the allowable limits of the product’s residue on various foods and animal feeds. In regards to cancer and the use of glyphosate, a study published by the EPA in 2013 on the pesticide tolerances of glyphosate state, “EPA has concluded that glyphosate does not pose a cancer risk to humans. Therefore, a dietary exposure assessment for the purpose of assessing cancer risk is unnecessary.” The study also stated, “There is no indication that glyphosate is a neurotoxic chemical and there is no need for a developmental neurotoxicity study or additional uncertainty factors (UFs) to account for neurotoxicity.”

Concerns about the herbicide’s use and its effects on our microbiome in a negative fashion, is still on the table of discussion and the continued apprehensions are backed up by recent studies. A German study conducted by the Institute of Bacteriology and Mycology, Faculty of Veterinary Medicine and Leipzig University, and published in the reputable microbiology journal, Elsevier as well as discussed in an article published by Genetic Literacy Project, seem to disagree with Monsanto and the EPA’s findings on the safety of the herbicide and our microbiome. 

The study tested various strains of intestinal bacteria and the effects of glyphosate on them. Disease-causing bacteria strains, such as Salmonella and Clostridium, which causes botulism and important friendly strains were tested in the study. The results showed that the disease-causing strains of bacteria were fairly resistant to glyphosate, while the important friendly strains have a moderate to high probability of being killed off by the herbicide. 

However, it should be noted that the German tests were conducted in vitro, which means all the bacteria strains were tested individually in a laboratory culture and this isn’t how the microbiology of our intestinal system works. Further research needs to be conducted in an in vivo or real life environment of the intestinal environment for more factual results, as many times results produced in vitro don’t produce concerns in living beings. 

David Perlmutter, M.D. noted in a video published on The Empowering Neurologist, “We hear more and more concern about the impact glyphosate, the lead ingredient in RoundUp, is having on the microbiome. While correlation does not mean causation, and while some of the science on this issue is still evolving, what we can say is that it does change the balance of the bacteria in the microbiome, setting the stage for leaky gut and autoimmune disease.”

With all this conflicting information on the effects of glyphosate and GMO products on our gut and its microorganisms, further research is needed to get to the gut of the issue. Until then, concerned consumers should try to avoid these products until more studies are completed that give factual evidence of how the herbicide truly affects our microbiome. 


David Perlmutter M.D. Empowering Neurologist: Do Pesticides Damage the Microbiome?

Genetic Literacy Project: Glyphosate Used With GMO Crops Under Attack for Disrupting Microbiome: Science or a gut feeling?

Science Direct: Glyphosate Suppresses the Antagonistic Effect of Enterococcus spp. On Clostridium Botulinum