Following on the heels of a study published late last year from Finland that suggests glyphosate—the main active ingredient in Roundup weed killer—adversely affects over half of the species of bacteria in the human gut, a paper published yesterday in Environmental Health Perspectives, found that low levels of the chemical can alter the composition of the gut microbiome in ways that may be linked to adverse health outcomes.

US Right To Know reports the study was co-authored by 13 researchers. The lead author of the study heads the Gene Expression and Therapy Group at King’s College in London. The researchers discovered that glyphosate may harm beneficial bacteria in the gut by the same mechanism in which it kills unwanted weeds. 

The study was conducted on animals. Should the conclusions of future research studies carry over in human participants, it could show that glyphosate causes damage to the immune system. Approximately 80 percent of immune cells reside in the gastrointestinal tract. “A disruption of that system can contribute to a range of diseases,” the researchers said in the paper.

Dr. Michael Antoniou, the lead author, added: “We know that our gut is inhabited by thousands of different types of bacteria and a balance in their composition, and more important in their function, is crucial for our health. So anything that negatively disturbs, the gut microbiome… has the potential of causing ill health because we go from balanced functioning that is conducive to health to imbalanced functioning that may lead to a whole spectrum of different diseases.”

The researchers conceded, however, that glyphosate does not act as an antibiotic. Rather, this research demonstrates—for the first time in a study—how glyphosate (which in addition to being an herbicide is licensed by the EPA as a pesticide) interferes with a pathway that bacteria rely on to thrive in the gut. 

And by interfering with this metabolic pathway, glyphosate, the researchers suggested, creates oxidative stress. Oxidative stress is what causes premature aging and inflammation. 

One Roundup product demonstrated significant oxidative stress: BioFlow. In another study that specifically used BioFlow, the researchers concluded that glyphosate exerted a negative impact on male reproductive cells, and that the collective ingredients in Roundup are more toxic than glyphosate alone. 

The researchers will next study whether the oxidative damage caused by glyphosate in the animals leads to DNA alterations. If so, this would demonstrate an association with cancer risk. 

In the new study, researchers used rats that were given glyphosate and Roundup through drinking water. The levels of the chemicals were at the acceptable daily intakes considered safe by the EPA and European regulatory agencies. 

Antoniou, the lead author, said the study results “build on other research that makes it clear regulators are relying on outdated methods when determining what constitutes ‘safe’ levels of glyphosate and other pesticides in food and water. 

In March of 2020, Bayer AG, the German-based pharmaceutical giant that acquired Monsanto in 2018 for $63 billion, paid nearly $40 million to settle Roundup false advertising lawsuits. The lawsuits were filed on the basis that Monsanto claimed that glyphosate only affects an enzyme that inhibits plant growth rather than also affects animal and human health. 

As part of the settlement, language was removed from all Roundup product labels saying that glyphosate only affects the plant enzyme. 

The specific enzyme that plaintiffs in the Roundup false advertising lawsuits claim affects human health, supports the immune system, digestion and brain function. 

This latest research adds to the growing body of evidence that shows an association between glyphosate and/or Roundup and chronic health conditions.