Exposure to glyphosate, the main ingredient in the weedkiller Roundup, could adversely affect the microbes in our gut, which could lead to poor health.
Glyphosate is a controversial broad action weedkiller that was introduced onto the market in 1974. Since then, its use has increased worldwide more than 100-fold.
It is controversial, as there have been many claims of toxicity in humans and animals. In 2018, a school groundskeeper in the US won a case against Monsanto – the maker of Roundup – who claimed that extended exposure to the herbicide had caused him to develop non-Hodgkin's lymphoma. He was awarded $289 million in damages.
Bayer acquired Monsanto in the same year and then agreed to pay more than $10 billion to settle further lawsuits claiming glyphosate causes cancer. Despite this, the company has no plans to discontinue production of the chemical.
Now new evidence shows that that 54% of around 101 species of bacteria commonly found in the human gut could be damaged or killed if exposed to glyphosate in high enough quantities.