Fatty liver disease and death of liver tissue were also confirmed in rats fed regulatory permitted and thus presumed safe doses of the weedkiller. Report: Claire Robinson

The primary mechanism of how glyphosate herbicides kill plants is by inhibiting an enzyme called EPSPS, which is part of a biochemical pathway known as the shikimate pathway. The shikimate pathway is responsible for the synthesis of certain aromatic amino acids that are vital for the production of proteins, the building blocks of life. Thus when the synthesis of the aromatic amino acids is blocked by glyphosate inhibition of EPSPS, the plant dies. 

Humans and animals do not have the shikimate pathway, so industry and regulators have claimed that glyphosate is nontoxic to humans.[1] However, some strains of gut bacteria do have the shikimate pathway, leading to much debate about whether Roundup and glyphosate could affect the gut microbiome (bacterial populations). Imbalances in gut bacteria have been found to be linked with many diseases, including cancer, type 2 diabetes, obesity, and depression.