This is according to a study conducted by an international group of researchers from France, Italy and the United Kingdom that was published in the journal Environmental Health on August 25.
Roundup, also known by the name of its active ingredient glyphosate, is the top-selling herbicide in the world. It is produced by Monsanto.
"There were more than 4,000 genes in the liver and kidneys [of the rats that were fed Roundup] whose levels of expression had changed," said lead researcher Michael Antoniou of King's College London.
"Given even very low levels of exposure, Roundup can potentially result in organ damage when it comes to liver and kidney function. The severity we don't know, but our data say there will be harm given enough time."