Glyphosate has demonstrated a very significant potential to impact gut microbiome. Imbalance in the gut biota has been linked to an extraordinary number of negative health conditions, including many cancers as well as modern epidemics such as obesity, depression and auto-immune illness. For example, glyphosate has been specifically linked to Celiac's, which is increasing significantly in prevalence.

I don't know if I'd be so quick to call it 'safe.' It requires an infinite number of experiments to prove any chemical is perfectly safe. It requires only a few to demonstrate the opposite.