Glyphosate and Microbiota: controversies and truths

How glyphosate and co-formulants may affect human health

Abstract

Glyphosate-based herbicides (GBHs), are currently the most widely used herbicides in the world. During the past fifty years million tons of GBHs have been sprayed globally, due to affordable price, effectiveness and broad-spectrum ability to kill weeds. Glyphosate can influence microbial survival directly as it inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) of the shikimate pathway, which produces essential amino acids in both plants and the majority of microbes. Since many years glyphosate was thought to impose minimal risks to mammals including humans. However, current emerging evidence suggests that glyphosate or GBHs, can adversely affect mammalian biology via multiple mechanisms. The gut microbiota has emerged as a possible link between glyphosate and adverse health effects reported in humans. Latest research confirmed the herbicide’s potential to disrupt healthy microbiomes, including the human microbiome. In addition, intensive glyphosate use seems to act as a stress factor inducing glyphosate-resistance in bacteria and increasing antibiotic resistance to antimicrobial agents.

More empirical studies are needed to assess the effect of glyphosate and co-formulants on the healthy human microbiota and additional epidemiological studies are needed to determine these proposed effects of glyphosate-based products on ecosystems, with potentially negative consequences on environmental health, ecology and sustainability. Moreover, if future evidence will confirm that glyphosate may act as one of the drivers for antibiotic resistance, its global impact on human health will need to be reassessed.