Roundup causes embryonic development failure and alters metabolic pathways and gut microbiota functionality in non-target species

Antonio Suppa,Hayley Mangelson,Jiarui Zhou,James B Brown,Stephen Kissane,Vignesh Dhandapani,Antoine Y Tian,Jouni Kvist,Alessio Perotti,Kyle Langford,Luisa Orsini,Hanan Almulla,Valeria Rossi,Xiaojing Li

doi:10.1186/s40168-020-00943-5

Abstract

BackgroundResearch around the weedkiller Roundup is among the most contentious of the twenty-first century. Scientists have provided inconclusive evidence that the weedkiller causes cancer and other life-threatening diseases, while industry-paid research reports that the weedkiller has no adverse effect on humans or animals. Much of the controversial evidence on Roundup is rooted in the approach used to determine safe use of chemicals, defined by outdated toxicity tests. We apply a system biology approach to the biomedical and ecological model species Daphnia to quantify the impact of glyphosate and of its commercial formula, Roundup, on fitness, genome-wide transcription and gut microbiota, taking full advantage of clonal reproduction in Daphnia. We then apply machine learning-based statistical analysis to identify and prioritize correlations between genome-wide transcriptional and microbiota changes.ResultsWe demonstrate that chronic exposure to ecologically relevant concentrations of glyphosate and Roundup at the approved regulatory threshold for drinking water in the US induce embryonic developmental failure, induce significant DNA damage (genotoxicity), and interfere with signaling. Furthermore, chronic exposure to the weedkiller alters the gut microbiota functionality and composition interfering with carbon and fat metabolism, as well as homeostasis. Using the “Reactome,” we identify conserved pathways across the Tree of Life, which are potential targets for Roundup in other species, including liver metabolism, inflammation pathways, and collagen degradation, responsible for the repair of wounds and tissue remodeling.ConclusionsOur results show that chronic exposure to concentrations of Roundup and glyphosate at the approved regulatory threshold for drinking water causes embryonic development failure and alteration of key metabolic functions via direct effect on the host molecular processes and indirect effect on the gut microbiota. The ecological model species Daphnia occupies a central position in the food web of aquatic ecosystems, being the preferred food of small vertebrates and invertebrates as well as a grazer of algae and bacteria. The impact of the weedkiller on this keystone species has cascading effects on aquatic food webs, affecting their ability to deliver critical ecosystem services.DJLGvZ7sRDZZrJVKuLAEkAVideo

Highlights

Research around the weedkiller Roundup is among the most contentious of the twenty-first century
The ecological model species Daphnia occupies a central position in the food web of aquatic ecosystems, being the preferred food of small vertebrates and invertebrates as well as a grazer of algae and bacteria
We found that that chronic exposure to glyphosate and its commercial formula, Roundup, corresponding to the US drinking water Maximum Contaminant Level (MCL) [30] have severe adverse effects on the non-target aquatic invertebrate Daphnia, inducing embryonic developmental failure and genotoxic effect

Summary

Introduction

Research around the weedkiller Roundup is among the most contentious of the twenty-first century. Scientists have provided inconclusive evidence that the weedkiller causes cancer and other life-threatening diseases, while industry-paid research reports that the weedkiller has no adverse effect on humans or animals. Much of the controversial evidence on Roundup is rooted in the approach used to determine safe use of chemicals, defined by outdated toxicity tests. Much of the controversial evidence on Roundup is rooted in outdated toxicity tests, called LC50 [5], from which safe use of chemicals in the environment is extrapolated. These outdated tests are the current state-of-the-art in regulatory science [6]. The adverse effect of Roundup documented to date is based on unrealistic concentrations of the compound; it has been largely correlative and missing, by design, potential pathological effects that may arise from long-term exposures to sublethal doses [1]

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