Glyphosate-based herbicides influence antioxidants, reproductive hormones and gut microbiome but not reproduction: A long-term experiment in an avian model. (November 2020)

• Record Type: Journal Article
• Authors: Ruuskanen, Suvi; Rainio, Miia J.; Gómez-Gallego, Carlos; Selenius, Otto; Salminen, Seppo; Collado, Maria Carmen; Saikkonen, Kari; Saloniemi, Irma; Helander, Marjo
• Is Part Of: Environmental pollution. Volume 266:Part 1(2020)
• Publication Date: 2020-11
• Subjects: Glyphosate -- Herbicide -- Residue -- Gut microbiome -- Endocrine disruption -- Oxidative status -- Testosterone; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115108
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Controversial glyphosate-based herbicides (GBHs) are the most frequently used herbicides globally. GBH residues in the wild, in animal and human food may expose non-target organisms to health risks, yet the developmental and cumulative effects of GBHs on physiology and reproduction remain poorly understood. We present the first long-term study on the effects of subtoxic GBH exposure (160 mg/kg) on multiple key physiological biomarkers (cellular oxidative status and neurotransmitters), gut microbiome, reproductive hormones, and reproduction in an avian model. We experimentally exposed in Japanese quail females and males ( Coturnix japonica ) to GBHs and respective controls from the age of 10 days–52 weeks. GBH exposure decreased hepatic activity of an intracellular antioxidant enzyme (catalase), independent of sex, but did not influence other intracellular oxidative stress biomarkers or neurotransmitter enzyme (acetylcholinesterase). GBH exposure altered overall gut microbiome composition, especially at a younger age and in females, and suppressed potentially beneficial microbes at an early age. Many of the microbial groups increased in frequency from 12 to 28 weeks under GBH exposure. GBH exposure decreased male testosterone levels both at sexual maturity and at 52 weeks of exposure, but did not clearly influence reproduction in either sex (maturation, testis size or egg production). Future studies are needed to characterize the effects on reproductive physiology in more detail. Our results suggest that cumulative GBH exposure may influence health and reproduction-related traits, which is important in predicting their effects on wild populations and global poultry industry. Graphical abstract: Image 1 Highlights: We performed the first long-term experiment on the most used and controversial herbicide, glyphosate, on poultry. GBH exposure decreased the activity of hepatic antioxidant biomarkers. GBH exposure decreased male testosterone in all ages. GBH exposure influenced gut microbiome composition, especially in early life. GBH exposure did not influence reproduction. Our results are important in predicting potential GBH effects on wild populations and poultry industry. Abstract : In the first long-term glyphosate-based herbicide exposure experiment in birds, we found that glyphosate lowers testosterone levels and influences gut microbiome, thus potentially affecting the health in non-target taxa.