Roundup-Induced Gut Dysbiosis, Irrelevant to Aromatic Amino Acid Deficiency, Impairs the Gut Function in Rats

Abstract

Glyphosate, the most popular herbicide globally, has long been considered safe for mammals. However, whether glyphosate can disturb gut microbiota via inhibiting aromatic amino acid (AAA) synthesis has been under debate recently. Here, we evaluated the impacts of chronic exposure to Roundup on gut health with the addition of AAA and explored the mechanism behind Roundup-induced gut dysfunction by performing fecal microbiota transplantation. 500 mg/kg·bw of Roundup, independent of AAA deficiency, caused severe damage to gut function, as characterized by gut microbial dysbiosis, oxidative stress damage, intestinal inflammation, and histopathological injury, particularly in female rats. Notably, similar to Roundup, Roundup-shaped gut microbiome evidently damaged serum, cecum, and colon profiling of oxidative stress biomarkers (malonaldehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), glutathione (GSH), and H₂O₂). Moreover, it induced 0.65-, 3.29-, and 2.36-fold increases in colonic IL-1β, IL-6, and TNF-α levels, and 0.34-fold decreases in the IL-10 level. Upon transplanting healthy fecal microbiota to Roundup-treated rats, they exhibited a healthier gut microenvironment with mitigated inflammation, oxidative damage, and intestinal injury. Overall, our findings provide new insights into the safety of Roundup, highlight the crucial role of gut microbiota in Roundup-induced gut dysfunction, and pave the way for developing gut-microbiota-based strategies to address Roundup-related safety issues.