Probiotics ameliorate growth retardation of glyphosate by regulating intestinal microbiota and metabolites in crucian carp (Carassius auratus)

Glyphosate (GLY) contamination widely occurred in aquatic environments including aquaculture systems and raised hazard to aquatic organisms such as fish. Probiotics have been reported to alleviate contaminants-induced toxicity. However, whether probiotics could reduce the health risk of GLY to fish remain unknown. Here we investigated the impacts of GLY on crucian carp (Carassius auratus) by focusing on the protective roles of two commonly used aquacul-ture probiotics, Bacillus coagulans (BC) and Clostridium butyricum (CB). Exposure to GLY significantly caused growth re-tardation and reduced visceral fat and intestinal lipase activity in crucian carp. 16S rRNA sequencing indicated that dysbiosis of Bacteroidetes at phylum level and Flavobacterium at genus level might be primarily responsible for GLY-induced negative growth performance. High throughput targeted quantification for metabolites revealed that GLY changed intestinal metabolites profiles, especially the reduced bile acids and short-chain fatty acids. However, the ad-dition of BC or CB effectively attenuated the adverse effects above by remodeling the gut microbiota composition and improving microbial metabolism. The present study provides novel evidence for ameliorating the harmful effects of GLY on fish species by adding probiotics, which highlights the potential application of probiotics in reducing the health risks of GLY in aquatic environment.

Automated summary

This study investigated the impacts of glyphosate (GLY) on crucian carp and the potential protective roles of two commonly used aquaculture probiotics. Results showed that GLY exposure caused growth retardation, reduced fat content, and altered gut microbiota composition and metabolism of the fish. However, the addition of the probiotics effectively attenuated these adverse effects. This study provides novel evidence for the potential application of probiotics in reducing the health risks of GLY in aquatic environments.