Effects of carbamazepine on gut microbiota, ARGs and intestinal health in zebrafish

Carbamazepine (CBZ) in the aquatic environment is recognized as a potential threat to aquatic organisms , public health. However, the response of organism intestinal health, resistome, microbiota , their relationship after CBZ exposure has been rarely reported. This study aimed to explore the impacts of CBZ on gut microbiota, antibiotic resistance genes (ARGs) and the expression of intestinal health related genes as well as their interaction using the zebrafish model. 16 S ribosomal RNA sequencing indicated CBZ altered the composition of gut microbiota. Using high-throughput quantitative polymerase chain reaction (HT-qPCR), we found the number and abundance of ARGs were impacted by CBZ levels and exposure duration. We also observed the upregulated expression of the pro-inflammatory gene IL6 and downregulated expression of toll-like receptor gene TLR2 and intestinal barrier gene TJP2a at different exposure times. Correlation analyses revealed that Geobacillus, Rho-dococcus, Ralstonia, Delftia, Luteolibacter and Escherichia-Shigella might be the main bacterial genera carrying ARGs. Meanwhile, Cetobacterium and Aeromonas could be the dominant bacteria affecting intestinal health related genes. Our results could contribute to understanding the health risks of CBZ to the intestinal micro -ecology of aquatic animals.

Automated summary

This study aimed to investigate the effects of CBZ on gut microbiota, antibiotic resistance genes (ARGs), and intestinal health-related gene expression using a zebrafish model. The results showed that CBZ altered gut microbiota composition, affected the quantity and abundance of ARGs, and led to changes in the expression of intestinal health-related genes. Correlation analysis revealed specific bacterial genera carrying ARGs and dominant bacteria affecting intestinal health-related genes. These findings contribute to understanding the health risks of CBZ to the intestinal microecology of aquatic animals.