- Fluoride declined total body length and body weight of tadpoles.
- Fluoride resulted in alteration of intestinal microbial community.
- Fluoride triggered histological changes in the gut.
- Fluoride induced metabolic disorder in tadpoles.
In this study, Bufo gargarizans (B. gargarizans) tadpoles were exposed to different fluorine concentrations (0, 0.5, 5 and 50?mg/L NaF) from the Gosner stage 26 to 38. We evaluated effects of fluorine exposure on morphological indicators, gut and intestinal microbiota in B. gargarizans tadpoles. Our results detected that B. gargarizans tadpoles exposure to 5 and 50?mg/L NaF significantly declined the total body length and changed the intestinal morphology. Furthermore, body weight of B. gargarizans tadpoles prominently decreased in 0.5, 5 and 50?mg/L NaF groups. In addition, high-throughput sequencing analysis showed that the diversity and composition of intestinal microbiota in B. gargarizans tadpoles differed among the control and treatment groups. At the phylum level, Proteobacteria increased significantly while Fusobacteria decreased significantly in fluorine exposure groups. At the genus level, the abundant of Raoultella, Shewanella and Escherichia-Shigella were increased in fluorine exposure groups, while Cetobacterium was declined. Also, functional prediction analysis of intestinal microbiota indicated that fluorine exposure obviously altered the metabolism of B. gargarizans tadpoles. Taken together, exposure to fluorine influenced the growth and development of B. gargarizans tadpoles and induced dysbiosis of the intestinal microbiota and metabolic disorder in tadpoles.