Changes in intestinal microbial community of Rana chensinensis tadpoles during metamorphosis

Intestinal microbiota plays important roles in animal development, but little is known about intestinal microbial community changes of amphibian during metamorphosis. In our research, we investigated the intestinal bacteria community in 120 tadpoles of Rana chensinensis (R. chensinensis) at five key developmental time points via 16S rRNA amplicon sequencing. We counted morphological parameters of the body and intestine of R. chensinensis tadpoles at varying developmental stages. Our survey revealed that intestinal length and intestinal weight were reduced by 89% and 83.2% during metamorphosis, respectively. The microbial diversity and composition of R. chensinensis intestine exhibited marked differences along with the process of metamorphosis. Compared to the aquatic stages, terrestrial stages showed major shifts in microbial composition, including reduction in Bacteroides, increases in Shewanella and Cetobacterium. The remodeling of intestinal microbiota is accompanied by the transition of diet type, host habitat and gut. Our evidence supports the idea that the composition of intestinal microbiota changed along with tadpole metamorphosis.