Gut microbiota are increasingly recognized for their crucial role in regulating the health and growth of the host. The mechanism by which the gut microbiome affects the growth rate of common carp, however, remains unclear. In this study, the gut contents of the fast-growing and slow-growing (High and Low) carp were collected for the fish gut microbiome. High throughput 16S rRNA gene sequencing showed that the overall gut microbiota of High group was distinct from that of Low group. For example, the Cetobacterium were highly enriched in the guts of High group (39.9%), vibrio is highly enriched in the gut microbiota of the Low group (20.0%). LEfSe analysis identified 13 different flora between the two groups, mainly located in 17 KEGG pathways, of which nearly 50% were involved in lipid, vitamin, and amino acid metabolism.
Compared with the Low group, the gut microbiota in the High group significantly enriched the pathways involved in Energy metabolism and Biosynthesis of other secondary metabolites. These metabolic pathways enrich some bioactive substances such as diarylheptane and gingerol, which can have a significant impact on the growth rate of carp.This study can not only elucidate the dynamic changes of gut microbiota of carp with different growth rates, but also help us to screen significant flora that affect growth rate and promote the development of microbiome technologies in aquaculture.