Beneficial effects of AMP Scy-hepc on the gut microbiota contribute to the potential growth of Larimichthys crocea

In light of the global ban on antibiotics in feedstuffs, antimicrobial peptides (AMPs) are gaining significant attention as a highly promising alternative to antibiotics when use as feed additives. Our previous study revealed that the extended (one-year) daily administration of the AMP Scy-hepc substantially boosted the growth of Larimichthys crocea. However, the precise impact of dietary supplementation with AMPs on the gut microbiota and the underlying beneficial mechanisms remain unclear. This study aim to investigate the shifts in gut microbiota across different gut sites in L. crocea after 60 days Scy-hepc feeding, expanding upon our earlier work. Utilizing 16S rRNA sequencing, we found that a 60-day dietary supplementation of Scy-hepc significantly enhanced the growth of L. crocea by inducing alterations in the microbial community within the foregut and midgut. Notable changes were observed in Tenericutes, Firmicutes, Proteobacteria, Cyanobacteria and Spirochaetes. Moreover, Scy-hepc supplementation increased the abundance of potential probiotics (Rhodobiaceae and Planococcaceae) and reduced the abundance of opportunistic pathogens (Flavobacteriia and Mollicutes). This led to a more intricate microbial network with enhanced metabolism-related functions. In summary, this study provides compelling evidences supporting the beneficial alteration of gut microbiota in the foregut and midgut as an underlying mechanism by which Scy-hepc feeding promotes host growth. These findings offer a novel perspective for investigating the advantageous effects of AMPs on fish health and the advancement of aquaculture.