Effects of dietary supplementation with novel organic rare earths on growth performance, gut and liver health, gut microbiota in golden pompano

Fish gut-liver health and gut microbial disorders have restricted the sustainable development of aquaculture. Rare earth elements are neglected potential trace elements in intensive farming. The aim of the study was to explore the effects of novel organic rare earths on growth performance, gut-liver health, and gut microbiota of golden pompano via supplementation of 0.2 g/kg novel organic rare earths in the diet. Firstly, the novel organic rare earths can effectively enhance the WG and SGR, and increase the CR of golden pompano, indicating that the novel organic rare earths could enhance growth performance. Meanwhile, dietary supplementation of novel organic rare earths alleviated liver inflammation by decreasing the expression of hepatic pro-inflammatory cytokines and elevating that of anti-inflammatory cytokines. In addition, the novel organic rare earths enhanced the tight junctions between intestinal epithelial cells to maintain the integrity of the intestinal barrier and reduced intestinal inflammation. Finally, the novel organic rare earths altered the composition (enrichment of beneficial bacteria), diversity and the ratio of ‘Functional Group 2/Functional Group 1’ of gut microbiota, which may contribute to the enhancement in growth of golden pompano. In conclusion, our study found that novel organic rare earths enhanced the growth performance of golden pompano and gut-liver health, altered the structure and function of the gut microbiota to alleviate microbiota imbalance. Thus, this study provides insights into the link between gut microbiota and host health and growth, and helps to promote the utilization of novel organic rare earths as dietary additive in fish culture. • Dietary supplementation of 0.2 g/kg RE can effectively enhance the WG and SGR, and increase the CR of golden pompano. • RE alleviated liver inflammation by decreasing hepatic pro-inflammatory cytokines and increasing anti-inflammatory cytokines. • RE enhanced the tight junctions to maintain the integrity of the intestinal barrier and reduced intestinal inflammation. • RE improved the composition (enrichment of beneficial bacteria), diversity and the ratio of “Functional Group 2/Functional Group 1” of gut microbiota.