Aquatic feed is an important cornerstone of the marine aquaculture industry, but China has a high dependence on imported feed materials such as fish meal. In this context, high-fat feed has attracted much attention due to its potential to save fish meal. However, high-fat feed can have adverse effects on the growth performance and intestinal function of grouper, which has become an urgent problem for the industry to solve.

Recently, the marine biological resources and seawater aquaculture team of Guangxi Academy of Marine Sciences conducted in-depth research on the effects and regulatory mechanisms of different types of bile acids on the growth and intestinal health of pearl gentian grouper fed with high-fat diet. The research results showed that adding glycocholic acid, taurine, or bile acid to high-fat feed had no significant effect on the feeding rate and growth rate of fish, but increased the relative abundance of intestinal pathogenic bacteria such as Staphylococcus and Pseudomonas. Meanwhile, the addition of glycocholic acid or bile acid can reduce the thickness of the intestinal muscle layer and villus height, increasing intestinal damage. On the contrary, after adding taurocholic acid, the width of intestinal villi and serum antioxidant enzyme activity increased, while the degree of intestinal damage and serum lipid peroxidation level decreased. At the molecular level, fish treated with taurocholic acid showed positive changes in proteins and genes involved in the PI3K/AKT/mTOR pathway, S6K1 signaling transduction, and bile acid metabolism, such as increased expression of P-P70 protein and nrf2, pi3k, pdk1, tsc2, akt, mtorc1, fxr, and tgr5 mRNA. In addition, serum metabolites and gut microbiota were also significantly affected. In summary, the study suggests supplementing the high-fat diet of grouper with 900 mg/kg of taurocholic acid. This discovery provides a theoretical basis for the development of bile acids as aquatic feed additives and an important reference for the scientific and efficient development of feed formulations for grouper.

The research results are titled "Effects of Dietary Primary bile acids on the growth, The article "Intentional Morphology, Gene Expression, Serum Metabolites, and Intentional Microbiota in Pearl Gentian Grouper Fed a High Lipid Diet" was published in the internationally renowned journal Aquaculture (First District of the Chinese Academy of Sciences). Dr. Ren Xing from the Fourth Institute of Oceanography of the Ministry of Natural Resources is the first author, and Dr. Xu Jia from Guangxi Academy of Marine Sciences is the corresponding author. This research has received funding from projects such as the Guangxi Natural Science Foundation.

Paper link:https://doi.org/10.1016/j.aquaculture.2024.741679.