Evaluation of different dietary n ‐3 lc‐pufa on the growth, intestinal health and microbiota profile of golden pompano ( Trachinotus ovatus )

The omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are essential fatty acids for marine fish. This study aimed to evaluate different dietary n-3 LC-PUFA on the growth, intestinal health and microbiome in carnivorous marine fish Trachinotus ovatus. Three diets, respectively, supplemented with fish oil, EPA-enriched oil and DHA-enriched oil were fed juvenile T. ovatus for 10 weeks. The results showed that the three groups showed no difference in the growth, histology and digestive enzyme activities of anterior intestine. Moreover, the intestinal ACP and ALP activities and tnfɑ mRNA level were increased in the EPA-enriched group, whereas the serum diamine oxidase activity and intestinal lysozyme activity and malondialdehyde content were decreased in both EPA- and DHA-enriched groups. Meanwhile, these two diets also down-regulated the mRNA expression of Mucin 2, Mucin 13, hes1-b, Krueppel-like factor 4 and Occludin, and up-regulated the zonula occludens-1 mRNA levels in intestine. Moreover, the two groups significantly decreased the intestinal Vibrio abundance and increased the probiotic proportions, especially in the EPA-enriched group. These results indicate dietary n-3 LC-PUFA would facilitate normal intestinal function and probiotics profiles of T. ovatus, and the EPA-enriched group appears to be more positive.