Abstract:

This study is conducted to investigate the effects of probiotics and antibiotic on non-specific immune and intestinal microbiome of Litopenaeus vannamei. L. vannamei with an average body weight of (2.2 ±0.1) g were randomly divided into three groups, 3 repeats in each group and 100 shrimp in each repeat. The control group was fed with basic diet (C0), the experimental groups were fed with 0.5% probiotic preparation (E1) and 0.5% antibiotic oxytetracycline (E2), respectively. The non-specific immune function of serum and composition of intestinal microbiome in L. vannamei were detected by biochemistry and high-throughput sequencing methods. The experiment lasted 14 days. The results showed that the activities of ACP and POD in the serum of E1 were significantly increased (P<0.05), the activities of GOT and GPT were reduced. But these effects in E2 antibiotic group were opposite. Antibiotics oxytetracycline enhanced the activity of T-AOC in the serum of L. vannamei significantly, but the effect was short, the activity dropped sharply when time went on. Probiotics had improved significantly activities of digestive enzymes such as amylase, lipase, trypsin in the intestine of L. vannamei (P<0.05), and those in antibiotic group were lower. And probiotics could optimize the composition of intestinal microbiome, the abundances of Proteobacteria, Actinobacteria, Verrucomicrobia and Candidatus Saccharibacteria were increased in E1 group, while the abundances of Actinobacteria, Candidatus Saccharibacteria and Bacteroidetes were increased slightly in E2 group. Therefore, 0.5% probiotics has positive effects on non-specific immune function and intestinal microbiome of L. vannamei, and the effects are better than those of oxytetracycline, which is suitable for using as an immunostimulants and feed-additives in the aquaculture of L. vannamei.

Key words: Litopenaeus vannamei, probiotic, antibiotic, non-specific immune, intestinal microbiome