25 / 2024-10-12 15:19:02

Caulerpa lentillifera polysaccharides enhance growth and Immunity in Litopenaeus vannamei in correlation with modulating gut microbiota

itopenaeus vannamei is the highest yields within global aquaculture. However, increasingly serious diseases in shrimp has led to excessive antibiotic use, causing resistance and residue issues. Caulerpa lentillifera Polysaccharides(CLP) have shown strong immunomodulatory effects in terrestrial animals. In this study, CLP as a feed supplement for shrimp to replace antibiotics, aiming to support sustainable aquaculture and safeguard human health. Our results indicated that the increase of 0.1% CLP could significantly enhance shrimp growth rate, weight gain, and hepatopancreas index, and all doses of CLP could greatly increase the shrimp crude protein content compared to the control. In addition, 0.1 % CLP significantly enhanced the shrimp phagocytic activity, hepatopancreatic acid phosphatase (ACP) activity, hepatopancreatic alkaline phosphatase (AKP) activity, and plasma superoxide dismutase (SOD) activity, while reducing plasma malondialdehyde (MDA) activity compared to the controlled diet. The 16S rDNA sequence of shrimp intestine microbiota indicated that the intestinal microbiota diversity in shrimp fed with 0.2 % CLP diets was higher than that in the control, including an increase in beneficial microbial groups (Proteobacteria, Actinobacteria, Firmicutes, and TM7) and a decrease in harmful ones (Shewanella and Vibrio). Feeding with CLP could enrich carbohydrate and amino acid metabolism. Correlation analysis indicated that peroxidase (POD) had the widest correlation with communities, being inversely correlated with seven distinct microbial taxa. Moreover, four distinct microbial taxa were significantly associated with weight. This study provides new insights into antibiotic alternatives in aquaculture and recommend the optimum dose of CLP inclusion to be 0.1 %–0.2 % in shrimp diets.