Dietary supplementation with Lycium barbarum polysaccharides conducive to maintaining the health of Luciobarbus capito via the enhancement of enzyme activities and the modulation of gut microbiota

Abstract

Lycium barbarum polysaccharide (LBP) is the main active component of Lycium barbarum (L. barbarum), which has important medicinal and nutritional value. However, the effect of LBP treatment on Luciobarbus capito (L. capito) still remains unknown. Given this, the current work aims to probe the underlying effect of different levels of LBP treatment (i.e. 0.10, 0.50 and 1.00 g/L) on L. capito in the context of enzymatic activity analysis, histological observations and gut microbiota analysis. Compared with control group, the activities of hepatic antioxidant enzymes, intestinal digestive enzymes and hepatic immune enzyme were found to be significantly increased after 0.10 g/L LBP and 0.50 g/L LBP treatment (P < 0.05). This result indicated that moderate levels of LBP treatment could dramatically enhance the immunity and antioxidant capacity of L. capito. Furthermore, the compositional structures of the gut microbiota in L. capito were found to be greatly shaped after LBP treatment, whereas the diversity and abundance of the gut microbiota were only found to be slightly changed (P > 0.05). No significant changes were screened in the morphologic structures of gut constructions. This work would provide theoretical and experimental basis for future application of LBP as supplement in the culture process of the farmed fish.