Gum Arabic-enriched diet modulates growth, antioxidant defenses, innate immune response, intestinal microbiota and immune related genes expression in tilapia fish

Abstract

This study was designed to assess the influence of dietary supplementation with Gum Arabic at various levels in Nile tilapia fish, Oreochromis niloticus. For 56 days feeding period, a total of 200 juvenile fish were allocated into 20 aquariums and divided into four equal groups, five replicates each, with Gum Arabic (GA) dietary inclusion as follow; the fish group was given a basal diet (CTR 0%); fish group fed a diet supplemented with GA 0.25%; fish group fed a diet supplemented with GA 0.5%; and fish group fed a diet supplemented with GA 1%. Dietary supplementation with 0.5 or 1% GA significantly improves final fish biomass, weight gain, weight gain percent, consumed feed, feed conversion ratio, innate immune response and antioxidant status compared to other treatments. The fish fed elevated levels of GA (1% GA) exhibited higher lipase and amylase activities as well as total protein, albumin, and globulin levels and lower uric acid, AST, and ALT levels. Furthermore, 1% GA enriched tilapia diets significantly up-regulated IL-1β and IL10, whereas downregulated TNFɑ mRNA expression in kidney and spleen tissues. Moreover, highly-AG enriched diets were associated with stronger antibacterial efficacy against pathogenic bacterial populations, together with increased counts of grown Bacillus in the mid gut. Overall, these findings suggest that dietary inclusion of 1% GA could be beneficial and should be explored as a functional feed supplement for Nile tilapia farming.