Response of growth performance, serum metabolites, intestinal tight junction structure and bacterial microbiomes to the long-term intervention of aflatoxin B1 in Lateolabrax maculatus diets

Abstract

Dietary inclusion of aflatoxin B1 (AFB1) has been reported to induce intestinal damage and dysregulate intestinal microbiota of shrimp, but limited information is available in fish. A 56-day feeding trial was conducted to assess the effects of dietary AFB1 on growth performance, serum metabolites, intestinal tight junction structure and bacterial microbiomes of Lateolabrax maculatus. Four diets were formulated to contain 0 (G0), 0.1 (G0.1), 0.5 (G0.5) and 1.0 (G1.0) mg/kg of AFB1, and each diet was randomly assigned to three groups of 40 fish per tank. Fish were fed to apparent satiation twice daily. Results indicated that increased dietary AFB1 concentration from 0 to 1.0 mg/kg decreased (P < 0.01) final body weight, weight gain rate, specific growth rate, feed intake, condition factor, viscerosomatic index, hepatosomatic index and intestinesomatic index of fish. The albumin, high density lipoprotein cholesterol and glucose were decreased (P < 0.05) but aspartate aminotransferase, diamine oxidase, lipopolysaccharide and D-lactate were increased (P < 0.01) as dietary AFB1 increasing. Intestinal tight junction structure appeared different degrees of ambiguous and damaged as reflected by the clear gap and vacuolated cells in fish fed AFB1-treated diets. Inclusion of AFB1 in diets increased (P < 0.05) abundance of Enterobacter and decreased (P < 0.05) abundance of Plesiomonas, but did not alter (P > 0.05) alpha diversity indexes of ace, chao, shannon and simpson in the intestinal microbiota of fish. In conclusion, inclusion of AFB1 up to 1.0 mg/kg in diets decreased growth performance, induced liver and intestinal injury, and altered intestinal microbiota composition without impacting the bacterial diversity of Lateolabrax maculatus.