Effect of fish protein-based diet on gut morphology of European Seabass (Dicentrarchus labrax)

Abstract

In physiological conditions, the intestinal barrier is an important defence mechanism against endogenous and exogenous agents and there are different factors related to the diet that can influence its normal functioning. Among the different ingredients, protein stands out, and the different effects derived from its use depending on its origin, animal, or vegetable. In order to define how diet quality may influence the gut health of fish in long-term juvenile European seabass (Dicentrarchus labrax) weighing 28 ± 0.1 g were fed three different treatments: CONTROL treatment based in a commercial diet during the entire trial; ELITE treatment based in a high-quality diet during the entire trial; and a COMBINED treatment, fish fed with the high-quality diet until 100 g and then the commercial diet to the end of the trial. 12 fish per diet were sample to carry out the morphometric analysis of the gut. Villus length and width, lamina propria width and goblet cell area were analysed to assess the fish intestinal health. Results showed how feeding the fish with the ELITE diet and combined diets resulted in lengthening of the intestinal villus of the fish, while fish fed the CONTROL diet showed shortening and narrowing of the villus. Also, fish fed the CONTROL diet presented an increase goblet cell area, which may be explained as an attempt to counteract the possible negative effect of the commercial diet. It was concluded that feeding a quality diet up to 100 grams and then switching it to a commercial diet was just as beneficial as maintaining the quality diet throughout the entire trial, and that the improvement achieved were maintained