Comparative Effects of Dietary Supplementations with Microencapsulated Sodium Butyrate, Glycerol Monolaurate and Tributyrin on Growth, Immunity, and Gut Health in Black Sea Bream

Abstract

This study investigates the effects of three dietary additives—microencapsulated sodium butyrate (MSB), glycerol monolaurate (GML), and tributyrin (TB)—on the growth performance, various physiological parameters, gene expression, intestinal morphology, and microflora in Acanthopagrus schlegelii (black sea bream). The experiment utilized a 43.5% soybean meal (SBM) inclusion diet with four isonitrogenous and isoenergetic formulations: a control diet, and diets supplemented with MSB (0.24%), GML (0.04%), or TB (0.22%). The growth trial spanned eight weeks, and triplicate tanks were randomly assigned to each diet, with each tank containing 30 fish, each having an initial weight of 1.55 ± 0.01 g. Key outcomes included measurements of weight gain, specific growth rate, digestive enzyme activity, serum immune markers, antioxidant status, and intestinal morphology and, gut microbiota. Additionally, gene expression and microbiota analysis were conducted on intestinal tissues to assess the impact of these additives on gut health and immune response. The findings revealed that all three additives enhanced growth performance and improved intestinal health and gut microbiota but GML exhibited the most pronounced effects on intestinal barrier function and immune modulation, gene expression, and microflora, followed by MSB and TB. This study provides a comprehensive comparison of MSB, GML, and TB as feed additives for black sea bream, offering insights into their potential for improving fish health and optimizing aquaculture feed formulations.