Application of dietary supplements (synbiotics and probiotics in combination with plant products and β-glucans) in aquaculture

This review addresses the dietary supplements, synbiotics and probiotics in combination with plant products or yeast/β-glucans in aquaculture. The potential applications of synbiotics have a relatively short history in aquaculture, but have generated interest because of numerous benefits reported in endothermic animals. Since the first study was published by (Aquaculture Science in 2009) the concept has been used in aquaculture to reveal effects on growth performance, gut microbiota, gut histology, immune parameters, haematological and biochemical parameters as well as increased disease resistance. However, a limited number of probiotic bacteria (mainly Bacillus and Enterococcus) and prebiotics (mannan oligosaccharides, fructooligosaccharides, short-chain fructooligosaccharides, galactooligosaccharides, arabinoxylan–oligosaccharides, isomaltooligosaccharide, chitosan oligosaccharide and inulin) have been used. Additionally, some studies have used plant products or yeast/β-glucans in combination with probiotics, and these studies suggested that these dietary supplements promote growth performance and boost some immune parameters. The present review identifies evaluations of gut microbiota and gut morphology, and mucosal immune response as significant gaps in existing knowledge and suggests issues that merit further investigations to conclude the potential of dietary supplements in aquaculture.