Strengthening growth, digestion, body composition, haemato-biochemical indices, gene expression, and resistance to Fusarium oxysporum infection and histological structure in Oreochromis niloticus by using fructooligosaccharides and β-1,3 glucan mixture

Prebiotics are fibers that promote beneficial gut bacteria and play a pivotal role in enhancing host health. This study delves into the impact of various levels of prebiotics, specifically fructooligosaccharides and β-1,3 glucan (Fβ), on the growth performance, biochemical, hematological parameters, gene expression, histological variations in the internal organs, and disease resistance to Fusarium oxysporum in tilapia (Oreochromis niloticus). Two hundred forty Nile tilapia, initially weighing 34.0 ± 0.1 g, were distributed into four groups and given a commercial diet with varying Fβ treatments: control (0 g/kg) (C), T1 (0.5 g/kg), T2 (1.0 g/kg), and T3 (1.5 g/kg) for 70 days. The study revealed significant improvement of the biochemical, hematological, and digestive enzyme activities, as well as histological changes in hepatopancreatic, intestine, and spleen sections with the use of Fβ. Moreover, the expression of innate humoral genes significantly increased (P < 0.05) in tilapia at the 1.5 g/kg Fβ group compared to the control. Notably, challenging with F. oxysporum exhibited lower mortality rates in the three treatments supplemented with additive prebiotics (P < 0.05). Consequently, the feed additives utilized in this study emerge as a viable alternative to enhance growth performance, biochemical and hematological parameters, gene expression, histological variations in internal organs, and disease resistance in fish farming on a large scale.