Dietary administration of a commercial mixed-species probiotic improves growth performance and modulates the intestinal immunity of tilapia, Oreochromis niloticus

• Published in: Fish & shellfish immunology 2016-02, Vol.49, p.427-435
• Main Authors: Standen, B.T., Peggs, D.L., Rawling, M.D., Foey, A., Davies, S.J., Santos, G.A., Merrifield, D.L.
• Format: Article
• Language: English
• Subjects: Animal Feed - analysis; Animals; Brackish; Cichlids - genetics; Cichlids - growth & development; Cichlids - immunology; Diet - veterinary; Fish; Fish Proteins - genetics; Fish Proteins - metabolism; Gastrointestinal Microbiome - immunology; Gene expression; Growth performance; Histology; Immunity; Intestinal microbiology; Intestines - immunology; Intestines - microbiology; Oreochromis niloticus; Probiotic; Probiotics; Random Allocation; Tilapia; Up-Regulation
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2015.11.037

The growth performance, immunological status, intestinal morphology and microbiology of tilapia, Oreochromis niloticus, were investigated after dietary administration of the commercial probiotic AquaStar® Growout. Tilapia (29.02 ± 0.33 g) were split into five treatments; control (CON), 1.5 g kg−1 probiotic (PRO-1.5), 3 g kg−1 probiotic (PRO-3), pulsed probiotic feeding (PRO-PULSE) or an initial probiotic feed followed by control feeding (PRO-INI). After six weeks of experimental feeding, fish fed PRO-3 displayed significantly higher final weight, weight gain and SGR compared to the CON or PRO-INI treatments. Supplementation of the probiotic at this dose induced an up-regulation of intestinal caspase-3, PCNA and HSP70 mRNA levels compared to the CON fed fish. Immuno-modulatory pathways were also affected; significantly higher expression of TLR2, pro-inflammatory genes TNFα and IL-1β, and anti-inflammatory genes IL-10 and TGFβ suggest that the probiotic may potentiate a higher state of mucosal tolerance and immuno-readiness. Histological appraisal revealed significantly higher numbers of intraepithelial leucocytes in the intestine of PRO-3 fed fish compared with treatments CON, PRO-PULSE and PRO-INI but not PRO-1.5. Additionally, fish receiving PRO-3 had a significantly higher abundance of goblet cells in their mid-intestine when compared with fish from all other treatments. Together, these data suggest that continuous provision of AquaStar® Growout at 3 g kg−1 can improve tilapia growth and elevate the intestinal immunological status of the host. •AquaStar® Growout improves the growth performance of juvenile tilapia.•AquaStar® Growout can augment mucosal tolerance.•AquaStar® Growout improves immune readiness.