Valorization of corn husk waste: Xylooligosaccharides as a sustainable prebiotic enhance growth, gut health, and fillet quality in Nile tilapia (Oreochromis niloticus)

Abstract

Xylooligosaccharides (XOS) are advantageous prebiotics that promote sustainable aquaculture. The growth performance, gut microbiota, and fillet composition of juvenile Nile tilapia (Oreochromis niloticus) were investigated in relation to the prebiotic effects of corn husk-derived XOS, extracted using alkaline extraction and autohydrolysis. Following 2 weeks of acclimatization, 270 fish were split into three groups: control, 0.5% XOS, and 1% XOS, with three replicates per group. For 56 days, fish were fed twice a day. Final weight (83.9 g in 1% XOS vs. 44.5 g in control, p < 0.001, Cohen's d = 2.1) and survival rate (94% in 1% XOS vs. 70% in control, p < 0.001) were both considerably increased by XOS supplementation. The feed conversion ratio dropped significantly from 2.69 (control) to 0.99 (1% XOS, p = 0.003). The nutritional quality of the fillet increased, with calcium levels more than doubling (2.6%–6.7%, p < 0.001) and protein content increasing by 35.6% (14.9% in control to 20.2% in 1% XOS, p < 0.001). A 36-fold increase in lactic acid bacteria (833 CFU/g in 1% XOS vs. 23 CFU/g in the control group, p < 0.05) and a decrease in coliforms were observed in the gut microbiota study, suggesting improved gut health. These results demonstrate that XOS derived from corn husks can serve as a sustainable feed additive improving fillet quality, shaping a favorable gut microbiota, enhancing fish development, and providing a viable substitute for antibiotic growth promoters in aquaculture.