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

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 &lt; 0.001, Cohen's d = 2.1) and survival rate (94% in 1% XOS vs. 70% in control, p &lt; 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 &lt; 0.001) and protein content increasing by 35.6% (14.9% in control to 20.2% in 1% XOS, p &lt; 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 &lt; 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.