Emerging roles of probiotics, prebiotics, and synbiotics in fish gut health and oxidative stress regulation

Abstract: The intensification of aquaculture has increased the prevalence of stress-related disorders and gastrointestinal imbalances in cultured fish, often leading to impaired growth, reduced disease resistance, and elevated oxidative stress. In this context, functional feed additives such as probiotics, prebiotics, and synbiotics have emerged as promising alternatives to antibiotics for enhancing fish health and production efficiency. This review synthesizes current knowledge on the emerging roles of these biologically active compounds in modulating fish gut health and oxidative stress regulation. Probiotics contribute to maintaining a balanced intestinal microbiota, improving digestive enzyme activity, enhancing nutrient assimilation, and stimulating innate immune responses. Prebiotics selectively promote the growth of beneficial microbial communities by serving as fermentable substrates, thereby strengthening gut integrity and metabolic functions. Synbiotics exhibit enhanced efficacy in optimizing gut microbial balance and improving physiological resilience. Furthermore, these functional additives play a critical role in mitigating oxidative stress by enhancing antioxidant enzyme activities and reducing reactive oxygen species accumulation, ultimately improving fish health and survival under intensive farming conditions. Overall, the integration of probiotics, prebiotics, and synbiotics into aquafeeds represents a sustainable strategy to promote gut health, strengthen immune competence, and regulate oxidative stress in aquaculture systems. E S H 

Keywords: Digestive health, growth performance, disease resistance, gut microbiota, water quality