THE ROLE OF FEED SUPPLEMENTATION ON GUT MICROBIOTA IN CULTURABLE CARPS: A COMPREHENSIVE REVIEW

Abstract

Carps are among the most valuable freshwater fish worldwide, with their intestinal microbiota playing a vital role in regulating nutrient assimilation, immune defense, and resistance to pathogens. In recent years, dietary interventions have gained considerable attention as a means to manipulate gut microbial communities and improve the overall health and productivity of cultured carp species. This review provides an in-depth analysis of the influence of different dietary supplements such as probiotics, prebiotics, synbiotics, polysaccharides, carotenoids, plant extracts, and microbial cultures on gut microbiota composition, growth efficiency, antioxidant capacity, and immune responses in key carp species, including Cyprinus carpio (common carp), Hypophthalmichthys molitrix (silver carp), Hypophthalmichthys nobilis (bighead carp), Carassius auratus (crucian carp), Mylopharyngodon piceus (black carp), and koi carp. Most findings demonstrate that these dietary additives foster the proliferation of beneficial bacterial groups such as Lactobacillus, Bifidobacterium, and Cetobacterium, while inhibiting pathogenic microorganisms and enhancing metabolic processes related to carbohydrate and amino acid utilization. Furthermore, bioactive compounds like polysaccharides and probiotics have been consistently shown to strengthen antioxidant defense mechanisms and upregulate immune-related gene expression, contributing to improved growth performance and resilience against stress. Nonetheless, the effectiveness of these supplements can vary depending on factors such as dosage, feeding duration, and environmental conditions. A deeper understanding of the interactions between gut microbes and dietary components is essential for developing sustainable aquaculture strategies and optimized nutritional management practices in carp farming systems.