Community Dynamics and Antibiotic Resistance Gene Profile of Gut Microbiota in Labeo rohita Sourced From Various Catches in Retail Fish Markets in Kolkata, India

ABSTRACT Freshwater fish and fish products are popular and widely consumed globally, including in India. The aquatic environment has a significant influence on the gut microbiota of fish produced in it and serves as a crucial indicator of food safety and quality. This study investigated and compared the gut microbial community composition of Rohu ( Labeo rohita ) sourced locally from Kolkata, West Bengal, India (i.e., local fish) and imported from Andhra Pradesh, India (i.e., non‐local fish), as well as the prevalence of antibiotic‐resistance genes (ARGs) in both. The gut microbiota in both groups was predominantly composed of Proteobacteria (79.9% in local fish and 71.6% in non‐local fish). Species‐level analysis indicated several Aeromonas spp. dominated the fish gut, while the relative abundance of Enterococcus hermanniensis was significantly ( p < 0.05) different between local and non‐local groups. Distinct antibiotic resistance genes were identified in the gut microbiota of local and non‐local fish, suggesting that regional variations in antibiotic usage and environmental conditions may shape resistance patterns. The high abundance of pathogenic species and the prevalence of ARGs in fish gut microbiota raise serious concerns about the consumption of these fish, which might pose significant human health risks.