This study investigates the protective effects of immunoglobulin Y (IgY) antibodies as a targeted treatment against Vibrio vulnificus infection in zebrafish (Danio rerio), focusing on survival outcomes and microbiota modulation. Zebrafish were administered IgY antibodies through injection and oral routes prior to V. vulnificus exposure. Results showed that IgY treatment significantly enhanced survival rates, with injected groups achieving up to 90% survival compared to only 40% in untreated controls. This protective effect is attributed to IgY pathogen-specific action against V. vulnificus, limiting bacterial load and infection severity. Additionally, 16S rRNA sequencing revealed favorable shifts in gut microbiota among IgY-treated fish, with increased abundances of beneficial bacteria such as Lactobacillus and Faecalibacterium prausnitzii, alongside reduced levels of pathogenic genera like Vibrio and Aeromonas. These findings highlight IgY dual benefits: pathogen-specific inhibition and microbiota-friendly action, positioning it as a promising alternative to antibiotics in aquaculture. IgY targeted approach supports microbial health and reduces risks of antibiotic resistance, aligning with sustainable aquaculture goals. Future research should explore optimized IgY dosing and its effects across different fish species, positioning IgY as a valuable tool for antibiotic-free disease management in fish farming.