IgY Antibodies as a Non-Antibiotic Approach to Combat Vibrio vulnificus Infection and Gut Microbiota Dysbiosis in Zebrafish

This study investigated the protective effect of immunoglobulin Y (IgY) antibodies as a targeted therapy against Vibrio vulnificus infection in zebrafish (Danio rerio), with a focus on survival outcomes and microbiota regulation. Zebrafish are administered IgY antibodies through injection and oral routes before exposure to Vibrio vulnificus. The results showed that IgY treatment significantly improved survival rates, with the injection group having a survival rate of up to 90%, while the untreated control group had only 40%. This protective effect is attributed to the specific action of IgY pathogen against Vibrio vulnificus, which limits bacterial load and severity of infection. In addition, 16S rRNA sequencing showed favorable changes in the gut microbiota of fish treated with IgY, with an increase in the abundance of beneficial bacteria such as lactobacilli and Pseudomonas aeruginosa, while the levels of pathogenic bacteria such as Vibrio and Aeromonas decreased. These findings highlight the dual benefits of IgY: pathogen specific inhibition and microbiome friendly effects, making it a promising alternative to antibiotics in aquaculture. The IgY targeted approach supports microbial health and reduces the risk of antibiotic resistance, consistent with sustainable aquaculture goals. Future research should explore optimized IgY doses and their effects on different fish species, positioning IgY as a valuable tool for antibiotic free disease management in the fish industry.