Epigenetics and postbiotics in Aquaculture: Unlocking sustainable solutions through innovation.

Epigenetics and postbiotics are emerging as promising strategies in aquaculture. Epigenetics refers to heritable changes in gene expression without altering the DNA sequence. Growing research highlights its influence on various aspects of fish and shellfish biology, including sex determination, gonadal development, stress response, survival, growth, morphology, and nutrient metabolism. Postbiotics, consisting of non-living microorganisms or their byproducts, have gained attention for their potential health benefits. Studies show postbiotics can reduce oxidative stress, support immunity, balance gut microbiota, and enhance epithelial barrier function. While sharing benefits with probiotics, postbiotics offer greater stability and safety, making them a more attractive option. Both strategies have been reported beneficial for a range of commercial aquaculture species, including fin fish, shrimp, and prawns. They contribute to improving gut health, immunity, nutrient absorption, and the overall welfare of aquaculture species. Protective responses elicited by the postbiotic may be associated with intestinal morphology and microbial diversity. Postbiotic-supplemented diets promote distinct gut microbial communities and help improve metabolic disorders. Epigenetic factors may act as intermediaries, helping to regulate the interaction between gut microbiota and the host. These approaches reduce the reliance on antibiotics, offering a more sustainable and eco-friendly solution for aquaculture. This review summarizes recent advances in the application of epigenetic and postbiotic strategies in aquaculture, highlighting their roles in promoting animal performance and disease resistance in both finfish and shellfish. Finally, we identify key knowledge gaps and propose directions for advancing the understanding of the interplay between epigenetic mechanisms and postbiotic actions to help guide future research priorities.