Postbiotics in Poultry Nutrition: Mechanisms of Action, Health Benefits and Future Perspectives

In the poultry industry, measures related to combating antimicrobial resistance have accelerated the search for safe and effective alternatives capable of sustaining production while limiting the spread of pathogens in livestock farms. Among these, postbiotics have recently emerged as a promising solution to overcome the use of traditional in-feed additives. Defined as a preparation of inanimate microorganisms and/or their components that confer a health benefit to the host, postbiotics appear to combine biological effects with improved technological stability. Numerous studies have highlighted their beneficial effects on gut morphology, mucus production, immune modulation, microbiota composition and feed conversion ratio. Moreover, several postbiotic formulations exhibit protective effects against pathogens, suggesting a potential role in disease prevention. Overall, current evidence indicates that postbiotics are a valuable tool for improving poultry health, productivity and food safety while reducing reliance on antibiotics. This review summarises the studies on the use of postbiotics in poultry, providing a framework for their documented benefits. It also aims to highlight the limitations associated with their application and the existing knowledge gaps—particularly regarding mechanisms of action, optimal dosages, and methods of administration—in order to support standardisation and ensure reproducibility within the livestock industry.