COMBINATION WITH PREBIOTICS (SYNBIOTICS)

Synbiotics are a combination of probiotics and prebiotics designed to provide a synergistic effect in supporting gut health and the immune system of poultry [246]. Probiotics provide live beneficial microorganisms, while prebiotics, typically in the form of non-digestible oligosaccharides, serve as a specific nutrient source for the growth and activity of beneficial microbes [247]. This combination enhances probiotic colonization in the gastrointestinal tract, stimulates the production of bioactive metabolites, and modulates both innate and adaptive immune responses [248]. From a practical and economic perspective, synbiotics may offer improved colonization and immune outcomes; however, their higher formulation cost must be justified by measurable improvements in performance, health status, or pathogen reduction under field conditions [249].

Administering synbiotics to poultry has been shown to strengthen the integrity of the intestinal epithelium by increasing mucosal thickness, villus length, and the villus/crypt ratio [250]. This promotes more efficient nutrient absorption and strengthens physical defenses against pathogens [251]. Immunologically, synbiotics stimulate phagocyte activity, increase T- and B-lymphocyte proliferation, and promote the production of mucosal (IgA) and systemic (IgY) antibodies, resulting in a more effective immune response to pathogens and vaccines [252].

Furthermore, synbiotics have been shown to be more effective than single probiotics in suppressing the colonization of pathogens, such as Salmonella spp. and Clostridium perfringens, through mechanisms such as competition for space and nutrients, production of antimicrobial metabolites, and stimulation of local immune responses [253]. Restoring this microbiota balance also helps reduce intestinal inflammation and oxidative stress, thus supporting improved poultry performance, including body weight gain and feed conversion efficiency [254].