Probiotics and prebiotics in poultry nutrition

Under normal circumstances, there is a delicate balance of beneficial and pathogenic bacteria in the gastrointestinal tract (GIT). This is influenced by symbiotic and competitive interactions and relationships. The microbial communities will not only protect the GIT but also enhance productivity in the host. The use of probiotics and prebiotics are two approaches that have been examined and can potentially reduce enteric diseases in poultry and also enhance their productivity. These substances have been proposed to assist in the prevention of carcass contamination and improve the immune response in the chicken. Probiotics have been defined as 'a live microbial feed supplement which beneficially affects the host animal by improving its intestinal balance' (Fuller, 1989). The probiotic mode of action is by 'competitive exclusion', meaning there is competition for attachment sites in the GIT.