Toward a better understanding of mechanisms of probiotics and prebiotics action in poultry species

For many decades, the poultry industry has benefitted from improved health and performance of birds due to inclusion of sub-therapeutic levels of antibiotics in feeds. However, several countries have prohibited, or are in the process of prohibiting, non-therapeutic uses of antibiotics in poultry. This is necessitated by the need to prevent development of antibiotic resistant strains (superbugs) of bacteria that may pose a threat to human health. The industry has responded with development of probiotic (direct-fed microbials)/prebiotic products that are claimed to have similar benefits as antibiotics. However, although many of these products have reasonable levels of field efficacy, significant variability still exists in their effectiveness in comparison with antibiotics. To complicate the issue further, many commercial vendors "oversell" their products with unsubstantiated claims of efficacy. A "systems" approach involving a better understanding of the microbiome, microbe-microbe and microbe-host interaction is being proposed for a better understanding of physiological mechanisms of probiotic/prebiotic action. This may require the use of advanced molecular, analytical and computational techniques. Although these techniques are expansive, the payoff for the poultry industry in terms of better predictability of prebiotics/probiotic effects is enormous.