Abstract
Since the early 1950s, antibiotics have been used in poultry for improving
feed efficiency and growth performance. Nevertheless, various side effects have
appeared, such as antibiotic resistance, antibiotic residues in eggs and meat, and
imbalance of beneficial intestinal bacteria. Consequently, it is essential to find other
alternatives that include probiotics that improve poultry production. Probiotics are live
microorganisms administered in adequate doses and improve host health. Probiotics are
available to be used as feed additives, increasing the availability of the nutrients for
enhanced growth by digesting the feed properly. Immunity and meat and egg quality
can be improved by supplementation of probiotics in poultry feed. Furthermore, the
major reason for using probiotics as feed additives is that they can compete with
various infectious diseases causing pathogens in poultry's gastrointestinal tract. Hence,
this chapter focuses on the types and mechanisms of action of probiotics and their
benefits, by feed supplementation, for poultry health and production.