Effects of probiotics on gut microbiota in poultry.

Probiotics are living microbes that impart overall health benefits when introduced appropriately. They play important roles in enhancing immunity, inhibiting harmful bacteria, balancing the gut microbiota, and increasing poultry growth performance. In this manuscript, we address the classifications of probiotics, the compositions and functions of the gut microbiota in poultry, and examine the connection between probiotics and the gut microbiota and their roles in promoting the poultry growth. Probiotics are widely used in poultry production, including Lactobacillus, Bacillus, Bifidobacterium, Streptococcus, Enterococcus, and Clostridium, which can exert beneficial effects through various mechanisms, such as increasing the abundance and diversity of the gut microbiota, promoting the secretion of digestive enzymes and antimicrobial substances, optimizing immune microenvironment homeostasis, and enhancing the intestinal barrier. Furthermore, new probiotic products are emerging in poultry production, including prebiotics, synbiotics, and postbiotics. Other novel approaches are used in poultry production to improve their growth and immune performances and inherit beneficial microbial communities, including the integration of probiotics with gut health-promoting agents and the genetic selection of microbiota. The paper demonstrates the potential of probiotics as effective alternatives of antibiotic growth promoters (AGPs) for the promotion of growth performance and intestinal health in poultry production.