The beneficial role of probiotics in monogastric animal nutrition and health

The practice of probiotics in farm animals’ health and production has increased significantly over the last 15 years. Probiotics are defined as live microorganisms that can confer a health benefit for the host when administered in appropriate and regular quantities. The isolation and identification of microorganisms is the first step in the selection of potential probiotics from gut, feces and milk of respective animals. The present molecular techniques mainly genomic and proteomic-knowledge based are employed to identify, characterize probiotics. The ability to examine fully sequenced genomes has accelerated the application of genetic approaches to elucidate the functional roles in the selection of new and specific probiotics. Identification of suitable probiotics may prove to be the next step to decrease the risk of intestinal diseases and reduce specific microbial disorders, as well as demonstrating their role in the production performance of animals, safety and wholesomeness of animals’ meat evidencing consumer’s protection. The mechanisms of action of probiotics include the inhibition of pathogen growth by competition for nutritional sources and adhesion sites, secretion of antimicrobial substances and toxin inactivation. Consequently, the primary interest in the application of probiotics has been in the prevention and treatment of gastrointestinal infections and antibiotic-associated animals’ diarrheal diseases. In this review, the most important benefits of probiotics upon the gastrointestinal microbial ecosystem in monogastric animals (equines, pigs, veal calf and poultry) are described, as well as their implications in terms of animal nutrition and health. Additional knowledge on the possible mechanisms of action is also provided.