A COMPREHENSIVE REVIEW ON THE SYNERGISTIC EFFECTS OF SACCHAROMYCES CEREVISIAE AND BACILLUS LICHENIFORMIS AS SYNBIOTICS IN POULTRY PRODUCTION

Synbiotics have emerged as an alternative to antibiotics in poultry production, enhancing nutrient utilization, performance, and gastrointestinal health. Several probiotic strains and prebiotics, including Bacillus licheniformis and Saccharomyces cerevisiae, have been identified for their potential to reduce pathogenic load in poultry. Bacillus licheniformis, a lactic acid-producing bacterium, is highly stable in the gastrointestinal tract and produces digestive enzymes, vitamins, metabolites, and short-chain fatty acids. On the other hand, Saccharomyces cerevisiae contains β-glucans and mannan-oligosaccharides as the main components; these two have the potential to improve growth performance, intestinal development, and boost immunity, thereby protecting against pathogenic infections. As dietary supplements, both Bacillus licheniformis and Saccharomyces cerevisiae have been shown to modulate the intestinal microbiota and improve gut health in animal models. Although many studies have explored the systemic and immunological effects of these two, not all have established the synergy between them. This review summarizes the characteristics of both probiotics, the mechanisms by which they resist pathogens, and their synergistic effects in poultry production.