Abstract: Saccharomyces boulardii,a subspecies of Saccharomyces cerevisiae,has high temperature and bile salt resistance.Saccharomyces boulardii reduces intestinal pathogens by altering the surface of pathogens.In addition,the secretion of Saccharomyces boulardii can increase enzyme activity in animals,thereby promoting digestion and absorption of nutrients.Furthermore,the secretion of Saccharomyces boulardii can improve the body's anti-inflammatory effect by interfering with pro-inflammatory factors.Saccharomyces boulardii can prevent and cure diseases such as antibiotic-associated diarrhea,Clostridium difficile infection,traveler's diarrhea,irritable bowel syndrome,crohn's disease and other diseases.Saccharomyces boulardii has been certified in Europe and North America as a feed additive.In livestock and poultry applications,Saccharomyces boulardii can promote the proliferation of intestinal beneficial bacteria,produce lactic acid to reduce the content of intestinal pathogenic bacteria,promote the release of immune factors and the development of immune organs,thus decrease feed and gain ratio,improve the production performance,enhance immunity,reduce diarrhea,and regulate intestinal flora balance.In this paper,the authors reviewed the biological function,mechanism of action and application of Saccharomyces boulardii.It was expected to provide reference for its further research and wide application in the future.

Key words: Saccharomyces boulardii; biological characteristics; mechanism of action; livestock application