Effect of live yeast Saccharomyces cerevisiae supplementation on the performance and cecum microbial profile of suckling piglets

Background: One mechanism through which S. cerevisiae may improve the performance of pigs is by altering the composition of the gut microbiota, a response that may be enhanced by early postnatal supplementation of probiotics during rapid microbial succession. To test this hypothesis, 48 newborn piglets were divided into 3 groups (n=16) and received either a regular dose (5 x 109 cfu of S. cerevisiae; Low), a high dose (2.5 x 1010 cfu S. cerevisiae; High) per pig or sterile water (Control) by oral gavage every other day until weaning. Performance data were taken every week, and at weaning (28±1 days of age), piglets were killed to collect cecum content samples for microbial profiling. DNA samples extracted from cecal contents were subjected to high throughput 454 pyrosequencing of the V1-V3 regions of the 16S rRNA gene. Results: Average daily gain (ADG) was higher in High yeast treated piglets compared with Control piglets (P<0.05). Alpha diversity analyses indicated a more diverse microbiota in the Control piglets compared with Low yeast group; the High yeas being intermediate (P<0.01). Similarly, Beta diversity analyses indicated differences among treatments (P = 0.03), mainly between Low yeast and Control groups (P = 0.02). The sparse Partial Least Squares Discriminant Analysis (sPLS-DA) indicated that Control group was discriminated by a higher abundance of Veillonella, Dorea, Oscillospira and Clostridium; Low yeast treated pigs by higher Blautia, Collinsella and Eubacterium; and High yeast treated pigs by higher Eubacterium, Anaerostipes, Parabacteroides, Mogibacterium and Phascolarctobacterium. Partial Least Squares (PLS) analysis showed that piglet ADG was positively correlated with genus Prevotella. Conclusions: Yeast supplementation significantly affected microbial diversity in cecal contents of suckling piglets associated with an improvement of short chain fatty acid producing bacteria in a dose-dependent manner. Therefore, yeast treatment may enhance the growth of beneficial bacterial and stabilize the developing gut microbial community of suckling piglets by reducing susceptibility to environmental influences.