Effect of live yeast Saccharomyces cerevisiae (Actisaf Sc 47) supplementation on the performance and hindgut microbiota composition of weanling pigs

As an alternative to antibiotic growth promoters, live yeast supplementation has proven useful in reducing weaning stress and improving performance parameters of piglets. Here, we compared the performance and hindgut microbiota of weanling piglets subjected to different pre- and post-weaning yeast supplementation regimens using a live strain of Saccharomyces cerevisiae (Actisaf Sc 47). Average feed intake and average daily weight gain of piglets within Yeast-Control and Yeast-Yeast groups were higher than those in the Control-Control group. Yeast supplementation resulted in development of microbial communities that were phylogenetically more homogenous and less dispersed compared to the microbiota of control piglets. Key bacterial taxa overrepresented in the microbiota of yeast supplemented piglets included phylum Actinobacteria, specifically family Coriobacteriaceae, as well as Firmicutes families Ruminococcaceae, Clostridiaceae, Peptostreptococcaceae, and Peptococcaceae. Correlation network analysis revealed that yeast supplementation was associated with enrichment of positive correlations among proportions of different bacterial genera within the hindgut ecosystem. In particular, within the cecal microbiota of supplemented piglets, higher numbers of positive correlations were observed among potentially beneficial genera of the phyla Actinobacteria and Firmicutes, suggesting a mechanism by which yeast supplementation may contribute to regulation of intestinal homeostasis and improved performance of piglets.