Proper sow nutrition during gestation will help ensure more homogenous litters with higher piglets’ weight and improved vitality. New research conducted in metabolic chambers coupled with advanced meta-genomic studies shows the effect of using the specific live yeast Saccharomyces cerevisiae var. boulardii CNCM I-1079 on energy metabolism. This has practical implications on sows’ nutrition: it can be applied through a partial energy substitution, partially compensating the inclusion cost of the additive, and still getting all the benefits of a probiotic yeast.