The aim of this study was to assess the effect that feeding Saccharomyces cerevisiae boulardii CNCM I-1079 (LSB) to lactating sows and their progeny has on inflammatory response and mucosal immunity after vaccination against Actinobacillus pleuropneumoniae. Sixty-seven Danbred sows were allotted into two treatments when they entered the farrowing room seven days before the expected farrowing date: control (CON: lactation diet) and LSB (CON + 12 × 109 colony forming units (CFU)/d until weaning). At weaning, piglets were equally allotted into two experimental diets according to sow diet: control (CON: 2-phase post-weaning diets) and LSB (CON + 2 × 109 CFU/kg and 1 × 109 CFU/kg in phases 1 and 2, respectively). The piglets were vaccinated at days 26 and 49 post-weaning. Growth performance and number of IgA producing cells and cytokine’s gene expression in lung, lymph node, and intestine samples at day 70 post-weaning were assessed and analyzed in SPSS Statistics 26: performance with a general linear model with sex, room, sow diet, piglet diet, and their interactions as main effects, and immunity with a Kruskal−Wallis test for k unrelated samples. Piglets from LSB-fed sows displayed a higher average daily gain (ADG; p < 0.01) and a heavier body weight (BW; p < 0.05) during lactation, tended (p < 0.1) to be heavier at day 49, and to have a higher ADG between days 26 and 49; had fewer number of IgA producing cells in the lymph node (p < 0.05); and all the cytokines studied were significantly under-regulated (p < 0.05) in the lung. It is concluded that feeding Saccharomyces cerevisiae boulardii CNCM I-1079 to sows improved piglet performance during lactation and showed a clear reduction in the inflammatory status of the lungs after vaccination against A. pleuropneumoniae, suggesting that there was a maternal imprinting effect on mucosal protection and a cross-talk between the gut microbiota and the lung.
Keywords: Saccharomyces cerevisiae boulardii; cytokines; gut-lung axis; maternal imprinting; weanling piglets.