Effects of prebiotic and multispecies probiotic supplementation on the gut microbiota, immune function, and growth performance of weaned piglets

In this study, we evaluated the impact of yeast cell wall prebiotics and multispecies probiotics on the gut microbiota, immune response, and growth performance of weaned piglets, as alternatives to antibiotics as growth promoters (AGPs). A randomized complete block design was employed, involving 160 piglets divided into four treatment groups during the nursery phase. The treatments applied throughout the experimental period were as follows: CONT+ = basal diet with halquinol (AGP); YCW = basal diet with yeast cell wall (cell wall of Saccharomyces cerevisiae yeast); SIM+ = basal diet with yeast cell wall + multispecies probiotic (Bacillus subtilis (2.0 x 109 CFU/g), Bacillus coagulans (5.0 x 108 CFU/g), Clostridium butyricum (5.0 x 107 CFU/g), and Bacillus licheniformis (2.0 x 109 CFU/g)); SIM- = basal diet with yeast cell wall + multispecies probiotic (half dose). The parameters assessed included daily feed intake, weight gain, feed conversion ratio (FCR), diarrhea score, serum cytokine levels, and chemokine concentrations, as well as microbiota analysis. During the 21 to 63-day study period, only FCR differed significantly (p = 0.0076). CONT+ and PREB had superior FCRs of 1.543 and 1.585, while SIM- had the least favorable FCR at 1.654. At 35 days, IL-10 levels were greater in the SIM- group, showing a 271.25% increase over those in the other groups. By 49 days, the IL-8 concentration was lower in the PREB group than in the CONT+ group, with a reduction of 247%, while the IL-8 concentrations in the SIM+ and SIM- groups were not significantly different from those in the other groups. The Firmicutes/Bacteroidetes (F/B) ratio in the CONT+ group was lower than that in the PREB, SIM+, and SIM- treatment groups. The Lactobacillaceae family was more abundant in the SIM+ treatment, followed by the SIM- and PREB treatments. The CONT+ treatment had the lowest abundance. The abundance of the genus Lactobacillus differed between the CONT+ group and the PREB, SIM+, and SIM- treatment groups. Prebiotics, used either alone or combined with probiotics, serve as effective substitutes for AGPs, boosting piglets' health and performance throughout the nursery phase.