Synergistic effects of compound probiotics and exogenous enzymes on growth performance and the microbe-metabolite network in weaned piglet
Background: Developing innovative nutritional strategies to alleviate post-weaning stress syndrome (PWSS) is crucial for antibiotic-free swine production. While probiotics and exogenous enzymes are widely used individually, their combined synergistic efficacy and underlying microbe-metabolite interactions remain unclear. This study systematically evaluated the impacts of their co-supplementation on the growth, digestibility, and multi-omics profiles of weaned piglets.Results: Sixty weaned piglets were assigned to four dietary treatments for 28 days: control (CON), probiotics (PRO), enzymes (ENZ), or their combination (COMBO). The COMBO intervention exerted a significant non-additive synergistic effect, achieving the highest average daily gain, optimal fiber digestibility, and the lowest feed-to-gain ratio. Furthermore, it significantly reduced systemic inflammation (e.g., IL-6) and muscle drip loss while elevating secretory IgA and antioxidant capacity. 16S rRNA sequencing revealed that the COMBO group exhibited a specific enrichment of fiber-degrading bacteria, notably Oscillibacter. Concurrently, serum metabolomics showed a widespread reduction in intermediate metabolites, indicating an accelerated anabolic flux, alongside a significant accumulation of phosphatidylinositols (PI) and secondary bile acids (e.g., taurohyocholate). Multi-omics correlations strongly linked these metabolic changes to enhanced muscle accretion and improved systemic metabolic homeostasis.Conclusions: Co-administering probiotics and exogenous enzymes synergistically mitigates PWSS. Exogenous enzymes facilitate the degradation of complex dietary fibers into fermentable substrates, which subsequently promote the growth of beneficial gut bacteria. This coordinated process specifically reshapes the gut microbiota and host systemic metabolism, directing nutritional resources toward robust growth and antioxidant defense.