Mechanism underlying the regulation of gut microbiota-metabolite axis and growth/immune function in lambs by leaf-derived polysaccharides from Taraxacum kok-saghyz.

Taraxacum kok-saghyz polysaccharide (TKP) possesses multiple biological activities and is a potential candidate for regulating lamb health. Using multi-omics analysis, this study investigated the immunomodulatory and growth-regulating effects of TKP produced from leaves (TKP-L) and roots (TKP-R) in lambs. Implementing untargeted metabolomics strategies and 16S rRNA gene sequencing we analyzed the mediating role of gut microbiota in improving lamb growth performance, has fully investigated how the gut microbiota-metabolite axis regulates immunological response and intestinal health. The average daily gain (ADG) of lambs was considerably greater in the TKP-L group than in the control group, and the levels of Growth Hormone(GH), Insulin (INS), Insulin-like Growth Factor 1 Receptor (IGF-1R), Immunoglobulin A (IgA), Immunoglobulin G (IgG), Immunoglobulin M (IgM), and TNF-α were all significantly higher (P < 0.05). In the meantime, TKP-L successfully raised the expression of intestinal mucosal mucin genes and boosted the intestinal mucosa's phase of growth. TKP-L increases the relative abundances of the microbial taxa Prevotellaceae_UCG-001, Butyrivibrio and Paraprevotella, per multi-omics analysis. Metabolomics analysis indicated that TKP-L elevated the level of argininosuccinic acid by regulating the amino acid metabolism pathway. Correlation analysis showed that TKP-L altered rumen Prevotella to activate immune cell activity, also there was a significant positive relationship between the amount of argininosuccinic acid and the overall number of Prevotellaceae_UCG-001. TKP-L may significantly improve lambs' gut mucosal barrier function and growth performance. and may achieve positive regulation of lamb growth and immune function by modulating the structure of Prevotella and mediating argininosuccinic acid metabolism.