摘要Background:Qiwenghuangbo powder(QP),composed of Astragalus,Phellodendron chinensis,and Radix pulsatilla,is a traditional Chinese herbal formula,but its effects on weaned piglets remained unclear.Methods:Weaned piglets fed with 0.5 kg/t QP(QP1),1 kg/t QP(QP2),low-zinc oxide(ZnO;negative control),and high-ZnO(positive control)diets in two phases,respec-tively,and the growth performance,intestinal morphology,cytokines,and microbial communities were profiled.The mouse models of colitis induced by Citrobacter roden-tium and dextran sulfate sodium(DSS)were employed to elucidate the potential role of QP-fed enriched key species.Results:Dietary 1.0kg/t QP alleviated diarrhea and inflammation and improved intes-tinal development and growth performance of weaned piglets.Moreover,this dietary intervention notably altered microbiota composition,characterized by the enrich-ment of Limosilactobacillus reuteri.Furthermore,out of three isolated L.reuteri,two strains could alleviate pathogen infection and intestinal inflammation,respectively.Specifically,the anti-inflammatory effect of one strain was achieved by promoting the colonization resistance of C.rodentium as significantly reduced pathogen loads.The other strain mitigated DSS-induced colitis by enhancing the goblet cell function and inhibiting the secretion of pro-inflammatory cytokines,particularly interleukin-1β(IL-1?)and tumor necrosis factor-α(TNF-α).Conclusions:Dietary QP improved the growth performance and intestinal health of weaned piglets by promoting the colonization of L.reuteri.The isolated commensal L.reuteri control colitis in a strain-specific mechanism,highlighting the potential of QP and L.reuteri in providing evidence for gut health promotion.