Objective To investigate the effect of aerobic exercise combined with silybin in improving intestinal mucosal barrier injury in mice with obstructive jaundice by activating the microRNA-21/TLR4/NF-κB pathway axis in intestinal tissue. Methods Healthy male Kunming mice were selected,and a model of obstructive jaundice was established by the method of hanging the common bile duct using an operating suture line at a right angle. The mice were randomly divided into model group( M group),exercise group( E group),silybin group( S group),and exercise + silybin group( ES group),and a sham-operation group was also established,with 10 mice in each group.After the intervention of aerobic exercise combined with intragastric administration of silybin for 7 weeks,general behavioral observation,ELISA,HE staining of ileal tissue,immunohistochemical staining,measurement of the protein and mRNA expression of intestinal tissue-related factors,and a sequencing analysis of mRNA expression profiles in liver tissue were performed to observe intervention effect. A one-way analysis of variance was used for continuous data,and the least significant difference t-test was used for comparison between groups. A multivariate analysis of variance was used to investigate the interaction effect between aerobic exercise and silybin,and a simple effect analysis was performed. Results The mice in the M group had severe jaundice on the skin of the abdomen and tail,yellow urine,and light gray feces,and laparotomy showed cystic dilatation at the bile duct suspension. Compared with the M group,the E,S,and ES groups had signif-icant reductions in the liver function parameters alanine aminotransferase,aspartate aminotransferase,and total bilirubin( F = 567. 56,1376. 09,and 512. 81,all P < 0. 001),as well as significant reductions in the plasma levels of diamine oxidase( DAO),D-lactic acid,and endotoxin( F = 650. 29,1130. 05,and 396. 04,all P < 0. 001),and there was a synergistic effect between aerobic exercise and silybin in all the above indices except DAO( all P < 0. 05). Microscopic observation showed that the M group had severe damage of the structure of the intestinal mucosa,sparse villi with different heights,a reduction in the depth of intestinal crypts,atrophy and detachment of some glands,and local infiltration of inflammatory cells and muscular atrophy. Compared with the M group,the E and S groups had significant improvements in the above pathological symptoms,and the ES group had the best intervention effect. Compared with the M group,the E,S,and ES groups had significant reductions in the mRNA and protein expression of TLR4,NF-κB,and TNFα( mRNA: F = 104. 69,153. 55,and 262. 38,all P < 0. 01; protein: F = 2683. 83,419. 73,and 572. 41,all P < 0. 01),as well as a significant increase in the expression of microRNA-21( F = 194. 58,P < 0. 01),and there was a synergistic effect between aerobic exercise and silybin in all the above indices except the expression of microRNA-21( all P < 0. 05). According to Illumina high-throughput sequencing for the screening of liver inflammation-related factors and correlation analysis,the differentially expressed factors were mainly enriched in the inflammatory pathways such as NF-κB,TGFβ,TNF,and TLR,which involved tissue cell signal transduction,apoptosis inhibition,immune response,and toxicity,and aerobic exercise and silybin significantly reduced the enrichment of inflammation and immune-related signaling pathways.Conclusion In mice with obstructive jaundice,aerobic exercise or intragastric administration of silybin for 7 weeks can exert a protective effect on intestinal mucosal barrier by upregulating the expression of microRNA-21 in intestinal tissue and inhibiting the TLR4/NF-κB signaling pathway and the release of its downstream inflammatory factors,and aerobic exercise combined with silybin has the optimal effect.