Objective: Selected the model of inflammatory bowel disease(IBD) to explore the anti-inflammatory property and regulatory effect on immunity and gut microbiota of milk powder added postbiotics Probio-Eco■. Methods: Seven-week Wistar male rats were used to induce IBD model by drinking 3% (3 g/100 mL) dextran sodium sulfate (DSS) solution for 7 days. The experiment included the model group， control milk powder group and postbiotics milk powder group. The rats were gavaged with the same amount of normal saline， control milk powder and postbiotics milk powder for 14 days. The body weight， serum cytokines and histopathological changes of the rats were monitored， and the feces of the rats were collected for untargeted metabolomics and metagenomics analysis. Results: Compared with the model group， the rat weight was significantly increased (P<0.01). Histopathological analysis showed that the intestinal mucosal epithelial cells in the model group were severely damaged， and the tissue congestion and edema were obvious. Both kinds of milk powder improved after intervention. At the same time， compared with the control milk powder， the intake of postbiotics milk powder could significantly reduce the colon tissue damage score， TNF-α and IL-1β level after DSS induction (P<0.05). The metagenomic results showed that the intake of postbiotics milk powder significantly reduced the gut microbiota heterogeneity among rats， and decreased the relative abundance of Mucispirillum schaedleri and Bacteroides intestinalis， and increased Bacteroides stercoris， Lactobacillus murinus， Parabacteroides distasonis and Lactobacillus vaginalis. In addition， postbiotics milk powder significantly up- and down regulated 113 and 68 fecal metabolites， respectively. Vitamin E biosynthesis， bile acid biosynthesis， butanoate metabolism， fatty acid biosynthesis， TCA cycle and tryptophan metabolism pathways were enriched. Conclusion: postbiotics milk powder reduced the serum proinflammatory cytokines level by regulating gut microbiota and changing fecal metabolites， and finally alleviated the symptoms of IBD in rats.