Objective: This study aimed to elucidate the possible mechanism of Gest-Aid Plus Oral Liquid (GAP) on healthcare function. Method: Ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based metabolomics and 16S rDNA sequencing of gut microbiota were performed on serum and fecal samples of GAP and control rats. Additionally, short-chain fatty acids (SCFAs) and inflammatory cytokines in fecal samples were determined through gas chromatography-mass spectrometry and enzyme-linked immunosorbent assay kits. Result: Metabolomics discovered 41 metabolites, which mainly involved amino acid metabolism, lipid metabolism, coenzyme factors, and vitamin metabolism. Administration of GAP increased abundance of Prevotella_9, Alloprevotella, Blautia, Phascolarctobacterium, Parabacteroides, and Fusicatenibacter, and six SCFAs were increased in the GAP group. Measurement of inflammatory cytokines showed that GAP had an anti-inflammatory effect in rats. Conclusion: Administration of GAP greatly affects the aspartate metabolism and microecology of rats, enhances intestinal motility and gut barrier integrity and anti-inflammation. These findings not only have possible implications for further application of GAP, but also provide a link between the gut microbiome, SCFAs, inflammation and serum metabolites in rats.