Abstract

BackgroundReflux esophagitis (RE), a common gastroesophageal reflux disease characterized by esophageal mucosal inflammation, is closely associated with gut microbiota dysbiosis and metabolic abnormalities. The glutamine-glutamate metabolic pathway regulates inflammation and mucosal barrier function, but its role in RE and association with gut microbiota remain unclear. This study aimed to characterize gut microbiota and serum metabolites in RE patients via integrated multi-omics (focusing on the gut microbiota-glutamine axis), and verify the activation status of this pathway in RE inflammatory models and the anti-inflammatory effect of its targeted inhibition.MethodsRE patients and healthy controls (HCs) were enrolled. Fecal metagenomic sequencing and serum untargeted metabolomics (LC-MS/MS) were performed to identify differential gut microbiota and serum metabolites between the two groups, followed by Pearson correlation analysis to explore their associations. In vitro experiments were conducted on human esophageal epithelial cells (HEECs) divided into four groups: normal, inflammatory, glutamine-supplemented, and inflammatory + glutamine + glutaminase inhibitor (BPTES) groups. qPCR was used to detect the mRNA expression of glutamine-glutamate pathway molecules (GLS, c-Myc, SLC1A5), mucosal barrier markers (ZO-1, Occludin), and pro-inflammatory cytokines (IL-8, IL-6, IL-1β, TNF-α). Intracellular concentrations of glutamine, glutamate, and α-ketoglutarate were measured, and the anti-inflammatory effect of BPTES was verified.ResultsRE patients showed significant differences in gut microbiota diversity and composition compared with HCs, with Bacteroidota, Pseudomonadota, Escherichia coli, and Klebsiella pneumoniae as dominant taxa. Serum metabolomics revealed elevated glutamine and glutamate in RE patients, which were identified as key differential metabolites related to RE pathogenesis. Pearson analysis revealed that alterations in serum metabolite profiles of RE p