Integrated Metabolomics and Microbial Profiling in Patients with Irritable Bowel Syndrome

This study was conducted to identify metabolic and gut microbial changes associated with the pathophysiology of irritable bowel syndrome (IBS) by comparing the plasma/urinary metabolite profiles and gut microbiota composition between healthy controls (HC) and IBS patients. There was no significant difference in overall microbial diversity; however, IBS patients showed relatively higher abundance of <i>Christensenellaceae</i> R-7 group, <i>Clostridium</i> sensu stricto 1, and <i>Negativibacillus</i>. Metabolite analysis identified statistically significant differences in 34 plasma metabolites (VIP > 1.2, <i>q</i> < 0.05). Metabolite set abundance analysis indicated that commonly disturbed metabolic pathways in both plasma and urinary metabolites were mainly related to carbohydrate, amino acid, and fatty acid metabolism. Among these metabolic pathways, fatty acid metabolism was associated with three metabolites that showed significant correlations with the discriminating gut microbial features, namely <i>Clostridium</i> sensu stricto 1, <i>Negativibacillus</i>, and <i>Klebsiella</i>. This study demonstrated that integrating the three datasets-plasma metabolites, urinary metabolites, and gut microbial communities-provides a comprehensive overview of IBS pathophysiology. Together, these findings indicate that functional interactions between discriminative gut microbial features and systemic metabolic alterations, particularly within fatty acid metabolism, may represent a mechanistic link between gut dysbiosis and the metabolic manifestations of IBS.