Provides example one-dimensional proton NMR spectra of murine urine samples collected before and after bariatric or sham surgery (Roux-en-Y gastric bypass). The data are adapted from Jia V Li et al. (2011), "Metabolic surgery profoundly influences gut microbial-host metabolic cross-talk", Gut, 60(9), 1214–1223. . This package serves as example data for metabolomics analysis and teaching purposes.