The Metabolomic Fingerprint of Obesity and Bariatric Surgery

Objectives: Obesity is associated with multiple diseases. Bariatric surgery is the most effective therapy for severe obesity that cannot only reduce body weight but also obesity-associated morbidity. The metabolic alterations associated with obesity and respective changes after bariatric surgery are incompletely understood. Material andMethods:We applied a 1H-NMR-based global, untargeted metabolomics strategy on human serum samples that were collected before and repeatedly up to one year after distinct bariatric procedures (sleeve gastrectomy, proximal and distal Roux-en Y gastric bypass; RYGB). For comparison, we also analyzed serum samples from normal-weight and less obesity obese subjects that were matched for 1- year postoperative BMI values of the surgical groups. Results: We identified a metabolomic fingerprint in obese subjects that can clearly be discriminated from that of normal-weight subjects. Furthermore, we found that bariatric surgery (sleeve gastrectomy, proximal and distal Roux-en Y gastric bypass; RYGB) dynamically affects this fingerprint in a procedure-dependent manner thereby establishing new fingerprints that can even be discriminated from those of body-mass-index-matched and normal-weight control subjects. Metabolites that largely contribute to the metabolomic fingerprints of severe obesity are e.g. aromatic and branched chain amino acids (elevated), metabolites related to energy metabolism (pyruvate and citrate; elevated), and metabolites suggested to derive from gut microbiota (formate, methanol, isopropanol; all elevated).