Metabolic Profiling of Type 2 Diabetes Patients after Bariatric Surgery by Raman Spectroscopy

Background: Bariatric surgery (BS) is an important procedure used for the treatment of morbid obesity and has been proven to improve, or even cure, type 2 diabetes mellitus (T2DM). However, of the patients with T2DM who initially go into remission, a proportion experience a relapse during the follow-up. In this context, Raman spectroscopy (RS) could be a promising technique for monitoring the metabolic profile of patients after surgical treatment with the aim of improving their postsurgical management. Methods: Fourteen obese patients with T2DM were recruited. Clinical parameters, adipokines, ghrelin, Fibroblast growth factor 19 (FGF-19) values, and Raman spectra were collected and analyzed before and after surgery. RS results were compared with profiles obtained from 23 healthy subjects (HC), to observe whether the metabolic fingerprint of bariatric patients normalized during the surgical follow-up. Results: The reduction in anthropometric measures and improved glycemic control and lipid profile after surgical treatment highlighted the benefits of BS. Consequently, adipokines, ghrelin and FGF-19 concentration returned to normal values after surgery. However, RS data highlighted an altered metabolic profile even after BS. Conclusion: RS suggests that BS does not fully restore the metabolic profile of patients in the immediate follow-up after the surgery.