Longitudinal analysis of short-chain fatty acid profiles in stool of sleeve gastrectomy patients.

Obesity presents significant health risks, including metabolic disorders and depressive symptoms, necessitating effective interventions such as sleeve gastrectomy (SG), which enables substantial weight loss and metabolic improvements. The primary question of this study was whether SG also affects faecal short-chain fatty acid (SCFA) profiles over 12 months, and whether these changes are related to anthropometric, biochemical, and psychological parameters. A total of 37 female patients with obesity were included in this prospective, observational study. Patients underwent SG and were followed for 12 months postoperatively. SCFA profiles were analysed by gas chromatography-mass spectrometry (GC-MS). Faecal samples for SCFA analysis, anthropometric measurements, blood biochemical markers, food intake and psychological assessments were collected at baseline and at regular intervals after surgery. Our results indicate that SG leads to significant reductions in body mass index, lipid profiles, and systemic inflammation markers, with concurrent alterations in SCFA concentrations, particularly a decrease in major SCFAs (acetic, propionic, and butyric acids) over time. An increase in branched SCFAs was observed post-surgery, which may reflect shifts in the gut microbiota composition and fermentation processes. Patients also reported improvements in emotional well-being and dietary habits. These findings support the hypothesis that SG induces changes in gut microbiota metabolism and underscore the complex interplay between bariatric surgery, gut microbiota, SCFA metabolism, and psychological health. They highlight the need for further research to clarify the long-term implications of these changes and the mechanisms involved.