OXYGUT

This is an ongoing project.

The OXYGUT Study (Gastrointestinal Oxygenation and the Gut Microbiome: Implications for Weight Management after Roux-en-Y Gastric Bypass) was initiated in 2025 by Dr. sc. med. Michele Serra (PhD) and Prof. Dr. med. Dr. phil. Marco Bueter at the University Hospital Zurich as a project "Further use with consent" according to HRA chapter. 4 (art. 32-35) and HRO chapter. 3 (art. 24-40). This study is performed in collaboration with PD Dr. Felix Sommer (Universitätsklinikum Schleswig-Holstein, Germany) and Dr. Prashantha Hebbar (Meta Biosciences Pvt. Ltd., India). The study investigates how differences in oxygen availability along the gastrointestinal tract following Roux-en-Y gastric bypass (RYGB) surgery affect the composition and circadian rhythm of the human gut microbiome.

This longitudinal clinical study involves patients undergoing RYGB with varying lengths of the biliopancreatic limb, which alters the point of microbiota exposure to oxygen and nutrients. Stool samples are collected at multiple time points before and after surgery to evaluate changes in microbial composition, diversity, and temporal activity. Simultaneously, appetite-regulating hormones, and metabolic parameters are assessed to uncover links between microbial dynamics, nutritional behavior, and surgical outcome.

OXYGUT bridges clinical insights with basic microbiological research, offering a translational platform to study how environmental factors such as oxygen gradients shape gut microbial ecology and its impact on host metabolism. By integrating chronobiology and bariatric surgery research, this study aims to improve our understanding of how surgical anatomy influences microbiome-driven metabolic adaptation.

Approval for this study by the Ethics Committee of Zurich is pending.

The results of this study will be presented in 2026.