This prospective, single-center pilot study will evaluate metabolic flux dysregulation in adults with obesity and suspected or confirmed metabolic dysfunction-associated steatotic liver disease (MASLD) who are scheduled for protocol-eligible bariatric surgery at Vanderbilt University Medical Center. Participants will undergo research assessments before surgery, during the planned bariatric surgery encounter, and approximately 6 months after surgery. The study uses non-radioactive stable isotope tracer infusions, serial blood sampling, abdominal MRI/MRE, and research tissue specimens collected only during clinically planned bariatric surgery to quantify hepatic and extrahepatic metabolic fluxes. The primary objective is to determine how hepatic citric acid cycle flux and related metabolic pathways change after bariatric surgery and how these metabolic measures relate to liver fat, liver stiffness, and biopsy-graded MASLD/MASH severity.
Scheduled and clinically cleared for protocol-eligible bariatric surgery at Vanderbilt University Medical Center.
BMI ≥40 kg/m², or BMI >35 kg/m² with at least one obesity-associated comorbidity, such as type 2 diabetes, cardiovascular disease, hypertension, hyperlipidemia, obstructive sleep apnea, MASLD, osteoarthritis, or polycystic ovarian syndrome.
Able and willing to complete study procedures, including informed consent, questionnaires, blood draws, MRI/MRE imaging, stable isotope tracer infusion, and research tissue collection during planned bariatric surgery.
Able to provide informed consent in English.
Contraindication to MRI/MRE, including implanted cardiac defibrillator, pacemaker, or other MRI-incompatible implanted device.
Prior gastric or intestinal surgery, pancreatic surgery, or other prior surgery that, in the judgment of the study team or bariatric surgeon, would interfere with study procedures or outcome interpretation.
Active cancer or ongoing cancer treatment.
Presence or history of HIV infection.