Hepatic Gene Response to Intravenous Glucose in Obese Patients With and Without MASLD Undergoing Bariatric Surgery

The goal of this clinical trial is to learn how the liver responds to sugar in people with obesity who are having bariatric surgery. Researchers want to understand differences between people with and without metabolic associated steatotic liver disease (MASLD). The main question is: Does giving sugar directly into the vein change how liver genes work in people with and without MASLD? Researchers will compare: * People with MASLD who receive sugar * People with MASLD who receive saline (salt water) * People without MASLD who receive sugar * People without MASLD who receive saline During surgery, participants will: * Receive either a sugar solution (35 grams of glucose in 150 mL fluid) or saline * Have small samples (biopsies) taken from the liver and fat tissue before and 45 minutes after the infusion * Provide blood samples to measure sugar, insulin, and other metabolites * Provide a one-time sample of intestinal tissue that is normally removed during surgery This study may help explain why MASLD develops and how the liver reacts to sugar. The results could lead to new ways to understand and treat liver disease in people with obesity.