Pilot Study of Salivary Bile Acids and Pepsin as Predictive Biomarkers of Reflux Disease After Sleeve Gastrectomy

The goal of this observational study is to learn whether bile acids and pepsin in saliva can help identify adults at higher risk of developing reflux-related esophageal disease after sleeve gastrectomy, including Los Angeles grade B-D erosive esophagitis and Barrett's esophagus. The study will include adults undergoing sleeve gastrectomy as part of their regular clinical care. Participants will be evaluated before and after surgery and will serve as their own comparison group over time. The main questions it aims to answer are: Are saliva bile acids and pepsin linked to Los Angeles grade B-D erosive esophagitis or Barrett's esophagus after sleeve gastrectomy? How do saliva bile acids and pepsin change before and after sleeve gastrectomy? Can saliva bile acids and pepsin become useful biomarkers for detecting reflux-related esophageal disease after sleeve gastrectomy? Are saliva biomarker levels linked to reflux symptoms and endoscopy results after surgery? Researchers will compare saliva biomarker levels before and after surgery and between participants with and without reflux-related esophageal disease. Participants will: Provide saliva samples before surgery and at 12 and 36 months after surgery Provide fasting and post-meal saliva samples Undergo routine postoperative clinical follow-up and upper gastrointestinal endoscopy Complete reflux symptom questionnaires during follow-up The study will also explore whether saliva biomarkers could help select participants for follow-up endoscopy after sleeve gastrectomy.