Efficacy of prophylactic ursodeoxycholic acid in preventing gallstone formation after metabolic bariatric surgery: an updated systematic review and meta-analysis of randomized controlled trials protocol

Background and objectives: Rapid weight loss following metabolic bariatric surgery (MBS) is associated with an increased risk of developing de novo gallstone formation. The aim of this systematic review and meta-analysis is to evaluate the efficacy of prophylactic ursodeoxycholic acid (UDCA) in preventing gallstone formation after MBS and to provide evidence-based recommendations. Methods: This systematic review will be conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. We will conduct a meta-analysis of randomized controlled trials evaluating prophylactic UDCA after MBS. The following databases will be searched: PubMed/MEDLINE, the Cochrane Central Register of Controlled Trials, Embase via Ovid, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform. Reference lists of the included trials and reviews will be manually screened for additional trials. Adults without preexisting gallstones will be enrolled to evaluate prophylactic UDCA versus placebo or no treatment. Two reviewers will conduct study selection, data extraction, and risk-of-bias assessment (Cochrane RoB 2.0). A third reviewer will resolve disagreements. Pooled risk ratios will be calculated using a random-effects model. Heterogeneity will be assessed using the I 2 statistic, and results will be presented as forest plots with subgroup analyses and UDCA dose. Exploratory meta-regression analyses will assess the potential influence of baseline body mass index (BMI) and patient age on treatment effects. Result: This review will synthesize the available randomized controlled trial evidence regarding prophylactic UDCA after metabolic bariatric surgery. Planned analyses include the evaluation of gallstone prevention efficacy, subgroup analyses according to bariatric procedure type and UDCA regimen, and an exploratory assessment of patient-related factors such as baseline BMI and age. Conclusion: This protocol outlines the methodology for an updated systematic review and meta-analysis evaluating prophylactic UDCA after MBS. The planned review aims to provide a comprehensive synthesis of the current evidence to help inform postoperative prophylactic strategies and future clinical guidelines.