This meta-analysis and trial sequential analysis (TSA) investigated the effects of probiotic supplementation on triglyceride levels in patients after bariatric surgery. A comprehensive literature search identified seven randomized controlled trials involving 411 participants. The meta-analysis revealed a significant reduction in triglyceride levels favoring probiotic supplementation (mean difference = - 18.46 mg/dL, 95% confidence interval [- 29.73, - 7.2], p = 0.001) with no heterogeneity (I