The Effects of Probiotic Yogurt and Resistance Training on Body Composition and Metabolic Parameters in Post-bariatric Surgery Patients: A Randomized Controlled Trial.

Background: Bariatric surgery (BS) is an effective intervention for morbid obesity; however, it is often accompanied by undesirable muscle mass loss, which can negatively affect metabolic function and physical performance. Probiotics and resistance training (RT) have been studied discretely to address this complication. The present randomized controlled trial investigated the independent and combined effects of fortified yogurt (FY) and RT on muscle preservation and related health outcomes in post-BS patients. Methods: In this parallel, randomized controlled trial, 52 participants who had recently undergone BS and met the eligibility criteria were randomly assigned to one of four groups: group A (FY+RT), group B (FY), group C (RT), and group D (control), with 13 participants in each group. Anthropometric indices, body composition, functional performance, inflammatory and oxidative stress markers, lipid profile, and liver enzymes were measured at baseline and after a 12-week intervention. Results: All participants completed the intervention. The FY+RT group showed the greatest preservation of muscle mass, with the smallest reductions in fat-free mass percentage (-2.32%, Conclusion: The combination of FY and RT was the most effective strategy for preserving muscle mass and improving strength following BS. Further research is warranted to elucidate the underlying mechanisms and validate these findings.