Randomized controlled clinical study on proteomic analysis of skeletal muscle adaptations to high-protein nutrition in post-bariatric surgery patients with obesity

Introduction: Bariatric surgery can cause complicated metabolic and physiological changes in some patients, leading to a significant amount of loss of lean mass. The preservation of skeletal muscle mass is important for metabolic health, functional performance, and long-term weight maintenance. Proteomics provides detailed information on muscle tissue molecular responses, but can be best utilized when coupled with intentional nutritional interventions such as high-protein diets. Objective: The intent of the present study was to examine skeletal muscle proteomic responses to bariatric surgery in obese males and females using a high-protein nutrition intervention. Methods: Patients with obesity after bariatric surgery followed a standardized high-protein nutritional intervention (≥ 1.5g protein per kg per day). Muscle biopsies were taken at baseline (pre-treatment) and 12 weeks post-surgery. Muscle biopsies were taken, proteins extracted, digested, and analyzed by LC-MS-MS (label-free quantification). It used bioinformatic applications to perform differential quantitative analysis of protein expression, pathway enrichment, and functional annotation of differentially expressed proteins. Results and Conclusion: High protein nutrition resulted in upregulation of proteins associated with mitochondrial function, oxidative phosphorylation, and translation, while demonstrating downregulation of proteins representing catabolic and inflammatory pathways. Also, many of the proteomic adaptations identified were supportive of improved muscle remodelling (i.e., improved structural contractile proteins and regulators of protein synthesis). High protein nutritional support after bariatric intervention promotes advantageous skeletal muscle proteomic remodelling, which promotes retention of lean mass and recovery of metabolic status. The data also demonstrated that high-protein nutrition, after bariatric surgery, was associated with positive molecular adaptations.