Clinical Research Directory

Effects of an Elderberry-Based Functional Beverage on Exercise Performance, Muscle Structure, and the Gut-Muscle Axis

Introduction: Increasing sedentary lifestyle, microbiota imbalance and exercise-induced muscle fatigue are among the main causes of metabolic stress and performance decline, even in young individuals. The potential effects of functional foods-particularly polyphenol and anthocyanin-rich beverages-on both gut microbiota and muscle performance have attracted attention in recent years. In this context, intervention studies focused on the gut-muscle axis represent a promising and valuable area of research. Objective: This study aims to investigate the effects of a functional beverage enriched with anthocyanins and polyphenols -extracted from Sambucus nigra L. (black elderberry)- combined with a regular exercise program on muscle performance, muscle morphology, fatigue level, and gut microbiota composition in healthy individuals. Method: This 12-week double-blind, randomized, placebo-controlled trial will include participants adhering to a berry-free diet. Participants will be randomly assigned to two groups: the intervention group will consume a functional elderberry beverage formulated with high-purity anthocyanins obtained via supercritical CO₂ extraction; the control group will receive a placebo beverage with matched taste and energy content but without active compounds. Both groups will engage in a structured combined exercise program (3 days/week). Pre- and post-intervention assessments will include gut microbiota profiling (16S rRNA sequencing), short-chain fatty acid analysis, systemic biomarkers, muscle morphology (via ultrasound), exercise performance, and body composition. Mediator analyses will be used to explore the role of the gut-muscle axis in the observed effects. Unique value: This project represents one of the few human-based intervention studies systematically evaluating the interaction between functional beverages, exercise, and microbiota through the lens of muscle fiber-type-specific adaptations. Furthermore, by integrating mediator analyses and multi-level outcome measures, the study aims to elucidate the physiological relevance of the gut-muscle axis in a holistic manner. The development, standardization, and sensory evaluation of the elderberry-based beverage also contribute valuable insights to functional product innovation.