A study protocol to evaluate a fermented rice bran supplement and resistance training on immune function and muscle performance in healthy older people

Introduction: Immunosenescence and sarcopenia reduce health-related quality of life in older adults by increasing the risk of infection, tumour growth, inflammatory disease, frailty, and falls risk. Strategies to protect against age-related immunological diseases and inflammatory mechanisms contributing to sarcopenia and subsequent losses in physical function are needed. We have developed a trial to evaluate the efficacy of dietary supplementation with rice bran fermented with Lentinus edodes (RBEP) and resistance training (RT) to enhance immune function, lean body mass, and muscular performance in healthy older adults. Methods: This trial will be conducted at a regional NSW university following ethics approval using a randomised, double-blind, placebo-controlled design. Sample participants will include a total 144 healthy men and women aged 60–80 years. To account for seasonal variations and circannual rhythms in immune function, data will be collected in three blocks across a 12-month period with each block involving a 12-week intervention consisting of daily ingestion of 3 g of RBEP and/or supervised, moderate intensity, whole body RT two days per week. Recruited participants in each block will be screened for inclusion/exclusion with the first 36 eligible participants distributed across four experimental groups: 1) Placebo + no RT; 2) RBEP + no RT; 3) Placebo + RT; and 4) RBEP + RT. Outcome measures will include lymphocyte proliferation, natural killer cell cytotoxicity, IL-6, TNF-α, IFN-γ, hs-CRP, body composition, muscular strength and endurance, pain score, and self-reported quality of life. Data will be assessed per-protocol within and between groups at weeks 0, 4, 8 and 12 using a mixed factorial ANOVA (treatment x condition x time) with p < 0.05. Results: We hypothesise that RBEP and RT will independently enhance immune properties and reduce systemic inflammation; while RT will also improve lean body mass and muscular fitness. A synergistic effect between RBEP is also predicted where group 4 will demonstrate greater immune and muscle performance benefits compared with groups 1–3. Discussion: This is the first trial to examine the independent effects of RBEP and combined effects of RBEP and RT on immune responses, systemic inflammation, body composition, and muscle performance in healthy older people. These results will enhance our understanding of the effectiveness of dietary and/or exercise interventions to ameliorate age-related deteriorations in the immune system and losses in physical capacity. Such findings may have implications for enhancing health status, functional independence, and quality of life in older people. Trial findings will be disseminated in peer-reviewed journals.