The physiological effects of intrinsic and isolated arabinoxylans on human immunometabolic response: A systematic review and meta-analysis.

Whole grains and dietary fibers like arabinoxylan (AX) are crucial for human health. However, randomized controlled trials on AX-rich supplements show inconsistent outcomes, with ambiguous explanations. This study aims to differentiate the impact of foods rich in intrinsic versus isolated AXs on immunometabolic profiles. A systematic search of databases including Embase, Scopus, PubMed, and Web of Science (up to August 4, 2024). Evidence certainty was assessed using GRADE. Thirty randomized controlled trials involving 1140 participants were included in the meta-analysis. Intrinsic AXs effectively reduced fasting blood glucose (standardized mean differences [SMD]: -0.44; 95 % CI: -0.75, -0.13; p = 0.005; I = 60 %) and systolic blood pressure (mean differences [MD]: -2.86; 95 % CI: -5.45, -0.27; p = 0.03; I = 0 %). More pronounced reductions in fasting blood glucose levels (SMD: -0.25; 95 % CI: -0.48, -0.03; p = 0.03; I = 0 %) were observed for individuals with overweight and obesity. The isolated AX(OS)s reduced fasting blood glucose (SMD: -0.19; 95 % CI: -0.36, -0.02; p = 0.03; I = 0 %) and total cholesterol (MD: -0.14; 95 % CI: -0.27, -0.01; p = 0.03; I = 0 %) levels, while increasing the lymphocyte count (MD: 3.52; 95 % CI: 0.75, 6.29; p = 0.01; I = 28 %). Attenuated fasting blood glucose levels were particularly pronounced for isolated AX(OS)s in norm weight individuals (SMD: -0.24; 95 % CI: -0.45, -0.02; p = 0.03; I = 0 %). Together, the findings of this meta-analysis emphasized the necessity of distinguishing between intrinsic and isolated AXs in dietary interventions affecting immunometabolism, which was also associated with participant characteristics. It provides clinical evidence for fiber related precision nutrition therapy in the future.