This study investigates the plasma metabolic effectiveness from 3.3g mixed linkage barley or oat β-glucan fibre per day by 1H NMR spectroscopy on plasma samples and multivariate data analysis. Three large-scale extracted, equally sized but structurally different β-glucans were tested in a blinded randomised cross-over design using young healthy adults, where the β-glucans were compared to a non-fibre control during a 21day dietary intervention period. Subject variance was found to dominate the metabolomics data although the variations in subject age and BMI were very small. The second most influential variation was found to be due to gender as characteristic lipoprotein profiles were found for male and female samples. The 3.3g/day did not perturb the blood homeostasis in healthy adults as no systematic differences between 3-week β-glucan treatments and control were found. The present study constitutes the first metabolomic β-glucan human intervention study which proves complementary and confirmatory with respect to previous nutritional investigations evaluating traditional cardiovascular disease risk markers.