Impact of Wheat Aleurone on Biomarkers of Cardiovascular Disease, Gut Microbiota and Metabolites in Adults with High Body Mass Index: a randomized control trial.. Aleurone human feeding trial

PURPOSE: Aleurone is a fraction of cereal grain that contains a variety of beneficial nutrients including polyphenols, fibers, minerals and vitamins. Evidence from animal and human studies supports the beneficial role of aleurone consumption against cardiovascular disease, particularly linked to decrease of plasma homocysteine, an emerging biomarker of atherosclerosis. Aleurone fermentation by the gut microbiota may mediate physiological effects of aleurone. This study evaluated whether wheat aleurone added to bread, biscuits and breakfast cereal modifies cardiovascular, metabolic and microbial biomarkers. METHODS: A parallel double-blind, placebo-controlled and randomized study was carried out in obese/overweight subjects (n=34) and in age-, BMI- and gender- matched subjects (n=33) who consumed either aleurone (AL) supplemented foods (27g/day) or placebo cellulose (PL) for 4 weeks (NCT02067026).RESULTS: Both AL and PL increased dietary fiber intake, while PL increased animal protein intake. A significant increase in faecal Bifidobacterium spp in AL only and a significant increase in Lactobacillus spp both in AL and PL were observed, despite little change in gut microbiota structure was found by 16S rRNA sequencing. No significant changes in plasma biochemistry and anthropometric markers were observed. Using high resolution LC-MS untargeted metabolomics a number of distinctive biomarkers of host:microbiota co-metabolism of aleurone/wheat bran were identified. Correlation analysis highlighted bacterial genera that might be linked with urinary compounds derived from aleurone metabolism. CONCLUSIONS: Aleurone shows potential to modulate the gut microbiota and especially its metabolic output, but in this study we did not observe a statistically significant reduction in homocysteine or other physiological markers measured.