Bioavailability of orange juice (poly)phenols: β-glucan-rich oat bran decreases urinary excretion of flavanone phase II metabolites and enhances excretion of microbiota-derived phenolic catabolites

Pereira-Caro, G., Almutairi, T. M., Cáceres-Jiménez, S., Moreno-Rojas, J. M., Malkova, D. , Garcia, A. L. and Crozier, A. (2023) Bioavailability of orange juice (poly)phenols: β-glucan-rich oat bran decreases urinary excretion of flavanone phase II metabolites and enhances excretion of microbiota-derived phenolic catabolites. Free Radical Biology and Medicine, 199, pp. 34-43. (doi: 10.1016/j.freeradbiomed.2023.02.002) (PMID:36764628)

Abstract

The impact of β-glucan-rich oat bran on the bioavailability of orange juice (OJ) flavanones was investigated. Volunteers consumed 500 mL of OJ with and without 22 g of oat bran containing 6 g of β-glucan (OB-6). Urine collected 12 h prior to and over a 0–24 h period post-supplementation was analysed by UHPLC-HRMS. Sixteen flavanone metabolites and thirty-nine colon-derived phenolic catabolites were identified and quantified. The major compounds were hesperetin-3′-glucuronide, along with hippuric acids and the C6–C3 phenolic acids 3-(3′-hydroxy-4′-methoxyphenyl)hydracrylic acid and 3-(4′-hydroxy-3′-methoxyphenyl)propanoic acid. A marked reduction in the 0–24 h excretion of flavanone metabolites from 29.7 μmol (9.3% recovery) to 9.3 μmol (2.9% recovery), occurred following consumption of OB-6 compared to OJ. This appeared not to be an effect of fiber on the rate of transport in the upper gut. After consumption of OJ there was a 163 ± 15 μmol excretion of colon-derived phenolic catabolites, equivalent to 43% of (poly)phenol intake and following OB-6 intake there was a further significant 30% increase. The β-oat bran in OB-6 contained 5.8 μmol of free and 52 μmol of bound phenolic derivatives compared to 371 μmol of OJ (poly)phenols. The elevated excretion of phenolics after OB-6 consumption appears not to be due to bound phenolics in the bran, rather it is consequence, principally, of a bran-mediated increase in the quantities of flavanones passing from the upper to the lower bowel where they were subjected to microbiota-mediated catabolism.

• Item Type: Articles
• Additional Information: Funding: T.M.A., A.C. and G.P.-C are grateful for support by the Distinguished Scientist Fellowship Program (DSFP) at King Saud University, Riyadh, Saudi Arabia. G.P.-C. was supported by a postdoctoral research contract “Programa Emergia 2020” funded by the Secretaría General de Universidades, Investigación e Innovación, Junta de Andalucía. S.C.-J. is supported by a predoctoral fellowship funded by the Spanish Ministry of Universities (FPU20/03549).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Malkova, Dr Dalia and Crozier, Professor Alan and Garcia, Dr Ada
• Authors: Pereira-Caro, G., Almutairi, T. M., Cáceres-Jiménez, S., Moreno-Rojas, J. M., Malkova, D., Garcia, A. L., and Crozier, A.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Free Radical Biology and Medicine
• Publisher: Elsevier
• ISSN: 0891-5849
• ISSN (Online): 1873-4596
• Published Online: 09 February 2023
• Copyright Holders: Copyright © 2023 Elsevier Inc.
• First Published: First published in Free Radical Biology and Medicine 199:34-43
• Publisher Policy: Reproduced in accordance with the publisher copyright policy