Mol Nutr Food Res. 2022 Mar 22:e2100349. doi: 10.1002/mnfr.202100349. Online ahead of print.
ABSTRACT
SCOPE: Dietary polyphenols can alter the gut microbiota (GM) and promote the production of bioactive metabolites. Several indoles result of GM metabolism of dietary tryptophan have been associated with intestinal barrier integrity. Our aim was to study the changes in GM-derived indoles during a polyphenol-rich (PR) diet intervention in older adults.
METHODS AND RESULTS: Randomized, controlled, crossover trial in adults ≥60y living in a residential care facility during an 8-week PR versus control diet (n = 51). Seven GM-tryptophan metabolites were measured in serum, and metataxonomic analysis of GM was performed on fecal samples. Exploratory subgroup analyses were performed based on renal function (RF). The PR-diet significantly increased serum IPA in subjects with normal RF, but not in subjects with impaired RF. Other GM-tryptophan metabolites were not affected. Comparison of baseline GM composition showed shifts in Bacteroidales order members as well as higher abundance of Clostridiales in participants with normal RF. During the trial, variations of IPA were associated with changes in C-reactive protein (β = 0.32, p = 0.010) and GM, particularly with the Clostridiales (r = 0.35, p<0.001) and Enterobacteriales (r = -0.15, p<0.05) orders.
CONCLUSION: A PR diet increases the serum concentration of IPA in older adults with normal RF. Our findings may be important when defining appropriate dietary interventions for older adults.
TRIAL REGISTRATION NUMBER: ISRCTN10214981 (https://doi.org/10.1186/ISRCTN10214981). This article is protected by copyright. All rights reserved.
PMID:35315592 | DOI:10.1002/mnfr.202100349
