Effects of short-term, high-dose cocoa-derived flavanol supplementation on gut microbiota composition: secondary findings from a randomized, double-blind, placebo-controlled crossover study.

Cassandra Suther, Billie Alba, Beau R Yurkevicius, Patrick N Radcliffe, Heather S Fagnant, John Castellani, J Philip Karl

Journal: Journal of nutritional science 2025;13():e22

PMID: 39776521

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The gut microbiota plays a crucial role in human health, and prebiotics—substances selectively used by gut microbes to confer health benefits—are one approach to improving its composition. This randomised, double-blind, placebo-controlled crossover study examined the effects of short-term high-dose cocoa-derived flavanol (CDF) supplementation (900 mg/day) on gut microbiota composition in healthy adults. Participants received either CDF or a placebo for eight days, followed by a two-week washout before switching conditions. Results showed that CDF supplementation led to lower gut microbiota diversity, indicating a reduction in rare microbial species. However, it did not significantly increase the absolute or relative abundance of beneficial bacteria such as Lactobacillus or Bifidobacterium. The authors concluded that further research is needed to explore the prebiotic potential of CDF, including the optimal dose and duration required to produce beneficial effects.

Abstract

Cocoa-derived flavanols (CDF) may act as prebiotics. However, evidence is inconsistent, and the duration and dose of CDF intake needed to elicit any prebiotic effect are undefined. This randomized, double-blind, crossover study determined the effects of short-term, high-dose dietary supplementation with CDF versus matched placebo on gut microbiota composition in 8 healthy adults. A single faecal sample was collected 8 d after supplementation with 900 mg/d CDF or placebo. Gut microbiota composition and spp. and spp. abundance were measured as secondary outcomes by 16S ribosomal ribonucleic acid (rRNA) amplicon sequencing and quantitative polymerase chain reaction, respectively. No between-treatment differences in the relative or absolute abundance of spp. (Cohen's = 0.89, = 0.22) or spp. (Cohen's = 0.42, = 0.65) were detected. Shannon diversity (Cohen's = 0.38, = 0.04) and overall community richness (Cohen's = 0.34, = 0.06) were lower following CDF supplementation versus placebo, but no between-treatment differences in β-diversity or taxa relative abundances were observed. Findings are not consistent with a clear prebiotic effect of this short-term, high-dose CDF supplementation strategy relative to placebo.

© The Author(s) 2024.

Address: Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA.; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA.; Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA.; Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA.

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