Association between dietary polyphenol intake and polyphenol-utilizing bacteria in healthy adults.
Level 4 - case-series / case-control
Cross-sectional observational study
PubMed 42300105 · doi:10.1039/d6fo00158k
What was done
Researchers evaluated the cross-sectional association between dietary polyphenol intake and the gut microbiome in 313 healthy adults balanced for age, sex, and BMI. Polyphenol consumption was estimated from multiple 24-hour dietary recalls mapped to the Food Database (FooDB). Fecal samples underwent shotgun metagenomic sequencing, and reads were mapped to dbPUP, a database of 60 gut-associated polyphenol utilization proteins (PUPs). Analyses assessed microbial diversity, PUP gene counts, abundance of PUP-containing genera, and lipopolysaccharide-producing bacteria, adjusting for age, sex, BMI, fiber intake, and diet quality.
What was found
Specific dietary polyphenols were linked to increased abundance of nine PUP-containing bacterial genera. The authors identified 117 associations between polyphenol intake and microbial PUP genes, with 85 involving hydrolysis PUPs. Diversity in polyphenol intake was positively associated with PUP gene diversity but not with overall microbial taxonomic diversity. Additionally, intake of olive-related polyphenol classes was positively associated with the relative abundance of the order *Bacteroidales*. Exact effect sizes, correlation coefficients, and p-values were not reported in the abstract.
Why it matters
This study provides metagenomic evidence that dietary polyphenol variety relates to functional bacterial capacity for polyphenol metabolism—particularly hydrolysis—even when overall microbiome community diversity remains unchanged.
Limits
The cross-sectional design cannot establish causality. Dietary intake relied on self-reported 24-hour recalls and database estimations. The functional analysis was limited to 60 characterized reference proteins in dbPUP, and clinical or metabolomic outcomes were not measured.
Cited by
- supports Fruits and vegetables provide polyphenols and non-nutrient compounds that feed the gut microbiome.