Association between dietary polyphenol intake and polyphenol-utilizing bacteria in healthy adults

Dietary polyphenols are bioactive compounds with a bidirectional impact on the gut microbiome; they shape the microbial community and are transformed through bacterial metabolism. However, there are limited studies pairing metagenomic and dietary data to investigate the relationship between polyphenol intake and the taxonomic and functional profiles of the human gut microbiome. We examined if dietary polyphenol intake associates with microbial composition and polyphenol utilization capacity. Healthy adults participated in a cross-sectional study balanced for age, sex, and BMI. Polyphenol intake was previously estimated by mapping multiple 24 h dietary recalls to the Food Database (FooDB). We coupled intake with microbial taxonomic and functional profiles from shotgun-sequenced fecal metagenomes (n = 313). Microbial reads were mapped to dbPUP, a database with 60 experimentally characterized, gut-associated polyphenol utilization proteins (PUPs). We assessed the relationship of polyphenol intake on microbial diversity, abundance of microbes with PUP genes, PUP gene counts, and select lipopolysaccharide (LPS) producers, accounting for age, sex, BMI, fiber intake, and diet quality. Specific polyphenols associated with an increased abundance of nine PUP-containing genera. We found 117 associations between polyphenol intake and microbial PUP genes, with 85 associations involving hydrolysis PUPs. Diversity in polyphenol intake was positively associated with diversity in PUP genes but not with microbial diversity. Lastly, we detected a positive relationship between intake of olive-related polyphenol classes and abundance of order Bacteroidales, a producer of immunoinhibitory LPS. Dietary polyphenol intake may influence the gut microbiome's capacity for polyphenol utilization, particularly its hydrolytic activity, without impacting taxonomic diversity or composition.