Discovery and Validation of Gut Microbiome Features Associated with Dietary Patterns in U.S. Black/African and Hispanic/Latino Populations.

BACKGROUND

Large-scale studies examining dietary patterns and gut microbiome have focused predominantly on European ancestry populations; evidence from other ancestry groups remains limited.

OBJECTIVES

We conducted a two-stage study to evaluate associations of multiple dietary patterns with gut microbiome diversity and composition among Black/African American adults and validate significant findings in a Hispanic/Latino population in the US.

METHODS

Included were 514 Black participants from the Southern Community Cohort Study (SCCS) and 2,133 participants from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Diet was collected by food frequency questionnaires or 24-h dietary recalls at cohort enrollment. Gut microbiome profiling was performed by shotgun metagenomic sequencing of stool samples collected during cohort follow-up. Five dietary patterns - Healthy Eating Index (HEI), Dietary Approaches to Stop Hypertension (DASH), Empirical Dietary Inflammatory Potential (EDIP), Empirical Dietary Index for Hyperinsulinemia (EDIH), and Ultra-Processed Foods (UPF) - were examined for associations with microbiome diversity and composition by linear regression after data transformation and confounders adjustment. Microbial taxa with FDR<0.1 and their constituent lower-level features identified in SCCS were targeted for validation in HCHS/SOL.

RESULTS

In SCCS, HEI, DASH, EDIP, or EDIH were associated with the relative abundances of 14 microbial taxa, primarily members of families Coriobacteriaceae and unclassified Firmicutes, as well as species Lactococcus lactis and Clostridium sp. AF20-17LB . Among these, the inverse associations of genus Collinsella and its species C. aerofaciens with HEI or DASH were validated in HCHS/SOL (all P <0.05). Additionally, Collinsella and C. aerofaciens were associated with higher odds of obesity in SCCS (BMI≥ 30 kg/m2; OR [95%CI]:1.24 [1.01, 1.53] and 1.32 [1.07, 1.63], respectively).

CONCLUSIONS

Healthier dietary patterns were consistently associated with lower abundances of Collinsella and C. aerofaciens in Black/African and Hispanic/Latino Americans. Further research should clarify causal pathway linking diet, gut microbiome, and health outcomes across diverse populations.