Healthy dietary patterns are associated with the gut microbiome in the Hispanic Community Health Study/Study of Latinos

Background: Dietary patterns high in healthy minimally processed plant foods play an important role in modulating the gut microbiome and promoting cardiometabolic health. Little is known on the diet–gut microbiome relationship in US Hispanics/Latinos, who have a high burden of obesity and diabetes. Objective: In a cross-sectional analysis, we sought to examine the relationships of 3 healthy dietary patterns—the alternate Mediterranean diet (aMED), the Healthy Eating Index (HEI)-2015, and the healthful plant-based diet index (hPDI)—with the gut microbiome in US Hispanic/Latino adults, and to study the association of diet-related species with cardiometabolic traits. Methods: The Hispanic Community Health Study/Study of Latinos is a multi-site community-based cohort. At baseline (2008-2011), diet was assessed by using 2, 24-hour recalls. Shotgun sequencing was performed on stool samples collected in 2014-17 (n = 2444). Analysis of Compositions of Microbiomes 2 (ANCOM2) was used to identify the associations of dietary pattern scores with gut microbiome species and functions, adjusting for sociodemographic, behavioral, and clinical covariates. Results: Better diet quality according to multiple healthy dietary patterns was associated with a higher abundance of species from class Clostridia, including [Eubacterium] eligens, Butyrivibrio crossotus, and Lachnospiraceae bacterium TF01-11, but functions related to better diet quality differed for the dietary patterns (e.g., aMED with pyruvate:ferredoxin oxidoreductase, hPDI with L-arabinose/lactose transport). Poorer diet quality was associated with a higher abundance of Acidaminococcus intestini and with functions of manganese/iron transport, adhesin protein transport, and nitrate reduction. Some healthy diet pattern-enriched Clostridia species were related to more favorable cardiometabolic traits such as lower triglycerides and waist-to-hip ratio. Conclusions: Healthy dietary patterns in this population are associated with a higher abundance of fiber-fermenting Clostridia species in the gut microbiome, consistent with previous studies in other racial/ethnic groups. Gut microbiota may be involved in the beneficial effect of higher diet quality on cardiometabolic disease risk.