Relationship Between Diet Quality, Intestinal Permeability, and Gut Microbiota Features in Individuals with Obesity

Background/Objectives: This study examined relationships between diet quality, as determined using three a priori-defined dietary patterns (Healthy Eating Index of 2010 dietary guidelines [HEI-2010], Mediterranean Dietary Pattern [MDP], and Dietary Approaches to Stop Hypertension [DASH]), intestinal permeability, and features of the gut microbiota in a diverse, obese sample. Methods: This was a post hoc, cross-sectional study including 103 healthy, obese individuals (43.8 ± 11.3 years, BMI: 37.5 ± 6.1 kg/m², 64.1% African American). Dietary intake was assessed using the Vioscreen food frequency questionnaire. Intestinal permeability was assessed via urinary sugar excretion and microbiota features were characterized using 16S rRNA gene amplicon sequencing. Relationships between dietary pattern adherence, intestinal permeability, and gut microbiota were assessed using correlation coefficients and a general linear model. Results: Higher dietary pattern scores correlated with lower levels of intestinal permeability measures such as 24 h urinary sucralose (HEI-2010: r = -0.33, p = 0.002; MDP: r = -0.31, p = 0.004; DASH: r = -0.38, p < 0.0001) and 24 h sucralose-to-lactulose ratio (HEI-2010: r = -0.23, p = 0.03; MDP: r = -0.32, p = 0.003; DASH: r = -0.24, p = 0.03). Fruit intake consistently correlated with lower intestinal permeability measures (p < 0.05) across all three dietary patterns. Higher DASH scores correlated with lower Proteobacteria (r = -0.28, p = 0.004) and higher Verrucomicrobia (r = 0.30, p = 0.002) phylum abundance. Conclusions: The current results suggest a potential role for diet quality in promoting intestinal health.