Dietary Index for Gut Microbiota and Leisure Time Physical Activity: The Potential Combined Protective Impact on Hypertension Risk

Emerging evidence highlights the gut microbiome's role in hypertension via microbial metabolites and endothelial dysfunction, while the Dietary Index for Gut Microbiota (DI-GM) quantifies diet quality for microbiota health. In addition, leisure-time physical activity (LTPA) also reduces blood pressure, but their combined impact on population-level hypertension remains unclear. Therefore, this study explores the individual and joint effects of DI-GM and LTPA on hypertension risk. To address this objective, we conducted a cross-sectional study analysis of data from 27,643 adults in the National Health and Nutrition Examination Survey (NHANES 2007-2020). Excluding individuals with incomplete data, key variables included the DI-GM and LTPA pattern (categorized by intensity, frequency, and regularity; regularly active defined as > 2 days/week). Weighted logistic regression models and restricted cubic splines (RCS) evaluated independent, joint, and non-linear associations of DI-GM and LTPA with hypertension, adjusting for covariates. The results showed that higher DI-GM scores and greater weekly LTPA were inversely correlated with hypertension risk, exhibiting dose-dependent patterns (16% lower odds for DI-GM ≥ 6 vs. lowest groups; 16%-24% lower odds for LTPA (≥ 150 min/week) vs. lowest groups). RCS analysis showed a linear inverse dose-response relationship between DI-GM and hypertension. The regularly active LTPA pattern (> 2 days/week) was linked to a 24% lower risk of hypertension (OR = 0.76, 95% CI = 0.69-0.84), and there was also a significant association observed for the weekend warrior LTPA pattern (1-2 days/week) (OR = 0.80, 95% CI = 0.64-0.99). Notably, joint analysis demonstrated that individuals with DI-GM > 4 scores and LTPA ≥ 150 min/week or regularly LTPA pattern exhibited the lowest hypertension odds. In conclusion, both a high DI-GM score (≥ 6 points) and sufficient LTPA (≥ 150 min/week) were independently associated with reduced odds of hypertension, with their combined effect amplifying protective benefits. Prospective studies are warranted to confirm temporality and causal pathways.