Association Between Diet Quality Linked to Gut Microbiota and Cardiovascular Risk Among South Asian Adults: A Cross-Sectional Study

Background Cardiovascular disease (CVD) is a significant public health issue worldwide that depends on various lifestyle and metabolic factors. Emerging research suggests that dietary patterns affecting the gut microbiota may influence cardiovascular risk. Nevertheless, not much research has been conducted on this relationship within South Asian communities. This study investigates the relationship between diet quality, as defined by patterns associated with gut microbiota in prior literature, and modifiable cardiovascular risk factors among South Asian adults. Methods This cross-sectional study was conducted from January to May 2025 in Pakistani community clinics and health centres. The study employed convenience sampling and recruited 385 South Asian adults. The participants were questioned using a structured questionnaire, and their demographic data, Global Diet Quality Questionnaire (GDQQ, Pakistan version), and INTERHEART Modifiable Risk Score (IHMRS) were obtained. Although gut microbiota was not directly assessed, diet quality was inferred to be linked with microbial changes based on previously validated dietary patterns in microbiome research. Both GDQQ and IHMRS have been validated in South Asian populations, with IHMRS demonstrating strong predictive performance (AUC > 0.75). Age categories used in the analysis included six groups: 18-24, 25-34, 35-44, 45-54, 55-64, and 65 years and older. The data were analysed using SPSS v.26, and associations between diet quality and cardiovascular risk were assessed using descriptive statistics, t-tests, analysis of variance (ANOVA), Pearson's correlation, and multivariable linear regression controlling for age, gender, physical activity, and comorbidities. Results Females had a significantly higher mean GDQQ score (M = 49.94, SD = 6.23) than males (M = 48.03, SD = 7.89), p < 0.001. Diet quality was inversely associated with cardiovascular risk (r = -0.827, p < 0.001). Multivariable regression confirmed that higher GDQQ scores were a strong independent predictor of lower IHMRS (β = -0.827, p < 0.001) after adjusting for key confounding variables. Significant relationships were also found between age and self-reported physical activity, as well as dietary quality and risk scores, using appropriate tests (t-tests, ANOVA, Pearson correlation). However, the use of convenience sampling may introduce selection bias and limit the generalizability of the results. Conclusion This study demonstrates an inverse correlation between diet quality, which is linked to gut microbiota based on previous evidence, and cardiovascular risk among South Asian adults. Older people had better diet quality, which was associated with reduced risk, whereas younger adults had a higher chance of poor diet and higher risks. These findings support the potential for culturally tailored dietary interventions targeting microbiome-related pathways to reduce the CVD burden in this region. However, the gut microbiota link is inferred, and further research involving direct microbiome assessment is warranted.