Dietary fiber intake and gallstones: The mediating role of serum lipids

Objective To investigate the mediating role of serum lipids in the association between dietary fiber intake and gallstones prevalence. Methods This study analyzed the data from 4896 adults participating in the National Health and Nutrition Examination Survey conducted between 2017–March 2020 and August 2021–August 2023. Logistic regression models and subgroup analyses were conducted to assess the correlation between dietary fiber intake and gallstone prevalence. Additionally, smooth curve fitting based on the generalized additive model was applied to elucidate nonlinear relationships. The mediating effects of lipid-related indicators, including low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, total cholesterol, non-high-density lipoprotein cholesterol, residual cholesterol, and atherogenic index of plasma were also evaluated. Results High-density lipoprotein cholesterol and atherogenic index of plasma significantly mediated the association between dietary fiber intake and gallstone prevalence, with mediation proportions of 5.06% and 4.26%, respectively (all p < 0.05). Conversely, the mediating effects of other lipid parameters (non-high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, triglycerides, and residual cholesterol) were not statistically significant. Conclusion There exists a complex relationship between dietary fiber intake, serum lipid levels, and gallstone formation, with serum lipids potentially serving as mediators. Future research should explore this mechanism in greater depth to offer new insights for the prevention and treatment of gallstones.