Abstract
BACKGROUND: Limited research has been conducted on the effects of dietary fiber (DF) intake on gallstones. We aimed to investigate the actual DF intake in a nationally representative sample in the United States (US) and explore its association with gallstones. METHODS: We used data from the National Health and Nutrition Examination Survey database, including the 2017-2020 and 2021-2023 cycles. Using participants' gallstone histories and their average 2-day DF intake, we investigated the actual DF intake among US adults. After adjusting for traditional confounders, we used weighted multivariable logistic regression models, trend tests, spline curve fitting, subgroup analyses, and interaction tests to explore the independent association between DF intake and gallstones. RESULTS: A total of 8,782 participants were included. The weighted analysis showed the prevalence of gallstones is 10.03%. The average DF intake among adult men and women is 18 ± 10 g/day and 15 ± 7.8 g/day, respectively, which is well below the recommended levels. Multivariable regression analysis revealed a statistically significant negative linear association between DF intake and gallstone prevalence. For every 10 g/day increase in DF intake, the risk of gallstones significantly decreases by 21% (OR = 0.79, 95% CI: 0.63-1.00, P = 0.047). Curve fitting showed a negative linear relationship between these two variables (P = 0.003, P for non-linearity = 0.134). CONCLUSION: A negative linear relationship between DF intake and gallstones among adults in the US was observed, and the current DF intake in the US is far below recommended levels.