The Association between Dietary fiber intake and pelvic inflammatory disease: Findings from the NHANES 2015-2018

Background and Aim: Pelvic inflammatory disease (PID) is a common inflammatory condition, and current research suggests that changes in dietary habits may influence its development. This study aimed to investigate the relationship between dietary fiber intake and PID. Methods and Results: This study used data from the 2015-2018 National Health and Nutrition Examination Survey (NHANES), which included a total of 2,345 female participants. We employed multivariable logistic regression analysis, stratified analysis, smoothed curve analysis, threshold analysis, and saturation effects to explore the association between dietary fiber intake and PID. In the fully adjusted model, each 1-unit increase in dietary fiber intake was associated with a 5% lower odds of PID prevalence. Additionally, participants in the highest quartile of dietary fiber intake had a 69% lower prevalence of PID compared to those in the lowest quartile. The smoothed curve fitting revealed an L-shaped relationship between dietary fiber intake and PID, with an inflection point at 19.45 g/day. When dietary fiber intake exceeded this threshold, it was significantly and negatively associated with the prevalence of PID. Conclusions: There is an association between higher dietary fiber intake and lower prevalence of PID, and it is important to increase daily dietary fiber intake.