Association Between Dietary Index for Gut Microbiota and the Risk of Pelvic Inflammatory Disease: Mediating Role of Anti‐ and Pro‐Inflammatory Dietary Patterns

Recent studies suggest that an imbalance in the gut microbiota, known as dysbiosis, may affect inflammation. The Dietary Index for Gut Microbiota (DI-GM) is a new measure of dietary quality that reflects gut microbiota diversity and abundance. However, its association with pelvic inflammatory disease (PID) remains unclear. This study explored the relationship between DI-GM and the risk of developing PID. This cross-sectional study analyzed data from 4539 women aged 18-59 years obtained from the National Health and Nutrition Examination Survey (NHANES) database for the period of 2013-2018. To explore the association between DI-GM and PID, we employed weighted multivariable linear and logistic regression, restricted cubic splines (RCS), and subgroup analyses. Additionally, mediation analysis was conducted to assess the influence of anti- and pro-inflammatory dietary patterns, represented by the Dietary Inflammatory Index (DII), on the relationship between DI-GM and PID. Among the eligible participants, 255 (5.62%) had PID. A higher proportion of participants with lower DI-GM scores experienced PID. Multivariable logistic regression analysis revealed a negative association between DI-GM and the risk of PID, regardless of whether the independent variable was considered a continuous variable or in quartiles in the fully adjusted model (Model 3, continuous variable: OR = 0.87, 95% confidence interval (CI): 0.79-0.96, <i>p</i> = 0.012; Q3 vs. Q1: OR = 0.58, 95% CI = 0.36-0.94, <i>p</i> = 0.036; Q4 vs. Q1: OR = 0.55, 95% CI = 0.35-0.87, <i>p</i> = 0.017, <i>p</i> for trend = 0.018). The RCS curves demonstrated a non-linear relationship between the DI-GM scores and PID risk. Subgroup analyses indicated an inverse correlation between DI-GM and PID risk across various covariates. Mediation analysis showed that inflammatory dietary patterns accounted for 26.82% of the mediation proportion in the association between DI-GM and PID. These results indicate that higher DI-GM scores are correlated with a decreased risk of PID. Inflammatory dietary patterns may mediate the association between DI-GM and PID, suggesting that restoring gut homeostasis and health through dietary interventions may prevent or ameliorate PID.