Causal Associations Between Dietary Factors and Uterine Inflammatory Diseases: A Mendelian Randomization Study

Uterine inflammatory diseases, such as endometritis, are linked to infertility and adverse reproductive outcomes. We performed a two-sample Mendelian randomization (MR) study using genetic instruments for 19 dietary exposures (e.g., fruits, meats, cereals, beverages) from UK Biobank GWAS. The outcome was inflammatory uterine disease (ICD-10: N71) from FinnGen. We applied inverse-variance weighted (IVW) regression as the primary analysis, with sensitivity analyses (MR-Egger, weighted median) and pleiotropy-robust methods (MR-PRESSO). Higher dried fruit intake showed a robust inverse association with uterine inflammatory disease (IVW OR = 0.277, 95% CI: 0.154-0.498; p = 1.72 × 10^-5, FDR-q = 3.27 × 10^-4), supported by weighted median analysis. Cereal intake was nominally protective (IVW OR = 0.446, 95% CI: 0.255-0.783; p = 0.00488, FDR-q = 0.0464) but not significant in weighted median analyses. No other dietary factors (alcohol, meat, fresh fruits) reached significance. MR-Egger detected no pleiotropy (p > 0.05). This study predicted dried fruit consumption and cereal consumption may reduce uterine inflammatory disease risk, suggesting diet as a modifiable protective factor. Further studies should validate mechanisms.