IL4 and gastroesophageal reflux disease: The mediation analysis results indicated that although changes in the levels of (1-enyl-oleoyl)-GPE (P-18:1), 4-methyl guaiacol sulfate, X-12730, and X-17685 are associated with the growth of IL-4 level, the evidence for their acting as potential mediators in the pathway between IL-4 and GERD risk is not sufficiently solid.