Maternal prenatal urinary metabolites associate with infant food allergy

Abstract Background Interplay between the maternal diet and gut microbiome may impact fetal immune development and allergic disease risk. This study investigated associations between maternal prenatal urinary metabolites and infant food allergy and then extended to potentially relevant dietary and microbial precursors. Methods We investigated 599 mother–infant dyads from an Australian population‐derived prebirth cohort. Maternal dietary data and fecal and urine samples were collected in the third trimester. NMR was used to measure prenatal urinary metabolites. Infant food allergy status was determined at 1 year by skin prick allergy testing and food challenge. Regression techniques were used to investigate associations and adjust for pre‐specific confounding factors. Results Higher concentration of hippuric acid in maternal urine, an end‐product of dietary polyphenol metabolism, was associated with a lower risk of infant food allergy (odds ratio (OR) 0.62 (95% CI 0.42, 0.93)). Consistent with this, dietary proanthocyanidins, a polyphenol, were positively associated with both higher urinary hippuric acid concentration (0.11 log units, CI 0.01, 0.22) and lower risk of infant food allergy (OR 0.58 (CI 0.36, 0.96)). Maternal carriage of the gut commensal Prevotella copri , previously associated with protection against infant allergic disease, was associated with 21% higher urinary hippuric acid concentrations (CI 4%, 40%, corresponding to 0.19 log units CI 0.04, 0.34); however there was no evidence of mediation. Conclusion Further studies are required to confirm whether higher dietary intake of proanthocyanidins during pregnancy is associated with protection against allergic disease in the infant via gut microbiome production of hippuric precursors and other immune‐active metabolites.