Maternal Mediterranean-style diet adherence during pregnancy and metabolomic signature in postpartum plasma: Findings from the Boston Birth Cohort

BACKGROUND:The health benefits of a Mediterranean-style diet (MSD) are well observed, but the underlying mechanisms are unclear. Metabolomic profiling offers a systematic approach for identifying what metabolic biomarkers and pathways might be affected by a MSD. OBJECTIVE:This study aimed to identify postpartum plasma metabolites that are associated with MSD adherence during pregnancy, and to further test whether these identified metabolites may vary by maternal characteristics. METHODS:We analyzed data from 1,410 mothers enrolled in the Boston Birth Cohort. A maternal food frequency questionnaire (FFQ) was administered and epidemiological information was obtained via an in-person standard questionnaire interview within 24 to 72 hours postpartum. Maternal clinical information was extracted from electronic medical records. A Mediterranean-style diet score (MSDS) was calculated using responses to the FFQ. Metabolomic profiling in postpartum plasma was conducted by liquid chromatography-mass spectrometry. Linear regression models were used to assess the associations of each metabolite with a MSDS, adjusting for covariates. RESULTS:Among the 380 postpartum plasma metabolites analyzed, 24 were associated with MSDS during pregnancy (false discovery rate; FDR <0.05). 19 out of 24 MSDS-associated metabolites were lipids (e.g., TAGs, PCs, PC plasmalogen, PS, and PE); others were amino acids (methionine sulfoxide and threonine), tropane (nor-psi-tropine), vitamin (vitamin A), and nucleotide (adenosine). The association of adenosine and methionine sulfoxide with MSDS differed by race (P for interaction = 0.033) and maternal overweight or obesity status (P for interaction = 0.021), respectively. CONCLUSION:In the Boston Birth Cohort, we identified 24 postpartum plasma metabolites associated with MSDS during pregnancy. The associations of two metabolites varied by maternal race and BMI. This study provides new insight into dietary effects on health under the skin. More studies are needed to better understand the metabolic pathways underlying the short- and long-term health benefits of a MSD during pregnancy.