Maternal Chrono-Nutrition and Placental DNA Methylation: The BiSC Study.

The impact of diet during pregnancy on birth outcomes and child health is well established, and epigenetic changes may be one mechanism underlying such associations, but the role of meal timing (chrono-nutrition) is unclear. We conducted an epigenome-wide association study (EWAS) of maternal meal timing and placental DNAm (plaDNAm). Data came from 389 pregnant women in the Barcelona Life Study Cohort (BiSC). Chrono-nutrition and dietary data were collected at 20 weeks of pregnancy, and plaDNAm at delivery was characterized using the Illumina EPIC array. Linear robust regression models tested associations between five chrono-nutritional behaviors (time of first and last meal, nighttime fasting duration, number of eating occasions, and eating jetlag) and plaDNAm. We identified 7 CpGs significantly associated with time of last meal (Bonferroni p < 1E-08) and 63 suggestive CpGs (p < 1E-05). Hits included cg13147785 (E2F8), linked to placental cell cycle regulation, cg17665505 (DAP) and cg18303215 (ABCG5), associated with smoking and lung diseases in adults. To conclude, maternal chrono-nutrition was associated with some CpGs in the placenta, particularly time of last meal. Further studies are needed to clarify how meal timing may influence fetal development and long-term health through epigenetic mechanisms.