Effect of lactation time and dietary patterns on human milk nucleotides: A longitudinal and cross-sectional study

Nucleotides play a crucial role in the growth and development of infants. Studying the dynamics of nucleotides variation in human milk and the influencing factors can provide insights to guide the diets of lactating mothers. The colostrum milk (CM, 0-5 d), transitional milk (TM, 10-15 d), and mature milk (MM1, 40-45 d) were collected as longitudinal study. Additionally, late term mature milk (MM2, 200-240 d; MM3, 300-400 d) were collected as the cross-sectional study. The human milk free nucleotides, including cytidine monophosphate (CMP), uridine monophosphate (UMP), guanosine monophosphate (GMP), and adenosine monophosphate (AMP), were assessed using High Performance Liquid Chromatography (HPLC), and the total potentially available nucleosides (TPAN) were calculated. The food frequency questionnaire (FFQ) was used to investigate the types and quantities of food consumed by lactating mothers. Principal component analysis (PCA) was then employed to identify their dietary patterns. The interaction of dietary patterns and lactation time on the levels of nucleotides was analyzed by factorial analysis. The levels of nucleotides in breast milk varied throughout the period of lactation. GMP and AMP decreased over time, while UMP, CMP, and TPAN decreased in the TM stage and then increased in the MM1 stage. Factorial analysis showed that lactation time affected all human milk nucleotides and an interaction of lactation time and dietary pattern could be observed on GMP and AMP. Further analysis indicated that dietary patterns influenced nucleotides during the late term mature milk stages (MM2 and MM3), while nucleotides in CM were not influenced by diet. Mothers who consumed the Beans-Nuts dietary pattern exhibited the highest nucleotides in their mature milk, followed by those who consumed the Potato-Vegetable dietary pattern. The levels of nucleotides in human milk are influenced by both the stage of lactation and maternal dietary patterns.