Water–soluble choline compounds in human milk : their variation and impact of storage and diet.

Choline is an essential nutrient with potentially important roles for infant neurodevelopment. During infancy, choline is usually provided by milk, where is present mostly as water-soluble cholines (WSC). However, published data suggest wide variability in the WSC content with unknown cause, but maternal diet has been suggested as an explanation. It is also unclear if variability results from methodological approach or stability in expressed milk. The objective was to determine the milk WSC content and composition, to determine if variability is present and results from storage, or from expressing WSC/ml, as well as to determine WSC variability within and across women and the potential role of maternal diet. Two studies were conducted: 1) Milk expression and storage on WSC (n=6). Complete milk expressions were analyzed immediately and after different storage conditions. 2) Milk WSC intra and inter-individual variability within one day (n=20), with collection of dietary data. WSC was analyzed using LC-MS/MS and kilocalorie content with a Human Milk Analyzer. ANOVA was used to determine changes in milk WSC following different storage. Correlation analysis was used to explore associations between WSC/ml or kcal, and between maternal diet and milk WSC. Concentration of milk WSC remained similar over short term storage, and only changed when milk was stored for 6 months at -80 °C. Glycerophosphocholine was the most stable WSC;, milk phosphocholine decreased 30% and free choline increased 53 % after 4 hours of storage at room temperature. WSC content and distribution of free choline, phosphocholine and glycerophosphocholine showed wide inter-individual variability, with some women showing high variability at different times in one day. Maternal choline intake was not related to the concentration of milk water-soluble cholines. Only 20% of participants consumed the Adequate Intake=550 mg/d, with eggs as the major food source of choline in the maternal diet. In summary, individual WSC compounds are not stable in expressed milk. The milk WSC content and composition is highly variable across and within women and sampling from one point might not represent infants’ intake. This is the first study addressing the storage and maternal diet as causes for the milk WSC variability.Land and Food Systems, Faculty ofGraduat

Relationships among Different Water-Soluble Choline Compounds Differ between Human Preterm and Donor Milk

Choline is essential for infant development. Human milk choline is predominately present in three water-soluble choline (WSC) forms: free choline (FC), phosphocholine (PhosC), and glycerophosphocholine (GPC). It is unclear whether mother’s own preterm milk and pooled donor milk differ in WSC composition and whether WSC compounds are interrelated. Mother’s own preterm milk (n = 75) and donor milk (n = 30) samples from the neonatal intensive care unit, BC Women’s Hospital were analyzed for WSC composition using liquid chromatography tandem mass spectrometry (LC-MS/MS). Associations between different WSC compounds were determined using Pearson’s correlations, followed by Fischer r-to-z transformation. Total WSC concentration and concentrations of FC, PhosC, and GPC did not significantly differ between mother’s own milk and donor milk. FC was negatively associated with PhosC and GPC in mother’s own milk (r = −0.27, p = 0.02; r = −0.34, p = 0.003, respectively), but not in donor milk (r = 0.26, p = 0.181 r = 0.37, p = 0.062, respectively). The difference in these associations between the two milk groups were statistically significant (p = 0.03 for the association between PhosC and FC; and p = 0.003 for the association between FC and GPC). PhosC and GPC were positively associated in mother’s own milk (r = 0.32, p = 0.036) but not donor milk (r = 0.36, p = 0.062), although the difference in correlation was not statistically significant. The metabolic and clinical implications of these associations on the preterm infant need to be further elucidated.Medicine, Faculty ofOther UBCNon UBCPediatrics, Department ofPopulation and Public Health (SPPH), School ofReviewedFacult

Variability of Water-Soluble Forms of Choline Concentrations in Human Milk during Storage, after Pasteurization, and among Women

Choline is critical for infant development and mother’s milk is the sole source of choline for fully breastfed infants until six months of age. Human milk choline consists to 85% of water-soluble forms of choline including free choline (FC), phosphocholine (PhosC), and glycerophosphocholine (GPC). Donor milk requires safe handling procedures such as cold storage and pasteurization. However, the stability of water-soluble forms of choline during these processes is not known. The objectives of this research were to determine the effect of storage and pasteurization on milk choline concentration, and the diurnal intra- and inter-individual variability of water-soluble choline forms. Milk samples were collected from healthy women who were fully breastfeeding a full-term, singleton infantMedicine, Faculty ofOther UBCPediatrics, Department ofReviewedFacult