Longitudinal changes in choline concentration and associated factors in human breast milk

Background: Human breast milk is the primary source of choline and choline-containing compounds for infants at early stages of life. Choline data across lactation in Chinese human milk were limited. Objective: This study aimed to quantify the five choline compounds in Chinese human breast milk and explore associated factors. Methods: A total of 540 lactating mothers from the MUAI (Maternal Nutrition and Infant Investigation) study were included. The content of water-soluble choline (free choline, phosphocholine, glycerophosphocholine) and lipid-soluble choline (phosphatidylcholine, sphingomyelin) in 892 human milk samples collected from 0 to 400 days postpartum were examined, and associated factors were explored. Results: Choline concentrations in human milk varied from postpartum day 0-400 (92.06 & PLUSMN; 65.22 to 171.01 & PLUSMN; 47.84 mg/L). Water-soluble choline was the major component (88.6%-93.8%) in human milk and ranged from 793.03 (659.22) to 1544.43 (443.32) mmol/L. Its trajectory followed that of total choline, increasing from colostrum to transitional milk and then declining in mature milk. In contrast, lipidsoluble choline accounted for 6.2%-11.4% over lactation and had an opposite trajectory. Choline composition varied by delivery mode and parity history. Conclusion: The concentrations of individual choline and choline-containing compounds during lactation in Chinese human breast milk were described for the first time. Our results address gaps in extant Chinese human milk choline data and support tailored dietary reference intakes for Chinese lactating women and infants. Our data describes the level and profile of choline from 0 to 400 days postpartum in Chinese human breast milk. This is the most updated data on choline and also the first report of watersoluble choline as the predominant type in Chinese human milk. Our results compensate for the deficiencies in data on choline in Chinese human milk. Clinical trial registration: Clinical Trial Registry number: ChiCTR1800015387. Web link to study on registry: https://www.chictr.org.cn/index.aspx. & COPY; 2023 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Automated summary

This study describes the concentration changes of individual choline and choline-containing compounds in Chinese human breast milk for the first time. Results show that water-soluble choline is the major component, with concentrations increasing from colostrum to transitional milk and then declining in mature milk, while lipid-soluble choline has the opposite trajectory. Delivery mode and parity history also influence choline composition.