Nutritional and immunological characteristics of fresh and refrigerated stored human milk in Hong Kong: A pilot study

Background: The nutritional and immunological qualities of human milk from Hong Kong mothers were profiled. Methods: A total of 25 colostrum (≤3 days postpartum) and 11 mature (30-45 days postpartum) milk specimens were collected from healthy Chinese women in Hong Kong. Parameters including total protein, whey, casein, triglycerides, lactose, lysozyme, secretory immunoglobulin A, lactoferrin and antibacterial activity of human milk were quantified. Result: Breast milk of Hong Kong Chinese mothers is nutritionally comparable to that of western mothers for colostrum and mature milk, with protein (25.0 ± 11.3. g/l vs 10.1 ± 1.4. g/l) and lactose (44.2 ± 7.5. g/l vs 66.6 ± 5.5. g/l) for growth and energy supply in infants, respectively. The milk of Hong Kong mothers is however characterized by its exceptionally high levels of sIgA (806.3 ± 792.6. mg/dl and 1545.9 ± 334.6. mg/dl) and low levels of triglycerides (10.8 ± 9.3. mmol/l and 11.1 ± 7.7. mmol/l). The human milk in Hong Kong was also shown to be superior to bovine formula milk, particularly in terms of lower total protein level, the high whey to casein protein ratio, rich immunological active contents, and significant antibacterial activity against 2 common Escherichia coli strains. Conclusions: Preliminary data also indicated that mature milk could be refrigerated for at least 3 days in order to maintain the major nutritional constituents and antibacterial activity.