Alterations in the Host Defense Properties of Human Milk Following Prolonged Storage or Pasteurization
ABSTRACT Preterm infants are often fed pasteurized donor milk or mother's milk that has been stored frozen for up to 4 weeks. Our objectives were to assess the impact of pasteurization or prolonged storage at -20 degrees C on the immunologic components of human milk and the capability of the different forms of human milk to support bacterial proliferation.
The concentrations and activities of major host defense proteins in the whey fractions of mother's milk stored for 4 weeks at -20 degrees C or pasteurized human donor milk were compared with freshly expressed human milk. Proliferation of bacteria incubated in the 3 forms of human milk was assessed.
Relative to freshly expressed human milk, the concentrations of lysozyme, lactoferrin, lactoperoxidase, and secretory immunoglobulin A were reduced 50% to 82% in pasteurized donor milk and the activities of lysozyme and lactoperoxidase were 74% to 88% lower (P < 0.01). Proliferation of bacterial pathogens in pasteurized donor milk was enhanced 1.8- to 4.6-fold compared with fresh or frozen human milk (P < 0.01).
The immunomodulatory proteins in human milk are reduced by pasteurization and, to a lesser extent, by frozen storage, resulting in decreased antibacterial capability. Stringent procedure to minimize bacterial contamination is essential during handling of pasteurized milk.
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ABSTRACT: Premature births are increasing worldwide (about 15 millions per year) due to several reasons (an advanced maternal age, fertility treatments, stress, smoking, nutritional deficiencies) and lead to a high societal overall cost. Among neonatal care procedures, the clinical nutrition practices are essential to promote the development and to minimize the sequelae. Premature newborns are at major risk of death by infections due to the immaturity of their intestine. Human milk provides not only nutrients but also a plethora of biologically active components that are tailored to contribute to the development of the intestinal tract early in postnatal life. Among them, some bioactive molecules exhibit trophic effects (LC—PUFA, sphingomyelin, IGF—I and IGF—II, EGF, insulin, leptin, adiponectin, lactoferrin, lactadherin, probiotics, prebiotics, miRNA) or are part of the intestinal cell membranes (PUFA, LC—PUFA, phospholipids, sphingolipids, cholesterol), others educate the intestine for innate microbial recognition (sCD14, sTLR—2, miRNA), many of them display direct fighting against pathogens (some fatty acids and monoglycerides, some phospholipids and sphingolipids, BSSL, insulin, lactoferrin, sIgAs, MUC—1, lactadherin, probiotics, prebiotics), or contribute to establish the gut microbiota (LC—PUFA, lactoferrin, probiotics, prebiotics). A synergetic action exists between several bioactive molecules. All together these precious agents regulate the maturation of the intestinal mucosal barrier, and might program early in postnatal life the future adult intestinal health. This review lists the main bioactive compounds and addresses their plausible roles and mechanisms of action.Cellular and molecular biology (Noisy-le-Grand, France) 01/2013; 59(1):108-131. · 1.46 Impact Factor
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ABSTRACT: Abstract Although freezing is the most common method used to preserve human milk, nutritional and immunological components may be lost during storage. Freeze-drying could increase the shelf life of human milk, while preserving its original characteristics. Seventy-two samples of freeze-dried human milk were stored for different periods of time, up to a maximum of 3 months, at 4 °C or 40 °C. Vitamin C, tocopherols, antioxidant capacity, and fatty acids composition were analyzed. A new HILIC-UHPLC method improving vitamin C determination was also validated. Ascorbic acid and total vitamin C concentrations significantly decreased at both temperatures, while antioxidant capacity only decreased at 40 °C. Fatty acids composition and both γ-tocopherol and δ-tocopherol contents remained unaltered. The stability after storage of freeze-dried milk was higher than that reported for frozen or fresh milk indicating that freeze-drying is a promising option to improve the preservation of human milk in banks.International Journal of Food Sciences and Nutrition 05/2014; 65(6):1-5. DOI:10.3109/09637486.2014.917154 · 1.20 Impact Factor
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ABSTRACT: Lactoferrin is the second most abundant whey protein in human milk and is known for its functional benefits, particularly antimicrobial activities. We report a comprehensive evaluation of the published literature on quantitative changes in lactoferrin in term and preterm human milk through the course of lactation. We also considered methods used to quantify lactoferrin. We critically evaluated 94 articles on human milk with 52 meeting study inclusion criteria (2724 women). A descriptive analysis of the data was performed. Lactoferrin concentration was highest during early lactation and rapidly declined to remain relatively unchanged from 1 month to 2 years of lactation. The unweighted mean of mean (±SEM) concentrations of lactoferrin in early milk (<28 days lactation) was 4.91 ± 0.31 g/L (range of means 0.34-17.94 g/L; median 4.03). For mature milk, the mean of means was 2.10 ± 0.87 g/L (range of means 0.44-4.4 g/L; median 1.91). The majority of data were derived from Europe with fewer studies from Africa and South America. There was a paucity of data on preterm milk. This comprehensive dataset explains in detail the longitudinal changes of lactoferrin concentrations in human milk throughout the world and briefly describes factors that may influence these concentrations.Critical reviews in food science and nutrition 01/2014; 54(12):1539-47. DOI:10.1080/10408398.2011.642422 · 5.55 Impact Factor