Human milk composition jc

Human milk composition

1. Journal club Human milk composition- Nutrient and bioactive factors

2. Authors : Olivia Ballard,Ardythe L Morrow Journal: Pediatric clinics of North America: Breast feeding Updates for the Pediatricaian . Morrow and Chantry February 2013,Volume 60,Number 1

3. Introduction: EBF for 6 months with continued breastfeeding for 1-2yrs of life is normative standard for infant feeding.` Human milk is uniquely suited to human infant in nutritional and bioactive factors that promote survival and healthy infant. Human milk composition is dynamic . ` WHO.infant and young children nutrition.Geneva:WHO;2003

4. Briefly reviews nutritional a components of human milk and provides overview of varied bioactive factors . Discuss impact on human milk with storage and pasteurization .

5. Stages of lactation: Colostrum Transitional milk Mature milk

6. Studies on human milk composition: Gold standard for milk collection involves sampling of all milk expressed over 24 hrs,with collection over time multiple times from same individual` ` Bauerj,Gerss.Longitudinal aanalysis of macro and mineral in human milk.Clin Nutr 2011;30(2)215-20

7. Nutritional components Nutritional components derived from 3 sources Synthesis in lactocyte . Dietary in origin Maternal stores

8. Macronutrients: V aries with mothers and across lactation Macronutrient composition is conserved across population despite variation in maternal status. After 4 months of postpartum associated with :maternal wt for ht,protein intake ,parity and nursing frequency and return of mensturation .` Higher quantity of milk lower conc. of fat and protein but higher concentration of lactose ` ` Nommsen LA et al.Determinants of energy,protein,lipid in humam milk in first 12 months of lactation:the DARLING Study.Am J Nutr 1991;53(2):457-65

9. Proteins: Term mature milk:0.9-1.2g/dl Predominantly whey and casein . Most abundant proteins are- casein,a-lactoalbumin,lactoferrin,sIgA,lysozyme and serum albumin. Non protein nitrogen compounds- urea,uric acid , creatinine,aa,nucleotides (25% of human milk nitrogen) Concentration is not affected by maternal diet,but increases with weight for height and decreases in mother producing more milk.

10. Changes in casein content as a percentage of total protein ( ie , ratio of whey protein to casein) in 2 mothers during lactation Bo Lönnerdal Am J Clin Nutr 2003;77:1537S-1543S

11. Fat: Term mature milk:3.2- 3.6gm/dl. High conc of palmitic and oleic acid Highly variable macronutrient-foremilk and hindmilk Significantly lower in night and morning compared to afternoon and evening` 25% variation in lipid concentration between mothers can be explained by maternal protein intake. ` Kent JC, Mitoulas LR, Cregan MD, Ramsay DT, Doherty DA, Hartmann PE. Volume and frequency of breastfeedings and fat content of breast milk throughout the day.  Pediatrics . 2006;117(3):e387–395 .

12. Fatty acid profile varies in relation to maternal diet particularly LCPUFA. LCPUFA intake in western is predominantly w-6,sup optimal w-3 fatty acids. DHA composition in human milk is low in N American population,supplementation to be considered for breast feeding women .

13. Carbhoydrate : Predominant sugar lactose 6.7-7.8gm/dl Least variable of macro nutrients Higher quantity in mothers producing more milk Oligosaccharide 1gm/dl bioactive factor

14. Micronutrients: Vary depending on maternal diet and body stores including Vit A,B1,B6,B2,B12,D and iodine. Maternal diet is not always optimal so continuing multivitamins during lactation is recommended.` Vit K and Vit D low quantity in human milk. `Greer FR. Do breastfed infants need supplemental vitamins?  Pediatric clinics of North America.2001;48(2):415–423.

15. Bioactive components: Elements that affect biologic processes or substrates and hence have an impact on body function or condition. Secreted by mammary epithelium,produced by cells in milk,drawn from maternal blood. 1.Growth factors . 2.Immunologic factors.

16. Growth factors Epidermal growth facto r:intestinal maturation and repair. Neuronal growth factors: BDNF,GDNF:growth and development of the enteral nervous system. Insulin like growth factor superfamil y:tissue growth

17. VEGF :regulation of vascular system Erythropoetin :Intestinal development and prevention of anaemia . Calcitonin and somatostatin: growth regulating hormones. Adiponectin :regulating metabolism and body composition.

18. Immunologic factors Cells of human milk :Macrophages,T cells,stem cells and lymphocytes Cytokines and chemokine s:TGF superfamily,G -CSF,IL 7,IL 10/pro infalmmotory-TNF-a,IL-6,IL-8 and interferons . Acquired and innate factors: sIgA,defensins-lactoferrin,lactoadherin,BSSL,MFG . HOMS :prebiotics

19. Storage and pasteurization: HTST ,Holder pasteurization(LTLT),Flash method. Heat treatment reduces bioactive components. Reduction in sIgA,lyzozyme,cytokines,lipases,TGF-B,adiponectin . More damage with multiple freeze thaw cycle LTLT method more damaging than HTST method

20. Conclusion: Many studies of human milk composition have been conducted ,components of human milk are still being identified. Standardised multipopulation studies of human milk composition are needed to create rigorous comprehnsive reference values.

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