Antimicrobial protein and Peptide concentrations and activity in human breast milk consumed by preterm infants at risk of late-onset neonatal sepsis

Objective: We investigated the levels and antimicrobial activity of antimicrobial proteins and peptides (AMPs) in breast milk consumed by preterm infants, and whether deficiencies of these factors were associated with late-onset neonatal sepsis (LOS), a bacterial infection that frequently occurs in preterm infants in the neonatal period. Study design: Breast milk from mothers of preterm infants (≤32 weeks gestation) was collected on days 7 (n = 88) and 21 (n = 77) postpartum. Concentrations of lactoferrin, LL-37, beta-defensins 1 and 2, and alpha-defensin 5 were measured by enzyme-linked immunosorbent assay. The antimicrobial activity of breast milk samples against Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Streptococcus agalactiae was compared to the activity of infant formula, alone or supplemented with physiological levels of AMPs. Samples of breast milk fed to infants with and without subsequent LOS were compared for levels of AMPs and inhibition of bacterial growth. Results: Levels of most AMPs and antibacterial activity in preterm breast milk were higher at day 7 than at day 21. Lactoferrin was the only AMP that limited pathogen growth >50% when added to formula at a concentration equivalent to that present in breast milk. Levels of AMPs were similar in the breast milk fed to infants with and without LOS, however, infants who developed LOS consumed significantly less breast milk and lower doses of milk AMPs than those who were free from LOS. Conclusions: The concentrations of lactoferrin and defensins in preterm breast milk have antimicrobial activity against common neonatal pathogens

Variation in fat lactose and protein in human milk over 24h and throughout the first year of lactation

Fat in human milk is extremely variable and can represent up to 50 % of infant energy intake. To accurately determine milk composition and infant intake at 1 (n 17), 2 (n 17), 4 (n 17), 6 (n 15), 9 (n 6) and 12 (n 5) months of lactation, samples of fore- and hind-milk were collected from each breast at each feed over 24 h periods from an initial group of seventeen women. The content of fat in milk varied over 24 h, with a mean CV of 47·6 (SE 2·1) % (N 76) AND 46·7 (se 1·7) % (n 76) for left and right breasts respectively. The 24 h amounts of fat, lactose and protein in milk differed between women (P=0·0001), but were consistent between left and right breasts. Daily milk production differed between breasts (P=0·0001) and women (P=0·0001). Accordingly, amounts of fat (P=0·0008), lactose (P=0·0385) and protein (P=0·0173) delivered to the infant over 24 h also differed between breasts and women (P=0·0001). The energy content of milk and the amount of energy delivered to the infant over 24 h were the same between breasts, but differed between women (P=0·0001). The growth rate of a group of only six infants in the present study was not related to either the concentrations or amounts of fat, lactose, protein and energy in milk over the first 6 months of life. These results show the individuality of milk composition and suggest that only a rigorous sampling routine that takes into account all levels of variation will allow the accurate determination of infant intake of fat, lactose, protein and energy

Longitudinal changes in breastfeeding patterns from 1 to 6 months of lactation

Objective: The most common reason given for discontinuation of exclusive breastfeeding is perceived insufficient milk supply. Breastfed infants show more variation in feeding frequency than bottle-fed infants, and this may lead to a mother lacking confidence in her milk supply if the frequency of breastfeeding sessions does not match expectations based on bottle feeding. We aimed to assist clinicians in supporting breastfeeding mothers by providing evidence-based information on expected changes in breastfeeding patterns and milk intake during exclusive breastfeeding for 6 months.Subjects and Methods: Mothers and their healthy infants who were exclusively breastfeeding (total 24-hour milk intake within the normal range) were studied during two to five 24-hour periods between 1 and 6 months of lactation.Results: Between 1 and 3 months of lactation, the frequency of breastfeeding sessions decreased, whereas both the median and maximum breastmilk intakes during each breastfeeding session increased. These parameters remained constant between 3 and 6 months. The duration of each breastfeeding session decreased steadily from 1 to 6 months, but the total 24-hour milk intake remained constant.Conclusions: Breastfeeding becomes more efficient between 1 and 3 months of lactation, although milk intake remains constant. Clinicians can give mothers confidence that these changes in breastfeeding behavior do not indicate insufficient milk supply, but may be a result of the increase in the stomach capacity of the infants and are an expected outcome of a healthy, normal breastfeeding relationship

Anatomy of the lactating human breast redefined with ultrasound imaging

The aim of this study was to use ultrasound imaging to re-investigate the anatomy of the lactating breast. The breasts of 21 fully lactating women (1–6 months post partum) were scanned using an ACUSON XP10 (5–10 MHz linear array probe). The number of main ducts was measured, ductal morphology was determined, and the distribution of glandular and adipose tissue was recorded. Milk ducts appeared as hypoechoic tubular structures with echogenic walls that often contained echoes. Ducts were easily compressed and did not display typical sinuses. All ducts branched within the areolar radius, the first branch occurring 8.0 ± 5.5 mm from the nipple. Duct diameter was 1.9 ± 0.6 mm, 2.0 ± 90.7 mm and the number of main ducts was 9.6 ± 2.9, 9.2 ± 2.9, for left and right breast, respectively. Milk ducts are superficial, easily compressible and echoes within the duct represent fat globules in breastmilk. The low number and size of the ducts, the rapid branching under the areola and the absence of sinuses suggest that ducts transport breastmilk, rather than store it. The distribution of adipose and glandular tissue showed wide variation between women but not between breasts within women. The proportion of glandular and fat tissue and the number and size of ducts were not related to milk production. This study highlights inconsistencies in anatomical literature that impact on breast physiology, breastfeeding management and ultrasound assessment

Identification of nestin-positive putative mammary stem cells in human breastmilk

10.1007/s00441-007-0390-xCell and Tissue Research3291129-13