Levels of S100B protein are higher in mature human milk than in colostrum and milk-formulae milks.
OBJECTIVE
Human milk is believed to contain biological factors involved in the regulation of newborn growth, including brain development. Recently, it has also been shown to contain the calcium-binding S100B protein, regarded as a neurotrophic factor. The present study investigates the concentrations of this protein in colostrum, human milk at different levels of maturation and in milk-formulae.


METHODS
Samples for S100B measurements were collected from human colostrum (on day 1 after birth), from transition milk (on post-delivery days 7 and 14) and from mature milk (on day 30 after delivery) in 14 healthy women and from 14 milk-formulae. The S100B protein levels were measured using a commercially available specific immunoluminometric assay.


RESULTS
Mean S100B protein levels were significantly higher in mature human milk (117.9+/-36.7 microg/l) than in transition milk at 14 days (106.7+/-38.1 microg/l) and at 7 days (92.7+/-37.8 microg/l), colostrum (74.6+/-37.6 microg/l) or milk-formulae (24.8+/-19.5 microg/l) (P<0.001, for all). A correlation between human milk S100B levels and the gestational age at which samples were obtained was also found (r=0.39; P<0.01).


CONCLUSIONS
These findings, possibly related to S100B's neurotrophic role, offers useful information to the investigation of the role of S100B protein in brain maturation.
Gazzolo
Diego
D
Department of Obstetrics and Pediatrics, Giannina Gaslini Children's University Hospital, I-16147 Genoa, Italy. dgazzlo@hotmail.com
Bruschettini
Matteo
M
Lituania
Mario
M
Serra
Giovanni
G
Santini
Pierina
P
Michetti
Fabrizio
F
D000328:Adult; D001921:Brain / Q000254:growth & development* / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000032:analysis; D003126:Colostrum / Q000737:chemistry*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007225:Infant Food; D041943:Infant Formula / Q000737:chemistry*; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D008895:Milk, Human / Q000737:chemistry*; D009414:Nerve Growth Factors / Q000032:analysis*; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000032:analysis*
D002135:Calcium-Binding Proteins; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human