tailieunhanh - Báo cáo khoa học: Human milk provides peptides highly stimulating the growth of bi®dobacteria

The large intestine of breast-fed infants is colonized predominantly by bi®dobacteria, which have a protective e ect against acute diarrhea. In this study we report for the ®rst time the identi®cation of human milk peptides that selectively stimulate the growth of bi®dobacteria. Several bi®dogenicpeptideswerepuri®edchromatographically from pepsin-treated human milk and identi®ed as proteolytically generated fragments from the secretory component of the soluble polyimmunoglobulin receptor and lactoferrin;. | Eur. J. Biochem. 269 712-718 2002 FEBS 2002 Human milk provides peptides highly stimulating the growth of bifidobacteria Cornelia Liepke Knut Adermann Manfred Raida Hans-Jiirgen Magert Wolf-Georg Forssmann and Hans-Dieter Zucht IPF PharmaCeuticals GmbH Hannover Germany The large intestine of breast-fed infants is colonized predominantly by bifidobacteria which have a protective effect against acute diarrhea. In this study we report for the first time the identification of human milk peptides that selectively stimulate the growth of bifidobacteria. Several bifidogenic peptides were purified chromatographically from pepsin-treated human milk and identified as proteolytically generated fragments from the secretory component of the soluble polyimmunoglobulin receptor and lactoferrin both of these proteins exhibit antimicrobial effects. Hydrolysis of the identified peptides with the gastrointestinal proteases pepsin trypsin and chymotrypsin did not lead to the loss of bifidogenic activity indicating their potential function in vivo. Sequential comparison revealed a similar structural motif within the identified peptides. A correspondingly designed small peptide prebiotic lactoferrin-derived peptide-I PRELP-I was found to stimulate the growth of bifidobacteria as effectively as the native peptides. The combination of antimicrobial and bifidobacterial growth stimulatory activity in human milk proteins leads to highly specific compounds capable of regulating the microbial composition of infants large intestine. Keywords bifidobacteria human milk intestinal microflora lactoferrin peptides. The colonization of the intestine with nonpathogenic microorganisms is essential for the health and wellbeing of the newborn. Breast-feeding creates an intraintestinal environment that favours a simple flora of bifidobacteria and few other microorganisms 1 2 . Several epidemiological studies have shown that the incidence of gastrointestinal infections is lower in infants who are .