Human Milk α1,2-Linked Fucosylated Oligosaccharides Decrease Risk of Diarrhea Due to Stable Toxin of E. Coli in Breastfed Infants

Abstract

Breastfed infants have a lower risk of diarrhea than infants fed artificial formula. Human milk components, including oligosaccharides, inhibit pathogens in vitro and are postulated to protect infants from disease. Most human milk oligosaccharides are fucosylated. The fucose terminus may be connected by an a 1,2 linkage catalyzed by a fucosyltransferase produced by the secretor gene (FUT2), or by an α1,3 or α1,4 linkage catalyzed by fucosyltransferases produced by the Lewis gene (FUT3) or other α1,3 transferase genes (FUT4,5,6,7,9) of this family. The secretor and Lewis genes also control expression of the Lewis blood group type (Erney et al. 2000, Henry et al. 1995). Some women are nonsecretors, i.e., they do not secrete 2-linked fucosyloligosaccharides into their milk and other bodily fluids. Even among secretors, however, the expression of milk fucosyloligosaccharides varies significantly (Chaturvedi et al. 2001, Erney et al. 2000, Thurl et al. 1997, Viverge et al. 1990). Enterotoxigenic Escherichia coli that produce stable toxin (ST-E. coli) is a common cause of diarrhea; the ability of stable toxin to cause diarrhea is inhibited by human milk α1,2-linked fucosyloligosaccharides in vitro and in vivo.