February 2, 1995: Vol26n15: Human milk may protect against diarrhea

By LOIS BAKER
News Bureau Staff
New findings by research teams at UB and the Shriver Center for Mental
Retardation in Boston indicate that a carbohydrate found in breast
milk may provide protection against a form of diarrhea that poses a
serious health threat to children in developing countries.
	Their study, published in the December issue of The Journal of
Nutrition, shows that fucose-containing oligosaccharides can prevent a
toxin produced by the bacteria Escherichia coli from initiating the
biochemical reaction in the small intestine that results in diarrhea.
	John K. Crane, UB assistant professor of medicine and lead
researcher on the study, said the discovery implies that breast milk
contains elements other than maternal antibodies that protect against
infectious organisms. "If laboratory results can be duplicated in
humans, the carbohydrate could be added to infant formula to help
prevent diarrhea," Crane said.
avid S. Newberg senior scientist at the
	Shriver Center, Crane's collaborator on the current study,
earlier had identified the human-milk carbohydrate that protected
against the E. coli toxin, using mice as a model, but did not
determine its method of action. Crane's study was designed to find out
how the protective mechanism worked and if it occurred in human cells.
	Using a human intestinal-cell line, the researchers discovered
that the carbohydrate acts by binding to the receptors for the toxin
STa in the intestinal wall, which prevents the toxin from stimulating
guanylate cyclase, an enzyme that initiates the diarrhea process.
	They were able to measure how much was needed to block
guanylate-cyclase activity in response to the STa toxin.
	"The findings indicate that a baby receiving .8 liters of
breast milk a day theoretically could be protected against a large
inoculation of E. coli," Crane said. Infants not exclusively
breast-fed likely would be protected in proportion to the amount of
breast milk consumed.
	"Further purification and characterization of the active
material may allow scientists to synthesize a novel oligosaccharide
antagonist for the toxin, which could have considerable utility in the
treatment or prevention of diarrhea caused by toxin-producing
E. coli," Crane stated.
	The work was completed while Crane was at the University of
Texas-Houston. Investigators participating in the study, in addition
to Crane and Newberg, were Shabnam S. Azar and Annick Stam from the
University of Texas-Houston.