Release Date: December 7, 1994 This content is archived.
BUFFALO, N.Y. -- New findings by a research team from the University at Buffalo 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, M.D., Ph.D., 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.
Crane collaborated in the research with David S. Newburg, senior scientist at the Shriver Center, who earlier 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. The current 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 of the milk oligosaccharide 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 inoculum of E. coli," Newburg 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 Newburg, were Shabnam S. Azar and Annick Stam from the University of Texas-Houston.