Cincinnati Children's Hospital Medical Center's latest research on breast milk is focusing on oligosaccharides - complex strings of sugar molecules that protect babies against infections.

ABOUT THE STUDY

The current cycle of the NIH Human Milk Program Project, now centered at Cincinnati Children's Hospital Medical Center, has four objectives: Identify protective factors in human milk and their effectiveness against disease. Determine how those protective factors bind to bacteria, viruses, etc., to prevent infection. Identify the genetic factors that account for individual variance in oligosaccharides and infant vulnerability to disease. Synthesize human milk oligosaccharides and test their effectiveness against specific infectious agents.

Ardythe L. Morrow, the director of the Center for Epidemiology and Biostatistics at Cincinnati Children's, says the sugar strings act as "decoys," tricking bacteria and viruses into latching onto them instead of cells in the infant's digestive tract. The sugar strings then bind to the germs and flush them out of the baby.

A study released earlier this month found that the higher the concentration of specific oligosaccharides a woman's breast milk contained, the less likely her baby was to develop diarrhea caused by campylobacter or caliciviruses - the class of viruses that includes Norwalk and the "cruise ship" infections.

Several genetic factors influence what types of sugar strings a mother's milk contains.

In general, a woman's milk protects against the types of infections her baby is most likely to encounter.

More than 100 oligosaccharides have been catalogued in human milk; researchers believe there could be as many as 1,000 or more.

Some of the structures are very simple, made up of only two or three sugar molecules. But others include hundreds of sugar molecules.

Morrow and her colleagues think the highly complex oligosaccharides are geared toward specific disease-causing agents, while the simpler sugars offer broad-based protection - much the same way as antibiotics are prescribed to fight infection.

Peggy O'Farrell