The researchers found large variations from woman to woman in both the number and type of oligosaccharides present. For instance, the total number varied for each individual from 33 to 124. Lebrilla suggests that this might be due to the different times during lactation at which each sample was taken, but that data was not gathered as a part of the study.

However, Lebrilla did find an intriguing consistency: regardless of the variation among the women, 60 percent of all oligosaccharides had a specific component, called fucose, that is known to bind to the cell walls of bacteria. It's a finding that Lebrilla did not expect but which may help explain exactly how oligosaccharides might ward off diseases in infants.

"The goal here is to say, If milk is the perfect food, what about milk makes it perfect?" says Lebrilla. "So once we've figured out which components are important, I think you'll start to see the synthesis of these things for human milk."

Artificial-milk companies have been searching for the perfect baby formula for decades, adding vitamins and nutrients such as omega-3 and omega-6 to cow's milk, as well as decreasing naturally present levels of sodium, which has been shown to increase the risk of dehydration and diarrhea. Even with increasing knowledge of the composition of human breast milk, researchers like Michael Kramer, professor of pediatrics at McGill University, say we're not even close to replicating nature. Kramer is encouraged by Lebrilla's results, however, and he sees applications for adults as well as for infants.

"This could lead to new discoveries about these pathogenic bacteria and viruses themselves, which could lead to the development of antivirals and new drugs," he says. "It's a ways off, but we could see this work in protecting infants that could also protect adults from the common cold."

For now, Lebrilla's lab is looking at a much wider sample of lactating women and analyzing the presence of oligosaccharides from specific lactation periods. In the future, he plans to study other factors, such as diet, race, and what makes human breast milk unique among all mammalian species. Down the line, he also hopes to use the chip to see which oligosaccharides interact with which bacteria--a line of research that may one day lead to not only improved baby formula, but also better nutrients for adults.