ST. LOUIS -- Researchers at Washington University have received $5.5 million from the Bill and Melinda Gates Foundation to study childhood malnutrition.

Dr. Jeffrey Gordon with the university's medical school is leading the three-year effort. He said Tuesday that the researchers are studying babies in the African nation of Malawi and Bangladesh in East Asia to determine if malnourished children have a different mix of intestinal microbes than healthy infants in the same areas.

The scientists previously established a link between obesity and friendly microbes in the intestine. They studied gut microbes in lean and obese twins for findings that support the idea that differences in the microbes contribute to obesity risks.

Friendly microbes in the intestine help the body "digest food, detoxify certain things we ingest and influence the expression of certain genes that control how energy is processed," Gordon explained.

Now they'll seek to determine if the organisms also contribute to severe malnutrition. The hope is to better understand some of the underlying complexities that relate to severe malnutrition, beyond a lack of adequate food. For instance, the researchers say it's not uncommon for a family with multiple children to have only one malnourished child, even though all are eating a similar diet.

The malnutrition research will focus on twins ages six months to 2 years, in which one or both are severely malnourished, as well as healthy twins as a comparison. Both identical and fraternal twins will be studied because of their similar genetic backgrounds and because they share the same early environment.

Malnourished babies will be given a nutritionally enriched food supplement. Researchers will use fecal samples to extract microbial DNA to monitor the microbes in the gut before, during and after the treatment. They'll also analyze microbes from the twins' mothers to see if the microbes have been transmitted to their children.

Gordon is working with the university's Dr. Mark Manary, who has spent more than two decades treating malnourished children in Malawi, and colleagues at the University of Colorado in Boulder. The group is also working with the International Center for Diarrheal Disease Research in Dhaka, Bangladesh.

Meanwhile, researchers at the University of Virginia in Charlottesville will investigate if the twins in the study have alterations in their human genes that regulate nutrient transport and processing.

Microsoft Corp. founder Bill Gates and his wife, Melinda, lead the nation's largest charitable foundation. The Seattle-based foundation focuses donations largely on global health, agriculture development and education.

Ellen Piwoz, the senior program officer for the foundation's global health program, said while much is known about malnutrition, the hope with the Washington University grant and others like it would be to develop new solutions.

"We know even when we treat infection and improve diet, we still have instances of undernutrition," she explained.

Gordon said researchers received word of the grant award last year and got funding earlier this year. They hope to finish the first phase of their work in 2011, he said.