CHARLOTTESVILLE, Va. (CBS19 NEWS) -- Almost half of all deaths of children under the age of five are associated with childhood undernutrition, and a new tool could help scientists better understand its effects.

Researchers at the University of Virginia School of Medicine have created a model that looks at the effects of undernutrition on the microbiome inside the gut and how that in turn impacts a child’s growth and the development of the immune system.

According to a release, scientists often study the complex interactions of the microbes that naturally live inside the human gut by taking samples from the microbiome and moving them into lab mice.

The researchers have learned that they could significantly improve the effectiveness of that work by introducing the microbes into the mice when they are very young.

It’s called “intergenerational colonization,” and the researchers say it better mimics the effect of undernutrition during early childhood.

“We believe this new model will help us investigate many of the major challenges facing undernourished children, including higher rates of infection and changes in cognitive development,” said Carrie A. Cowardin, PhD, part of UVA’s Department of Pediatrics. “Our current studies are using this system to identify specific microbes that impact development, with the goal of using these microbes as therapies to promote healthy growth.”

Using this new model, researchers have found that unweaned mice with microbes from children with impaired growth also suffered from stunted growth.

The mice also developed immune system responses similar to the ones seen in human children.

Comparatively, when the microbes are introduced into older mice, the effects were less similar to what is seen in people.

The release says this suggests that this new approach offers a better way to study childhood undernutrition.

Additionally, the results align with previous research that suggests infancy is a critical period shaping the health and strength of the immune system.

The researchers say this new model should help scientists and doctors better understand the underlying biological causes of stunted growth and the other harmful impacts of undernutrition in developing countries.

That could then advance efforts to develop new approaches to prevent such impacts, resulting in children living longer and healthier lives.

“We hope this work also allows us to answer fundamental questions about how the microbiome interacts with our own cells to shape the course of development,” Cowardin said. “Growth stunting due to undernutrition is a really difficult problem facing global child health, and the lessons we learn will likely apply to many other conditions as well.”

Cowardin is part of UVA’s TransUniversity Microbiome Initiative, which brings together researchers from across the university to explore the role of the microbiome in human health, expanding understanding of the microbiome to better treat and prevent disease.

Her lab is part of the UVA Health Children’s Child Health Research Center.

The new model has been described in the scientific journal Microbiome.