Treating the Cow to Save the Kid: Where Human and Animal Health Intersect
People fighting hunger in the developing world have noticed a troubling mystery: malnourished children sometimes fail to get healthier even when given a lot of extra nutrients.
The key to helping them may be to focus not on the kids, but on their cows, according to a team led by a University of Washington professor.
The researchers from UW, Washington State University and CDC-Kenya just received a Gates Foundation grant to examine the values of a holistic approach—one that focuses on the intersection of human, animal and environmental health.
“You can’t just look at the pigs or just look at the chickens or just look at the people. You have to look at how we’re all interacting on an increasingly crowded planet,” said Peter Rabinowotz, associate professor of environmental and occupational health sciences at UW.
‘One Health,’ One Science
The paradigm, called One Health, emerged in part from recent disease scares and outbreaks, such as SARS and swine flu, in which microorganisms have crossed species boundaries. But scientists have broadened it, applying it to their thinking about other ways humans, animals and ecosystems interact.
For example, animals can present early warnings of environmental problems. They may be more susceptible to something like toxic pollution (think six-legged frogs), and can be sentinels of threats to human health.
“It’s the whole concept of a canary in the coal mine,” said Rabinowitz. “If we only monitor the humans. we’re going to miss this very important signal.”
A Gut-Level Connection
The Bill and Melinda Gates Foundation’s Grand Challenges in Global Health program targeted proposals that use One Health thinking to tackle persistent problems.
Rabinowitz and his collaborators secured money to take their work to rural Kenya where villagers live and work side-by-side with animals.
They’ll be looking carefully at how the humans and animals share microorganisms, but not quite in the way someone studying bird flu might. The question has to do with the colonies of bacteria and other organisms that inhabit the gut, skin and mouths of both humans and animals—our microbiome.
What if an animal’s microbiome and a human’s actually influence each other?
A Malnutrition Mystery
Rabinowitz says malnutrition affects one-third or more of children under age 5 in some of the places he plans to work. And many go right on starving, even when they get nutrition supplements.
Rabinowitz hypothesizes that imbalances in a child’s gut biome could prevent the child from absorbing needed nutrients. Gut bacteria are key players in the digestive and metabolic process, breaking down nutrients and allowing the body to process them.
The grant will allow his team to explore how much sharing of microbiota is going on between kids and cattle, and “if this sharing is in any way related to problems with the [children’s] microbiome becoming out of balance,” he said.
And here’s where Rabinowitz’s team wants to double down on the One Health concept: They think the link might not just explain the problem, but could hold the key to solving it. And the intervention they propose might not even touch the child directly.
Treat the Cow, Save the Kid
The human-animal medicine project wants to explore whether “resetting” the microbiome of the cows could then help heal the children’s dysfunctional gut flora. That, in turn, might improve their ability to take in nourishment.
“This whole concept of One Health is that sometimes helping the animals may be a way to help the people, sometimes helping the people may be a way to help the animals,” Rabinowitz said. “We’re looking for win-win solutions that ideally benefit both the humans and the animals, and the environment.”