image title

ASU research applies Darwinian medicine to bird guts

Evolutionary medicine applies evolutionary theory to health and disease.
Studying bird health might uncover solutions for human health.
March 9, 2017

School of Life Sciences doctoral candidate Pierce Hutton says study of microbes could lead to solutions in human health

The stomach of a house finch might hold secrets to how humans absorb nutrients, age and deal with the omniprescence of nighttime light pollution.

Pierce Hutton, doctoral candidate in Arizona State University’s School of Life SciencesThe School of Life Sciences is part of the College of Liberal Arts and Sciences., is studying the gut microbiome — the cocktail of microbes in the stomach that help digest food and promote health — of house finches to answer these questions.

His research is funded by ASU’s Center for Evolution and Medicine. Evolutionary medicine, also called Darwinian medicine, is the application of modern evolutionary theory to understanding health and disease. The goal is to understand why people and animals get sick, not simply how they get sick.

Human and animal common denominators can be used to diagnose, treat and heal all species. Human and veterinary medicine are the same, if examined from an evolutionary medicine standpoint.

Two years ago, the Center for Evolution and Medicine Venture Fund was launched to finance research projects that connect evolutionary biology and topics relevant to medicine or public health. The fund is open to all ASU, Mayo Clinic faculty and students.

Hutton had questions that arose from work in the behavioral ecology lab. Working along with postdoc Mathieu Giraudeau, he studied four questions relating to the gut biome of house finches: What do carotenoids tell us about overall health? What is the effect of light pollution? What role does the gut play in aging? What role does microbe diversity play in health?

The males have bright red breasts. Those plumage colors are made by chemicals called carotenoids, which they get from their diet. The intestine is a gatekeeper, so to speak.

“We think the males might vary in how well they absorb the carotenoids,” Hutton said. “One thing that might be helping them absorb them is the gut microbiome. It’s beneficial for them to absorb them, because the plumage colors they have are evaluated by females when they’re selecting mates. It could be some microbes in the gut are helping them become sexier. We wanted to manipulate their diet and see if certain microbes get more abundant. That would tell us which ones are beneficial for uptaking those carotenoids.”

Carotenoids are also linked to health. They have important health benefits in the forms of antioxidants and immune stimulants.

“You could make some extensions to human health and biology by saying, ‘Well, if we know these microbes are beneficial for taking in these key nutrients, then it might be the same case for humans as well,’” Hutton said. “There’s the medicine angle.”

Humans have carotenoids in their bodies, and it changes their appearance too. If Caucasians eat an excessive amount of carrots, they will take on an orange hue.

Hutton and Giraudeau added carotenoids to the birds’ diet. “We did find a major effect,” he said. “’We think these microbes might be related to the uptick of those.”

A second ongoing study is looking at how light pollution affects humans and wild animals. How does living with light in our homes and outside at night affect intestinal health?

“Light pollution is a global epidemic, so we were looking at how it affects the gut microbiome,” Hutton said.

They put birds in separate rooms, one with a blue light (blue light is more disruptive to sleep than any other wavelength) that switched on at night.

Hutton is also trying to manipulate the rate of aging in house finches by regulating their gut microbiome.

DNA has strands of non-coding DNA on the ends called telomeres. They protect DNA from damage.

“As you age and as your cells divide, those end caps shorten over time,” Hutton said. “It opens up DNA to becoming damaged more quickly. There are enzymes we can target to regrow these end caps. We can essentially slow or reverse biological aging in a way. We can do this by up-regulating this enzyme that does that. ... Intestinal health and the microbiome might change as people age. It might be helpful for medicine to know how it’s aging, if it does age, those sorts of things.”

The fourth experiment looked at how the cleanliness of bird feeders affects microbiome in birds. Many people neglect to clean their backyard bird feeders, and so birds are defecating on and eating from the same surface.

“This means that both pathogenic and beneficial microbes might have an easier time colonizing new hosts,” Hutton said.

They put up bird feeders in the wild. During some periods they allowed the feeders to accumulate dirt, and other periods they cleaned them daily.

“We are expecting to see a rise in the diversity of their gut microbe community when the feeder was dirty relative to when it was clean, which might also include more pathogenic bacteria,” Hutton said. “This might connect to humans because many human populations eat under less cleanly conditions, which could lead to similar effects. It also might help us understand how the process of urbanization, and feeding wildlife, affects their gastrointestinal health.”

 

Researchers are studying house finches because human and animal common denominators can be used to diagnose, treat and heal all species, according to evolutionary medicine. Photo courtesy of Creative Commons. 

Scott Seckel

Reporter , ASU Now

480-727-4502

 
image title
Community garden at ASU Polytechnic campus teaches sustainability.
Organizer says ASU Poly community garden is ready to expand.
March 10, 2017

ASU community garden helps students understand food systems and water conservation in the desert

It’s harvest season at Arizona State University’s Polytechnic campus community garden.

Green-thumbed Sun Devils are bringing in winter crops such as peas, kale and carrots on a plot of land situated in the North Village between two rows of homes built when Polytechnic was Williams Air Force Base.

Available to faculty, staff and students, the garden has been used for capstone projects and outdoor class lessons.

Susan Norton, program manager in University Sustainability PracticesPart of University Business Services., said the garden helps students understand food systems, waste management, electricity and water conservation in the desert.

Also, “it opens the minds of students to what it means to eat local, what it tastes like, and why it is important,” she said.

 

The garden itself is a model of sustainability. Those who lease space through Norton’s program maintain it.

Norton said there’s a waiting list and that she wants to expand to a more accessible space.

“Our future goal is to move this garden to the center of campus,” she said.

Much of what the garden grows is donated to food banks, about 370 pounds so far, Norton said.

Summer crops will include tomatoes, squash and cucumber. Norton hopes students who leave the Polytechnic community growing patch after graduation will take the principles they learn about urban gardening and sustainable practices and implement those skills once they become homeowners or renters, continuing to use sustainable land-design techniques to improve their communities.

“We are trying to teach students that urban gardens are good for greening a community and give students ideas on how to be sustainable with gardening practices,” Norton said. 

Watch a video tour of the proposed expansion below.

 

Top photo: Susan Norton, program manager in University Sustainability Practices, shows Kodanda Phani Raj Dandamudi around the community garden at ASU's Polytechnic campus during the recent harvest. The community space is poised to expand, Norton says. Photo by Kenneth Fagan/ASU Now

Ken Fagan

Videographer , ASU Now

480-727-2080