
Inside the Mind of researcher Dave Dallas
Dave Dallas, the endowed director of the Moore Family Center for Whole Grain Foods, Nutrition and Preventive Health, explores how milk impacts infants and works to optimize their health.
What made you decide to get into your field? Is there one specific moment that inspired your career path?
As an undergraduate, I studied biology and was planning to go to medical school. In my attempts to be well prepared for medical school, I took a broad array of courses that would be related. One of those courses was nutrition. I became fascinated by nutrition and soon realized that it was far more interesting to me than a medical career.
I wanted to have big impacts on health by improving nutrition. When applying for graduate school in nutrition, I met a professor at UC Davis, Bruce German, who convinced me that studying milk was the ideal way to understand nutrition, because milk is the only food that has evolved over millions of years to nourish the suckling infant. Every component of milk has a benefit to the infant. That concept really excited me, and I have been studying the components of human and bovine milk and their functions ever since.
What does your current research entail?
My research group examines human and bovine milk and how they are digested in infants and adults.
We mostly focus on milk's hundreds of bioactive proteins. We examine which of these survive during digestion and which release functional components called peptides.
We then study how these components interact with cells in the gut, including intestinal epithelial cells, immune cells and bacteria. We have identified many milk peptides with functions including antibacterial, immunomodulatory and antioxidant.
We also examine how these peptides differ between infants born at term and those born prematurely (<37 weeks gestation), because these infants have decreased digestive capacity and increased risks for infections and other problems.
Recently, we have been examining best practices for processing donor human milk for premature infants. Preterm infants are typically given some donor milk because their lactating parents often do not produce enough, and human milk is known to decrease infection risks, among other benefits. But this milk must be pasteurized first to reduce potential bacterial pathogens.
The current pasteurization methods using heat for donor milk cause degradation of a wide array of important bioactive proteins. We are applying alternative, non-thermal processes to allow milk safety, including high pressure processing and UV-C irradiation.
We have shown that both of these alternative processes provide much better preservation of key milk proteins than heat-based pasteurization. Now, we are carrying on a study in premature human infants to evaluate how well the better preservation of proteins from high-pressure processing results in improved fat absorption in these infants compared to heat-based pasteurization.
What inspired you to focus on this research area?
I was inspired to focus on milk because it is the product of over 250 million years of evolution to nourish the infant. No other food is like that. We can learn so much about nutrition by studying milk.
How does your work make a difference?
My work will help increase understanding of the biology of human milk and how it affects infants, and the same for bovine milk and adults.
My work will lead to changes in how we feed premature infants so that we provide them milk components in their optimal forms to enhance their health outcomes.
My work is helping to guide how we process human donor milk, which can lead to direct changes in practice that could affect the growth trajectory and health outcomes of thousands of infants.
Are there any exciting upcoming projects or goals you're working toward?
We are currently working on proposals to study how high-pressure processing and ultraviolet-C treatment of human milk can lead to improvements in fat and protein absorption and growth in premature infants. That work is essential to move the field forward to changing practices in donor milk processing.
How do you collaborate with other researchers, either within the college or internationally?
I have wonderful collaborators at OSU, including Joy Waite-Cusic in Food Science and Technology (working on microbial safety of milks), Adam Higgins in Bioengineering (working on novel devices for processing human milk), Gerd Bobe in Animal Sciences (collaborating on statistical analyses), and Si Hong Park in Food Science and Technology (examining the effects of milk components on the microbiome). I collaborate with the OSU Mass Spectrometry Center run by Claudia Maier for analysis of milk compounds. Many others as well!
Outside of OSU, I collaborate with Brian Scottoline a neonatologist at Oregon Health and Sciences University to collect samples from the gut of preterm and term infants and Sarah Andres a gut physiologist at OHSU to examine how milk components affect the intestinal cells.
I also collaborate with Yimin Chen at the University of Idaho to examine the impacts of milk peptides on intestinal epithelial cells.
What’s the best advice you’ve ever received, and who gave it?
Try, try and try again. I learned that in grad school from my advisor. It applies to experiments, manuscript submission and especially grant writing. The key is to not get discouraged when you fail, and just keep trying.
What are your favorite activities outside of work?
I love training and playing with my dog, gardening, reading, hiking and traveling.