Milk Bioactives and Functional Glycobiology Programs Graduate David Sela Awarded Prestigious Kinsella Dissertation Prize


By: Natalie Telis

Dr. Sela characterizes himself as a microbiologist “straddling the gap between pure and applied science.” His primary interests are in the relationship between food, intestinal microbiota, and their host. He began his career as a scientist with an undergraduate degree in molecular biology. His interest has always been mechanistic: the methods of life’s pathways and regulatory systems. When he was applying to graduate programs, he had to make the decision between a program in food microbiology and pure microbiology. He decided that in an applied program, he would be able to gather the best of both worlds. He joined the Mills Lab and quickly became interested in the research areas of the Milk Bioactives and Functional Glycobiology Programs, which became the flagship programs of the Foods For Health Institute.

Dr. Sela’s new research article focuses on the relationship between milk bioactives – compounds found in milk with biological activities that promote health – and the gut microbiota population. The ability to metabolize oligosaccharides, or complex sugar molecules, from human milk seems unique to microbiota that tend to colonize the intestinal tracts of breastfed infants. Some subspecies of Bifidobacteria, which are among the microbiota that normally colonize the infant human intestinal tract, have extensive genetic resources dedicated to human milk oligosaccharide metabolism. On the other hand, species of microbiota typically found colonizing the intestinal tracts of adults lack these specialized capabilities. This indicates that human milk oligosaccharide consumption is an adaptive trait for the purposes of colonizing infants.

These findings of an evolutionary relationship between specific microbiota and their preferred food source – oligosaccharides from human milk – are very reflective of Dr. Sela’s research interests, which lie in “the black box” of the gastrointestinal tract. “We know what comes in, and what comes out, but not what happens in between,” he says. His desire is to connect the proverbial dots: it is apparent that microbiota populations affect host health, and that nutrient intake affects microbiota by influencing which microbiota have the correct types of food available for their growth. His desire, as a microbiologist, is to elucidate the mechanisms of each factor’s influence over the other.

Ultimately, Dr. Sela hopes to be able to apply his research to human health. “If you think about it in terms of nature, there’s no such thing as good or bad microbes,” he says. “[As] a microbiologist interested in host health,” however, he focuses on “what helps immunological, biochemical processes” in humans. When applying the investigative and mechanistic research in microbiology, one can “use ‘good’ bugs to mitigate diseases, or to take healthy individuals and make them healthier.”

As he transitions to a postdoctoral appointment in Stanford, his take-away message is the importance of a broad, multidisciplinary outlook. Dr. Sela sees his focus as “looking at the intersection of fundamental research fields and disciplines to understand the link between foods and human health.” He approaches his work with a broad perspective, but is working toward expanding his specific skillset in order to contribute to the field. “I want to tease apart mechanisms that underly [the gut] as well as understand it from a descriptive point of view.” He has been an excellent contributor to the Foods For Health during his time in the Mills Lab, and we look forward to his future successes in the field.


  • Milk Bioactives Program
  • Functional Glycobiology Program
  • Milk Oligosaccharides Project
  • Infant Microbiome Project