ASN Fellow

Becoming a distinguished fellow with the American Society of Nutrition (ASN) will be especially meaningful to University of Idaho Professor Shelley McGuire because she’ll be following in the footsteps of her mentor, the late Mary Frances Picciano.

McGuire, director of the Margaret Ritchie School of Family and Consumer Sciences (FCS) and a leading scholar of maternal and infant nutrition, will receive ASN’s highest honor June 1 during the society’s Nutrition 2025 meeting in Orlando, Florida.

At Picciano’s urging, McGuire joined ASN in 1988 as a master’s student studying nutrition at the University of Illinois in Urbana-Champaign. Picciano, who died in 2010, was also an ASN fellow and a past ASN president. Like her mentor, McGuire went on to be active in ASN, serving on most of its committees and holding many leadership positions.

“This means so much to me because these are the people I have looked up to for my entire career,” McGuire said. “This is the premier nutrition society in the world — there’s no question about it. They publish the top journals, and anything I could do for that society over the years I did out of a servant’s heart because they’ve been in existence for a very long time and they’re as good as it gets.”

As an undergraduate, McGuire planned to pursue a career as a doctor and had already accepted a medical school seat when she took an introductory nutrition class, taught by Picciano, during the final semester of her senior year.

“It was like a lightbulb came on. I fell in love with it,” McGuire recalled.

Picciano, who also specialized in lactation and maternal and infant health, hired McGuire to work in her laboratory during the summer. McGuire decided to pursue research rather than medicine and went on to earn a master’s in nutrition from Illinois and a doctorate in nutrition from Cornell University.

“It’s so interesting because Mary Frances was also a nutrition textbook writer and I have become one as well,” McGuire said. “It’s just amazing how you follow in these giants’ footsteps without even realizing what you’re doing, and this society means that to me.”

For the past three decades, McGuire has built upon her mentor’s legacy, making monumental discoveries in human milk, lactation and infant nutrition. She’s worked consistently with the same research team — also including her husband, University Distinguished Professor Mark McGuire, with the Department of Animal, Veterinary and Food Sciences (AVFS), and Janet Williams, a senior research scientist within AVFS.

“Hopefully, they will also become distinguished fellows because that would only be fair,” McGuire said.

In 2011, the team published a paper providing the first evidence that human milk has a microbiome — harboring communities of microorganisms that colonize infants’ gastrointestinal tract and contribute to important health outcomes. Prior to that paper, human milk was believed to be sterile. Skeptics of their findings argued their milk samples must have been contaminated.

“That was a paradigm shift for the whole field of nutrition,” McGuire said. “Now, it’s a whole field upon itself. Every year, there are another 200 to 300 papers that come out.”

The team has continued research into understanding variation in the milk microbiome, as well as effects on infant health.

They made another crucial discovery amid the COVID-19 pandemic, when women throughout the world were hesitant to breastfeed their children based upon concerns about transmitting the disease. The team found COVID-19 isn’t spread through human milk, and breastfeeding poses virtually no risk. Rather, they confirmed breastfeeding protects infants from COVID-19, as milk contains antibodies.

“That might be the most important work we ever do because it was a crisis and it allowed breastfeeding women to continue to breastfeed without being worried,” McGuire said.

The team is now participating in collaborative research on how maternal cannabis use affects breastfeeding infants.

The FCS program McGuire oversees also makes significant contributions to the field of nutrition, teaching roughly 60 food and nutrition students, providing nutrition outreach through a pair of Extension specialists and conducting nutrition research. The school’s nutrition research efforts have been furthered by an $11 million National Institutes of Health Center of Biomedical Research Excellence (COBRE) grant McGuire received to create a research center devoted to women’s health and nutrition.

In the fall of 2022, McGuire also became Idaho’s first inductee into the vaunted National Academy of Medicine. As a member of that organization, McGuire was selected to serve on a committee of experts that reviewed scientific literature to guide updates on the consumption of alcohol for the Dietary Guidelines for Americans. She reviewed literature pertaining to how alcohol consumption by breastfeeding mothers may affect their infants.

Published in Catching Up with CALS