Gary Gray, who co-discovered possible celiac disease treatment, dies at 89

Gastroenterologist Gary Gray, part of Stanford Medicine for nearly 50 years, helped find the molecular cause of celiac disease and a potential treatment.

- By Emily Moskal

Gary Gray enjoyed photography, taking the photos for his family’s yearly holiday card.
Courtesy of the Gray family

Gary Gray, MD, former chair of gastroenterology and hepatology at Stanford Medicine and an expert in celiac disease, died Oct. 31, 2022. He was 89.

Gray was the head of the Division of Gastroenterology and Hepatology for 17 years and the director of two previous organizations at Stanford Medicine: the Stanford Celiac Sprue Clinic and the Digestive Disease Center. He saw patients until around 2015.

“Dr. Gray was fully immersed in his work on the molecular chemistry of the gastrointestinal tract, becoming a major influence at Stanford Medicine and globally for many decades,” said Lloyd Minor, MD, dean of the Stanford School of Medicine. “We stand in the wake of his achievements.”

In 2002, Gray co-authored a paper on the molecular cause of celiac disease, an autoimmune condition that causes gluten intolerance. He studied a peptide — a short chain of amino acids, the building blocks of proteins — that causes the inflammatory response to gluten in affected patients. He and his co-authors found that an enzyme, prolyl endopeptidase, could be used as an oral therapy to detoxify gluten in celiac patients. Researchers plan to conduct late-stage clinical trials on the treatment in 2024.

“Gary was a scholar of the highest caliber,” said Chaitan Khosla, PhD, the Marc and Jennifer Lipschultz Director of the Stanford Innovative Medicines Accelerator and a professor of chemistry who was the senior author of the 2002 paper. “He was a true physician-scientist at a time when that wasn’t well recognized, let alone a thing to admire and strive for around the mid-’60s.”

Gray focused on the chemistry that allows food to be converted to energy in the small intestine, specializing in the enzymes sucrase, lactase and aminopeptidase, which have roles in digesting dietary sugars and proteins.

Early in his career, enzymes like these were hard to study because they are large proteins stuck inside cell membranes. But Gray pioneered a method to prepare these enzymes in a concentrated form directly from intestinal tissue, opening the door to studying their chemistry and regulation.

Gray published more than 140 peer-reviewed articles and textbook chapters on the topic, receiving more than 40 National Institutes of Health grants in roughly 12 years. He practiced translational medicine, which brought clinical applications to basic science research.

“I saw in Gary the ability to connect chemistry, biology, medicine and engineering in ways that were unique among his generation of physician-scientists,” Khosla said.

Decades-long career

Born June 4, 1933, in Seattle, Gray received his bachelor’s degrees in chemistry and mathematics from Seattle University in 1955, then completed his medical training at the University of Washington in 1959. He held two postdoctoral fellowships, one in biochemistry at the University of Chicago and another in gastroenterology at Boston University.

Gray became acquainted with tropical sprue, a rare digestive disorder that shares many features found in celiac disease, when he was working as the chief of metabolic studies for the U.S. Army Tropical Research Medical Laboratory in 1964 and 1965 in Puerto Rico. A year later, he arrived at Stanford Medicine.

“Gary’s contributions to basic science and gastroenterology were fundamental to building the School of Medicine to what it is today,” said Chris Cartwright, MD, emerita professor of gastroenterology. “He was a triple threat: an outstanding physician, scientist and mentor.”

He was a triple threat: an outstanding physician, scientist and mentor.

Gray was a chairman for the growth, development and nutrition section of the American Gastroenterological Association for two years ending in 1995; was a major contributor to the gastroenterology sections in Scientific American Medicine; and was on the board of Gastroenterology and Viewpoints on Gastroenterology. He helped found the Celiac Sprue Research Foundation, a nonprofit that merged with another to form the Celiac Community Foundation of Northern California, and he was a visiting professor at many universities including Harvard and Yale.

He was inducted into the American Society for Clinical Investigation and the Association of American Physicians. He continued to publish 10 years after becoming an emeritus professorin 1999.

Eric Sibley, MD, PhD, a professor of pediatric gastroenterology who, as a postdoctoral scholar investigated lactase with Gray in 1993, said that Gray was also a champion of diversity, giving visibility and independence to Sibley and enabling him to become among the first Black professors on tenure track at Stanford Medicine.

“Gary was a strong advocate, mentor and sponsor,” Sibley said. “Even with him as my supervisor, it was hard not to be good friends with Gary. I would call him at different stages in my career, and he always was glad to take the time to talk.”

Besides research and mentorship, Gray also stood out with his devotion to his patients,according to Nielsen Fernandez-Becker, MD, PhD, a clinical associate professor of gastroenterology, who now treats many patients who were once Gray’s. Rather than relying on pathologists, Gray insisted on studying his own small intestinal samples to diagnose celiac disease. He was so devoted to his patients, Fernandez-Becker said, he gave them each his cell number.

Edifying passions

Outside of work, Gray had a love of hot rods. Khosla fondly remembers driving in Gray’s ’89 Corvette between the main Stanford University campus and the Stanford Research Park in Palo Alto.

“It was clear Gary enjoyed things not because of their external appearance but because of his ability to connect what they do to how they do it — and that was true with the human body and that was true with his Corvette,” Khosla said.

Gray also enjoyed photography, focusing on candid shots, and took the photos for his family’s yearly holiday card.

Gray had season tickets to the 49ers and the American Conservatory Theater, and he liked to spend time at his beach house in Pajaro Dunes, California, where he invited friends to an annual Thanksgiving celebration. Gathering at the dinner table is one of the fondest memories Michael Gray has of his dad.

“Having five boys at the dinner table was like herding cats, but my dad made it priority, and I think we’re better for it,” Michael Gray said.

David Gray, the eldest son, said that his family dinners were different from dinners at his friends’ homes. His father would quote The New York Times and hold engaging discussions about the latest news.

The dinners weren’t possible without the tight-knit connection between Gary Gray and his wife, Mary Gray. The two, high school sweethearts, were married for 62 years before shedied in 2021.

In addition to Michael and David, Gray is survived by sons Jeff, Peter and Jason as well as 12 grandchildren.

About Stanford Medicine

Stanford Medicine is an integrated academic health system comprising the Stanford School of Medicine and adult and pediatric health care delivery systems. Together, they harness the full potential of biomedicine through collaborative research, education and clinical care for patients. For more information, please visit

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