Alessio Fasano

Alessio Fasano is an Italian-born physician, scientist and academic recognized for his contributions to pediatric gastroenterology, mucosal immunology, and the study of celiac disease. He is a professor of Pediatrics at Harvard Medical School and a professor of Nutrition at Harvard T.H. Chan School of Public Health, both in Boston, Massachusetts. Fasano is director of the Mucosal Immunology and Biology Research Center (MIBRC) at Massachusetts General Hospital (MGH) and scientific director of the European Biomedical Institute of Salerno in Salerno, Italy. At Mead Johnson Nutrition in Evansville, Indiana, Fasano is Chief Science and Medical Officer and Senior Vice President of Research and Development.

Education Fasano was born and educated in Italy. He graduated summa cum laude from the University of Naples School of Medicine, where he completed training in medicine, surgery, pediatrics, emergency medicine and pediatric social medicine. In 1993, he joined the faculty of the University of Maryland School of Medicine in the United States, where he established a career in pediatric gastroenterology and biomedical research.

Career At the University of Maryland, he founded the Center for Celiac Research in 1996, helping to transform the understanding of celiac disease in North America. In 2013 the center moved to Massachusetts General Hospital, where he continued as its director until 2025. He also became chief of Pediatric Gastroenterology and Nutrition and director of the MIBRC at MGH in 2013.

Fasano's research spans translational medicine, autoimmune diseases, host-microbe interactions, and the role of the intestinal barrier in human health and disease. He has maintained an active clinical practice while leading multidisciplinary research programs focused on gastrointestinal disorders and immune-mediated diseases.

Scientific Contributions Fasano is known for several major scientific discoveries.

Celiac Disease Epidemiology

In 2003, Fasano led a landmark study demonstrating that celiac disease affects approximately 1 percent of the U.S. population and is substantially more common than previously believed. The finding helped reshape clinical guidelines and public awareness regarding the disease.

Discovery of Zonulin

While investigating mechanisms of infectious cholera diarrhea and developing vaccine strategies against enteric pathogens, Fasano's research team identified zonulin, a protein that regulates the permeability of intestinal tight junctions. This discovery provided important insights into how the intestinal barrier functions and how its dysregulation may contribute to autoimmune and inflammatory diseases.

Autoimmunity and the Gut Barrier

Fasano's work advanced the concept that impaired intestinal barrier function may play a role in the development of a variety of chronic inflammatory conditions such as celiac disease, metabolic disorders, neurodevelopmental and neurodgenerative disorders, autoimmune diseases, and other immune-mediated disorders.

He is also a frequent contributor to public discussions on nutrition, autoimmune diseases, and the microbiome and has appeared in major media outlets including The New York Times, The Wall Street Journal, CNN, NPR and the BBC.

Selected Areas of Research Celiac disease and gluten-related disorders Intestinal permeability and zonulin biology Mucosal immunology Autoimmune diseases Microbiome-host interactions Pediatric gastroenterology Translational medicine His discoveries concerning the prevalence of celiac disease and the role of zonulin in regulating intestinal permeability have influenced both clinical practice and basic biomedical research, helping to shape the current understanding of the relationship between the gut barrier, immunity, and chronic inflammatory disease.

Book publications

Fast Facts. Celiac Disease. By Fasano A, Holmes G, Catassi C. Oxford: Health Press, 2009. Gluten Freedom. By Fasano A, Flaherty S. Wiley, 2014. Senza glutine. La celiachia non si cura, si gestisce (in Italian). By Fasano A. Mondadori, 2017. Se libérer du gluten: Le guide référence de la sensibilité au gluten et de la maladie coeliaque (Essai-Santé) (French Edition). By Fasano A. Marabout, 2017. A Clinical Guide to Gluten-Related Disorders Paperback. By Fasano A. LWW, 2013. Frontiers in Celiac Disease. By Fasano A, Troncone R, Branski D, eds. S. Karger Publishers, 2008. From Ptolemaus to Copernicus: The Evolving System of Gluten-Related Disorder. By Catassi C, Fasano A. Mdpi AG, 2018. Dieta Sem Glúten - Um Guia Para Uma Vida Saudável (in Portuguese). By Fasano A, Flaherty S, Rocha B. Madras, 2015. Gut Feelings: The Microbiome and Our Health. By Fasano A, Flaherty S. MIT Press, 2021.

Cited publications Fasano has authored (or co-authored) over 300 peer-reviewed publications. Some high-impact publications include: