Gut health has become a familiar term in both scientific papers and marketing campaigns. Although scientists generally agree that gut health is a key component of overall health and wellness, the concept of gut health has been interpreted by different people in different ways. The absence of a shared definition has led some to focus on narrow components of gut health, such as the gut microbiome, without taking into account the full picture of digestive function and symptoms. As a result, no criteria have been established to measure or track gut health over time.
Now a global group of 13 scientists and clinicians is helping establish clarity by publishing a consensus definition of gut health in Nature Reviews Gastroenterology and Hepatology . In the paper, the experts define gut health as “a state of normal gastrointestinal function without active gastrointestinal disease and gut-related symptoms that affect quality of life.” The definition encompasses both physiological function and an individual’s experience of their symptoms – and importantly, it includes scope for the possibility that those with a diagnosed digestive disorder may experience gut health when symptoms and their impacts are controlled.
The definition paper is the result of a working group brought together by the International Scientific Association for Probiotics and Prebiotics (ISAPP) in September 2024. The scientists and physicians, whose expertise encompassed gastroenterology, pediatrics, nutrition, immunology, microbiology and more, gathered to discuss the various domains of gut health and possible ways to evaluate each domain. The resulting paper provides a framework for understanding the full scope of gut health, with applications for researchers designing gut health studies, as well as for the clinical management of digestive health and disease.
The paper’s authors classify gut physiology into six different domains: digestion, microbiome, gut barrier, immunity, metabolism, and gut-brain axis. Each one is measured in distinct ways, depending on the research or clinical aims, with validated symptom assessment tools remaining pivotal. A key limitation identified with many physiological metrics is their lack of validation against clinically meaningful endpoints – an area of research the panel expects will continue to advance.
“Recent evidence showing how the gut microbiome has a major role in our overall health is just one way new insights on gut health are emerging,” says first author Prof. Maria L. Marco PhD. “By defining gut health, we provide a framework to use the term in a more thoughtful and coordinated way between researchers, clinicians, and the broader public alike.”
The authors emphasize that the definition is a starting point for understanding what contributes to gut health and overall health in different populations.
ISAPP Executive Director Marla Cunningham says, “The term gut health is used so widely, but its use often suffers from a lack of clarity and precision. ISAPP convened this panel to help advance more comprehensive, consistent and specific approaches to research and reporting on gut health. We hope that this will be another step in the field's efforts towards a better understanding of how to maintain and promote health in the gut, and ultimately, to better health outcomes.”
Nature Reviews Gastroenterology & Hepatology
Literature review
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The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of gut health
18-Feb-2026
The consensus group was convened by the International Scientific Association for Probiotics and Prebiotics.