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8 new insights about diet and gut health

Three experts share their takeaways from the 2019 James W. Freston Conference: Food at the Intersection of Gut Health and Disease.

During your four years of medical school, you likely only received just four hours of nutrition training. Yet we know diet is so integral to the care of GI patients. That’s why AGA focused the 2019 James W. Freston Conference on the topic: Food at the Intersection of Gut Health and Disease.

Our course directors William Chey, MD, AGAF, Sheila E. Crowe, MD, AGAF, and Gerard E. Mullin, MD, AGAF, share eight points from the meeting that stuck with them and can help all practicing GIs as they consider dietary treatments for their patients.

    • 1. Personalized nutrition is important. Genetic differences lead to differences in health outcomes. One size or recommendation does not fit all. This is why certain diets only work on certain people. There is no one diet for all and for all disease states. Genetic tests can be helpful, but they rely on reporting that isn’t readily available yet.
    • 2. Dietary therapy is key to managing eosinophilic esophagitis (EoE). EoE is becoming more and more prevalent. Genes can’t change that fast, but epigenetic factors can, and the evidence seems to be in food. EoE is not an IgE-mediated disease and therefore most allergy tests will not prove useful; however, food is often the trigger — most common, dairy. Dietary therapy is likely the best way to manage. You want to reduce the number of eliminated foods by way of a reintroduction protocol. The six-food elimination diet is standard, though some are moving to a four-food elimination diet (dairy, wheat, egg and soy).
    • 3. There has been a reported increase in those with food allergies, sensitivities, celiac disease and other adverse reactions to food. Many of the food allergy tests available are not helpful. In addition, many afflicted patients are conducting self-imposed diets rather than working with a GI, allergist or dietitian. This needs to change.
    • 4. There is currently insufficient evidence to support a gluten-free diet for irritable bowel syndrome (IBS). It is possible that fructans, more than gluten, are causing the GI issues. Typically, the low-FODMAP diet is beneficial to IBS patients if done correctly with the guidance of a dietitian; however, not everyone with IBS improves on it. All the steps are important though, including reintroduction and maintenance.
    • 5. When working with patients on the low-FODMAP or other restrictive diets, it is important to know their food and eating history. Avoidance/Restrictive Food Intake Disorder (ARFID) is something we need to be aware of when it comes to patients with a history or likelihood to develop disordered eating/eating disorders. The patient team may need to include an eating disorder therapist.
    • 6. The general population in the U.S. has increased the adoption of a gluten-free diet although the number of cases of celiac disease has not increased. Many have self-reported gluten sensitivities. Those that have removed gluten following trends are more at risk of bowel irregularity (low fiber), weight gain and disordered eating. Celiac disease is not a do-it-yourself disease, patients will be best served working with a dietitian and GI.
    • 7. Food can induce symptoms in patients with inflammatory bowel disease (IBD). It can also trigger gut inflammation resulting in incident or relapse. There is experimental plausibility for some factors of the relationship to be causal and we may be able to modify the diet to prevent and manage IBD.
    • 8. The focus on nutrition education must continue! Nutrition should be a required part of continuing medical education for physicians. And physicians should work with dietitians to improve the care of GI patients.


For resources to help your patients understand how diet and nutrition can impact their digestive health, visit the AGA GI Patient Center. Each disease-based resource provides tips from leading experts on the role of diet in managing GI health.


The 2019 James W. Freston Single Topic Conference took place Aug. 9 and 10 in Chicago, Illinois. The Freston conference is the only conference organized by AGA Institute Council in which the agenda is determined through an open call for proposals from AGA membership. The purpose of the conference is to focus on scientific dialogue, present opportunities for scientific collaboration and explore new ideas that may lead to enhanced patient therapies or potential opportunities for cures of digestive diseases. The 2019 conference was sponsored by the AGA Institute Council Obesity, Metabolism & Nutrition Section. Vice chair of the section, Dr. Gerard Mullin, served as co-course director.


Want more on this topic? Check out the AGA Community expert roundtable on diet and nutrition, led by 2019 Freston faculty Emily Haller, MS, RDN, and Kate Scarlata, RDN, LDN.



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