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Optimal design of clinical trials of dietary interventions in disorders of gut-brain interaction

Research output: Contribution to journalArticlepeer-review

Heidi M Staudacher, Chu Kion Yao, William D Chey, Kevin Whelan

Original languageEnglish
Pages (from-to)973-984
Number of pages12
JournalAmerican Journal of Gastroenterology
Issue number6
Early online date16 Mar 2022
Accepted/In press11 Mar 2022
E-pub ahead of print16 Mar 2022
Published1 Jun 2022

Bibliographical note

Funding Information: Potential competing interests: H.M.S. has received nonfinancial and financial support from CD Investments VSL Pharmaceuticals. C.K.Y. has received research funding from Crohn's Colitis Australia, Atmo Biosciences, and the International Organization for the Study of Inflammatory Bowel Disease. C.K.Y. works in a department that financially benefits from the sales of a digital application and booklets on the low FODMAP diet. Funds raised contribute to research of the Department of Gastroenterology and to the University. No author receives personal remuneration. W.D.C. is a consultant for AbbVie, Allakos, Alnylam, Bayer, Biomerica, Gemelli, Ironwood, Nestle, QOL Medical, Salix, Takeda, Urovant, and Vibrant and has research grants from NIH, FDA, Biomerica, Commonwealth Diagnostics, QOL Medical, and Salix. W.D.C. has stock options from GI on Demand/GastroGirl and Modify Health. KW receives research funding from the Almond Board of California, Danone, and the International Nut and Dried Fruit Council and is the coinventor of testing of VOC in the diagnosis and dietary management of IBS. Publisher Copyright: © 2022 by The American College of Gastroenterology. Unauthorized reproduction of this article is prohibited. .

King's Authors


There is accumulating evidence for the fundamental role of diet in the integrated care of disorders of gut-brain interaction. Food is a complex mixture of components with individual, synergistic, and antagonistic effects, compared with the relative purity of a pharmaceutical. Food is also an inherent part of individuals' daily lives, and food choice is strongly tied to food preferences, personal beliefs, cultural and religious practices, and economic status, which can influence its ability to function as a therapeutic intervention. Hence, randomized controlled trials of dietary interventions carry unique methodological complexities that are not applicable to pharmaceutical trials that if disregarded can pose significant risk to trial quality. The challenges of designing and delivering the dietary intervention depend on the type of intervention (i.e., nutrient vs food supplementation or whole-diet intervention). Furthermore, there are multiple modes of delivery of dietary interventions, each with their own advantages (e.g., the high precision of feeding trials and the strong clinical applicability of dietary counseling trials). Randomized placebo-controlled trials of dietary interventions are possible with sufficient attention to their design and methodological nuances. Collaboration with experts in nutrition and dietetics is essential for the planning phase; however, even with expert input, not all challenges can be overcome. Researchers undertaking future dietary trials must be transparent in reporting these challenges and approaches for overcoming them. This review aims to provide guiding principles and recommendations for addressing these challenges to facilitate the conduct and reporting of high-quality trials that inform and improve clinical practice.

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