Hippocrates once mused, “Let food be your medicine and medicine be your food.” Despite pleas for dietary advice from patients with gastrointestinal symptoms, practitioners of western medicine have largely shunned this sage advice. Within the past 5 to 7 years, the role of food in the pathogenesis and treatment of irritable bowel syndrome (IBS) has enjoyed a renaissance. Indeed, the science linking food and diet interventions for IBS is evolving at a very rapid pace. Thus, the review on this topic by Lacy is timely.
The article starts with a necessarily brief discussion of true food allergies vs the heterogeneous universe of food intolerances before reviewing why food might cause gastrointestinal symptoms in IBS patients. It then pivots to review the strengths, weaknesses, and gaps in the available literature on diet interventions for IBS. The article focuses on dietary restriction and concisely reviews the available literature on biomarker-directed and -undirected exclusion diets, low-/no-gluten, very–low carbohydrate, and low-FODMAP diets. The article concludes with Dr. Lacy’s insights on how to implement dietary management in the care of IBS patients. The article makes clear that, while diet occupies an increasingly important role in managing IBS patients, the level of enthusiasm on the part of patients and providers may not be justified by the available scientific evidence. More research is desperately needed to more fully understand the pathophysiology, efficacy, implementation, and long-term safety of dietary interventions for IBS.
– Commentary by Dr. William Chey