Authors: William D. Chey, Jana G. Hashash, Laura Manning, and Lin Chang
Journal: Gastroenterology
Year: 2022
Volume: 162
Pages: 1737–1745
DOI: https://doi.org/10.1053/j.gastro.2021.12.248
Study at a Glance
- Study type: Expert review
- Number of studies: Not applicable
- Participants: Not applicable
- Population studied: Adults with irritable bowel syndrome
- Intervention or approach studied: Dietary modifications including low-FODMAP diet, soluble fibre, gluten-free diet
- Comparison group: Various comparison diets and standard care approaches
- Follow-up duration: Not applicable
- Main outcome(s): Best practice advice statements on the role of diet in treating irritable bowel syndrome
Why Was This Study Done?
Irritable bowel syndrome (IBS) is a commonly diagnosed gut disorder that substantially affects quality of life. Most patients with IBS connect their symptoms with eating food. Growing evidence supports dietary changes, such as the low-FODMAP diet, as a main treatment for IBS symptoms.
Chey and colleagues wanted to provide practical guidance to gastroenterologists on the role of diet in treating IBS. The American Gastroenterological Association commissioned this expert review to offer timely advice on this important topic.
How Was the Study Performed?
The authors reviewed existing research on dietary treatments for IBS and combined this with their expert opinion to develop practical advice statements. These covered when to recommend dietary changes, which patients are suitable candidates for restrictive diets, and which specific diets have the most evidence.
The expert review was approved by the American Gastroenterological Association and underwent internal and external review. As this was not a systematic review, the authors did not formally rate evidence quality or recommendation strength.
What Did the Researchers Find?
The authors presented nine best practice advice statements covering diet use in IBS treatment.
Dietary advice should be given to patients who understand their symptoms relate to meals and are motivated to make changes. Patients should be referred to a registered dietitian nutritionist when willing or unable to implement changes independently. When a specialist gut dietitian is unavailable, other resources can help.
Poor candidates for restrictive diets include people already consuming few trigger foods, those at risk for malnutrition, those who are food insecure, and those with eating disorders or uncontrolled psychiatric disorders. Routine screening for disordered eating is critical as these conditions are common and often overlooked.
Diet treatments should be attempted for a predetermined length of time. Without response, the treatment should be stopped in favour of another option, such as a different diet, medication, or other therapy.
Soluble fibre is effective in treating overall IBS symptoms. The low-FODMAP diet is currently the most evidence-based diet treatment for IBS. Healthy eating advice from guidelines such as those from the National Institute of Health and Care Excellence also offers benefit to some patients.
The low-FODMAP diet consists of three phases: restriction lasting no more than four to six weeks, reintroduction of FODMAP foods, and personalisation based on reintroduction results.
Regarding gluten-free diets, observational studies found most patients with IBS improve, but randomised controlled trials have yielded mixed results.
Limited data show selected biological markers can predict response to diet treatments, but there is insufficient evidence to support their routine clinical use.
What Did the Authors Conclude?
The authors concluded that diet has assumed an increasingly prominent role in understanding and treating IBS. Identifying appropriate patients for dietary treatments, particularly elimination diets, is an important first step. Partnering with a registered dietitian nutritionist is essential for successful symptom management.
Soluble fibre can improve overall IBS symptoms, particularly in constipation-predominant IBS. The low-FODMAP diet is the most evidence-based dietary treatment, reducing overall and individual symptoms in randomised controlled trials. However, studies are limited by methodological issues, including lack of blinding and small sample sizes.
The authors concluded there is a lack of strong evidence supporting gluten-free diets for relieving IBS symptoms. Further efforts to identify and validate biological markers predicting response to dietary treatments are needed to deliver personalised nutrition.
Key Takeaways
- Dietary advice for IBS is most suitable for patients who recognise that their gut symptoms are related to eating and who are motivated to make dietary changes.
- Patients with eating disorders, those at risk for malnutrition, those who are food insecure, and those already eating few trigger foods are poor candidates for restrictive diets.
- Soluble fibre is effective for treating overall IBS symptoms, particularly in patients with constipation-predominant IBS.
- The low-FODMAP diet is currently the most evidence-based dietary treatment for IBS and consists of three phases: restriction, reintroduction, and personalisation.
- Evidence supporting gluten-free diets for IBS is mixed, with randomised controlled trials showing inconsistent results.
This Scientific Publication Summary is an objective summary of the published study for personal and educational use. It does not constitute medical advice, endorsement of the intervention, or a recommendation to alter clinical practice.