Patients' experiences of dietary changes during a structured dietary intervention for irritable bowel syndrome.

Diet plays an important role in management of gastrointestinal (GI) symptoms in patients with irritable bowel syndrome (IBS). Restrictive diets have gained popularity as treatment for IBS, but no studies have examined the patients' experiences of implementing such diets. Thus, the present study aimed to explore the experience of patients with IBS undergoing a structured dietary intervention. Using inductive content analysis, semi-structured interviews were conducted in 19 patients with IBS, who were recruited from a randomised controlled trial evaluating two different restrictive diets for 4 weeks: a diet low in total carbohydrates; and a diet low in fermentable oligo-, di- and monosaccharides and polyols (i.e., FODMAP) combined with traditional IBS dietary advice. Three main themes developed from the qualitative analysis and together they describe the dietary intervention as supportive, as well as the dietary changes as challenging and contributing to reflection. Patients found the dietary support effective in both initiating and adhering to their dietary changes. Despite the support, the implementation of the diet was perceived as challenging when it interfered with other important aspects of their lives. However, going through the dietary change process, the patients began to reflect on their eating behaviours, which enabled individual dietary adjustments. The adjustments that patients maintained were not only a result of alleviation of GI symptoms, but also based on personal preferences. Patients with IBS undergoing restrictive diets appear to benefit from structured support. However, considering the individual patient's life situation and personal preferences, individualised dietary options should be encouraged to achieve long-term dietary changes.

Weznaver C ，Nybacka S ，Simren M ，Törnblom H ，Jakobsson S ，Störsrud S ... -  《-》

A low FODMAP diet plus traditional dietary advice versus a low-carbohydrate diet versus pharmacological treatment in irritable bowel syndrome (CARIBS): a single-centre, single-blind, randomised controlled trial.

Dietary advice and medical treatments are recommended to patients with irritable bowel syndrome (IBS). Studies have not yet compared the efficacy of dietary treatment with pharmacological treatment targeting the predominant IBS symptom. We therefore aimed to compare the effects of two restrictive dietary treatment options versus optimised medical treatment in people with IBS. This single-centre, single-blind, randomised controlled trial was conducted in a specialised outpatient clinic at the Sahlgrenska University Hospital, Gothenburg, Sweden. Participants (aged ≥18 years) with moderate-to-severe IBS (Rome IV; IBS Severity Scoring System [IBS-SSS] ≥175) and no other serious diseases or food allergies were randomly assigned (1:1:1) by web-based randomisation to receive a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) plus traditional IBS dietary advice recommended by the UK National Institute for Health and Care Excellence (hereafter the LFTD diet), a fibre-optimised diet low in total carbohydrates and high in protein and fat (hereafter the low-carbohydrate diet), or optimised medical treatment based on predominant IBS symptom. Participants were masked to the names of the diets, but the pharmacological treatment was open-label. The intervention lasted 4 weeks, after which time participants in the dietary interventions were unmasked to their diets and encouraged to continue during 6 months' follow-up, participants in the LFTD group were instructed on how to reintroduce FODMAPs, and participants receiving pharmacological treatment were offered diet counselling and to continue with their medication. The primary endpoint was the proportion of participants who responded to the 4-week intervention, defined as a reduction of 50 or more in IBS-SSS relative to baseline, and was analysed per modified intention-to-treat (ie, all participants who started the intervention). Safety was analysed in the modified intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02970591, and is complete. Between Jan 24, 2017, and Sept 2, 2021, 1104 participants were assessed for eligibility and 304 were randomly assigned. Ten participants did not receive their intervention after randomisation and thus 294 participants were included in the modified intention-to-treat population (96 assigned to the LFTD diet, 97 to the low-carbohydrate diet, and 101 to optimised medical treatment). 241 (82%) of 294 participants were women and 53 (18%) were men and the mean age was 38 (SD 13). After 4 weeks, 73 (76%) of 96 participants in the LFTD diet group, 69 (71%) of 97 participants in the low-carbohydrate diet group, and 59 (58%) of 101 participants in the optimised medical treatment group had a reduction of 50 or more in IBS-SSS compared with baseline, with a significant difference between the groups (p=0·023). 91 (95%) of 96 participants completed 4 weeks in the LFTD group, 92 (95%) of 97 completed 4 weeks in the low-carbohydrate group, and 91 (90%) of 101 completed 4 weeks in the optimised medical treatment group. Two individuals in each of the intervention groups stated that adverse events were the reason for discontinuing the 4-week intervention. Five (5%) of 91 participants in the optimised medical treatment group stopped treatment prematurely due to side-effects. No serious adverse events or treatment-related deaths occurred. Two 4-week dietary interventions and optimised medical treatment reduced the severity of IBS symptoms, with a larger effect size in the diet groups. Dietary interventions might be considered as an initial treatment for patients with IBS. Research is needed to enable personalised treatment strategies. The Healthcare Board Region Västra Götaland, the Swedish Research Council, the Swedish Research Council for Health, Working Life and Welfare, AFA Insurance, grants from the Swedish state, the Wilhelm and Martina Lundgren Science Foundation, Skandia, the Dietary Science Foundation, and the Nanna Swartz Foundation.

Nybacka S ，Törnblom H ，Josefsson A ，Hreinsson JP ，Böhn L ，Frändemark Å ，Weznaver C ，Störsrud S ，Simrén M ... -  《The Lancet Gastroenterology & Hepatology》

Low fermentable oligo-di-mono-saccharides and polyols diet versus general dietary advice in patients with diarrhea-predominant irritable bowel syndrome: A randomized controlled trial.

Recent evidence indicates that new approach of the diet with low fermentable oligo-di-mono-saccharides and polyols (FODMAPs) may have an effective role in management of the patients with irritable bowel syndrome (IBS). We compared the results of low FODMAP diet with current dietary treatment, general dietary advices (GDA), on the clinical response in patients with diarrhea subtype of IBS (IBS-D). In this randomized, controlled, single-blind trial, we included 110 patients with IBS-D in two intervention groups. Participants were randomly assigned to the low FODMAP diet (n = 55) and GDA (n = 55) for 6 weeks after a 10-day screening period. Gastrointestinal symptoms and bowel habit status were evaluated using a symptom severity scoring system and Bristol stool form scale pre-intervention and post-intervention. Patients completed 3-day food diary before and after the intervention. Of 110 patients, 101 completed the dietary interventions. At the baseline, the nutrient intake, severity of symptoms, and demographic data were similar between two groups. After 6 weeks, the low FODMAP diet improves significantly overall gastrointestinal symptoms scores, stool frequency, and consistency versus GDA group (P < 0.001, P < 0.001, and P = 0.003, respectively). Compared with the baseline, both intervention groups expressed a significant reduction in overall scores of symptom severity scoring system, abdominal pain, distension, consistency, and frequency, but this reduction is greater in low FODMAP diet group. Both low FODMAP diet and GDA in patients with IBS-D led to adequate improvement of gastrointestinal symptoms for 6 weeks. However, the low FODMAP diet has greater benefits in IBS improvement.

Zahedi MJ ，Behrouz V ，Azimi M 《-》

The long-term effect and adherence of a low fermentable oligosaccharides disaccharides monosaccharides and polyols (FODMAP) diet in patients with irritable bowel syndrome.

Short-term trials with a low-FODMAP (fermentable oligosaccharides disaccharides monosaccharides and polyols) diet (LFD) show promising results in the symptomatic management of irritable bowel syndrome (IBS). The present study investigated the long-term adherence to an LFD diet, factors associated with adherence, and associations between LFD and quality of life (QOL), IBS symptoms and disease course on a long-term basis. A retrospective cross-sectional study was conducted. Two hundred and thirty-four patients were enrolled from Ghent University hospital. Health-related QOL, long-term adherence to the LFD, disease course and IBS symptoms were assessed using a validated and self-developed questionnaire. Ninety (38.5%) patients completed the questionnaires. The median time span between the first dietary consultation and completion of the questionnaires was 99.5 weeks (approaching 2 years). The predominant disease course was mild IBS with an indolent course (43.0%). Eighty percent reported still following a diet in which certain FODMAP-rich food types are avoided. Eighty patients (88.9%) were satisfied that they follow or had followed the diet. The IBS-QOL did not differ between patients following the diet strictly and patients deviating from the diet (P = 0.669). Patients still following the LFD experienced less severe abdominal pain than patients who stopped following the diet (P = 0.044). The long-term adherence and satisfaction with the LFD is high in patients with IBS. Nevertheless, patients indicated that it was difficult to follow the LFD in daily life. Practical issues, social factors and the absence of symptoms were indicated as the main reasons for a drop in adherence.

Weynants A ，Goossens L ，Genetello M ，De Looze D ，Van Winckel M ... -  《-》

AGA Clinical Practice Update on the Role of Diet in Irritable Bowel Syndrome: Expert Review.

Irritable bowel syndrome (IBS) is a commonly diagnosed gastrointestinal disorder that can have a substantial impact on quality of life. Most patients with IBS associate their gastrointestinal symptoms with eating food. Mounting evidence supports dietary modifications, such as the low-fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) diet, as a primary treatment for IBS symptoms. The aim of this American Gastroenterological Association (AGA) Clinical Practice Update (CPU) is to provide best practice advice statements, primarily to clinical gastroenterologists, covering the role of diet in IBS treatment. This expert review was commissioned and approved by the AGA CPU Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPU Committee and external peer review through standard procedures of Gastroenterology. The best practice advice statements were drawn from reviewing existing literature combined with expert opinion to provide practical advice on the role of diet in treating patients with IBS. Because this was not a systematic review, formal rating of the quality of evidence or strength of the presented considerations was not performed. Best Practice Advice Statements BEST PRACTICE ADVICE 1: Dietary advice is ideally prescribed to patients with IBS who have insight into their meal-related gastrointestinal symptoms and are motivated to make the necessary changes. To optimize the quality of teaching and clinical response, referral to a registered dietitian nutritionist (RDN) should be made to patients who are willing to collaborate with a RDN and patients who are not able to implement beneficial dietary changes on their own. If a gastrointestinal RDN is not available, other resources can assist with implementation of diet interventions. BEST PRACTICE ADVICE 2: Patients with IBS who are poor candidates for restrictive diet interventions include those consuming few culprit foods, those at risk for malnutrition, those who are food insecure, and those with an eating disorder or uncontrolled psychiatric disorder. Routine screening for disordered eating or eating disorders by careful dietary history is critical because they are common and often overlooked in gastrointestinal conditions. BEST PRACTICE ADVICE 3: Specific diet interventions should be attempted for a predetermined length of time. If there is no clinical response, the diet intervention should be abandoned for another treatment alternative, for example, a different diet, medication, or other form of therapy. BEST PRACTICE ADVICE 4: In preparation for a visit with a RDN, patients should provide dietary information that will assist in developing an individualized nutrition care plan. BEST PRACTICE ADVICE 5: Soluble fiber is efficacious in treating global symptoms of IBS. BEST PRACTICE ADVICE 6: The low-FODMAP diet is currently the most evidence-based diet intervention for IBS. Healthy eating advice as described by the National Institute of Health and Care Excellence Guidelines, among others, also offers benefit to a subset of patients with IBS. BEST PRACTICE ADVICE 7: The low-FODMAP diet consists of the following 3 phases: 1) restriction (lasting no more than 4-6 weeks), 2) reintroduction of FODMAP foods, and 3) personalization based on results from reintroduction. BEST PRACTICE ADVICE 8: Although observational studies found that most patients with IBS improve with a gluten-free diet, randomized controlled trials have yielded mixed results. BEST PRACTICE ADVICE 9: There are limited data showing that selected biomarkers can predict response to diet interventions in patients with IBS, but there is insufficient evidence to support their routine use in clinical practice.

Chey WD ，Hashash JG ，Manning L ，Chang L ... -  《-》