The Effect of Dietary Intervention on Irritable Bowel Syndrome: A Systematic Review.
ABSTRACT: Elimination diets have been used for many years to treat irritable bowel syndrome (IBS). These approaches had fallen out of favor until a recent resurgence, which was based on new randomized controlled trial (RCT) data that suggested it might be effective. The evidence for the efficacy of dietary therapies has not been evaluated systematically. We have therefore conducted a systematic review to examine this issue.MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched up to December 2013. Trials recruiting adults with IBS, which compared any form of dietary restriction or addition of an offending food group in patients already on a restricted diet vs. placebo, control therapy, or "usual management", were eligible. Dichotomous symptom data were pooled to obtain a relative risk of remaining symptomatic after therapy as well as the number needed to treat with a 95% confidence interval.We identified 17 RCTs involving 1,568 IBS patients that assessed elimination diets. Only three RCTs involving 230 patients met our eligibility criteria, all of which evaluated different approaches, and thus a meta-analysis could not be conducted.More evidence is needed before generally recommending elimination diets for IBS patients.
Project description:BACKGROUND:Food-related quality of life (FRQoL) evaluates the impact of diet, eating behaviors, and food-related anxiety on a person's quality of life. This is the first study to evaluate FRQoL in inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), two illnesses where food and diet are of importance. METHODS:One hundred seventy-five participants (80 IBS, 95 IBD) participated in the study by completing measures evaluating FRQoL, psychological distress, and health-related quality of life. Primary analyses evaluated differences in FRQoL between IBD and IBS patients. Secondary analyses compared differences based on remission status, dietary use, and dietary consultation, as well as evaluated potential predictors of FRQoL. RESULTS:IBD patients in remission report the highest FRQoL (IBD-remission: 91.2 (26.5) vs. IBD-active: 67.7 (19.6) and IBS-active: 67.6 (18.3), p?<?.001). Using more dietary treatments is associated with decreased FRQoL for IBS (r?=?-?0.23, p?<?.05) and IBD patients (r?=?-?0.31, p?<?.01). IBS patients are more likely to use dietary treatments than IBD (IBS?=?81% vs. IBD?=?64%, p?<?.01), with self-directed diets being the most commonly used approach. Symptom severity is the strongest predictor of FRQoL in both groups (IBD: R2?=?.27, p?<?.01; IBS: R2?=?.23, p?<?.001). CONCLUSION:FRQoL is a unique construct for IBD and IBS patients that can be influenced by several clinical and dietary factors, including number of diets and type of diet used, depending on the diagnosis. Thus, FRQoL should be considered when working with both IBD and IBS patients.
Project description:Irritable bowel syndrome (IBS) affects 7-15% of the general population. A recently devised dietary approach consists of restricting foods with highly fermentable oligo-, di-, and monosaccharides, and polyols (FODMAPs), which can trigger and/or exacerbate IBS symptoms. The aim of this study is to use meta-analysis to provide an update on the randomised control trials (RCTs) and cohort studies, and examine them separately in relation to diet type. Papers were selected using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart. Cohen's d and odds ratios were used as a measure of effect size for RCTs. A random effects model was used to account for different sources of variation among studies. Heterogeneity was assessed using Q statistics, I², Tau, and Tau². Publication bias was analysed and represented by a funnel plot, and funnel plot symmetry was assessed with Egger's test. The results showed that in the RCTs, the patients receiving a low-FODMAP diet experienced a statistically significant pain and bloating reduction compared with those receiving a traditional diet; as regards to stool consistency, there was no significant difference between treatments. A significant reduction in abdominal pain and bloating were described by patients receiving a low-FODMAP diet compared with those receiving a high-FODMAP diet. In cohort studies, pain and bloating were significantly reduced after treatment compared with the baseline diet. We conclude that there is evidence that a low-FODMAP diet could have a favourable impact on IBS symptoms, especially abdominal pain and bloating. However, it remains to be demonstrated whether a low-FODMAP diet is superior to conventional IBS diets, especially in the long term.
Project description:OBJECTIVES:Irritable bowel syndrome (IBS) is a common gastrointestinal condition with a heterogeneous pathophysiology. An altered gut microbiome has been identified in some IBS patients, and fecal microbiota transplantation (FMT) has been suggested to treat IBS. We performed meta-analyses and systematic review of available randomized controlled trials (RCTs) to evaluate the efficacy of FMT in IBS. METHODS:We performed a systematic literature search of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science. Selection criteria included RCTs of FMT vs placebo using FMT excipients or autologous FMT in IBS. Meta-analyses were conducted to evaluate the summary relative risk (RR) and 95% confidence intervals (CIs) of combined studies for primary outcome of improvement in global IBS symptoms as measured by accepted integrative symptom questionnaires or dichotomous responses to questions of overall symptom improvement. RESULTS:Among 742 citations identified, 7 were deemed to be potentially relevant, of which 4 studies involving 254 participants met eligibility. No significant difference in global improvement of IBS symptoms was observed at 12 weeks in FMT vs placebo (RR = 0.93; 95% CI 0.48-1.79). Heterogeneity among studies was significant (I = 79%). Subgroup analyses revealed benefits of single-dose FMT using colonoscopy and nasojejunal tubes in comparison with autologous FMT for placebo treatment (number needed to treat = 5, RR = 1.59; 95% CI 1.06-2.39; I = 0%) and a reduction in likelihood of improvement of multiple-dose capsule FMT RCTs (number needed to harm = 3, RR = 0.54; 95% CI 0.34-0.85; I = 13%). Placebo response was 33.7% in nonoral FMT RCTs and 67.8% in capsule FMT RCTs. The Grading of Recommendations Assessment, Development and Evaluation quality of the body of evidence was very low. DISCUSSION:Current evidence from RCTs does not suggest a benefit of FMT for global IBS symptoms. There remain questions regarding the efficacy of FMT in IBS as well as the lack of a clean explanation on the discrepant results among RCTs in subgroup analyses.
Project description:Background/Aims:To evaluate the efficacy and safety of Aloe vera (AV) in patients with irritable bowel syndrome (IBS). Methods:We searched the MEDLINE, EMBASE, and Cochrane databases for studies dated between 1st January 1960 and 30th December 2017. Eligible randomized controlled trials (RCTs) compared AV to placebo in patients with IBS. The primary outcome was standardized mean difference of the change in severity of IBS symptoms as measured by patient-rated scales. Secondary outcomes included response rate of IBS symptoms and adverse events. Heterogeneity among studies was assessed using Cochrane's Q and I2 statistics. Results:Three RCTs with a total of 151 patients with IBS were included. The meta-analysis showed a significant difference for patients with AV compared to those with placebo regarding improvement in IBS symptom score (standardized mean difference, 0.41; 95% CI, 0.07-0.75; P = 0.020). Using intention-to-treat analysis, the AV patients showed significantly better response rates of IBS symptoms compared to placebo (pooled risk ratio, 1.69; 95% CI, 1.05-2.73; P = 0.030). No adverse events related with AV were found in included studies. There was no significant heterogeneity of effects across studies (P = 0.900; I2 = 0%). Conclusion:AV is effective and safe for the treatment of patients with IBS compared to placebo.
Project description:BACKGROUND:Recent studies indicate that gut microbiota disorders potentially contribute to the pathogenesis of irritable bowel syndrome (IBS), which can be partly reflected by fecal short-chain fatty acids (SCFAs) generated from gut microbiota. Previous studies on SCFA alterations in patients with IBS have yielded conflicting results. No prior systematic review has been conducted on the alterations in fecal SCFAs in IBS patients. AIMS:We performed a meta-analysis to explore and clarify alterations in fecal SCFAs in IBS patients. METHODS:Case-control studies, randomized controlled trials (RCTs), and self-controlled studies were identified through electronic database searches. The standardized mean difference (SMD) with 95% confidence interval (CI) in fecal SCFA levels between different groups was calculated. RESULTS:The proportion of fecal propionate in patients with IBS was significantly higher than in healthy controls (HCs) (SMD = 0.44, 95% CI = 0.12, 0.76). A subgroup analysis showed that the concentration of fecal propionate (SMD = -0.91, 95% CI = -1.41, -0.41) and butyrate (SMD = -0.53, 95% CI = -1.01, -0.04) in patients with constipation-predominant IBS (IBS-C) was significantly lower than that in HCs, and the concentration of fecal butyrate in patients with diarrhea-predominant IBS (IBS-D) was higher than that in HCs (SMD = 0.34, 95% CI = 0.00, 0.67). Finally, we found that restricted diets correlated with fecal butyrate reduction in IBS (SMD = -0.26, 95% CI = -0.51, -0.01). CONCLUSIONS:In terms of fecal SCFAs, there were differences between patients with IBS and HCs. In IBS-C patients, propionate and butyrate were reduced, whereas butyrate was increased in IBS-D patients in comparison to HCs. Propionate and butyrate could be used as biomarkers for IBS diagnosis.
Project description:BACKGROUND:Peppermint oil (PO) has intrinsic properties that may benefit patients with irritable bowel syndrome (IBS) symptoms. The study objective was to determine the effect of peppermint oil in the treatment of the IBS. METHODS:We systematically searched MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (Cochrane CENTRAL), ClinicalTrials.gov, EMBASE (Ovid), and Web of Science for randomized controlled trials (RCTs) of PO for IBS. We appraised the eligible studies by the Cochrane risk of bias tool. We performed random-effects meta-analysis on primary outcomes including global improvement in IBS symptoms and abdominal pain. A PRISMA-compliant study protocol is registered in PROSPERO Register [2016, CRD42016050917]. RESULTS:Twelve randomized trials with 835 patients were included. For global symptom improvement, the risk ratio (RR) from seven RCTs for the effect of PO (n?=?253) versus placebo (n?=?254) on global symptoms was 2.39 [95% confidence interval (CI): 1.93, 2.97], I2 =?0%, z?=?7.93 (p?<?0.00001). Regarding abdominal pain, the RR from six RCTs for the effect of PO (n?=?278) versus placebo (n?=?278) was 1.78 [95% CI: 1.43, 2.20], I2 =?0%, z?=?5.23 (p?<?0.00001). Overall, there were no differences in the reported adverse effects: PO (32 events, 344 total, 9.3%) versus placebo (20 events, 327 total, 6.1%) for eight RCTs; RR 1.40 [95% CI: 0.87, 2.26] I2 =?0%, z?=?1.39 (p?=?0.16). The number needed to treat with PO to prevent one patient from having persistent symptoms was three for global symptoms and four for abdominal pain. CONCLUSIONS:In the most comprehensive meta-analysis to date, PO was shown to be a safe and effective therapy for pain and global symptoms in adults with IBS.
Project description:Eosinophilic esophagitis (EoE) is an immune-mediated disease triggered by food antigens for which dietary elimination treatment can induce and sustain histologic remission. Our review aims to describe the state of the art regarding dietary treatment of EoE, highlighting a number of areas of controversy related to dietary therapy in EoE, including novel modalities for determining food triggers, making the empiric dietary elimination process more efficient, issues of cross-contamination and "dosing" of how much food to avoid or add back, costs and effects on quality of life, long-term efficacy, and the risk of developing immediate IgE-type reactions after initial dietary elimination. Elemental formulas, empiric elimination diets, and targeted allergy test-directed elimination diets are well-described treatments for EoE. Although elemental diets are most efficacious, their clinical use is limited by cost and the palatability of an exclusively liquid diet. While empiric elimination is less effective than elemental formula-based diets, they are more easily implemented and often sustainable. Since the comparative effectiveness of elimination diets with proton-pump inhibitors and swallowed topical steroids remains unknown, there are multiple areas to address with future research.
Project description:BACKGROUND: Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. Many patients suffer from IBS that can be difficult to treat, thus complementary therapies which may be effective and have a lower likelihood of adverse effects are being sought.This systematic review and meta-analysis aimed at critically evaluating the current evidence on moxibustion for improving global symptoms of IBS. METHODS: We searched Medline, EMBASE, the Cochrane Central Register of Controlled Trials, AMED, CINAHL, and CNKI databases for randomised controlled trials (RCTs) of moxibustion comparing with sham moxibustion, pharmacological medications, and other active treatments in patients with IBS. Trials should report global symptom improvement as an outcome measure. Risk of bias for each RCT was assessed according to criteria by the Cochrane Collaboration, and the dichotomous data were pooled according to the control intervention to obtain a risk ratio (RR) of global symptom improvement after moxibustion, with 95% confidence intervals (CI). RESULTS: A total of 20 RCTs were eligible for inclusion (n = 1625). The risk of bias was generally high. Compared with pharmacological medications, moxibustion significantly alleviated overall IBS symptoms but there was a moderate inconsistency among studies (7 RCTs, RR 1.33, 95% CI [1.15, 1.55], I² = 46%). Moxibustion combined with acupuncture was more effective than pharmacological therapy but a moderate inconsistency among studies was found (4 RCTs, RR 1.24, 95% CI [1.09, 1.41], I² = 36%). When moxibustion was added to pharmacological medications or herbal medicine, no additive benefit of moxibustion was shown compared with pharmacological medications or herbal medicine alone. One small sham-controlled trial found no difference between moxibustion and sham control in symptom severity (mean difference 0.35, 95% CI [-0.77, 1.47]). Moxibustion appears to be associated with few adverse events but the evidence is limited due to poor reporting. CONCLUSIONS: This systematic review and meta-analysis suggests that moxibustion may provide benefit to IBS patients although the risk of bias in the included studies is relatively high. Future studies are necessary to confirm whether this finding is reproducible in carefully-designed and conducted trials and to firmly establish the place of moxibustion in current practice.
Project description:Children with food allergy have been shown to have increased small intestinal permeability (IP) following ingestion of the offending food as well as during elimination diets. We investigated IP in asymptomatic food allergic children during an elimination diet to identify clinical characteristics associated with altered IP.Urinary recovery ratios of lactulose and mannitol (L/M) were determined 5 h following ingestion of 7.5 g of lactulose and 2 g of mannitol in 131 cow's milk and egg allergic children. An L/M ratio of ?0.025 was considered abnormal based upon previously established laboratory internal references. A chart review was conducted to assess the clinical characteristics of these patients.A total of 50 (38%) of the 131 children (median 6.7, range 4.8-8.9 yr; 66.2% male) with food allergy had elevated IP while asymptomatic on strict elimination diets. Age and height negatively correlated with IP. However, in the regression model analysis, abnormal IP was associated with shorter stature independently of age. Otherwise, food allergic patients with increased IP were comparable in gender, nutritional status, age of onset of food allergy, history of reactions, atopic diseases, and family history of food allergies to those with normal IP.Elevated IP was found in about one-third of asymptomatic food allergic children on elimination diets and was associated with shorter stature. Our results suggest that increased IP may be an intrinsic trait in a subset of food allergic children. However, large, prospective studies are necessary to determine the role of impaired intestinal barrier in food allergy.
Project description:Background:Modulating gut microbiota is a potential treatment for irritable bowel syndrome (IBS). This meta-analysis explored whether fecal microbiota transplantation (FMT) is successful in treating IBS. Methods:A systematic review was performed to find trials on FMT in IBS. Ratios and relative ratios (RR) of improvement for single-arm trials (SATs) and randomized controlled trials (RCTs) were calculated, respectively. Changes in IBS Severity Scoring System (IBS-SSS) and IBS Quality of Life (IBS-QOL) instrument compared to baseline in FMT versus placebo groups were pooled. Results:In SATs, 59.5% (95% confidence interval (CI) 49.1-69.3) of IBS patients showed significant improvement. In RCTs, there were no differences between FMT and control in improvement (RR=0.93 (95% CI 0.50-1.75)) or changes in the IBS-SSS and IBS-QOL. Conclusions:FMT was not effective in IBS. Variations in FMT methods and patient factors may contribute to the heterogeneous results of the trials.