-
1.
Exploration of differential responses to FODMAPs and gluten in people with irritable bowel syndrome- a double-blind randomized cross-over challenge study.
Nordin, E, Landberg, R, Hellström, PM, Brunius, C
Metabolomics : Official journal of the Metabolomic Society. 2024;20(2):21
-
-
-
Free full text
Plain language summary
Irritable bowel syndrome (IBS) is a complex condition characterized by recurrent abdominal pain associated with abnormal bowel habits. Diet is considered a main cause of symptoms in IBS, and fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) are of major concern. The aim of this study was to unravel determinants of differential IBS responses to FODMAP and gluten provocation interventions from molecular data. This study was a randomised, double-blind, placebo-controlled three-way crossover study. Participants were randomised in blocks of 12 into the sequences CBA, ACB, and BAC (A=FODMAPs, B=Gluten, and C=Placebo). Results showed that despite a comprehensive set of methods applied to explore IBS responses, including both regression and classification, predictors of differential response could not be established. Authors concluded by encouraging the application of molecular subtyping methodologies in future studies due to the differential responses to treatment.
Abstract
INTRODUCTION There is large variation in response to diet in irritable bowel syndrome (IBS) and determinants for differential response are poorly understood. OBJECTIVES Our aim was to investigate differential clinical and molecular responses to provocation with fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) and gluten in individuals with IBS. METHODS Data were used from a crossover study with week-long interventions with either FODMAPs, gluten or placebo. The study also included a rapid provocation test. Molecular data consisted of fecal microbiota, short chain fatty acids, and untargeted plasma metabolomics. IBS symptoms were evaluated with the IBS severity scoring system. IBS symptoms were modelled against molecular and baseline questionnaire data, using Random Forest (RF; regression and clustering), Parallel Factor Analysis (PARAFAC), and univariate methods. RESULTS Regression and classification RF models were in general of low predictive power (Q2 ≤ 0.22, classification rate < 0.73). Out of 864 clustering models, only 2 had significant associations to clusters (0.69 < CR < 0.73, p < 0.05), but with no associations to baseline clinical measures. Similarly, PARAFAC revealed no clear association between metabolome data and IBS symptoms. CONCLUSION Differential IBS responses to FODMAPs or gluten exposures could not be explained from clinical and molecular data despite extensive exploration with different data analytical approaches. The trial is registered at www. CLINICALTRIALS gov as NCT03653689 31/08/2018.
-
2.
Effects of FODMAPs and Gluten on Gut Microbiota and Their Association with the Metabolome in Irritable Bowel Syndrome: A Double-Blind, Randomized, Cross-Over Intervention Study.
Nordin, E, Hellström, PM, Dicksved, J, Pelve, E, Landberg, R, Brunius, C
Nutrients. 2023;15(13)
-
-
-
Free full text
Plain language summary
Irritable bowel syndrome (IBS) is defined as recurring abdominal pain in relation to stool irregularities. The mechanisms behind IBS are poorly understood, but changes in gut microbiota composition, intestinal barrier function, enteroendocrine cell population, low-grade inflammation and gut–brain axis modulations are believed to play a role. The aim of this study was to investigate how fermentable oligo-, di-, mono-saccharides, and polyols (FODMAPs) and gluten affected gut microbiota and circulating metabolite profiles, as well as to investigate potential links between gut microbiota, metabolites, and IBS symptoms. This study was a double-blind, placebo-controlled three-way crossover study. Both the study personnel and participants were blinded. Results showed that consumption of high FODMAP foods, but not gluten, altered the gut microbiota composition, in particular causing changes to microbiota and metabolites, previously associated with improved metabolic health and reduced inflammation. There were also minor effects of FODMAPs and gluten on short-chain fatty acids. Authors conclude that the intake of FODMAP, but not gluten, over one week altered the gut microbiota composition, with only weak associations with IBS symptoms. Healthcare practitioners working with IBS should consider the impacts on the gut microbiome when advising the use of a low-FODMAP diet.
Abstract
BACKGROUND A mechanistic understanding of the effects of dietary treatment in irritable bowel syndrome (IBS) is lacking. Our aim was therefore to investigate how fermentable oligo- di-, monosaccharides, and polyols (FODMAPs) and gluten affected gut microbiota and circulating metabolite profiles, as well as to investigate potential links between gut microbiota, metabolites, and IBS symptoms. METHODS We used data from a double-blind, randomized, crossover study with week-long provocations of FODMAPs, gluten, and placebo in participants with IBS. To study the effects of the provocations on fecal microbiota, fecal and plasma short-chain fatty acids, the untargeted plasma metabolome, and IBS symptoms, we used Random Forest, linear mixed model and Spearman correlation analysis. RESULTS FODMAPs increased fecal saccharolytic bacteria, plasma phenolic-derived metabolites, 3-indolepropionate, and decreased isobutyrate and bile acids. Gluten decreased fecal isovalerate and altered carnitine derivatives, CoA, and fatty acids in plasma. For FODMAPs, modest correlations were observed between microbiota and phenolic-derived metabolites and 3-indolepropionate, previously associated with improved metabolic health, and reduced inflammation. Correlations between molecular data and IBS symptoms were weak. CONCLUSIONS FODMAPs, but not gluten, altered microbiota composition and correlated with phenolic-derived metabolites and 3-indolepropionate, with only weak associations with IBS symptoms. Thus, the minor effect of FODMAPs on IBS symptoms must be weighed against the effect on microbiota and metabolites related to positive health factors.
-
3.
Effects of a low FODMAP diet on gut microbiota in individuals with treated coeliac disease having persistent gastrointestinal symptoms - a randomised controlled trial.
Herfindal, AM, van Megen, F, Gilde, MKO, Valeur, J, Rudi, K, Skodje, GI, Lundin, KEA, Henriksen, C, Bøhn, SK
The British journal of nutrition. 2023;130(12):2061-2075
-
-
-
Free full text
-
Plain language summary
Coeliac disease (CeD) is a common immune-mediated disease where intolerance to gluten can lead to severe health problems with a wide range of gastrointestinal (GI) and extra-intestinal symptoms. Research shows that a diet low in fermentable oligo-, di-, mono-saccharides and polyols (FODMAP) helps to reduce GI symptoms in irritable-bowel syndrome and gluten-free diet treated CeD. The aim of this study was to investigate whether a low FODMAP diet (LFD) in this patient group affects (i) the faecal microbiota, (ii) the concentrations of faecal short-chain fatty acids (SCFA) and (iii) the concentrations of faecal human neutrophil gelatinase-associated lipocalin (a biomarker of gut inflammation). This study is part of a clinical trial which followed a nonblinded, parallel randomised design. The participants were randomised to either an LFD group or a control group. Results showed that after four weeks, certain differences in gut microbiota were detected between the control and LFD group. The SCFA results indicated that the LFD resulted in lower concentrations of propionic and valeric acid in participants with initially high concentrations. Biomarker of gut inflammation was, however, unaffected by the LFD. Authors conclude that the LFD led to changes in overall community structure of the faecal microbiota, with a possible unfavourable low faecal abundance of Anaerostipes, and low concentrations of the faecal SCFA propionic and valeric acid in participants with high concentrations of these acids at baseline.
Abstract
Individuals with coeliac disease (CeD) often experience gastrointestinal symptoms despite adherence to a gluten-free diet (GFD). While we recently showed that a diet low in fermentable oligo-, di-, monosaccharides and polyols (FODMAP) successfully provided symptom relief in GFD-treated CeD patients, there have been concerns that the low FODMAP diet (LFD) could adversely affect the gut microbiota. Our main objective was therefore to investigate whether the LFD affects the faecal microbiota and related variables of gut health. In a randomised controlled trial GFD-treated CeD adults, having persistent gastrointestinal symptoms, were randomised to either consume a combined LFD and GFD (n 39) for 4 weeks or continue with GFD (controls, n 36). Compared with the control group, the LFD group displayed greater changes in the overall faecal microbiota profile (16S rRNA gene sequencing) from baseline to follow-up (within-subject β-diversity, P < 0·001), characterised by lower and higher follow-up abundances (%) of genus Anaerostipes (Pgroup < 0·001) and class Erysipelotrichia (Pgroup = 0·02), respectively. Compared with the control group, the LFD led to lower follow-up concentrations of faecal propionic and valeric acid (GC-FID) in participants with high concentrations at baseline (Pinteraction ≤ 0·009). No differences were found in faecal bacterial α-diversity (Pgroup ≥ 0·20) or in faecal neutrophil gelatinase-associated lipocalin (ELISA), a biomarker of gut integrity and inflammation (Pgroup = 0·74), between the groups at follow-up. The modest effects of the LFD on the gut microbiota and related variables in the CeD patients of the present study are encouraging given the beneficial effects of the LFD strategy to treat functional GI symptoms (Registered at clinicaltrials.gov as NCT03678935).
-
4.
The Usefulness of the Low-FODMAP Diet with Limited Tryptophan Intake in the Treatment of Diarrhea-Predominant Irritable Bowel Syndrome.
Chojnacki, C, Poplawski, T, Blonska, A, Konrad, P, Chojnacki, J, Blasiak, J
Nutrients. 2023;15(8)
-
-
-
Free full text
Plain language summary
Several pathogenic factors are responsible for the occurrence of irritable bowel syndrome (IBS-D), and food products are present among them. The human diet contains various nutrients, which may have beneficial or unfavourable effects. Numerous patients with IBS attribute their abdominal symptoms to food, and in fact, certain foods ingested can cause exaggerated gastrointestinal complaints. The aim of this study was to evaluate the effect of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (known as the low-FODMAP) diet with a limitation of Tryptophan (TRP) intake on the clinical symptoms of patients with IBS-D in relation to its metabolism along the serotonin and kynurenine pathways. This study enrolled 40 healthy people (controls) and 80 patients with IBS-D. The IBS-D patients were randomly divided into two groups of 40 each (Groups IIA and IIB). In Group IIA, the low-FODMAP diet was recommended, while in Group IIB, the same diet was recommended but with limited TRP intake for 8 weeks. Results showed that: - both groups did not differ in clinical parameters or daily TRP consumption. - all IBS-D patients in both subgroups showed similar severity of abdominal complaints as well as anxiety and depressive symptoms before nutritional intervention. - reducing the amount of TRP content in a low-FODMAP diet improves its effectiveness in the treatment of IBS-D patients. Authors concluded that lowering the tryptophan content of a low-FODMAP diet may be useful in treating diarrhoea-predominant irritable bowel syndrome.
Abstract
(1) Background: A low-FODMAP diet is often recommended in the treatment of irritable bowel syndrome, but it does not improve abdominal symptoms in all patients, and an alternative diet is desirable. The purpose of this study was to evaluate the efficacy of a low-FODMAP diet with a concomitant reduction in tryptophan (TRP) intake in irritable bowel syndrome with diarrhea predominance (IBS-D) in relation to its metabolism via the serotonin and kynurenine pathways. (2) Methods: 40 healthy people (Group I, Controls) and 80 patients with IBS-D were included in the study. IBS-D patients were randomly divided into two groups of 40 each (Groups IIA and IIB). In Group IIA, the low-FODMAP diet was recommended, while in Group IIB, the same diet was recommended but with limited TRP intake for 8 weeks. The TRP intake was analyzed with the use of the nutritional calculator. Abdominal complaints were assessed using the Gastrointestinal Symptom Rating Scale (GSRS-IBS), and psychological status was simultaneously determined using two scales: the Hamilton Anxiety Scale (HAM-A) and the Hamilton Depression Scale (HAM-D). TRP and its metabolites: 5-hydoxyindoleacetic acid (5-HIAA), kynurenine (KYN), kynurenic acid (KYNA), and quinolinic acid (QA) were measured in urine using liquid chromatography tandem mass spectrometry (LC-MS/MS). (3) Results: The consumption of TRP per mg/kg/b.w./24 h has decreased in Group IIA from 20.9 ± 2.39 to 17.45 ± 2.41 (16.5%) and in Group IIB from 21.3 ± 2.33 to 14.32 (34.4%). Significantly greater improvement was found after nutritional treatment in patients in Group IIB as compared to Group IIA (GSRS score: 38.1% vs. 49.8%; HAM-A: 38.7% vs. 49.9%; HAM-D: 13.8% vs. 35.0%; p < 0.01). Reducing TRP intake showed a negative correlation with the degree of improvement in the GSRS score. (4) Conclusions: Lowering the TRP content in a low-FODMAP diet may be useful in treating IBS-D.
-
5.
Randomised controlled trial: effects of gluten-free diet on symptoms and the gut microenvironment in irritable bowel syndrome.
Algera, JP, Magnusson, MK, Öhman, L, Störsrud, S, Simrén, M, Törnblom, H
Alimentary pharmacology & therapeutics. 2022;56(9):1318-1327
-
-
-
Free full text
-
Plain language summary
The majority of irritable bowel syndrome (IBS) patients relate their symptoms to intake of certain foods. The gut microenvironment, where microbiota, food components and the nervous system interact, is suggested to play a key role in gastrointestinal (GI) symptom generation in a subset of IBS patients. The main aim of this study was to assess and compare the efficacy of the gluten-free and gluten-containing diets in terms of effects on GI symptoms in IBS patients. Secondary aims where to identify the putative link between gut microenvironment and the diets´ effect on GI symptoms, and to identify potential predictors of clinical response to the gluten-free diet. This study is a single-centre, double-blind, randomised, placebo-controlled, cross-over trial. Adult sex- and age-matched IBS patients (n=20) and healthy controls (HC) (n=21) were recruited, randomised and challenged with gluten (14 g/day) and rice flour, both for 2 weeks, while adhering to a strict gluten-free diet. Results indicate that a gluten-free diet may affect IBS symptoms in general, and bowel habits in a subset of IBS patients. The gluten-free diet has distinct effect on the gut microenvironment in IBS patients who respond favourably to gluten reduction. Authors conclude that the gut microenvironment may be of importance in the clinical response to the gluten-free diet in IBS, and future studies should aim to further assess these factors in relation to clinical response to the gluten-free diet.
Abstract
BACKGROUND A gluten-free diet reduces symptoms in some patients with irritable bowel syndrome (IBS) through unclear mechanisms. AIMS To assess the effects of gluten-free versus gluten-containing diet on symptoms and the gut microenvironment, and to identify predictors of response to the gluten-free diet in IBS METHODS Twenty patients with IBS and 18 healthy controls (HC) followed a gluten-free diet during two 14-day intervention periods where they sprinkled either gluten (14 g/day) or rice flour powder over their meals. Primary outcomes included effects of the interventions on IBS symptoms (IBS-SSS) and bowel habits. Secondary outcomes included effects of gluten-free diet on faecal microbiota and metabolite profile. RESULTS IBS symptoms improved during the gluten-free (p = 0.02), but not the gluten-containing period, with no difference between the interventions. IBS patients reported fewer loose stools during the gluten-free intervention (p = 0.01). Patients with IBS and HC presented distinct metabolite profiles based on the effects of the gluten-free diet (p < 0.001). True responders (reduced IBS-SSS by ≥50 solely after gluten-free period) and non-responders were discriminated based on the effects of the gluten-free diet on the microbiota (p < 0.01) and metabolite profiles (p < 0.001). The response to the gluten-free diet could be predicted by the metabolite profile before the intervention (p < 0.001). CONCLUSIONS A gluten-free diet may influence symptoms in a subset of patients with IBS, with a particular effect on bowel habits. A gluten-free diet seems to impact the gut microenvironment. Responsiveness to the gluten-free diet may be predicted by the metabolite profile. CLINICALTRIALS gov: NCT03869359.
-
6.
Efficacy and Acceptability of Dietary Therapies in Non-Constipated Irritable Bowel Syndrome: A Randomized Trial of Traditional Dietary Advice, the Low FODMAP Diet, and the Gluten-Free Diet.
Rej, A, Sanders, DS, Shaw, CC, Buckle, R, Trott, N, Agrawal, A, Aziz, I
Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2022;20(12):2876-2887.e15
-
-
-
-
Free full text
-
Plain language summary
Irritable bowel syndrome (IBS) is a common disorder characterised by stomach pain, bloating, and altered bowel movements. Dietary therapy is a way to manage IBS, with 3 diets becoming popular amongst health care professionals and those who suffer from IBS. Traditional dietary advice (TD), which involves adopting healthy, sensible eating patterns with adequate hydration, is the first line recommendation in the UK. The low-FODMAP diet (LFD) is the avoidance of carbohydrates, which tend to ferment in the stomach and are found in certain fruits and vegetables. The gluten free diet (GFD) is the avoidance of foods which contain gluten such as bread and pasta. All three diets have little evidence to support their use in IBS and this randomised control trial of 101 individuals with IBS aimed to determine whether the GFD and LFD are superior in relieving IBS symptoms compared to TD. The results showed that GFD, LFD and TD were all effective in the management of non-constipated IBS, but that TD was easier to follow and cheaper compared to the other two diets. It was concluded that TD should be used as first-line therapy for people with non-constipated IBS and that GFD and LFD should be reserved for specific patients under the care of a health care professional.
Expert Review
Conflicts of interest:
None
Take Home Message:
- TDA, LFD and GFD can all lead to significant improvements in non-constipation IBS with no statistically significant difference in effectiveness between the diets.
- Most patients find a TDA easier and cheaper to implement than a LFD or GFD.
- TDA is therefore recommended as a first line approach in non-constipation IBS.
Evidence Category:
-
X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
Introduction
The aim of this study was to compare the effectiveness and patient acceptability of traditional dietary advice (TDA) vs a low FODMAP diet (LFD) vs a gluten-free diet (GFD, cross-contamination allowed) in patients with non-constipation irritable bowel syndrome (IBS).
TDA definition: healthy, sensible eating pattern, including regular meals, not eating too little/too much, adequate hydration, and reducing the intake of: alcohol/caffeine/fizzydrinks/fatty/spicy/ processed foods; fresh fruit (maximum of 3 per day); fibre/gas-producing foods and perceived food intolerances.
Methods
This was a randomised dietary trial over 4 weeks. Dietary advice was provided by a specialist dietitian in a session lasting 45-60 minutes. 99 patients completed the study (33 in each group). Stool analysis was performed in “around half“ (study authors terminology) of participants due to disruption of trial caused by COVID-19.
Results:
- Primary endpoint (reduction of 50 points or more on IBS symptom severity score) was met by 42% of patients on the TDA, 55% on LFD and 58% on GFD. The differences between groups were not statistically significant, p=0.43.
- Patients on the LFD had greater improvements in mood compared to the other diets under examination, reaching statistical significance (p=0.03) for Hospital Anxiety and Depression scale and (p<0.01) for dysphoria score on IBS-QOL scale.
- Patients on TDA found their diet cheaper (p<0.01), less time consuming to shop (p<0.01) and easier to follow when eating out with family and friends (p=0.03), whilst TDA and GFD were considered easier to incorporate into daily diet than LFD (p=0.02).
- No significant differences were found between groups in changes to macro- and micronutrient composition, except a trend to lower fibre intake with LFD (p=0.06).
- There was a significant reduction in intake of FODMAPs in all groups, with greatest reduction in LFD (27.7 to 7.6 g/day, p<0.01), followed by TDA (24.9 to 15.2 g/day, p<0.01) and GFD (27.4 to 22.4 g/day, p=0.03). Differences between groups were statistically significant (p<0.01).
- No differences were noted in change to the dysbiosis index between groups.
- Neither clinical characteristics nor dysbiosis index predicted response to any of the diets.
Conclusion
- TDA, LFD and GFD are all effective approaches for non-constipation IBS.
- TDA should be first-line dietary advice due to being the most patient-friendly.
Clinical practice applications:
- When working with clients with non-constipation IBS, a TDA approach may be favoured over LFD and GFD as a first line intervention if the patient has not already tried a TDA diet.
- Patient preferences, budget, time and living situation should be taken into account when deciding on best dietary advice for IBS.
Considerations for future research:
- As all 3 approaches led to reduction in FODMAPs, trials comparing different levels of FODMAP exclusion could lead to valuable information, as a strict FODMAP exclusion, which is commonly recommended in IBS, is difficult and may not be necessary.
- Studies of longer duration would be valuable to confirm that benefits observed with the 3 approaches are not short-term only.
- Comparing individual approaches to appropriate control group would ensure that improvements are not due to a placebo effect.
Abstract
BACKGROUND & AIMS Various diets are proposed as first-line therapies for non-constipated irritable bowel syndrome (IBS) despite insufficient or low-quality evidence. We performed a randomized trial comparing traditional dietary advice (TDA) against the low FODMAP diet (LFD) and gluten-free diet (GFD). METHODS Patients with Rome IV-defined non-constipated IBS were randomized to TDA, LFD, or GFD (the latter allowing for minute gluten cross-contamination). The primary end point was clinical response after 4 weeks of dietary intervention, as defined by ≥50-point reduction in IBS symptom severity score (IBS-SSS). Secondary end points included (1) changes in individual IBS-SSS items within clinical responders, (2) acceptability and food-related quality of life with dietary therapy, (3) changes in nutritional intake, (4) alterations in stool dysbiosis index, and (5) baseline factors associated with clinical response. RESULTS The primary end point of ≥50-point reduction in IBS-SSS was met by 42% (n = 14/33) undertaking TDA, 55% (n = 18/33) for LFD, and 58% (n = 19/33) for GFD (P = .43). Responders had similar improvements in IBS-SSS items regardless of their allocated diet. Individuals found TDA cheaper (P < .01), less time-consuming to shop (P < .01), and easier to follow when eating out (P = .03) than the GFD and LFD. TDA was also easier to incorporate into daily life than the LFD (P = .02). Overall reductions in micronutrient and macronutrient intake did not significantly differ across the diets. However, the LFD group had the greatest reduction in total FODMAP content (27.7 g/day before intervention to 7.6 g/day at week 4) compared with the GFD (27.4 g/day to 22.4 g/day) and TDA (24.9 g/day to 15.2 g/day) (P < .01). Alterations in stool dysbiosis index were similar across the diets, with 22%-29% showing reduced dysbiosis, 35%-39% no change, and 35%-40% increased dysbiosis (P = .99). Baseline clinical characteristics and stool dysbiosis index did not predict response to dietary therapy. CONCLUSIONS TDA, LFD, and GFD are effective approaches in non-constipated IBS, but TDA is the most patient-friendly in terms of cost and convenience. We recommend TDA as the first-choice dietary therapy in non-constipated IBS, with LFD and GFD reserved according to specific patient preferences and specialist dietetic input. CLINICALTRIALS gov: NCT04072991.
-
7.
Fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), but not gluten, elicit modest symptoms of irritable bowel syndrome: a double-blind, placebo-controlled, randomized three-way crossover trial.
Nordin, E, Brunius, C, Landberg, R, Hellström, PM
The American journal of clinical nutrition. 2022;115(2):344-352
-
-
-
Free full text
-
Plain language summary
Irritable bowel syndrome (IBS) is a chronic functional bowel disorder that is characterised by recurring abdominal pain over ≥3 months within a 6-month period in association with altered bowel habits. Symptomatic treatment of IBS includes dietary adaptation, with a focus on prebiotics, probiotics, gluten, and fermentable oligo-, di-, monosaccharides and polyols (FODMAPs). The main aim of this study was to investigate the effects of weeklong interventions with high intakes of a wide range of FODMAPs, gluten, or a nonfermentable placebo in subjects with moderate to severe IBS. This study is a double-blind, placebo-controlled, randomised 3-way study with triple crossover design. One-hundred and ten participants were enrolled and randomly assigned for the study. Results show that a mixture of widely consumed FODMAPs caused only modest worsening of gastrointestinal symptoms compared with gluten and placebo. Authors conclude that there were interindividual variability in the intervention responses. Thus, future studies should investigate these differences to understand possible underlying disease mechanisms.
Abstract
BACKGROUND Irritable bowel syndrome (IBS) has been associated with diets rich in fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), and gluten. Most previous studies have been single-blind and have focused on the elimination of FODMAPs or provocation with single FODMAPs. The effect of gluten is unclear, large trials isolating the effect of gluten from that of FODMAPs are needed. OBJECTIVES The aims of this study were to ensure high intakes of a wide range of FODMAPs, gluten, or placebo, and to evaluate the effects on IBS symptoms using the IBS-severity scoring system (IBS-SSS). METHODS The study was carried out with a double-blind, placebo-controlled, randomized 3-way crossover design in a clinical facility in Uppsala from September 2018 to June 2019. In all, 110 participants fulfilling the IBS Rome IV criteria, with moderate to severe IBS, were randomly assigned; 103 (90 female, 13 male) completed the trial. Throughout, IBS participants maintained a diet with minimal FODMAP content and no gluten. Participants were block-randomly assigned to 1-wk interventions with FODMAPs (50 g/d), gluten (17.3 g/d), or placebo, separated by 1-wk washout. All participants who completed ≥1 intervention were included in the intention-to-treat analysis. RESULTS In participants with IBS (n = 103), FODMAPs caused higher IBS-SSS scores (mean 240 [95% CI: 222, 257]) than placebo (198 [180, 215]; P = 0.00056) or gluten (208 [190, 226]; P = 0.013); no differences were found between the placebo and gluten groups (P = 1.0). There were large interindividual differences in IBS-SSS scores associated with treatment. No adverse events were reported. CONCLUSION In participants with IBS, FODMAPs had a modest effect on typical IBS symptoms, whereas gluten had no effect. The large interindividual differences in responses to the interventions warrant further detailed studies to identify possible underlying causes and enable individual prediction of responses. This trial was registered at www.clinicaltrials.gov as NCT03653689.
-
8.
Predictors of Symptom-Specific Treatment Response to Dietary Interventions in Irritable Bowel Syndrome.
Colomier, E, Van Oudenhove, L, Tack, J, Böhn, L, Bennet, S, Nybacka, S, Störsrud, S, Öhman, L, Törnblom, H, Simrén, M
Nutrients. 2022;14(2)
-
-
-
-
Free full text
Plain language summary
Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction, formerly known as a functional gastrointestinal (GI) disorder. Apart from abdominal pain, altered stool frequency, diarrhoea, and constipation, a large proportion of patients with IBS also experience other GI symptoms such as abdominal distention, bloating and flatulence. The aim of this study was to investigate predictors of treatment response to the low FODMAP (short-chain carbohydrates, i.e., fermentable oligo-, di-, monosaccharides, and polyols) and the traditional IBS diet while focusing on the four core IBS symptoms (bloating, constipation, diarrhoea, and pain). This study was a post-hoc analysis of a previously published randomised controlled trial. In total, 33 patients on low FODMAP diet and 34 patients on the traditional IBS diet were included in the analysis. Results showed that patterns of psychological, dietary, and microbial factors can predict IBS symptom response to two dietary advice systems—the traditional IBS and the low FODMAP diet. A clinical profile with less severe IBS features appears to predict a better symptom-specific response to both dietary interventions. Authors conclude that larger prospective randomised controlled trials which include different treatment approaches are required as they may help to optimize personalized treatment algorithms in IBS.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Dietary intervention for IBS related symptoms was efficacious for up to 75% of patients in this study
- Recommendation for a traditional IBS dietary intervention should supersede the low-FODMAP diet, with the latter only implemented when symptoms persist.
Evidence Category:
-
X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
Introduction
This randomised controlled intervention study of 67 individuals fulfilling the Rome III criteria for IBS drew comparisons between the efficacy of the traditional IBS diet - as directed by the British Dietetic Association and National Institute for Health and Care Excellence (NICE) - and the low fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) diet on specific IBS-related symptoms (pain, constipation, diarrhoea, and bloating).
Methods
A 10-day screening period included faecal sample analysis, 4-day food diary (pre-randomisation and last week of intervention), and daily stool diary (Bristol Stool Form scale). After 10 days, patients compiled several GI and non-GI related questionnaires, inclusive of IBS severity scoring system (IBS-SSS). Patients who scored ≥175 for the IBS-SSS were randomly allocated to follow either a low-FODMAP or traditional IBS diet for a period of 4-weeks. Thorough explanations were provided by trained Dietitians. During intervention, patients compiled symptom questionnaires (Gastrointestinal Symptoms Rating Scale-IBS) on a weekly basis.
Results
- Both diets reduced symptoms of pain, diarrhoea and bloating (all p<0.0001), but not constipation (p=0.15)
- There was no difference between following the traditional IBS diet and low-FODMAP diet in terms of pain (p=0.80), constipation (p=0.63), diarrhoea (p=0.96) and bloating (p=0.35)
- Less severe gut dysbiosis was weakly associated with better dietary response and improvement of constipation (p=0.05)
- Higher energy intake at baseline predicted better pain improvement with both dietary types compared to lower energy intake (p=0.03)
- More severe psychological distress predicted worse intervention response for bloating (p=0.03)
- Higher baseline oligosaccharide intake predicted a worse response to the low FODMAP diet (p=0.01) but not the traditional IBS diet (p=0.16).
Conclusion
This study demonstrated that based on 4 distinct IBS-related symptomatology, better treatment response to 2 different dietary strategies was noted in patients with less severe clinical characteristics. Higher energy intake at baseline and gut dysbiosis scores that were similar to healthy controls were associated with better improvements following dietary interventions. Thus patients who already follow a calorie restricted diet and who have more significant gut dysbiosis profiles might need more bespoke intervention. Severe psychological distress patients responded worse to both diets.
Clinical practice applications:
- Even a short 4-week specific dietary intervention (low FODMAP or traditional IBS diet) can result in IBS-related symptomatic improvement for pain, bloating, and diarrhoea, but not constipation
- The preferred starting point for dietary intervention should be the traditional IBS diet given its relative ease to follow
- The more restrictive low FODMAP protocol could be considered if symptoms persist
- More bespoke interventions are required for patients who suffer with severe psychological stress, have tested and found gut dysbiosis, and individuals who already follow a restrictive diet.
Considerations for future research:
- Future studies need to include not only larger but more diverse cultural and socio-economic cohorts to ascertain the efficacy of IBS symptom-related dietary interventions
- Longer periods of intervention are needed to confirm dietary intervention efficacy.
Abstract
(1) Background: Predictors of dietary treatment response in irritable bowel syndrome (IBS) remain understudied. We aimed to investigate predictors of symptom improvement during the low FODMAP and the traditional IBS diet for four weeks. (2) Methods: Baseline measures included faecal Dysbiosis Index, food diaries with daily energy and FODMAP intake, non-gastrointestinal (GI) somatic symptoms, GI-specific anxiety, and psychological distress. Outcomes were bloating, constipation, diarrhea, and pain symptom scores treated as continuous variables in linear mixed models. (3) Results: We included 33 and 34 patients on the low FODMAP and traditional IBS diet, respectively. Less severe dysbiosis and higher energy intake predicted better pain response to both diets. Less severe dysbiosis also predicted better constipation response to both diets. More severe psychological distress predicted worse bloating response to both diets. For the different outcomes, several differential predictors were identified, indicating that baseline factors could predict better improvement in one treatment arm, but worse improvement in the other treatment arm. (4) Conclusions: Psychological, nutritional, and microbial factors predict symptom improvement when following the low FODMAP and traditional IBS diet. Findings may help individualize dietary treatment in IBS.
-
9.
Gluten and FODMAPs Relationship with Mental Disorders: Systematic Review.
Aranburu, E, Matias, S, Simón, E, Larretxi, I, Martínez, O, Bustamante, MÁ, Fernández-Gil, MDP, Miranda, J
Nutrients. 2021;13(6)
-
-
-
Free full text
Plain language summary
There is growing evidence that gluten and FODMAPs, such as fermentable oligosaccharides, disaccharides, monosaccharides and polyols, can cause gastrointestinal symptoms, inflammation, and immune responses in patients with celiac disease and irritable bowel syndrome. In addition, a high intake of gluten and FODMAPs may also be associated with neurological and psychiatric disorders. Thirteen studies were included in this systematic review to examine the relationship between gluten and FODMAP consumption and illnesses affecting the central nervous system. In addition, the studies examined the effects of potential dietary strategies that consider gluten and FODMAP intake on mental disorders, anxiety, depression, schizophrenia, Alzheimer’s disease, and autism spectrum disorders. Several possible mechanisms identified in this systematic review could contribute to neurological and psychiatric disorders, including the release of proinflammatory cytokines, immune responses, gut dysbiosis, intestinal permeability, and interactions between the gut-brain axis. In patients with fibromyalgia, celiac disease, and irritable bowel syndrome, avoiding or limiting gluten may reduce depression, anxiety, and cognitive impairment. However, the effects of a low-FODMAP diet on the central nervous system are inconclusive. There is some evidence that gluten-free diets can improve cognition in schizophrenia patients. In addition, those with autism spectrum disorders may benefit from a gluten-free diet and a low-FODMAP diet. Further robust research is required to evaluate the beneficial effects of interventions that avoid or restrict the consumption of foods high in FODMAPs and gluten. However, healthcare professionals can use the results of this systematic review to understand the potential benefits of therapeutic interventions that consider the intake of FODMAPs and gluten on illnesses affecting the central nervous system and their possible mechanisms of action.
Abstract
Nowadays, gluten and FODMAP food components (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) are increasingly studied due to their possible relation with extraintestinal-associated conditions. In recent years, gluten-free diets (GFD) and low-FODMAP diets (LFD) are becoming more popular not only in order to avoid the food components that cause intolerances or allergies in some people, but also due to the direct influence of marketing movements or diet trends on feeding habits. Likewise, neurological and psychiatric diseases are currently of increasing importance in developed countries. For this reason, a bibliographic systematic review has been carried out to analyse whether there is a pathophysiological relationship between the dietary intake of gluten or FODMAPs with mental disorders. This review collects 13 clinical and randomized controlled trials, based on the PRISMA statement, which have been published in the last ten years. Based on these results, limiting or ruling out gluten or FODMAPs in the diet might be beneficial for symptoms such as depression, anxiety (7 out of 7 articles found any positive effect), or cognition deficiency (improvements in several cognition test measurements in one trial), and to a lesser extent for schizophrenia and the autism spectrum. Nevertheless, further studies are needed to obtain completely reliable conclusions.
-
10.
Small Intestinal Bacterial Overgrowth in Children: A State-Of-The-Art Review.
Avelar Rodriguez, D, Ryan, PM, Toro Monjaraz, EM, Ramirez Mayans, JA, Quigley, EM
Frontiers in pediatrics. 2019;7:363
-
-
-
Free full text
Plain language summary
Small intestinal bacterial overgrowth (SIBO) occurs when microorganisms overpopulate the small intestine and is characterised by gastrointestinal symptoms such as abdominal pain, diarrhoea, and flatulence. This review focuses on paediatric SIBO, known to be increasing, with emphasis on the impact on gut microbiota. The gut microbiota is influenced by several factors including genetics, vaginal delivery, exercise and diet. SIBO in children has been studied in the context of stunting, irritable bowel syndrome (IBS), obesity, and related to use of proton pump inhibitors (PPIs). This review analysed 149 studies published since 2000 through till May 2019 with the aim of presenting the most up-to-date information. Risk factors included gastric acids and medications which suppress this activity, intestinal motility disturbances leading to bacterial overgrowth, anatomical anomalies where there is an absence of one or more intestinal valves, and poor socioeconomic status and diet. The review concluded that the recommended diagnosis is by methane and hydrogen breath testing and that Gold Standard treatment is antibiotic ‘rifaximin’ at 1,200 mg/d, reduced to 600 mg/d for 1 week in children. Alternative treatments discussed include FODMAP diets and probiotic protocols with best results coming from combining antibiotic and probiotic protocols. It concludes that SIBO in children is heterogenous and poorly understood and that a better diagnostic criteria is necessary in paediatrics.
Abstract
Small intestinal bacterial overgrowth (SIBO) is a heterogenous and poorly understood entity characterised by an excessive growth of select microorganisms within the small intestine. This excessive bacterial biomass, in turn, disrupts host physiology in a myriad of ways, leading to gastrointestinal and non-gastrointestinal symptoms and complications. SIBO is a common cause of non-specific gastrointestinal symptoms in children, such as chronic abdominal pain, abdominal distention, diarrhoea, and flatulence, amongst others. In addition, it has recently been implicated in the pathophysiology of stunting, a disease that affects millions of children worldwide. Risk factors such as acid-suppressive therapies, alterations in gastrointestinal motility and anatomy, as well as impoverished conditions, have been shown to predispose children to SIBO. SIBO can be diagnosed via culture-dependant or culture-independent approaches. SIBO's epidemiology is limited due to the lack of uniformity and consensus of its diagnostic criteria, as well as the paucity of literature available. Antibiotics remain the first-line treatment option for SIBO, although emerging modalities such as probiotics and diet manipulation could also have a role. Herein, we present a state-of-the-art-review which aims to comprehensively outline the most current information on SIBO in children, with particular emphasis on the gut microbiota.