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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
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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.
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Examining the Association between Coffee Intake and the Risk of Developing Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis.
Lee, JY, Yau, CY, Loh, CYL, Lim, WS, Teoh, SE, Yau, CE, Ong, C, Thumboo, J, Namasivayam, VSO, Ng, QX
Nutrients. 2023;15(22)
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Irritable bowel syndrome (IBS) is a highly prevalent disorder of brain–gut interaction with a significant impact on quality of life and social functioning. Diet has been implicated in the pathophysiology of IBS as well as disease flares. A significant proportion of IBS patients experience food-related symptoms associated with consuming or eliminating certain foods. This study's aim was to determine if there is an association between coffee intake and the likelihood of developing IBS. This study was a systematic review and meta-analysis of eight studies with 432,022 participants. Results showed that coffee drinkers (any intake) may have a decreased risk of developing IBS compared to controls. However, these findings must be interpreted in light of several shortcomings. Authors concluded that future studies should (1) prioritise high-quality prospective cohort studies with well-documented coffee consumption (and exposure) and track the development of incident IBS in previously healthy individuals over time, and (2) investigate biological mechanisms.
Abstract
Irritable bowel syndrome (IBS) is a highly prevalent disorder of brain-gut interaction with a significant impact on quality of life. Coffee is a widely consumed beverage with numerous bioactive compounds that have potential effects on human health and disease states. Current studies on the effect of regular coffee consumption on the risk of developing IBS symptoms have yielded conflicting results. This systematic review and meta-analysis aimed to determine whether coffee intake is associated with developing IBS. A systematic literature search was performed in three electronic databases, namely PubMed, EMBASE, and The Cochrane Library, from inception until 31 March 2023. All original studies reporting associations between coffee intake and IBS were considered for inclusion. Odds ratios (ORs) were calculated for each study, and estimates were pooled, and where appropriate, 95% confidence intervals (95% CI) and p-values were calculated. Eight studies comprising 432,022 patients were included in the final meta-analysis. Using a fixed-effects model, coffee drinkers (any intake) had a reduced likelihood of developing IBS compared to controls, with a pooled OR of 0.84 (95% CI: 0.80 to 0.84). Sensitivity analysis confirmed the stability of the estimates. Future research should prioritise prospective cohort studies that are robust and closely track the development of incident IBS in previously healthy individuals.
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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)
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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.
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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
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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).
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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)
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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.
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How to reduce brain inflammation: 4 actions you can take today
Dr Ruscio is a Doctor of Natural Medicine, Doctor of Chiropractic, clinical researcher and author. His podcast, Dr Ruscio Radio presents cutting edge information in health, nutrition and functional medicine distilled into practical advice that can be used to improve our health.
2023
Abstract
Dr Ruscio focuses on the link between brain inflammation and neurodegenerative diseases such as Alzheimer’s and Parkinson’s but also brain fog and mood. He summarises how it might be possible to reduce neuroinflammation through diet, looking at the links with dysbiosis and leaky gut but also exercise, sleep hygiene, and stress management. A concise overview of the evidence for diets such as Paleo, Low FODMAP, Ketogenic and Low Carb, as well as the Mediterranean diet for reducing inflammation and supporting brain health is provided. The potential for lab testing via anti and pro-inflammatory markers is also reviewed.
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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)
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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:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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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.
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Low FODMAP diet reduces gastrointestinal symptoms in irritable bowel syndrome and clinical response could be predicted by symptom severity: A randomized crossover trial.
Algera, JP, Demir, D, Törnblom, H, Nybacka, S, Simrén, M, Störsrud, S
Clinical nutrition (Edinburgh, Scotland). 2022;41(12):2792-2800
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Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction, characterised by chronic abdominal pain and altered bowel habits. Currently, many patients follow an exclusion diet where specific food components are eliminated. One of these exclusion diets is a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). The primary aim of this study was to compare the effects of diets with low vs. moderate FODMAP content on gastrointestinal (GI) symptoms in IBS. This study was a double-blind, randomised, controlled, crossover study which enrolled 31 participants who were randomly assigned to the diet periods. Results showed that the severity of GI symptoms was reduced, and bowel habits were affected in the direction of less frequent and firmer stool by the low FODMAP diet, but not by a diet with moderate amounts of FODMAPs. Authors conclude that assessment of overall IBS severity and predominant bowel habits before the intervention may be helpful for clinicians in their IBS management before considering a trial period with the low FODMAP diet as a treatment option.
Expert Review
Conflicts of interest:
None
Take Home Message:
A low (4 g/day) FODMAP diet could provide clinical benefits in the context of an acute strategy for IBS clients with frequent loose stools (IBS-Diarrhoea and/or IBS-Mixed) compared to those with hard and less frequent stools (IBS-Constipation) to improve the severity of GI symptoms, including lower abdominal pain intensity and frequency, bowel habits, daily life interference, and psychological distress.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
The aim of this paper was to investigate the effects of diets with low vs. moderate FODMAP content on gastrointestinal (GI) symptoms and bowel habits, and to identify possible predictors of clinical response to a low FODMAP diet and FODMAP sensitivity in Irritable Bowel Syndrome (IBS).
Methods
- This study involved a double-blind, randomised, controlled, crossover trial of 29 participants (18-75 years), mostly female, diagnosed with IBS (Rome IV)
- The primary outcome was to assess the effects of a low (4 g/day) vs. moderate (23 g/day) FODMAP diet on GI symptoms over a 7-day period
- Secondary outcomes involved assessing the effects of low vs. moderate FODMAP diets on i) somatic symptoms, ii) psychological distress, iii) predictors of clinical and IBS-Severity Scoring System (IBS-SSS) sensitivity to FODMAP
- Breakfast was standardised, with prescribed low FODMAP list deviations recorded
- Main dishes and snacks were also provided
- Participants were requested to limit alcohol, caffeine, fatty- and spicy foods, ate regularly, chewed thoroughly and drank enough water
- GI symptoms and bowel habits were recorded during the 7-day screening period, then participants undertook a Lactulose Nutrient Challenge Test (LNCT)
- The first 7-day diet started one day after the LNCT
- A 14-day wash-out period allowed participants to eat and drink as usual, thereafter following the second 7-day diet period as part of the cross over design.
Results
A low FODMAP intervention (compared to a moderate FODMAP diet); resulted in:
- Reduced overall IBS rating (10 ± 72 vs. 57 ± 108, P=0.04)
- Improved abdominal pain frequency (10 ± 32 vs. 18 ± 29 (P=0.02)
- Improved stool consistency (0.2 ± 1.0 vs. 0.6 ± 1.2, P= 0.01) and frequency (0.1 ± 0.7 vs. 0.4 ± 0.7, P= 0.01)
- Overall, 34% of participants positively responded to the low FODMAP diet, which could be predicted based on higher baseline IBS-SSS scores (P=0.02)
- Participants sensitive to FODMAPs had increased pre- and postprandial ratings of gas, abdominal pain and bloating and higher exhaled methane concentrations compared to non-sensitive participants to FODMAPs
- Authors highlighted a non-significant association between FODMAP sensitivity and GI symptoms during the LNCT, with higher visceral hypersensitivity (45 ± 20, P=0.73) after ingestion of poorly absorbed and fermentable carbohydrates, with no independent predictors identified.
Conclusions
This study showed that a diet low in FODMAPs reduces GI symptoms and positively impacts bowel habits in IBS, compared with a moderate FODMAP diet.
Clinical practice applications:
- While this was a short term study, a low FODMAP diet reduced GI symptoms and affected bowel habits (more firm and less frequent stools) in IBS, compared with a diet containing moderate amounts of FODMAPs
- Knowing the above, an assessment of overall IBS severity and predominant bowel habits before the intervention may be helpful for clinicians working with younger females in their IBS management before considering a trial period with the low FOD-MAP diet as a treatment option.
Considerations for future research:
- Future trials could target a larger sample size with a more representative population, as well as assessing low FODMAP interventions over longer timeframes
- . Additionally, the assessment of biological measures such as microbiota diversity and stability, as well as metabolites (such as short chain fatty acids) could be important to understand mechanistic attributes of low FODMAP diets in IBS.
Abstract
BACKGROUND & AIMS Fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) can provoke symptoms in patients with irritable bowel syndrome (IBS). We aimed to compare the effects of diets with low vs. moderate FODMAP content on gastrointestinal (GI) symptoms and bowel habits, and to identify possible predictors of clinical response to a low FODMAP diet and FODMAP sensitivity in IBS. METHODS Adult participants with IBS (Rome IV criteria, n = 29) were included and adhered to two 7-day diet periods, with either low (4 g/day) or moderate (23 g/day) amounts of FODMAPs, in this randomized, double-blind, crossover study. The periods were separated by a wash-out period (≥14 days). IBS-Severity Scoring System (IBS-SSS) and a stool diary (Bristol Stool Form) were completed before and after the diet periods. At baseline, severity of GI symptoms and gut microbial fermentation were assessed (every 15 min, 4 h) during the Lactulose Nutrient Challenge Test (LNCT). Clinical response and FODMAP sensitivity were defined by reduction after low FODMAP period, and increase after moderate FODMAP period in IBS-SSS (≥50 points), respectively. RESULTS Severity of GI symptoms (P = 0.04), stool consistency (P = 0.01), and stool frequency (P = 0.01) differed between the interventions, with reduced overall GI symptom severity, abdominal pain intensity and frequency, bowel habits dissatisfaction, and daily life interference (P < 0.05 for all), as well as more firm (P = 0.03) and less frequent (P < 0.01) stools after low FODMAP intervention, but not after moderate FODMAP intervention. A third (34%) responded clinically to the low FODMAP diet, and the response could be predicted by higher IBS-SSS at baseline (P = 0.02). Although modest associations between FODMAP sensitivity (22%) and GI symptoms during LNCT were observed, no independent predictors could be identified. CONCLUSIONS A diet low in FODMAPs reduces GI symptoms and affects bowel habits in IBS, compared with a moderate FODMAP diet. Assessment of IBS severity before the intervention may be used to predict clinical response to a low FODMAP diet. Trial registry (http://www. CLINICALTRIALS gov): Registered under Clinical Trial number NCT05182593.
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A Low-FODMAP Diet Provides Benefits for Functional Gastrointestinal Symptoms but Not for Improving Stool Consistency and Mucosal Inflammation in IBD: A Systematic Review and Meta-Analysis.
Peng, Z, Yi, J, Liu, X
Nutrients. 2022;14(10)
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Plain language summary
The low-FODMAP diet eliminates carbohydrates that cannot be easily digested in order to reduce functional gastrointestinal symptoms associated with irritable bowel disease (IBD). The symptoms of irritable bowel disease include abdominal pain and bloating. This systematic review and meta-analysis aimed to evaluate whether a low-FODMAP diet can alleviate functional gastrointestinal symptoms in individuals with inflammatory bowel disease. In comparison with a regular diet, a low-FODMAP diet significantly reduced symptoms of bloating, wind, flatulence, abdominal pain, fatigue, and lethargy in patients with IBD. In addition, patients with Crohn's disease have achieved remission or reduced symptoms after following a low-FODMAP diet. Healthcare professionals can use this study to understand better the effects of a low-FODMAP diet on patients with IBD who have functional gastrointestinal symptoms. Further robust studies are, however, required to evaluate the evidence's robustness and identify the mechanism behind the improvement of symptoms.
Expert Review
Conflicts of interest:
None
Take Home Message:
- LFD use in IBD improved symptoms of bloating, wind or flatulence, borborygmi, abdominal pain, and fatigue or lethargy, but not nausea and vomiting.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This meta-analysis assesses the efficacy of a low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet (LFD) in inflammatory bowel disease [IBD: ulcerative colitis (UC) and Crohn’s disease (UC)] participants with functional gastrointestinal symptoms (FGSs).
Methods
A search was performed on PubMed, Web of Science, EMBASE, Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure (CNKI), WanFang (Chinese) Database up to March 2022. Quality assessment of all included studies was performed.
Results
9 studies (4 randomised controlled trials, 5 non-randomised studies) with a total of 351 participants diagnosed with IBD were included, and compared LFD with a placebo diet or normal diet (ND), overall and individual
LFD Effects of FGS:
- Overall 9 studies: an improvement (0.47, 0.33–0.66, p = 0.0000)
- No difference in the subgroup classified by disease type
- CD and UC: no improvement
Individual improvement:
- Bloating (0.37, 0,24-0,57, p=0.0000); wind or flatulence (0.38, 0,28-0,51, p=0.0000); borborygmi (0.48, 0,26-0,89, p=0.0000), abdominal pain (0.5, 0,37-0,68, p=0.0000), fatigue/lethargy (0.71, 0,61-0,82, p=0.0000)
- No difference in nausea and vomiting (0.54, 0,22-1,32, p=018)
IBS Quality of Life Score:
- 2 studies: reduced Short IBD Questionnaire (SIBDQ) score (11.24, 6.61-15.87, p=0.0000)
Bristol Stool Form Chart:
- 2 studies: normal stool consistency (type 3-4); no difference (5.99, 0.17-216.51, p=0.33)
- 2 other studies: no difference (-0.17, 0.48 - 0.15, p=0.30)
Diseases activity (Harvey-Bradshaw index):
- 2 studies using the Mayo score: no difference (-32, -1,09-0.45, p=0.41)
- 3 studies using BHi score: reduction (-1.09, -1,77-0.42, p=0.002)
Faecal calprotectin:
- 2 studies: no change (-16.03, -36,78-4.73, p=0.13)
Limitations
- Comparison diets were not standardised, suggesting the potential of different dietary habits to bias results..
- Heterogeneity of included studies, and the relatively small sample size of the studies can reduce the reliability of the results.
Conclusion
While the study found inconsistent definition standards for FGS, all the nine studies showed that LFD was associated with an improvement in some symptoms.
Clinical practice applications:
- This study suggests that IBD patients with FGSs may benefit from LFD treatment with the assistance of a healthcare professional.
Considerations for future research:
- This study has shown that LFD can improve FGSs in IBD, but further research with a larger sample size and more comprehensive analysis is warranted to replicate the results.
- The description of the findings and Quality of Life data are a little unclear. The impact on Quality of Life warrants further investigation, as clinicians need to consider the impact of following a restrictive diet on Quality of Life.
Abstract
BACKGROUND A low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet (LFD) is claimed to improve functional gastrointestinal symptoms (FGSs). However, the role of LFD in inflammatory bowel disease (IBD) patients with FGSs remains unclear. OBJECTIVE To systematically assess the efficacy of LFD in IBD patients with FGSs. METHODS Six databases were searched from inception to 1 January 2022. Data were synthesized as the relative risk of symptoms improvement and normal stool consistency, mean difference of Bristol Stool Form Scale (BSFS), Short IBD Questionnaire (SIBDQ), IBS Quality of Life (IBS-QoL), Harvey-Bradshaw index (HBi), Mayo score, and fecal calprotectin (FC). Risk of bias was assessed based on study types. A funnel plot and Egger's test were used to analyze publication bias. RESULTS This review screened and included nine eligible studies, including four randomized controlled trials (RCTs) and five before-after studies, involving a total of 446 participants (351 patients with LFD vs. 95 controls). LFD alleviated overall FGSs (RR: 0.47, 95% CI: 0.33-0.66, p = 0.0000) and obtained higher SIBDQ scores (MD = 11.24, 95% CI 6.61 to 15.87, p = 0.0000) and lower HBi score of Crohn's disease (MD = -1.09, 95% CI -1.77 to -0.42, p = 0.002). However, there were no statistically significant differences in normal stool consistency, BSFS, IBS-QoL, Mayo score of ulcerative colitis, and FC. No publication bias was found. CONCLUSIONS LFD provides a benefit in FGSs and QoL but not for improving stool consistency and mucosal inflammation in IBD patients. Further well-designed RCTs are needed to develop the optimal LFD strategy for IBD.
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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
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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.