Functional bowel symptoms and diet

Effects of a low-FODMAP diet on patients with endometriosis, a prospective cohort study

BACKGROUND

Patients with endometriosis often experience bowel symptoms such as changing stool, abdominal pain and bloating similar to those associated with irritable bowel syndrome. These symptoms reduce quality of life (QoL). Visceral hypersensitivity seems to be a shared pathogenic factor. The low-FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols) diet is a known visceral hypersensitivity targeted therapy with significant reduction in bowel symptoms. The aim of this study was to evaluate the effect of low-FODMAP diet on bowel symptoms such as constipation and bloating, pain and QoL in patients with endometriosis.

METHODS

The diet involved four weeks of FODMAP elimination, followed by a reintroduction-period of at least ten weeks, varying by patient. Questionnaires were sent at baseline and after these periods. The primary outcome was constipation change after the reintroduction period compared to baseline, assessed by Groningen-DeFeC-questionnaire (0-30 scale) with paired-T-test or Wilcoxon-signed-rank-test. Secondary outcomes included changes in bloating, QoL and abdominal pain, assessed by Endometriosis Health Profile-30 (EHP-30). P-value < 0,05 indicated statistical significance.

RESULTS

Forty-seven patients were included; thirteen withdrew before starting the diet, mostly due to lack of motivation. Of the remaining 34, 24 (71%) completed the diet (i.e. following the prescribed periods) Constipation scores improved significantly after low-FODMAP diet compared to baseline from 7.0 to 5.0 (p = 0.023). There was no significant difference observed in bloating, however 53% of patients that completed the diet mentioned a decrease. The following domains of the EHP-30 improved significantly: pain (from 47.8 to 29.2 (p = 0.002)), control and powerlessness (from 69.4 to 36.7 (p = 0.000)), emotional well-being (from 45.2 to 29.2 (p = 0.001)), social support (from 46.4 to 31.3 (p = 0.0017)), self-image (from 51.2 to 40.5 (p = 0.035)), work-life (from 35.0 to 21.7 (p = 0.003)) and sexual intercourse (from 61.6 to 45.7 (p = 0.023)). 65% of patients that completed the diet mentioned a decrease in pain, especially chronic pelvic pain.

CONCLUSIONS

This study suggests the low-FODMAP diet may improve bowel symptoms and QoL in endometriosis patients motivated to follow the diet, highlighting its potential in endometriosis care. However, further research in larger populations is needed to explore factors like endometriosis type, pain intensity and dropout rates to confirm these findings.

TRIAL REGISTRATION

ICTRP: NL-OMON28996: Feasibility study: The effect of the low FODMAP diet on women suffering from endometriosis ( https://trialsearch.who.int/Trial2.aspx?TrialID=NL-OMON28996 ) on September 13th 2019.

Alterations in fecal β-defensin-3 secretion as a marker of instability of the gut microbiota

Compositional changes in the microbiota (dysbiosis) may be a basis for Irritable Bowel Syndrome (IBS), but biomarkers are currently unavailable to direct microbiota-directed therapy. We therefore examined whether changes in fecal β-defensin could be a marker of dysbiosis in a murine model. Experimental dysbiosis was induced using four interventions relevant to IBS: a mix of antimicrobials, westernized diets (high-fat/high-sugar and high salt diets), or mild restraint stress. Fecal mouse β-defensin-3 and 16S rRNA-based microbiome profiles were assessed at baseline and during and following these interventions. Each intervention, except for mild restraint stress, altered compositional and diversity profiles of the microbiota. Exposure to antimicrobials or a high-fat/high-sugar diet, but not mild restraint stress, resulted in decreased fecal β-defensin-3 compared to baseline. In contrast, exposure to the high salt diet increased β-defensin-3 compared to baseline. Mice exposed to the mix of antimicrobials showed the largest compositional changes and the most significant correlations between β-defensin-3 levels and bacterial diversity. The high salt diet was also associated with significant correlations between changes in β-defensin-3 and bacterial diversity, and this was not accompanied by discernible inflammatory changes in the host. Thus, dietary change or antimicrobial exposure, both recognized factors in IBS exacerbations, induced marked dysbiosis that was accompanied by changes in fecal β-defensin-3 levels. We propose that serial monitoring of fecal β-defensins may serve as a marker of dysbiosis and help identify those IBS patients who may benefit from microbiota-directed therapeutic interventions.

The Effect of the Low FODMAP Diet on Gastrointestinal Symptoms, Behavioral Problems and Nutrient Intake in Children with Autism Spectrum Disorder: A Randomized Controlled Pilot Trial

Some research suggests that GI symptoms seen in children with ASD may relate to behavior problems. The objective of this pilot study was to assess the effect of the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet on GI and behavioral problems in children with ASD. At follow-up, the low FODMAP diet group had significant relief in some GI problems compared with both baseline in the group and control group. At baseline and at follow-up, there were no significant differences in behavioral problems between the low FODMAP diet group and the control group. Randomized controlled studies including larger sample sizes are needed to confirm the effects of low FODMAP diets in children with autism who have gastrointestinal problems.

A randomized double-blind placebo-controlled crossover pilot study: Acute effects of the enzyme α-galactosidase on gastrointestinal symptoms in irritable bowel syndrome patients

BACKGROUND

Postprandial symptoms presumably related to intestinal gas production are common in patients with irritable bowel syndrome (IBS). The aim of the study was to assess if oral α-galactosidase is superior to placebo in reducing gastrointestinal (GI) symptoms and intestinal gas production after ingestion of carbohydrate-rich meals in adult patients with IBS.

METHODS

We studied the effect of 1200 GaIU/meal α-galactosidase (Nogasin^® ) or placebo capsules on GI symptoms in patients with IBS after three standardized, meals high in oligosaccharides, in a randomized, double-blind, crossover study. The intensity of eight GI symptoms was rated, and breath hydrogen and methane were measured every 30 min during 7.5 h. The severity of GI symptoms the following morning was assessed and compared with baseline.

S KEY RESULTS

Twenty adult patients with IBS (19 females), mean age 49 years (range 22-75 years), were included. All test meals were well tolerated but induced a gradual increase in GI symptom severity. Neither GI symptom ratings over time, nor hydrogen and methane concentrations differed between the days with α-galactosidase or placebo. The severity of abdominal pain and bloating was lower the following morning, but with no differences between α-galactosidase and placebo.

CONCLUSIONS & INFERENCES

The use of α-galactosidase together with meals high in oligosaccharides was in this pilot study not superior to placebo in reducing postprandial GI symptoms or the concentration of hydrogen and methane in expired air in IBS.

Irritable bowel syndrome and lactose intolerance: the importance of differential diagnosis. A monocentric study

BACKGROUND

Nowadays irritable bowel syndrome (IBS) and lactose intolerance (LI) are two very frequent diseases. IBS is a functional disorder, while LI is caused by the inability to digest lactose. LI is often incorrectly diagnosed as IBS. The aim of our study is to identify LI patients among IBS patients, so as to set up a correct therapy.

METHODS

We enrolled 259 patients with IBS and we compared them to a control group of 108 patients. All patients underwent H2 Breath-Test (HBT) and two questionnaires regarding the symptoms associated with IBS and LI were administered to the intolerant subjects and one questionnaire to IBS patients with no LI.

RESULTS

At the HBT, 79.9% (N.=207) of patients with IBS were positive, while in the control group were positive 25.0% (N.=27) of subjects (P<0.001). The questionnaires showed, after a month of therapy, a marked improvement in LI symptoms subjects. In addition, there was also a prevalence of more severe symptoms among subjects with IBS and LI than those with IBS and no LI.

CONCLUSIONS

We can affirm that most patients with initial diagnosis of IBS are, instead, lactose intolerant. This diagnosis allows us to undertake an adequate therapy so as to improve symptoms and quality of life. Therefore it is important to include LI in the pathologies with which IBS enters into differential diagnosis.

Functional Gastrointestinal Disorders and the Microbiome-What Is the Best Strategy for Moving Microbiome-based Therapies for Functional Gastrointestinal Disorders into the Clinic?

There have been numerous human studies reporting associations between the intestinal microbiome and functional gastrointestinal disorders (FGIDs), and independently animal studies have explored microbiome-driven mechanisms underlying FGIDs. However, there is often a disconnect between human and animal studies, which hampers translation of microbiome findings to the clinic. Changes in the microbiota composition of patients with FGIDs are generally subtle, whereas changes in microbial function, reflected in the fecal metabolome, appear to be more precise indicators of disease subtype-specific mechanisms. Although we have made significant progress in characterizing the microbiome, to effectively translate microbiome science in a timely manner, we need concurrent and iterative longitudinal studies in humans and animals to determine the precise microbial functions that can be targeted to address specific pathophysiological processes in FGIDs. A systems approach integrating multiple data layers rather than evaluating individual data layers of symptoms, physiological changes, or -omics data in isolation will allow for validation of mechanistic insights from animal studies while also allowing new discovery. Patient stratification for clinical trials based on functional microbiome alterations and/or pathophysiological measurements may allow for more accurate determination of efficacy of individual microbiome-targeted interventions designed to correct an underlying abnormality. In this review, we outline current approaches and knowledge, and identify gaps, to provide a potential roadmap for accelerating translation of microbiome science toward microbiome-targeted personalized treatments for FGIDs.

Chain length of dietary fatty acids determines gastrointestinal motility and visceromotor function in mice in a fatty acid binding protein 4-dependent manner

Purpose

We hypothesize that different types of dietary fatty acids (FAs) affect gastrointestinal (GI) motility and visceromotor function and that this effect can be regulated by the fatty acid binding protein 4 (FABP4).

Methods

Mice were fed for 60 days with standard diet (STD), STD with 7% (by weight) coconut oil, rich in medium-chain FAs (MCFAs) (COCO), or with 7% evening primrose oil, rich in long-chain FAs (LCFAs) (EPO). In each group, half of the mice received FABP4 inhibitor, BMS309403 (1 mg/kg; i.p.) twice a week. Body weight (BW) and food intake were measured; well-established tests were performed to characterize the changes in GI motility and visceral pain. White adipose tissue and colonic samples were collected for cell culturing and molecular studies.

Results

COCO significantly increased GI transit, but not colonic motility. COCO and EPO delayed the onset of diarrhea, but none affected the effect of loperamide. EPO reduced BW and increased the visceromotor response (VMR) to colorectal distension (CRD). COCO and EPO reduced differentiation of preadipocytes. Treatment with BMS309403: (1) reversed the effects induced by COCO in physiological conditions and in mouse models of diarrhea; (2) prevented the effects of EPO on BW, VMR to CRD and castor oil-induced diarrhea; (3) affected proliferation of preadipocytes; (4) changed the expression of Fabp4 in colonic and adipocyte samples from COCO and EPO.

Conclusion

Modifying dietary intake of MCFAs and LCFAs may be used to control GI motility or visceral pain and thus modulate the symptoms of functional GI disorders. The effect is dependent on the expression of FABP4.

Electronic supplementary material

The online version of this article (10.1007/s00394-019-02094-2) contains supplementary material, which is available to authorized users.

Protein Supplements and Their Relation with Nutrition, Microbiota Composition and Health: Is More Protein Always Better for Sportspeople?

Sports nutrition products are developed and targeted mainly for athletes to improve their nutrient intake, performance, and muscle growth. The fastest growing consumer groups for these products are recreational sportspeople and lifestyle users. Although athletes may have elevated physiological protein requirements and they may benefit from dietary supplements, the evidence regarding the role of dietary protein and supplements in the nutrition of recreational sportspeople and sedentary populations is somewhat complex and contradictory. In high-protein diets, more undigested protein-derived constituents end up in the large intestine compared to moderate or low-protein diets, and hence, more bacterial amino acid metabolism takes place in the colon, having both positive and negative systemic and metabolic effects on the host. The aim of the present review is to summarize the impact of the high-protein products and diets on nutrition and health, in sportspeople and in sedentary consumers. We are opening the debate about the current protein intake recommendations, with an emphasis on evidence-based effects on intestinal microbiota and personalized guidelines regarding protein and amino acid supplementation in sportspeople and lifestyle consumers.

An integrative review of dietetic and naturopathic approaches to functional bowel disorders

OBJECTIVES

Naturopathy and dietetics have evolved as two separate but parallel professions that use diet to promote optimal health and manage many illnesses and diseases. Given the increasing recognition of the influence of diet on health outcomes, there is increasing demand for the services of both professions. The aim of this research was to investigate similarities and differences between naturopathic and dietetic approaches to functional bowel disorders (FBDs).

DESIGN

For this integrative review AMED, CINAHL, the Cochrane Database of Systematic Reviews, EMBASE, Medline and PubMed databases were searched for articles that focused on dietetic or naturopathic diagnosis and treatment of food intolerance expressing as a FBD in adults. (Registration: PROSPERO 2016 CRD42016049469).

RESULTS

Of the 55 papers in the final review, 10 discussed complementary medicine approaches to FBDs. Both dietitians and naturopaths used similar holistic approaches to diagnosis and treatment, adjusted diets as a primary treatment approach, and individualised treatment for their patients. The professions differed in their use of vitamin, mineral and herbal supplements and in their willingness to recommend other treatments like osteopathy and acupuncture.

CONCLUSIONS

There is much overlap between dietetic and naturopathic approaches to assessment and treatment of FBDs. Further publications that describe naturopathic treatments for FBDs are needed to confirm these results and to provide opportunities for increased recognition and scrutiny of any distinctively naturopathic approaches. Without doing so, naturopathic practices are likely to remain marginalised and poorly understood. Moreover, the opportunity to fully contribute to the management of lifestyle-related diseases will be missed.

Food and functional dyspepsia: a systematic review

BACKGROUND

Functional dyspepsia (FD) is a debilitating functional gastrointestinal disorder characterised by early satiety, post-prandial fullness or epigastric pain related to meals, which affects up to 20% of western populations. A high dietary fat intake has been linked to FD and duodenal eosinophilia has been noted in FD. We hypothesised that an allergen such as wheat is a risk factor for FD and that withdrawal will improve symptoms of FD. We aimed to investigate the relationship between food and functional dyspepsia.

METHODS

Sixteen out of 6451 studies identified in a database search of six databases met the inclusion criteria of studies examining the effect of nutrients, foods and food components in adults with FD or FD symptoms.

RESULTS

Wheat-containing foods were implicated in FD symptom induction in six studies, four of which were not specifically investigating gluten and two that were gluten-specific, with the implementation of a gluten-free diet demonstrating a reduction in symptoms. Dietary fat was associated with FD in all three studies that specifically measured this association. Specific foods reported as inducing symptoms were high in either natural food chemicals, high in fermentable carbohydrates or high in wheat/gluten. Caffeine was associated with FD in four studies, although any association with alcohol was uncertain.

CONCLUSIONS

Wheat and dietary fats may play key roles in the generation of FD symptoms and reduction or withdrawal eased symptoms. Randomised trials investigating the roles of gluten, FODMAPs (fermentable oligosaccharide, disaccharide, monosaccharide and polyols) and high fat ingestion and naturally occurring food chemicals in the generation of functional dyspepsia symptoms are warranted and further investigation of the mechanisms is now required.

Effect of diet and individual dietary guidance on gastrointestinal endocrine cells in patients with irritable bowel syndrome (Review)

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal (GI) disorder that is characterized by a combination of abdominal pain or discomfort, bloating and alterations in bowel movements. This review presents recent developments concerning the roles of diet and GI endocrine cells in the pathophysiology of IBS and of individual dietary guidance in the management of IBS. Patients with IBS typically report that food aggravates their IBS symptoms. The interactions between specific types of foodstuffs rich in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and GI endocrine cells induce changes in cell densities. Providing individual dietary guidance about a low FODMAP intake, high soluble-fiber intake, and changing the proportions of protein, fat and carbohydrates helps to reduce the symptoms experienced by patients with IBS and to improve their quality of life. These improvements are due to restoring the densities of the GI endocrine cells back to normal. The reported observations emphasize the role of GI endocrine cells in the pathophysiology of IBS and support the provision of dietary guidance as a first-line treatment for managing IBS.

Endometriosis in patients with irritable bowel syndrome: Specific symptomatic and demographic profile, and response to the low FODMAP diet

BACKGROUND

Women with endometriosis are frequently misdiagnosed with irritable bowel syndrome (IBS) for some time before a correct diagnosis is made. Visceral hypersensitivity is a key feature in both conditions.

AIMS

To determine if there are distinct symptom patterns in women with IBS and endometriosis, and to determine the response of these women to a low FODMAP diet in comparison to those with IBS alone.

MATERIALS AND METHODS

A retrospective analysis of prospectively collected data from women attending a specialist IBS service in Christchurch New Zealand. Data from those who met Rome III criteria for IBS were sorted into two groups: concurrent endometriosis and those with IBS alone. Demographics and symptom patterns were identified from a prospective questionnaire. A low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet was taught to all women as the primary therapeutic intervention. Responses to the diet were noted against their ultimate disposition.

RESULTS

Of the 160 women who met Rome III criteria for IBS, 36% had concurrent endometriosis. The presence of dyspareunia (P > 0.0001), referred pain (P = 0.005), bowel symptoms exacerbated by menstruation (P = 0.0004) and a family history of endometriosis (P = 0.0003) were associated with concurrent endometriosis. Seventy two percent of these women reported a >50% improvement in bowel symptoms after four weeks of a low FODMAP diet compared with 49% in those with no known endometriosis (P = 0.001, odds ratio 3.11, 95% CI, 1.5-6.2).

CONCLUSIONS

Women with concurrent endometriosis and IBS report a unique symptom phenotype. The low FODMAP diet appears effective in women with gut symptoms and endometriosis.

IBD: In Food We Trust

BACKGROUND AND AIMS

Both science and patients associate diet with inflammatory bowel disease [IBD]. There is no doubt that links between IBD and diet are numerous, based on both epidemiological studies and experimental studies. However, scientific evidence to support dietary advice is currently lacking, and dietary counselling for IBD patients is often limited in clinical practice to the improvement of nutrient intake. This review aimed to focus on both patient's beliefs about and molecular mechanisms for crosstalk between nutrients and inflammation.

METHODS

A literature search using PubMed was performed to identify relevant studies on diet and/or nutrients and their role in IBD. Pubmed [from inception to January 20, 2016] was searched using the terms: 'Crohn', 'colitis',' intestinal epithelial cells', and a list of terms relating to diet or numerous specific nutrients. Terms associated with nutrients were individually tested in the context of IBD. Reference lists from studies selected were manually searched to identify further relevant reports. Manuscripts about diet in the context of IBD from basic science, epidemiological studies, or clinical trials were selected and reviewed. Only articles published in English were included.

RESULTS

Epidemiological studies highlight the key role of diet in IBD development, and many IBD patients report diet as a triggering factor in relapse of disease. In addition, we present research on the impact of nutrients on innate immunity.

CONCLUSION

Diet may offer an alternative approach to restoring deficient innate immunity in IBD, and this may be the scientific rationale for providing dietary counselling for IBD patients.

Changes in small intestinal chromogranin A-immunoreactive cell densities in patients with irritable bowel syndrome after receiving dietary guidance

Chromogranin A (CgA) is a common marker for enteroendocrine cells in the gut, and CgA-immunoreactive cell densities are abnormal in patients with irritable bowel syndrome (IBS). The majority of patients with IBS report that their symptoms develop after consuming certain foodstuffs. In the present study, we investigated the effects of dietary guidance on the total enteroendocrine cell densities in the small intestine, as detected by CgA. A total of 14 patients with IBS underwent a gastroscopy with duodenal biopsies and 11 of them also underwent a colonoscopy, with biopsy samples obtained from the ileum. Fourteen control subjects were also included. Each patient received 3 sessions of dietary guidance. Gastroscopies and colonoscopies were performed on both the controls and patients with IBS (at baseline and at 3–9 months after receiving guidance). Biopsy samples obtained from the duodenum and ileum were immunostained for CgA using the avidin-biotin complex (ABC) method and were quantified using computerized image analysis. The density of CgA-immunoreactive cells in the duodenum (mean ± SEM values) in the control subjects was 235.9±31.9 cells/mm²; in the patients with IBS, the density was 36.9±9.8 and 103.7±16.9 cells/mm² before and after they received dietary guidance, respectively (P=0.007). The density of CgA-immunoreactive cells in the ileum in the control subjects was 47.4±8.3 cells/mm²; in the patients with IBS, the density was 48.4±8.1 and 17.9±4.4 cells/mm², before and after they received dietary guidance, respectively (P=0.0006). These data indicate that changes in CgA-immunoreactive cell densities in patients with IBS after receiving dietary guidance may reflect a change in the densities of the small intestinal enteroendocrine cells, which may contribute to an improvement in the IBS symptoms.

Impact of palm date consumption on microbiota growth and large intestinal health: a randomised, controlled, cross-over, human intervention study

The reported inverse association between the intake of plant-based foods and a reduction in the prevalence of colorectal cancer may be partly mediated by interactions between insoluble fibre and (poly)phenols and the intestinal microbiota. In the present study, we assessed the impact of palm date consumption, rich in both polyphenols and fibre, on the growth of colonic microbiota and markers of colon cancer risk in a randomised, controlled, cross-over human intervention study. A total of twenty-two healthy human volunteers were randomly assigned to either a control group (maltodextrin-dextrose, 37·1 g) or an intervention group (seven dates, approximately 50 g). Each arm was of 21 d duration and was separated by a 14-d washout period in a cross-over manner. Changes in the growth of microbiota were assessed by fluorescence in situ hybridisation analysis, whereas SCFA levels were assessed using HPLC. Further, ammonia concentrations, faecal water genotoxicity and anti-proliferation ability were also assessed using different assays, which included cell work and the Comet assay. Accordingly, dietary intakes, anthropometric measurements and bowel movement assessment were also carried out. Although the consumption of dates did not induce significant changes in the growth of select bacterial groups or SCFA, there were significant increases in bowel movements and stool frequency (P<0·01; n 21) and significant reductions in stool ammonia concentration (P<0·05; n 21) after consumption of dates, relative to baseline. Furthermore, date fruit intake significantly reduced genotoxicity in human faecal water relative to control (P<0·01; n 21). Our data indicate that consumption of date fruit may reduce colon cancer risk without inducing changes in the microbiota.

Role of FODMAPs in Patients With Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a condition characterized by abdominal pain, bloating, flatus, and altered bowel habits. The role of dietary components in inducing IBS symptoms is difficult to explore. To date, foods are not considered a cause but rather symptom-triggering factors. Particular interest has been given to the so-called FODMAPs (fermentable oligo-, di-, and monosaccharides and polyols). We aimed to summarize the evidence from the most common approaches to manage suspected food intolerance in IBS, with a particular interest in the role of FODMAPs and the effects of a low FODMAP diet. We reviewed literature, consulting PubMed and Medline by using the search terms FODMAP(s), fructose, lactose, fructans, galactans, polyols (sorbitol, mannitol, maltitol, xylitol, erythritol, polydextrose, and isomalt), irritable bowel syndrome, and functional gastrointestinal symptoms. FODMAP-restricted diets have been used for a long time to manage patients with IBS. The innovation in the so-called FODMAP concept is that a global restriction should have a more consistent effect than a limited one in preventing abdominal distension. Even though all the potential low FODMAP diets provide good relief of symptoms in many patients, there is just a little relief in others. Several studies highlight the role of low FODMAP diets to improve symptoms in patients with IBS. The evidence on this dietary approach supports the hypothesis that a low FODMAP diet should be the first dietary approach. However, many points remain to be clarified, including the evaluation of possibly significant nutrition concerns.

Colonic Fermentation of Unavailable Carbohydrates from Unripe Banana and its Influence over Glycemic Control

The aim of this study was to evaluate the effect of the colonic fermentation of unavailable carbohydrates from unripe banana (mass - UBM - and starch - UBS) over parameters related to glucose and insulin response in rats. Wistar male rats were fed either a control diet, a UBM diet (5 % resistant starch - RS) or a UBS diet (10 % RS) for 28 days. In vivo (oral glucose tolerance test) and in vitro (cecum fecal fermentation, pancreatic islet insulin secretion) analyses were performed. The consumption of UBM and UBS diets by Wistar rats for 28 days improved insulin/glucose ratio. Also, pancreatic islets isolated from the test groups presented significant lower insulin secretion compared to the control group, when the same in vitro glucose stimulation was done. Total short chain fatty acids produced were higher in both experimental groups in relation to the control group. These findings suggest that UBM and UBS diets promote colonic fermentation and can influence glycemic control, improving insulin sensitivity in rats.

Low-FODMAP Diet for Irritable Bowel Syndrome: Is It Ready for Prime Time?

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disease, which adversely affects the quality of life. Its prevalence has been reported to be around 10-15 % in North America and constitutes the most common cause for gastroenterology referral. Unfortunately, the pathophysiology of IBS is not completely understood. Not surprisingly, the management strategies can leave the patients with inadequate symptom control, making IBS a debilitating gastrointestinal syndrome. Dietary interventions as a treatment strategy for IBS have been recently evaluated. One such intervention includes dietary restriction of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs). FODMAPs define a group of short-chain carbohydrates that are incompletely absorbed in small intestine and later fermented in the colon. Evidence in the form of randomized controlled trials and observational studies have evaluated the mechanism of action and efficacy of low-FODMAP diet. This dietary intervention has showed promising results in symptom reduction in IBS patients. However, latest trials have also shown that the low-FODMAP diet is associated with marked changes in gut microbiota specifically reduction in microbiota with prebiotic properties. Implications of such changes on gastrointestinal health need to be further evaluated in future trials.

Dietary treatment of irritable bowel syndrome

INTRODUCTION

Food is a recognized trigger for most patients with irritable bowel syndrome (IBS). In recent years, an emerging evidence base has identified dietary manipulation as an important therapeutic approach in IBS.

SOURCES OF DATA

Original and review articles were identified through selective searches performed on PubMed and Google Scholar.

AREAS OF AGREEMENT

Randomized controlled trials have supported the use of a diet that restricts a group of short-chain carbohydrates known collectively as fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs). There is evidence that specific probiotics may improve symptoms in IBS.

AREAS OF CONTROVERSY

The role of a high-fibre diet remains subject to ongoing debate with a lack of high-quality evidence. The long-term durability and safety of a low FODMAP diet are unclear.

GROWING POINTS

A paradigm shift has led to a focus on the relationship between diet and pathophysiological mechanisms in IBS such as effects on intestinal microbiota, inflammation, motility, permeability and visceral hypersensitivity.

AREAS TIMELY FOR DEVELOPING RESEARCH

Future large, randomized controlled trials with rigorous end points are required. In addition, predictors of response need to be identified to offer personalized therapy.

Ehealth: Low FODMAP diet vs Lactobacillus rhamnosus GG in irritable bowel syndrome

AIM: To investigate the effects of a low fermentable, oligosaccharides, disaccharides, monosaccharides and polyols diet (LFD) and the probiotic Lactobacillus rhamnosus GG (LGG) in irritable bowel syndrome (IBS).

METHODS: Randomised, unblinded controlled trial on the effect of 6-wk treatment with LFD, LGG or a normal Danish/Western diet (ND) in patients with IBS fulfilling Rome III diagnostic criteria, recruited between November 2009 and April 2013. Patients were required to complete on a weekly basis the IBS severity score system (IBS-SSS) and IBS quality of life (IBS-QOL) questionnaires in a specially developed IBS web self-monitoring application. We investigated whether LFD or LGG could reduce IBS-SSS and improve QOL in IBS patients.

RESULTS: One hundred twenty-three patients (median age 37 years, range: 18-74 years), 90 (73%) females were randomised: 42 to LFD, 41 to LGG and 40 to ND. A significant reduction in mean ± SD of IBS-SSS from baseline to week 6 between LFD vs LGG vs ND was revealed: 133 ± 122 vs 68 ± 107, 133 ± 122 vs 34 ± 95, P < 0.01. Adjusted changes of IBS-SSS for baseline covariates showed statistically significant reduction of IBS-SSS in LFD group compared to ND (IBS-SSS score 75; 95%CI: 24-126, P < 0.01), but not in LGG compared to ND (IBS-SSS score 32; 95%CI: 18-80, P = 0.20). IBS-QOL was not altered significantly in any of the three groups: mean ± SD in LFD 8 ± 18 vs LGG 7 ± 17, LFD 8 ± 18 vs ND 0.1 ± 15, P = 0.13.

CONCLUSION: Both LFD and LGG are efficatious in patients with IBS.