Dietary intake of inulin-type fructans in active and inactive Crohn's disease and healthy controls: a case-control study

Fructan content in most commonly consumed Slovenian foods and estimation of daily fructan consumption

Fructans can be considered as part of the group of fermentable oligo-, di- and monosaccharides and polyols (FODMAPs). Short-chain fructans have a rapid fermentation rate and can thus worsen symptoms in patients with irritable bowel syndrome. In this study, the fructan content in 40 of the most commonly consumed foods in Slovenia was measured. Overall, the fructan content was relatively low: 0.1-1.97 g/100 g fresh weight. The highest fructan content was found in onion (1.97 g/100 g), followed by wheat flour (0.75 g/100 g). A simple model for calculating fructan intake was developed based on the results of the SI. Menu 2017/2018 national survey, which collected data on the frequency of intake of different foods and food groups (expressed in g/day). After calculating the daily intake of the surveyed foods, we used our results on fructan content to estimate daily fructan consumption. Mean daily fructan intake reaches 1.6-1.7 g/day, with no differences between men and women. Our assessment of fructan intake at the national level represents the first step toward the creation of a database on FODMAP intake.

Association not found between dietary fermentable oligosaccharides, disaccharides, monosaccharides, and polyols score and disease severity in patients with ulcerative colitis

OBJECTIVES

We hypothesized that a low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet may be associated with the disease severity of ulcerative colitis (UC). Therefore, this cross-sectional study was undertaken to assess the association between FODMAP score and UC severity.

METHODS

In this study, 158 patients with UC were enrolled. The disease severity was designated using the Mayo score. The diet relation information was obtained using the 160-item food frequency questionnaire. To calculate the FODMAP score, the consumption of all food items was converted to a gram per day and multiplied by the FODMAP factor. The FODMAP factor was obtained from the application developed by Monash University (Melbourne, Victoria, Australia). The association between disease severity (dependent factor) and FODMAP score tertiles (independent factors) was assessed by logistic regression adjusted for different covariates.

RESULTS

In the present study, the age range of participants was 18 to 64 y old, and 46.2% of patients had moderate or severe disease activity. There were significant differences in sex, body mass index, and supplement use across different tertiles of FODMAP score. There was no significant association between the FODMAP score tertiles and disease severity in the crude model and adjusted models.

CONCLUSIONS

The results of the present study showed that there was no significant association between the FODMAP score and UC severity. However, considering the limitations of the study, more studies with prospective and interventional designs using more accurate methods of dietary assessments are needed to confirm these preliminary results.

Dietary Fiber in Inflammatory Bowel Disease: Are We Ready to Change the Paradigm?

Accumulating evidence from pre-clinical and clinical studies demonstrate the benefit of dietary fibers for inflammatory bowel disease (IBD). However, the majority of patients avoid or limit their consumption to manage their symptoms during the active and remission phases, although limited research supports these long-term dietary habits. Although recent evidence-based dietary guidelines highlight the importance of promoting an adequate intake of dietary fiber in IBD patients, intervention trials have not yet clearly clarified the quality and quantity of dietary fiber that should be consumed to be equally tolerated by and provide benefit for patients with IBD. This narrative review describes dietary fibers and their characteristics, analyzes the real-word studies on the impact of dietary fiber consumption in IBD in different clinical settings, and concludes with potential future directions in fiber research, focusing on the real-world needs of characterizing the consumption of fiber-rich foods and promoting their adequate intake.

Inulin: Unveiling its potential as a multifaceted biopolymer in prebiotics, drug delivery, and therapeutics

In recent years, inulin has gained much attention as a promising multifunctional natural biopolymer with numerous applications in drug delivery, prebiotics, and therapeutics. It reveals a multifaceted biopolymer with transformative implications by elucidating the intricate interplay between inulin and the host, microbiome, and therapeutic agents. Their flexible structure, exceptional targetability, biocompatibility, inherent ability to control release behavior, tunable degradation kinetics, and protective ability make them outstanding carriers in healthcare and biomedicine. USFDA has approved Inulin as a nutritional dietary supplement for infants. The possible applications of inulin in biomedicine research inspired by nature are presented. The therapeutic potential of inulin goes beyond its role in prebiotics and drug delivery. Recently, significant research efforts have been made towards inulin's anti-inflammatory, antioxidant, and immunomodulatory properties for their potential applications in treating various chronic diseases. Moreover, its ability to reduce inflammation and modulate immune responses opens new avenues for treating conditions such as autoimmune disorders and gastrointestinal ailments. This review will attempt to illustrate the inulin's numerous and interconnected roles, shedding light on its critical contributions to the advancement of healthcare and biomedicine and its recent advancement in therapeutics, and conclude by taking valuable insights into the prospects and opportunities of inulin.

Prebiotics and the Risk of Upper Digestive Tract and Stomach Cancers: The PrebiotiCa Study

BACKGROUND

Fiber intake may lower digestive tract cancer risk, possibly by modulating the composition of gut microbiota. However, no data are available about the role of specific fiber fractions with prebiotic activity (e.g., inulin-type fructans (ITFs), fructo-oligosaccharides (FOSs) and galactooligosaccharides (GOSs)) on the risk lower digestive tract cancers.

OBJECTIVE

The objective was to assess the association between prebiotic intake and the risk of cancers of the upper digestive tract and stomach.

DESIGN

Within the PrebiotiCa study, data were derived from a network of Italian case-control studies conducted between 1992 and 2009. Participants' usual diet was assessed using a food frequency questionnaire. ITFs, and selected FOSs (nystose, kestose, and 1F-β-fructofuranosylnystose) and GOSs (raffinose and stachyose) were quantified in several food products via laboratory analyses. Participants' prebiotic intake was calculated by multiplying food frequency questionnaire intake by the prebiotic content of each food item.

PARTICIPANTS/SETTING

Cases were patients admitted to major hospitals with incident histologically confirmed cancers; there were 946 cases of cancer of the oral cavity/pharynx, 198 of the nasopharynx, 304 of the esophagus, 230 of the stomach. More than 4,000 patients admitted to the same hospitals for acute nonneoplastic and not diet-related conditions were selected as control subjects.

MAIN OUTCOME MEASURES

The outcomes were oral and pharyngeal, nasopharyngeal, esophageal, and stomach cancers.

STATISTICAL ANALYSES PERFORMED

The odds ratios and corresponding 95% CIs of the various cancers were derived using logistic regression models adjusted for major confounders and energy intake.

RESULTS

No association was observed between intake of prebiotics and risk of cancers of the oral cavity and pharynx, nasopharynx, and esophagus. High raffinose intake reduced stomach cancer risk (odds ratio for the third vs the first tertile 0.6, 95% CI 0.3 to 0.9); no other prebiotic was associated with stomach cancer.

CONCLUSIONS

The current study does not support a major role of prebiotic fibers on selected upper digestive tract cancers. The association between high raffinose intake and reduced stomach cancer risk needs further investigation.

Global Trends in Research of Pain-Gut-Microbiota Relationship and How Nutrition Can Modulate This Link

INTRODUCTION

The link between gut microbiota and chronic painful conditions has recently gained attention. Nutrition, as a common intervention in daily life and medical practice, is closely related to microbiota and pain. However, no published bibliometric reports have analyzed the scientific literature concerning the link.

METHODS AND RESULTS

We used bibliometrics to identify the characteristics of the global scientific output over the past 20 years. We also aimed to capture and describe how nutrition can modulate the abovementioned link. Relevant papers were searched in the Web of Science database. All necessary publication and citation data were acquired and exported to Bibliometrix for further analyses. The keywords mentioned were illustrated using visualization maps. In total, 1551 papers shed light on the relationship from 2003 to 2022. However, only 122 papers discussed how nutritional interventions can modulate this link. The citations and attention were concentrated on the gut microbiota, pain, and probiotics in terms of the pain-gut relationship. Nutritional status has gained attention in motor themes of a thematic map.

CONCLUSIONS

This bibliometric analysis was applied to identify the scientific literature linking gut microbiota, chronic painful conditions, and nutrition, revealing the popular research topics and authors, scientific institutions, countries, and journals in this field. This study enriches the evidence moving boundaries of microbiota medicine as a clinical medicine.

Components of the Fiber Diet in the Prevention and Treatment of IBD-An Update

Inflammatory bowel disease (IBD) is a group of diseases with a chronic course, characterized by periods of exacerbation and remission. One of the elements that could potentially predispose to IBD is, among others, a low-fiber diet. Dietary fiber has many functions in the human body. One of the most important is its influence on the composition of the intestinal microflora. Intestinal dysbiosis, as well as chronic inflammation that occurs, are hallmarks of IBD. Individual components of dietary fiber, such as β-glucan, pectin, starch, inulin, fructooligosaccharides, or hemicellulose, can significantly affect preventive effects in IBD by modulating the composition of the intestinal microbiota or sealing the intestinal barrier, among other things. The main objective of the review is to provide information on the effects of individual fiber components of the diet on the risk of IBD, including, among other things, altering the composition of the intestinal microbiota.

Diets for inflammatory bowel disease: What do we know so far?

In recent years, the role of diet in the pathogenesis of inflammatory bowel disease (IBD) has gained great interest within the scientific community. Eating habits from industrialised countries (the so-called western diet or WD) have been associated with a higher incidence of IBD in observational studies, although the dietary factors responsible for the development of the disease are still to be elucidated. Some components of the diet with proinflammatory potential may cause changes in immunity and intestinal microbiota, leading to the inflammatory reaction that causes IBD-related lesions. The quality of available evidence is low, due to methodological issues, such as the lack of intervention studies, small sample size and heterogeneity of studies. For this reason, scientific societies have offered their recommendations using clinical practice guidelines and consensus documents, in order to establish a common criterion in the nutritional treatment of patients with IBD. The objective of this review was to summarise the data published regarding diet in IBD and review the recommendations given by scientific societies.

Manipulation of Gut Microbiota as a Key Target for Crohn's Disease

Crohn's disease (CD) is an inflammatory bowel disease (IBD) sub-type characterized by transmural chronic inflammation of the gastrointestinal tract. Research indicates a complex CD etiology involving genetic predisposition and immune dysregulation in response to environmental triggers. The chronic mucosal inflammation has been associated with a dysregulated state, or dysbiosis, of the gut microbiome (bacteria), mycobiome (fungi), virome (bacteriophages and viruses), and archeaome (archaea) further affecting the interkingdom syntrophic relationships and host metabolism. Microbiota dysbiosis in CD is largely described by an increase in facultative anaerobic pathobionts at the expense of strict anaerobic Firmicutes, such as Faecalibacterium prausnitzii. In the mycobiome, reduced fungal diversity and fungal-bacteria interactions, along with a significantly increased abundance of Candida spp. and a decrease in Saccharomyces cerevisiae are well documented. Virome analysis also indicates a significant decrease in phage diversity, but an overall increase in phages infecting bacterial groups associated with intestinal inflammation. Finally, an increase in methanogenic archaea such as Methanosphaera stadtmanae exhibits high immunogenic potential and is associated with CD etiology. Common anti-inflammatory medications used in CD management (amino-salicylates, immunomodulators, and biologics) could also directly or indirectly affect the gut microbiome in CD. Other medications often used concomitantly in IBD, such as antibiotics, antidepressants, oral contraceptives, opioids, and proton pump inhibitors, have shown to alter the gut microbiota and account for increased susceptibility to disease onset or worsening of disease progression. In contrast, some environmental modifications through alternative therapies including fecal microbiota transplant (FMT), diet and dietary supplements with prebiotics, probiotics, and synbiotics have shown potential protective effects by reversing microbiota dysbiosis or by directly promoting beneficial microbes, together with minimal long-term adverse effects. In this review, we discuss the different approaches to modulating the global consortium of bacteria, fungi, viruses, and archaea in patients with CD through therapies that include antibiotics, probiotics, prebiotics, synbiotics, personalized diets, and FMT. We hope to provide evidence to encourage clinicians and researchers to incorporate these therapies into CD treatment options, along with making them aware of the limitations of these therapies, and indicate where more research is needed.

Nutrition in Patients with Inflammatory Bowel Diseases: A Narrative Review

Inflammatory bowel diseases (IBD) affect the gastrointestinal tract: they include Crohn's disease (CD) and ulcerative colitis (UC). Each has a different phenotypic spectrum, characterized by gastrointestinal and extra-intestinal manifestations. People living with IBD are very interested in diet, but little is known about the impact of diet on these patients; no guidelines are available yet. In this review, we analyze the dietary patterns of patients with IBD and the approach to the choices of foods both in adults and pediatric patients. Very often, IBD patients report an intentional avoidance of gluten to manage the disease; furthermore, a proportion of IBD patients believe that dairy products worsen their symptoms and that avoidance may help the disease. They have a low compliance with the Mediterranean Diet, which is considered to have potential benefits but is little used in practice. In conclusion, the review underscores the pivotal role of nutritional counselling in IBD patients, and the importance of future clinical studies to evaluate the beneficial effects of dietary recommendations in the management of IBD.

Nutrient, Fibre, and FODMAP Intakes and Food-related Quality of Life in Patients with Inflammatory Bowel Disease, and Their Relationship with Gastrointestinal Symptoms of Differing Aetiologies

BACKGROUND AND AIMS

Certain foods are reported as gut symptom triggers in inflammatory bowel disease [IBD], and fructans are shown to worsen non-inflammatory symptoms in inactive IBD, which may result in self-imposed dietary restrictions. The aim of this study was to investigate nutrient and FODMAP intakes, and the relationship between gut symptoms and dietary intake, in IBD.

METHODS

Nutrient, fibre, and FODMAP intakes were estimated using 7-day food records in patients with active IBD [Active IBD], inactive IBD with non-inflammatory gut symptoms [Inactive IBD-GI], inactive IBD without gut symptoms [Inactive IBD], and healthy controls. Nutrient intakes, numbers of participants achieving national recommendations, and food-related quality of life [FR-QoL] were compared across study groups.

RESULTS

Food diaries were obtained from 232 patients with IBD [65 Active IBD, 86 Inactive IBD-GI, 81 Inactive IBD] and 84 healthy controls. Patients with Active IBD had significantly lower intakes of numerous micronutrients, including iron, folate, and vitamin C, compared with controls. All IBD groups consumed less total fibre [4.5 to 5.8 g/day] than controls [p = 0.001], and total FODMAP and fructan intakes were lower in Active IBD compared with controls. Strikingly, FR-QoL was significantly lower in all IBD groups compared with controls [all p = 0.001].

CONCLUSIONS

This study revealed lower intakes of fibre, FODMAPs, and micronutrients, in addition to poorer FR-QoL, in Active IBD and Inactive IBD-GI with gut symptoms compared with healthy controls. Future research should address dietary restrictions responsible for these differences.

Present and Future Therapeutic Approaches to Barrier Dysfunction

There is converging and increasing evidence, but also uncertainty, for the role of abnormal intestinal epithelial barrier function in the origin and development of a growing number of human gastrointestinal and extraintestinal inflammatory disorders, and their related complaints. Despite a vast literature addressing factors and mechanisms underlying changes in intestinal permeability in humans, and its connection to the appearance and severity of clinical symptoms, the ultimate link remains to be established in many cases. Accordingly, there are no directives or clinical guidelines related to the therapeutic management of intestinal permeability disorders that allow health professionals involved in the management of these patients to carry out a consensus treatment based on clinical evidence. Instead, there are multiple pseudoscientific approaches and commercial propaganda scattered on the internet that confuse those affected and health professionals and that often lack scientific rigor. Therefore, in this review we aim to shed light on the different therapeutic options, which include, among others, dietary management, nutraceuticals and medical devices, microbiota and drugs, and epigenetic and exosomes-manipulation, through an objective evaluation of the scientific publications in this field. Advances in the knowledge and management of intestinal permeability will sure enable better options of dealing with this group of common disorders to enhance quality of life of those affected.

Prebiotic fructans have greater impact on luminal microbiology and CD3+ T cells in healthy siblings than patients with Crohn's disease: A pilot study investigating the potential for primary prevention of inflammatory bowel disease

BACKGROUND & AIMS

Siblings of people with Crohn's disease (CD) share aspects of the disease phenotype (raised faecal calprotectin, altered microbiota), which are markers of risk for their own development of CD. The aim was to determine whether supplementation with prebiotic oligofructose/inulin induces a prebiotic response and impacts the risk phenotype in CD patients and siblings.

METHODS

Patients with inactive CD (n = 19, CD activity index <150) and 12 of their unaffected siblings (with calprotectin >50 μg/g) ingested oligofructose/inulin (15 g/day) for three weeks. Faecal microbiota (qPCR), intestinal permeability (lactulose-rhamnose test), blood T cells (flow-cytometry) and calprotectin (ELISA) were measured at baseline and follow-up.

RESULTS

Following oligofructose/inulin, calprotectin did not significantly change in patients (baseline mean 537 SD 535 μg/g; follow-up mean 974 SD 1318 μg/g, p = 0.08) or siblings (baseline mean 73 SD 90 μg/g: follow up mean 58 SD 72 μg/g, p = 0.62). Faecal Bifidobacteria and Bifidobacterium longum increased in patients and siblings; Bifidobacterium adolescentis and Roseburia spp. increased only in siblings. Compared with patients, siblings had a greater magnitude change in Bifidobacteria (+14.6% vs +0.4%, p = 0.028), B. adolescentis (+1.1% vs 0.0% p = 0.006) and Roseburia spp. (+1.5% vs -0.1% p = 0.004). Intestinal permeability decreased significantly in patients after oligofructose/inulin to a level that was similar to siblings. Blood T cell abundance reduced in siblings but not patients following oligofructose/inulin.

CONCLUSIONS

Oligofructose/inulin supplementation did not significantly impact calprotectin, but the prebiotic effect was more marked in healthy siblings compared with patients with inactive CD and was associated with alterations in other CD risk markers. Future research should focus on dietary intervention, including with prebiotics, in the primary prevention of CD.

High Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols (FODMAP) Consumption Among Endurance Athletes and Relationship to Gastrointestinal Symptoms

Endurance athletes commonly experience lower gastrointestinal (GI) symptoms similar to those of irritable bowel syndrome (IBS). Previous research on the restriction of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP), a diet-based mitigation strategy initially developed for IBS, has shown promise for application in athlete populations. Athlete's dietary strategies surrounding exercise have not been formally assessed in relation to FODMAP content of foods or sports nutrition products. Additionally, the FODMAP content of athlete's habitual diets has not been examined in larger sample sizes. This research aims to investigate the FODMAP content of endurance athlete diets by examining these three areas, in conjunction with GI symptoms. Dietary habits surrounding exercise and GI symptoms were examined in 430 endurance athletes using a previously validated Endurance Athlete Questionnaire. A subset of athletes (n = 73) completed a FODMAP-specific food frequency questionnaire for habitual intake. The most commonly reported sports nutrition products were analyzed for FODMAP content using standardized analytical methods. Mean habitual intakes were compared to previous FODMAP studies and medians were compared between those with and without lower GI symptoms. Athletes commonly consumed high FODMAP foods during pre-race dinners and breakfasts, with over 60% reporting specific high FODMAP foods. More frequent nutrition product use, particularly solid, gel/gummy, and homemade products, was often related to increased frequency of GI symptoms. Of the sixteen commonly used sports nutrition products tested, seven were high FODMAP in one serving. All but one of the remaining products became high FODMAP when consumed in multiple servings, as is likely the case during endurance exercise. Average habitual FODMAP intake was 26.1 g (±15.9 g), similar to intakes classified as high FODMAP in previous research on FODMAPs and IBS or GI symptoms. Only 15.1% of athletes consumed a diet that would be considered low in FODMAP. Exploratory analyses showed higher intake of some FODMAP types among athletes exhibiting various lower GI symptoms. Overall, this study demonstrated that FODMAP intake by endurance athletes is high both surrounding exercise and habitually, and may be contributing to GI symptoms experienced during exercise. This information can be utilized when analyzing athlete diets and selecting foods to decrease GI symptoms.

The Adequacy of Habitual Dietary Fiber Intake in Individuals With Inflammatory Bowel Disease: A Systematic Review

BACKGROUND

Dietary fiber may influence disease course in individuals with inflammatory bowel disease (IBD), yet there is a paucity of understanding of habitual fiber intakes.

OBJECTIVES

To identify studies measuring fiber intakes of individuals with IBD, compare the adequacy of fiber intakes with that of control groups or respective national dietary guidelines, and examine factors associated with fiber consumption.

METHODS

Five electronic databases-MEDLINE, CINAHL, SCOPUS, PROQUEST, and COCHRANE LIBRARY-were systematically searched, using search terms inflammatory bowel disease, Crohn's disease, ulcerative colitis, dietary intake, and fiber, until December 2019, with hand searching of reference lists. Primary studies were included if fiber intakes were measured in participants 18 years of age or older, with confirmed IBD, with or without comparison to a control.

RESULTS

A total of 2105 publications were identified, and 26 met inclusion criteria. Total fiber intake of 4164 participants with IBD ranged broadly (9.9 ± 7.8 g/day to 21.0 ± 10.5 g/day). Most (18/26) used cross-sectional study design, with a large degree of heterogeneity in tools measuring fiber intake. Sixty-six percent of studies comparing participants with IBD with control groups found that participants with IBD consumed significantly less fiber than control subjects. Four studies reported that less than 10% to 21% of IBD participants met their national fiber recommendations. Data conflicted regarding an association between disease type, disease activity, or rate of relapse and fiber intake.

CONCLUSIONS

Individuals with IBD consume less fiber than healthy populations. Fiber intakes are inadequate compared with respective national fiber guidelines. Interpretation of factors associated with fiber intakes were limited by data quality and conflicting results. Future research is required into factors associated with fiber intake and whether increasing fiber intakes can influence disease course and behavior.

Presence of Fermentable Oligo-, Di-, Monosaccharides, and Polyols (FODMAPs) in commonly eaten foods: extension of a database to indicate dietary FODMAP content and calculation of intake in the general population from food diary data

Background

FODMAPs (Fermentable Oligo-, Di-, Monosaccharides And Polyols) are known for their health benefits but their fermentation may trigger gastrointestinal symptoms and a low-FODMAP diet is a commonly used intervention for functional gastrointestinal disorders. The use of direct measures of FODMAP is labor intensive and expensive and to facilitate the assessment of FODMAP intake in research and clinical work, a nutritional content database with good quality estimates on FODMAP values is needed. Further, the average intake of FODMAP in a general population would be a useful reference and knowledge of the most commonly eaten foods containing FODMAPs would facilitate clinical work utilizing FODMAP diet interventions.

Methods

A nutritional content database was extended with published FODMAP content data. The database was used to calculate FODMAP intake from four-day food diaries from 117 individuals from the general population in Sweden and the most common food items containing FODMAPs were identified.

Results

FODMAP content for 1060 food items was added to the database resulting in 1805 listed FODMAP values. Mean intake of total FODMAP in the diaries was 19 g (fructose: 15.2 g; fructan: 3.5 g; lactose: 14.1 g; galacto-oligosaccharides (GOS) 0.43 g and polyols 1.3 g per day). Overall the most common eaten food items containing FODMAPs were rye and wheat based foods.

Conclusion

Intake of FODMAPs as calculated using the extended database were in line with previous studies supporting its use of the database in both research and clinical interventions. The lists of the most commonly eaten FODMAP food items are provided and may be used to facilitate FODMAP diet interventions.

A randomized, 6-wk trial of a low FODMAP diet in patients with inflammatory bowel disease

OBJECTIVE

The aim of this study was to assess the safety and efficacy of a low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet (LFD) in patients with inflammatory bowel disease (IBD).

METHODS

An LFD is associated with symptom improvement in patients with functional intestinal disorders, although its safety and efficacy has not been characterized in patients with IBD. Fifty-five patients with IBD in remission or with mild disease activity were randomized to a 6-wk LFD or standard diet (SD). Disease activity (Harvey-Bradshaw index [HBi], partial Mayo score), fecal calprotectin, and disease-specific quality of life (IBD-Q) were assessed at baseline and at the end of dietary intervention.

RESULTS

After the 6-wk dietary intervention, median HBi decreased in the LFD (4; IQR, 3-5 versus 3; IQR, 2-3; P = 0.024) but not in the SD (3; IQR, 3-3 versus 3; IQR, 2-4), whereas Mayo scores were numerically decreased in the LFD group and unmodified in the SD group. Median calprotectin decreased in the LFD (76.6 mg/kg; IQR, 50-286.3 versus 50 mg/kg; IQR, 50.6-81; P = 0.004) but not in the SD group (91 mg/kg; IQR, 50.6-143.6 versus 87 mg/kg; IQR, 50-235.6). Lastly, we observed a barely significant increase in median IBD-Q in the LFD group (166; IQR, 139-182 versus 177; IQR, 155-188; P = 0.05) and no modification in the SD group (181; IQR, 153-197 versus 166; IQR, 153-200).

CONCLUSIONS

A short-term, LFD is safe for patients with IBD, and is associated with an amelioration of fecal inflammatory markers and quality of life even in patients with mainly quiescent disease.

Fermentable Carbohydrates [FODMAPs] Exacerbate Functional Gastrointestinal Symptoms in Patients With Inflammatory Bowel Disease: A Randomised, Double-blind, Placebo-controlled, Cross-over, Re-challenge Trial

BACKGROUND AND AIMS

Preliminary evidence suggests that fermentable carbohydrate restriction might ameliorate functional gastrointestinal symptoms [FGS] in inflammatory bowel disease [IBD]. Our aim was to determine whether fermentable carbohydrates exacerbate FGS in IBD using a randomised, double-blinded, placebo-controlled, re-challenge trial.

METHODS

Patients with quiescent IBD and FGS responsive to a low FODMAP diet were allocated to a series of 3-day [d] fermentable carbohydrate challenges in random order [fructan, 12 g/d; galacto-oligosaccharides [GOS] 6 g/d; sorbitol, 6 g/d; and glucose placebo, 12 g/d], each separated by a washout period. Symptoms and stool output were measured daily during the challenges.

RESULTS

Thirty-two patients with IBD, fulfilling criteria for irritable bowel syndrome, functional bloating, or functional diarrhoea, were recruited and data were available for 29 patients completing all arms [12 Crohn's disease, 17 ulcerative colitis]. Significantly fewer patients reported adequate relief of FGS on the final day day of the fructan challenge [18/29, 62.1%] compared with glucose [26/29, 89.7%] [p = 0.033]. There was greater severity of pain [1.1 vs 0.5, p = 0.004], bloating [1.3 vs 0.6, p = 0.002], flatulence [1.5 vs 0.7, p = 0.004], and faecal urgency [0.9 vs 0.4, p = 0.014] on the final day of fructan challenge compared with glucose.

CONCLUSIONS

At the relatively high doses used, fructans, but not GOS or sorbitol, exacerbated FGS in quiescent IBD. Further research is required to determine whether a low FODMAP diet reduces FGS in IBD and the degree of FODMAP restriction required for symptom improvement.

Prebiotic inulin-type fructans and galacto-oligosaccharides: definition, specificity, function, and application in gastrointestinal disorders

Prebiotics are non-digestible selectively fermented dietary fibers that specifically promote the growth of one or more bacterial genera in the gastrointestinal tract and thus provide health benefit to the host. The two most investigated prebiotics being the inulin-type fructans and galacto-oligosaccharides. Prebiotic specificity is mediated through species-specific gene clusters within saccharolytic bacteria controlled by signaling sensors for various substrates. Prebiotic health benefits are attributed to immune regulation and bacterial metabolite production. In humans, prebiotic supplementation leads to increased growth of specific gut microbiota (e.g., bifidobacteria), immune modulation, and depending on the bacterial augmentation, short-chain fatty acid production. Irritable bowel syndrome and Crohn's disease are gastrointestinal disorders associated with reductions in some gut bacteria and greater mucosal inflammation. Prebiotic supplementation studies have shown some promise at low doses for modulation of the gut bacteria and reduction of symptoms in IBS; however, larger doses may have neutral or negative impact on symptoms. Studies in Crohn's disease have not shown benefit to bacterial modulation or inflammatory response with prebiotic supplementation. Dietary restriction of fermentable carbohydrates (low FODMAP diet), which restricts some naturally occurring prebiotics from the diet, has shown efficacy in improving symptoms in irritable bowel syndrome, but it lowers the numbers of some key gut microbiota. Further research is required on the effect of prebiotics in gastrointestinal disorders and, in particular, on their use in conjunction with the low FODMAP diet.

Use of the low-FODMAP diet in inflammatory bowel disease

Irritable bowel syndrome (IBS)-like symptoms are not uncommon in patients with quiescent inflammatory bowel disease (IBD). While gluten-free diet is applied by patients, there are no reported interventional studies. The low-FODMAP diet, on the other hand, has efficacy similar to that seen in patients with IBS in three unblinded or observational studies of IBD cohorts who had well-controlled inflammatory disease and in one small randomized cross-over study. FODMAP intake by patients with IBD is not elevated, and, in one study, fructan intakes were lower in patients with Crohn's disease than in controls. There is no clear relationship between the level of FODMAP intake and intestinal inflammation. The risk of compromising nutritional status with a restrictive diet must be seriously considered especially as under-nutrition is already common in this patient population. The effects of FODMAPs on the gut microbiota of patients with Crohn's disease mimic that in IBS, with a balance between prebiosis from the addition of FODMAPs and loss of prebiosis from their reduction. As undernutrition is common in IBD, the use of restrictive diets should be supervised by a dietitian. Thus, low-FODMAP diet is a viable option for IBS-like symptoms but should be carefully supervised to mitigate risk.

IBS and IBD - separate entities or on a spectrum?

The acute phase of IBD with inflamed gut and often ulcerated mucosa is clearly different from the apparently normal mucosa characteristic of IBS. However, more detailed assessment has detected immune activation, increased gut permeability, increased mucosal serotonin availability, abnormalities of enteric nerve structure and function, and dysbiosis in gut microbiota in IBS - all features seen in IBD. Furthermore, as treatments for inflammation in IBD have become more effective it is now apparent that ∼1 in 3 patients with IBD in remission from inflammation still have persistent abnormalities of sensation, motility and gut microbiota, which might cause IBS-like symptoms. This Perspective explores the overlap between IBS and IBD and their treatments, proposing future directions for research in this stimulating area.

Potential Benefits of Dietary Fibre Intervention in Inflammatory Bowel Disease

Intestinal dysbiosis is thought to be an important cause of disease progression and the gastrointestinal symptoms experienced in patients with inflammatory bowel disease (IBD). Inflammation appears to be a major contributor in perpetuating a dysregulated gut microbiota. Although current drug therapies can significantly induce and maintain disease remission, there is no cure for these diseases. Nevertheless, ongoing human studies investigating dietary fibre interventions may potentially prove to exert beneficial outcomes for IBD. Postulated mechanisms include direct interactions with the gut mucosa through immunomodulation, or indirectly through the microbiome. Component species of the microbiome may degrade dietary-fibre polysaccharides and ferment the products to form short-chain fatty acids such as butyrate. Prebiotic dietary fibres may also act more directly by altering the composition of the microbiome. Longer term benefits in reducing the risk of more aggressive disease or colorectal cancer may require other dietary fibre sources such as wheat bran or psyllium. By critically examining clinical trials that have used dietary fibre supplements or dietary patterns containing specific types or amounts of dietary fibres, it may be possible to assess whether varying the intake of specific dietary fibres may offer an efficient treatment for IBD patients.

Fermentable Carbohydrate Restriction (Low FODMAP Diet) in Clinical Practice Improves Functional Gastrointestinal Symptoms in Patients with Inflammatory Bowel Disease

BACKGROUND

A significant proportion of patients with inflammatory bowel disease (IBD) experience functional-like gastrointestinal symptoms (FGS) even during remission. Research suggests that dietary restriction of fermentable carbohydrates (low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet) can improve FGS, albeit in irritable bowel syndrome. The aim of this study was to investigate the effectiveness of the low FODMAP diet delivered in routine clinical practice in patients with IBD and coexisting FGS.

METHODS

Gastrointestinal symptom scores were compared in consecutive patients with IBD referred for low FODMAP dietary education for symptom management (n = 88). Symptoms were assessed using the Gastrointestinal Symptoms Rating Scale, and stool output was assessed using the Bristol Stool Form Scale at both baseline and follow-up (minimum of 6 weeks).

RESULTS

There was a significant and large increase in the numbers of patients reporting satisfactory relief of symptoms between baseline (14/88, 16%) and low FODMAP diet (69/88, 78%; P < 0.001). Following dietary intervention, there was also a significant decrease in severity for most symptoms and a reduction in composite symptom score (baseline mean: 1.2, SD: 0.5 versus low FODMAP diet mean: 0.7, SD: 0.5; P < 0.001). Improvements in stool consistency and frequency were observed, including an increase in "normal" stool form (P = 0.002) and "normal" stool frequency (P < 0.001).

CONCLUSIONS

The low FODMAP diet delivered in routine clinical practice seems effective in improving satisfaction with, and severity of, FGS in IBD. Randomized controlled trials are warranted to definitively establish effectiveness.

Bugging inflammation: role of the gut microbiota

The advent of vaccination and improved hygiene have eliminated many of the deadly infectious pathogens in developed nations. However, the incidences of inflammatory diseases, such as inflammatory bowel disease, asthma, obesity and diabetes are increasing dramatically. Research in the recent decades revealed that it is indeed the lack of early childhood microbial exposure, increase use of antibiotics, as well as increase consumption of processed foods high in carbohydrates and fats, and lacking fibre, which wreak havoc on the proper development of immunity and predispose the host to elevated inflammatory conditions. Although largely unexplored and under-appreciated until recent years, these factors impact significantly on the composition of the gut microbiota (a collection of microorganisms that live within the host mucosal tissue) and inadvertently play intricate and pivotal roles in modulating an appropriate host immune response. The suggestion that shifts in the composition of host microbiota is a risk factor for inflammatory disease raises an exciting opportunity whereby the microbiota may also present as a potential modifiable component or therapeutic target for inflammatory diseases. This review provides insights into the interactions between the microbiota and the immune system, how these affect disease phenotypes, and explore current and emerging therapies that target the gut microbiota as potential treatment for inflammatory diseases.

Consistent Prebiotic Effect on Gut Microbiota With Altered FODMAP Intake in Patients with Crohn's Disease: A Randomised, Controlled Cross-Over Trial of Well-Defined Diets

Objectives:

Altering FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) intake has substantial effects on gut microbiota. This study aimed to investigate effects of altering FODMAP intake on markers of colonic health in patients with Crohn's disease.

Methods:

After evaluation of their habitual diet, 9 patients with clinically quiescent Crohn's disease were randomised to 21 days of provided low or typical (“Australian”) FODMAP diets with ≥21-day washout in between. Five-day fecal samples were collected at the end of each diet and analyzed for calprotectin, pH, short-chain fatty acids (SCFA) and bacterial abundance. Gastrointestinal symptoms were recorded daily.

Results:

Eight participants collected feces and were adherent to the diets. FODMAP intake differed across the three dietary periods with low<habitual<Australian diet. SCFA, pH and total bacterial abundance remained unaltered, but relative abundance was higher for butyrate-producing Clostridium cluster XIVa (P=0.008) and mucus-associated Akkermansia muciniphila (P=0.016), and lower for Ruminococcus torques (P=0.034) during the Australian compared with low FODMAP diet. Results during habitual diet were similar to the low FODMAP intervention, but significantly different to the Australian diet. The diets had no effects on calprotectin, but symptoms doubled in severity with the Australian diet (n=9; P<0.001).

Conclusions:

In clinically quiescent Crohn's disease, altering dietary FODMAP intake is associated with marked changes in fecal microbiota, most consistent with a prebiotic effect of increasing FODMAPs as shown in an irritable bowel/healthy cohort. This strategy might be favorable for gut health in Crohn's disease, but at the cost of inducing symptoms.