Exposure to Eosinophilic Esophagitis Limits Esophageal Carcinogenesis in a Murine Model

INTRODUCTION

Epidemiological data suggest that eosinophilic esophagitis (EoE) patients do not develop esophageal cancer. Here, we paired murine models of EoE and esophageal squamous cell carcinoma (ESCC) to perform the first functional interrogation of the relationship between EoE and esophageal cancer.

METHODS

C57B6 mice were treated with MC903/Ovalbumin (OVA) to induce EoE and the esophageal carcinogen 4-nitroquinoline 1-oxide (4NQO) to induce ESCC according to the experimental scheme shown in Fig 1A. Esophagi of mice treated with vehicle controls (n=6), MC903/OVA alone (n=4), 4NQO alone (n=10), and MC903 in combination with 4NQO (n=5) were dissected. Tumor frequency was recorded and tumor load (tumor size x tumor number) was determined under a dissecting microscope. H&E stained tissues were evaluated for esophageal lesions. CD45-positive immune cells were isolated from the spleens of mice with EoE or naïve controls then co-cultured with the murine-derived esophageal cell line AKR. After 24-72 hours of co-culture, live/dead dye was used to assess AKR viability.

RESULTS

10/10 mice treated with 4NQO alone developed ESCC as expected in this robust tumor model. In mice co-treated with MC903/OVA and 4NQO, ESCC was detected in 4/5 mice with a significant decrease in tumor load as compared to mice treated with 4NQO alone (Fig 1B, C). 6/6 mice treated with MC903/OVA alone and 4/4 mice treated with propylene glycol (vehicle for 4NQO) failed to display tumors (Fig 1C). We further evaluated esophageal epithelium of 4NQO-treated animals to characterize distribution of ESCC lesions. While squamous dysplasia (pre-malignant), early ESCC and late ESCC were present in all tumor-bearing animals; there was a decrease in early ESCC and a lack of late ESCC lesions in 4NQO-treated mice that were exposed to MC903/OVA-induced EoE (Fig 1D). Moreover, the total percentage of esophageal epithelium occupied by neoplastic lesions was significantly diminished in mice co-treated with 4NQO and MC903/OVA (Fig 1E). To investigate how EoE limits esophageal carcinogenesis, we exposed AKR esophageal tumor cells to CD45-positive cells isolated from spleens of strain-matched donor mice with or without EoE (Fig 2A). We found a robust induction of cell death in tumor cells exposed to immune cells from EoE donor mice compared to those exposed to immune cells from vehicle-treated controls at 48 hours (n=3, p<0.05) (Fig 2B, C).

CONCLUSIONS

These data indicate that exposure to EoE activates an anti-tumoral immune response that limits esophageal carcinogenesis. These studies have the potential for significant implications related to the clinical care of patients affected by EoE and ESCC.

Esophageal 3D organoids of MPV17-/- mouse model of mitochondrial DNA depletion show epithelial cell plasticity and telomere attrition

Esophageal squamous cell carcinoma (ESCC) is an aggressive cancer with late-stage detection and poor prognosis. This emphasizes the need to identify new markers for early diagnosis and treatment. Altered mitochondrial genome (mtDNA) content in primary tumors correlates with poor patient prognosis. Here we used three-dimensional (3D) organoids of esophageal epithelial cells (EECs) from the MPV17-/- mouse model of mtDNA depletion to investigate the contribution of reduced mtDNA content in ESCC oncogenicity. To test if mtDNA defects are a contributing factor in ESCC, we used oncogenic stimuli such as ESCC carcinogen 4-nitroquinoline oxide (4-NQO) treatment, or expressing p53R175H oncogenic driver mutation. We observed that EECs and 3D-organoids with mtDNA depletion had cellular, morphological and genetic alterations typical of an oncogenic transition. Furthermore, mitochondrial dysfunction induced cellular transformation is accompanied by elevated mitochondrial fission protein, DRP1 and pharmacologic inhibition of mitochondrial fission by mDivi-1 in the MPV17-/- organoids reversed the phenotype to that of normal EEC organoids. Our studies show that mtDNA copy number depletion, activates a mitochondrial retrograde response, potentiates telomere defects, and increases the oncogenic susceptibility towards ESCC. Furthermore, mtDNA depletion driven cellular plasticity is mediated via altered mitochondrial fission-fusion dynamics.

Perceptions and psychosocial impact of food, nutrition, eating and drinking in people with inflammatory bowel disease: a qualitative investigation of food-related quality of life

INTRODUCTION

Extensive research has provided an important understanding of the impact of inflammatory bowel disease (IBD) on nutrient intake, requirements and metabolism. By contrast, there has been limited research examining the psychosocial aspects of food, eating and drinking in IBD. The present study aimed to address this unmet need.

METHODS

Qualitative semi-structured interviews regarding the perceptions and psychosocial impact of food, eating and drinking were undertaken with 28 purposively selected people with IBD. Interviews were audio-recorded and transcribed verbatim. Colaizzi's framework was used to structure the data analysis.

RESULTS

Five major themes were identified. IBD symptoms and both surgical and medical treatments were described as having a direct impact on eating and drinking, with participants also using different food-related strategies to control IBD symptoms. These included a process of experimentation to identify trigger foods, following a severely restricted and limited diet, eating small portions, and eating more frequently. However, their limited knowledge about if, and how, food affected their symptoms, often resulted in negative coping strategies that impacted on psychosocial functioning, including a lack of enjoyment of eating, being afraid to eat and finding social occasions stressful. Managing food and drinking also made food shopping and preparation more burdensome, creating problems with families, at work and for social life, as well as the need for careful preparation and advanced planning of activities.

CONCLUSIONS

Inflammatory bowel disease has a profound impact on psychosocial aspects of food and nutrition, which impacts on 'food-related quality of life' (FRQoL). Further research is required to identify interventions that will improve FRQoL in patients with IBD.

Nutritional status, the development and persistence of malnutrition and dietary intake in oesophago-gastric cancer: a longitudinal cohort study

BACKGROUND

Patients with oesophago-gastric (OG) cancer may be at risk of malnutrition, troublesome gastrointestinal symptoms (GI) and reduced dietary intake in view of the tumour location and multimodality curative treatment approach. Longitudinal research is lacking. The present study aimed to assess (i) nutritional status and how it evolved over the first year; (ii) the association between nutritional status scores and GI symptom scores; and (iii) the nutrient and food group intake pattern.

METHODS

This was a prospective, observational study of patients with an OG lesion planned for radical treatment, with assessment at diagnosis, 3 months and 12 months after the start of treatment. Nutritional assessment was performed using the Patient-Generated Subjective Global Assessment, GI symptoms measured using the modified Gastrointestinal Symptom Rating Scale and dietary intake assessed using a semi-quantitative food frequency approach.

RESULTS

Eighty patients (61 males, 19 females; aged 46-89 years) were recruited. At baseline, 3 (n = 68) and 12 months (n = 57), 61%, 62% and 60%, respectively, were moderately/severely malnourished. Higher symptom burden was associated with poorer nutritional status at baseline (r = 0.55, P < 0.001), 3 months (r = 0.51, P < 0.001) and 12 months (r = 0.42, P = 0.001). At each respective time point, 37%, 38% and 42% were meeting their estimated average requirement for energy. No change in mean (SD) intake of energy, fibre, nutrient and food groups was observed over time.

CONCLUSIONS

Patients with OG cancer have progressive weight loss, with malnutrition present over the majority of the 12-month study period. Optimising nutritional status and symptom management throughout the treatment pathway should be a clinical priority.

Long-term impact of the low-FODMAP diet on gastrointestinal symptoms, dietary intake, patient acceptability, and healthcare utilization in irritable bowel syndrome

BACKGROUND

The low-FODMAP diet is a frequently used treatment for irritable bowel syndrome (IBS). Most research has focused on short-term FODMAP restriction; however, guidelines recommend that high-FODMAP foods are reintroduced to individual tolerance. This study aimed to assess the long-term effectiveness of the low-FODMAP diet following FODMAP reintroduction in IBS patients.

METHODS

Patients with IBS were prospectively recruited to a questionnaire study following completion of dietitian-led low-FODMAP education. At baseline and following FODMAP restriction (short term) only, gastrointestinal symptoms were measured as part of routine clinical care. Following FODMAP reintroduction, (long term), symptoms, dietary intake, acceptability, food-related quality of life (QOL), and healthcare utilization were assessed. Data were reported for patients who continued long-term FODMAP restriction (adapted FODMAP) and/or returned to a habitual diet (habitual).

KEY RESULTS

Of 103 patients, satisfactory relief of symptoms was reported in 12% at baseline, 61% at short-term follow-up, and 57% at long-term follow-up. At long-term follow-up, 84 (82%) patients continued an 'adapted FODMAP' diet (total FODMAP intake mean 20.6, SD 14.9 g/d) compared with 19 (18%) of patients following a 'habitual' diet (29.4, SD 22.9 g/d, P=.039). Nutritional adequacy was not compromised for either group. The 'adapted FODMAP' group reported the diet cost significantly more than the 'habitual' group (P<.001) and affected social eating (P<.01) but there was no effect on food-related QOL. Healthcare utilization was similar between both groups.

CONCLUSION AND INFERENCES

Low-FODMAP education is effective for long-term IBS management, enables a nutritionally adequate diet, and is broadly acceptable to patients.

Validity and reliability of the Bristol Stool Form Scale in healthy adults and patients with diarrhoea-predominant irritable bowel syndrome

BACKGROUND

The Bristol Stool Form Scale (BSFS) is a 7-point scale used extensively in clinical practice and research for stool form measurement, which has undergone limited validity and reliability testing.

AIM

To determine the validity and reliability of the BSFS in measuring stool form in healthy adults and patients with diarrhoea-predominant irritable bowel syndrome (IBS-D).

METHODS

One hundred and sixty-nine healthy volunteers provided a stool sample and used the BSFS to classify stool form, which was compared with measured stool water content and with values from 19 patients with IBS-D. Eighty-six volunteers used the BSFS to classify 26 stool models to determine accuracy and reliability.

RESULTS

Volunteers' classifications of stool type correlated with stool water (Spearman's rho = 0.491, P < 0.001), which increased in hard (Types 1-2), normal (Types 3-5) and loose stools (Types 6-7) (P < 0.001). The BSFS detected differences in stool form between healthy volunteers (mean 3.7, s.d. 1.5) and IBS-D patients (mean 5.0, s.d. 1.2) (P < 0.001). Overall, 977/1204 (81%) stool models were correctly classified (substantial accuracy, κ = 0.78), although <80% of Types 2, 3, 5 and 6 were classified correctly. On 852/1118 (76%) occasions, volunteers classified covert duplicate models to the same stool type (substantial reliability, κ = 0.72), but with only moderate reliability for Types 2 (63%, κ = 0.57) and 3 (62%, κ = 0.55).

CONCLUSIONS

The BSFS demonstrated substantial validity and reliability, although difficulties arose around clinical decision points (Types 2, 3, 5, 6) that warrant investigation in larger clinical populations. Potential for improving validity and reliability through modifications to the BSFS or training in its use should be explored.

JARID1B Enables Transit between Distinct States of the Stem-like Cell Population in Oral Cancers

The degree of heterogeneity among cancer stem cells (CSC) remains ill-defined and may hinder effective anti-CSC therapy. Evaluation of oral cancers for such heterogeneity identified two compartments within the CSC pool. One compartment was detected using a reporter for expression of the H3K4me3 demethylase JARID1B to isolate a JARID1B(high) fraction of cells with stem cell-like function. JARID1B(high) cells expressed oral CSC markers including CD44 and ALDH1 and showed increased PI3K pathway activation. They were distinguished from a fraction in a G0-like cell-cycle state characterized by low reactive oxygen species and suppressed PI3K/AKT signaling. G0-like cells lacked conventional CSC markers but were primed to acquire stem cell-like function by upregulating JARID1B, which directly mediated transition to a state expressing known oral CSC markers. The transition was regulated by PI3K signals acting upstream of JARID1B expression, resulting in PI3K inhibition depleting JARID1B(high) cells but expanding the G0-like subset. These findings define a novel developmental relationship between two cell phenotypes that may jointly contribute to CSC maintenance. Expansion of the G0-like subset during targeted depletion of JARID1B(high) cells implicates it as a candidate therapeutic target within the oral CSC pool. Cancer Res; 76(18); 5538-49. ©2016 AACR.

Systematic review with meta-analysis: effect of fibre supplementation on chronic idiopathic constipation in adults

BACKGROUND

Chronic idiopathic constipation is a common symptom-based gastrointestinal disorder responsible for a substantial economic health service burden. Current guidelines recommend the use of fibre as a first-line treatment.

AIM

To investigate the effect of fibre (including prebiotic) supplementation on global symptom response, stool output, gut microbiota composition and adverse events in adults with chronic idiopathic constipation.

METHODS

Medline, EmBase, Web of Science, Scopus and the Cochrane central register of controlled trials were searched through to February 2016. Conference proceedings from 2003 to 2015 were hand-searched. There were no language restrictions. Forest plots with 95% CIs were generated using a random-effects model.

RESULTS

The search strategy generated 1072 citations, of which seven individual randomised controlled trials were eligible. Overall, 113 of 147 (77%) patients assigned to fibre responded to therapy, compared with 61 of 140 (44%) allocated to placebo (RR of success to respond 1.71, 95% CI 1.20-2.42, P = 0.003). Fibre significantly increased stool frequency (SMD, standardised mean difference = 0.39; 95% CI 0.03-0.76; P = 0.03) and softened stool consistency (SMD = 0.35; 95% CI 0.04-0.65; P = 0.02) compared with placebo. Flatulence was significantly higher with fibre compared to placebo (SMD 0.56, 0.12-1.00, P = 0.01). Overall quality of evidence was low.

CONCLUSIONS

This meta-analysis demonstrates that fibre is moderately effective, but also causes moderate gastrointestinal side effects. However, these findings need to be treated with caution due to a high risk of bias. Accordingly, further large, methodologically rigorous trials are required, before any definitive recommendation regarding its risk-benefit profile can be made. PROSPERO registration number CRD42014007005.

An eDNA assay for Irish Petromyzon marinus and Salmo trutta and field validation in running water

This pilot study presents an environmental DNA (eDNA) assay for sea lamprey Petromyzon marinus and brown trout Salmo trutta, two species of economic and conservation importance in the Republic of Ireland. The results demonstrate the effectiveness of eDNA for assessing presence of low-abundance taxa (here, P. marinus) for environmental managers, and they highlight the potential for assessing relative abundance of rare or invasive freshwater species.

What role do bacteria play in persisting fistula formation in idiopathic and Crohn's anal fistula?

AIM

The aetiology of Crohn's disease-related anal fistula remains obscure. Microbiological, genetic and immunological factors are thought to play a role but are not well understood. The microbiota within anal fistula tracts has never been examined using molecular techniques. The present study aimed to characterize the microbiota in the tracts of patients with Crohn's and idiopathic anal fistula.

METHOD

Samples from the fistula tract and rectum of patients with Crohn's and idiopathic anal fistula were analysed using fluorescent in situ hybridization, Gram staining and scanning electron microscopy were performed to identify and quantify the bacteria present.

RESULTS

Fifty-one patients, including 20 with Crohn's anal fistula, 18 with idiopathic anal fistula and 13 with luminal Crohn's disease and no anal fistula, were recruited. Bacteria were not found in close association with the luminal surface of any of the anal fistula tracts.

CONCLUSION

Anal fistula tracts generally do not harbour high levels of mucosa-associated microbiota. Crohn's anal fistulas do not seem to harbour specific bacteria. Alternative explanations for the persistence of anal fistula are needed.

Mechanisms of Barrett's oesophagus: intestinal differentiation, stem cells, and tissue models

Barrett's oesophagus (BE) is defined as any metaplastic columnar epithelium in the distal oesophagus which replaces normal squamous epithelium and which predisposes to cancer development. It is this second requirement, the predisposition to cancer, which makes this condition both clinically highly relevant and an important area for ongoing research. While BE has been defined pathologically since the 1950's (Allison and Johnstone, Thorax 1955), and identified as a risk factor for esophageal adenocarcinoma since the 1970's (Naef A.P., et al J Thorac Cardiovasc Surg. 1975), our understanding of the molecular events giving rise to this condition remains limited. Herein we will examine what is known about the intestinal features of BE and how well it recapitulates the intestinal epithelium, including stem identity and function. Finally, we will explore laboratory models of this condition presently in use and under development, to identify new insights they may provide into this important clinical condition.

Abstract A74: TGF-β in tumor microenvironment changes a switch of Notch1-mediated signaling to maintain cancer stem-like cells in esophageal squamous cell carcinoma

There exists a highly tumorigenic subset of esophageal squamous cell carcinoma (ESCC) cells defined by high expression of CD44 (CD44H). CD44H cells have cancer stem-like characteristics and as few as ten CD44H cells can form tumors in an athymic nude mouse. Epithelial-mesenchymal transition (EMT) has a critical role to maintain CD44H cells in ESCC. Notch1-mediated signaling may facilitate either EMT or squamous-cell differentiation in a context-dependent manner. However, detailed mechanism how Notch signaling promotes either EMT or differentiation remains unclear. We investigated how TGF-β in tumor microenvironment might influence Notch signaling to maintain CD44H cells via EMT in ESCC. TGF-β promoted EMT and enriched CD44H cells by activating Notch1 and ZEB1 and suppressing Notch3, while in absence of TGF-β, Notch1 rather activated Notch3, one of pivotal transcription factors in keratinocyte differentiation, led to keratinocyte differentiation. Highly conserved binding sites of ZEB1 exist in the 2nd intron of Notch3. ZEB1 induced by TGF-β bound to the 2nd intron of Notch3 and sharply suppressed the Notch3 transcription, confirmed by CHIP and luciferase assay. Thus TGF-β and Notch1 cooperatively promote EMT and maintain tumor initiating cells. TGF-β signaling influences the tumor initiating capacity of ESCC by modulating novel opposing activities of Notch1 and Notch3 in EMT, and may have translational implications.

Citation Format: Mitsuteru Natsuizaka, Shingo Kagawa, Kelly Whelan, Shinya Ohashi, Shunsuke Ohnishi, Goki Suda, Naoya Sakamoto, Anil K. Rustgi, Hiroshi Nakagawa. TGF-β in tumor microenvironment changes a switch of Notch1-mediated signaling to maintain cancer stem-like cells in esophageal squamous cell carcinoma. [abstract]. In: Abstracts: AACR Special Conference on Cellular Heterogeneity in the Tumor Microenvironment; 2014 Feb 26-Mar 1; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(1 Suppl):Abstract nr A74. doi:10.1158/1538-7445.CHTME14-A74

Systematic review: the effect of prunes on gastrointestinal function

BACKGROUND

Prunes (dried plums) are high in fibre and are perceived to promote healthy gastrointestinal (GI) function.

AIM

To assess the effect of prunes on GI function through a systematic review of randomised controlled trials (RCTs).

METHODS

Sixteen electronic databases were searched, a hand search was performed and key opinion leaders were contacted. RCTs investigating the effect of prunes on GI function were included. Two reviewers independently screened relevant articles, extracted data and assessed risk of bias.

RESULTS

Four trials met the inclusion criteria, one in constipation and three in non-constipated subjects. In constipation, 3 weeks of prune consumption (100 g/day) improved stool frequency (3.5 vs. 2.8 CSBM per week, P = 0.006) and stool consistency (3.2 vs. 2.8 on Bristol stool form scale, P = 0.02) compared with psyllium (22 g/day). In non-constipated subjects, prunes softened stool consistency in one trial and increased stool weight (628 g vs. 514 g/72 h wet weight, P = 0.001) in another trial, compared with control. No trials found differences in GI symptoms between prunes and comparator. Meta-analysis was not appropriate due to heterogeneity in populations and methods. Two of the trials were limited by unclear risk of bias.

CONCLUSIONS

In constipation, prunes appear superior to psyllium for improving stool frequency and consistency, however, the evidence for other outcomes and the effects in non-constipated subjects is weak. Although prunes may be a promising intervention for the management of constipation and increasing stool weight, this needs to be confirmed by further rigorous research.

Review article: small intestinal bacterial overgrowth--prevalence, clinical features, current and developing diagnostic tests, and treatment

BACKGROUND

The symptoms and signs of small intestinal bacterial overgrowth (SIBO) are often identical to a variety of diseases and can lead to diagnostic confusion.

AIMS

To review the diagnostic options for SIBO and present new investigative options for the condition.

METHODS

A literature search was performed on MEDLINE, EMBASE and Web of Science for English articles and abstracts. Search terms included free text words and combinations of the following terms 'small intestinal bacterial overgrowth', 'small bowel bacterial overgrowth', 'diagnostic tests', 'treatment', 'antibiotics', 'probiotics', 'metabonomics', 'proton nuclear magnetic resonance spectroscopy', 'electronic nose' and 'field asymmetric ion mobility spectrometry'.

RESULTS

All of the available methods to test for SIBO have inherent limitations and no 'gold-standard' diagnostic test for the condition exists. Accurate diagnosis of SIBO requires identification of bacterial species growing inappropriately within the small intestine and symptom response to antibiotics. Proton nuclear magnetic resonance spectroscopy, electronic nose technology and/or field asymmetric ion mobility spectrometry may represent better investigative options for the condition.

CONCLUSIONS

Novel diagnostic options are needed to supplement or replace available tests.

Systematic review: the efficacy of nutritional interventions to counteract acute gastrointestinal toxicity during therapeutic pelvic radiotherapy

BACKGROUND

Radiotherapy-induced damage to noncancerous gastrointestinal mucosa has effects on secretory and absorptive functions and can interfere with normal gastrointestinal physiology. Nutrient absorption and digestion may be compromised. Dietary manipulation is an attractive option for the prevention and management of symptoms.

AIM

To synthesise the evidence for the use of elemental formula low- or modified-fat diets, fibre, lactose restriction and probiotics, prebiotics and synbiotics to protect the gastrointestinal tract during pelvic radiotherapy.

METHODS

Four electronic databases were searched. Randomised controlled trials (RCT), controlled trials (CT) and case series in adult patients receiving radiotherapy for pelvic cancers employing nutritional interventions to reduce gastrointestinal toxicity were included. Methodological quality was assessed using a bespoke tool.

RESULTS

Twenty-two original studies (2446 patients) were identified. Study quality was highly variable with only 37% scoring ≥10 points (maximum 17: bespoke scale). Few studies assessed compliance with the intervention. End-points varied and included symptom scales (IBDQ, CTC, Bristol Stool and RTOG). Evidence from RCTs was weak for elemental, low- or modified-fat, fibre and low-lactose interventions with 1/4, 3/4, 1/2, 0/1 trials respectively reporting favourable outcomes. Evidence for probiotics as prophylactic interventions was more promising (4/5 favourable), but dose, strains and methodologies varied.

CONCLUSIONS

There is insufficient high-grade evidence to recommend nutritional intervention during pelvic radiotherapy. Total replacement of diet with elemental formula may be appropriate in severe toxicity. Probiotics offer promise, but cannot be introduced into clinical practice without rigorous safety analysis, not least in immunocompromised patients. The methodological quality of nutritional intervention studies needs to be improved.

Systematic review: faecal microbiota transplantation in the management of inflammatory bowel disease

BACKGROUND

The intestinal microbiota is involved in the pathogenesis of inflammatory bowel disease (IBD). Faecal microbiota transplantation (FMT) has been used for the management of IBD as well as infectious diarrhoea.

AIM

To undertake a systematic review of FMT in patients with IBD.

METHODS

The systematic review followed Cochrane and PRISMA recommendations. Nine electronic databases were searched in addition to hand searching and contacting experts. Inclusion criteria were reports (RCT, nonrandomised trials, case series and case reports) of FMT in patients with IBD.

RESULTS

Of the 5320 articles identified, 17 fulfilled the inclusion criteria, none of which were controlled trials. There were nine case series/case reports of patients receiving FMT for management of their IBD, and eight where FMT was for the treatment of infectious diarrhoea in IBD. These 17 articles reported on 41 patients with IBD (27 UC, 12 Crohn's, 2 unclassified) with a follow-up period of between 2 weeks and 13 years. Where reported, FMT was administered via colonoscopy/enema (26/33) or via enteral tube (7/33). In patients treated for their IBD, the majority experienced a reduction of symptoms (19/25), cessation of IBD medications (13/17) and disease remission (15/24). There was resolution of C. difficile infection in all those treated for such (15/15).

CONCLUSIONS

Whilst the available evidence is limited and weak, it suggests that faecal microbiota transplantation has the potential to be an effective and safe treatment for IBD, at least when standard treatments have failed. Well-designed randomised controlled trials are required to investigate these findings.

Systematic review: faecal microbiota transplantation in the management of inflammatory bowel disease

BACKGROUND

The intestinal microbiota is involved in the pathogenesis of inflammatory bowel disease (IBD). Faecal microbiota transplantation (FMT) has been used for the management of IBD as well as infectious diarrhoea.

AIM

To undertake a systematic review of FMT in patients with IBD.

METHODS

The systematic review followed Cochrane and PRISMA recommendations. Nine electronic databases were searched in addition to hand searching and contacting experts. Inclusion criteria were reports (RCT, nonrandomised trials, case series and case reports) of FMT in patients with IBD.

RESULTS

Of the 5320 articles identified, 17 fulfilled the inclusion criteria, none of which were controlled trials. There were nine case series/case reports of patients receiving FMT for management of their IBD, and eight where FMT was for the treatment of infectious diarrhoea in IBD. These 17 articles reported on 41 patients with IBD (27 UC, 12 Crohn's, 2 unclassified) with a follow-up period of between 2 weeks and 13 years. Where reported, FMT was administered via colonoscopy/enema (26/33) or via enteral tube (7/33). In patients treated for their IBD, the majority experienced a reduction of symptoms (19/25), cessation of IBD medications (13/17) and disease remission (15/24). There was resolution of C. difficile infection in all those treated for such (15/15).

CONCLUSIONS

Whilst the available evidence is limited and weak, it suggests that faecal microbiota transplantation has the potential to be an effective and safe treatment for IBD, at least when standard treatments have failed. Well-designed randomised controlled trials are required to investigate these findings.

Distinct microbial populations exist in the mucosa-associated microbiota of sub-groups of irritable bowel syndrome

BACKGROUND

There is increasing evidence to support a role for the gastrointestinal microbiota in the etiology of irritable bowel syndrome (IBS). Given the evidence of an inflammatory component to IBS, the mucosa-associated microbiota potentially play a key role in its pathogenesis. The objectives were to compare the mucosa-associated microbiota between patients with diarrhea predominant IBS (IBS-D), constipation predominant IBS (IBS-C) and controls using fluorescent in situ hybridization and to correlate specific bacteria groups with individual IBS symptoms.

METHODS

Forty-seven patients with IBS (27 IBS-D and 20 IBS-C) and 26 healthy controls were recruited to the study. Snap-frozen rectal biopsies were taken at colonoscopy and bacterial quantification performed by hybridizing frozen sections with bacterial-group specific oligonucleotide probes.

KEY RESULTS

Patients with IBS had significantly greater numbers of total mucosa-associated bacteria per mm of rectal epithelium than controls [median 218 (IQR - 209) vs 128 (121) P = 0.007], and this was chiefly comprised of bacteroides IBS [69 (67) vs 14 (41) P = 0.001] and Eubacterium rectale-Clostridium coccoides [52 (58) vs 25 (35) P = 0.03]. Analysis of IBS sub-groups demonstrated that bifidobacteria were lower in the IBS-D group than in the IBS-C group and controls [24 (32) vs 54 (88) vs 32 (35) P = 0.011]. Finally, amongst patients with IBS, the maximum number of stools per day negatively correlated with the number of mucosa-associated bifidobacteria (P < 0.001) and lactobacilli (P = 0.002).

CONCLUSIONS & INFERENCES

The mucosa-associated microbiota in patients with IBS is significantly different from healthy controls with increases in bacteroides and clostridia and a reduction in bifidobacteria in patients with IBS-D.

Relationship between human intestinal dendritic cells, gut microbiota, and disease activity in Crohn's disease

BACKGROUND

Altered intestinal dendritic cell (DC) function underlies dysregulated T-cell responses to bacteria in Crohn's disease (CD) but it is unclear whether composition of the intestinal microbiota impacts local DC function. We assessed the relationship between DC function with disease activity and intestinal microbiota in patients with CD.

METHODS

Surface expression of Toll-like receptor (TLR)-2, TLR-4, and spontaneous intracellular interleukin (IL)-10, IL-12p40, IL-6 production by freshly isolated DC were analyzed by multicolor flow cytometry of cells extracted from rectal tissue of 10 controls and 28 CD patients. Myeloid DC were identified as CD11c(+) HLA-DR(+lin-/dim) cells (lin = anti-CD3, CD14, CD16, CD19, CD34). Intestinal microbiota were analyzed by fluorescent in situ hybridization of fecal samples with oligonucleotide probes targeting 16S rRNA of bifidobacteria, bacteroides-prevotella, C. coccoides-E. rectale, and Faecalibacterium prausnitzii.

RESULTS

DC from CD produced higher amounts of IL-12p40 and IL-6 than control DC. IL-6(+) DC were associated with the CD Activity Index (r = 0.425; P = 0.024) and serum C-reactive protein (CRP) (r = 0.643; P = 0.004). DC expression of TLR-4 correlated with disease activity. IL-12p40(+) DC correlated with ratio of bacteroides: bifidobacteria (r = 0.535, P = 0.003). IL-10(+) DC correlated with bifidobacteria, and IL-6(+) DC correlated negatively with F. prausnitzii (r = -0.50; P = 0.008). The amount of TLR-4 on DC correlated negatively with the concentration of F. prausnitzii.

CONCLUSIONS

IL-6 production by intestinal DC is increased in CD and correlates with disease activity and CRP. Bacterially driven local IL-6 production by intestinal DC may overcome regulatory activity, resulting in unopposed effector function and tissue damage. Intestinal DC function may be influenced by the composition of the commensal microbiota.

Comparison of symptom response following advice for a diet low in fermentable carbohydrates (FODMAPs) versus standard dietary advice in patients with irritable bowel syndrome

BACKGROUND

Emerging evidence indicates that the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) may result in symptoms in some patients with irritable bowel syndrome (IBS). The present study aimed to determine whether a low FODMAP diet is effective for symptom control in patients with IBS and to compare its effects with those of standard dietary advice based on the UK National Institute for Health and Clinical Excellence (NICE) guidelines.

METHODS

Consecutive patients with IBS who attended a follow-up dietetic outpatient visit for dietary management of their symptoms were included. Questionnaires were completed for patients who received standard (n = 39) or low FODMAP dietary advice (n = 43). Data were recorded on symptom change and comparisons were made between groups.

RESULTS

In total, more patients in the low FODMAP group reported satisfaction with their symptom response (76%) compared to the standard group (54%, P = 0.038). Composite symptom score data showed better overall symptom response in the low FODMAP group (86%) compared to the standard group (49%, P < 0.001). Significantly more patients in the low FODMAP group compared to the standard group reported improvements in bloating (low FODMAP 82% versus standard 49%, P = 0.002), abdominal pain (low FODMAP 85% versus standard 61%, P = 0.023) and flatulence (low FODMAP 87% versus standard 50%, P = 0.001).

CONCLUSIONS

A low FODMAP diet appears to be more effective than standard dietary advice for symptom control in IBS.

Limited availability and higher cost of gluten-free foods

BACKGROUND

A gluten-free diet is the only treatment for patients with coeliac disease, although it can be burdensome to follow and result in inadequate nutrient intake. The cost and availability of a gluten-free diet has been cited as a cause of incomplete dietary compliance; however, this has not been extensively investigated. The aim was to investigate the availability and cost of gluten-free foods across a wide range of stores.

METHODS

The availability and cost of 20 foods (both wheat-based and everyday foods) was surveyed at 30 different stores across five different store categories. For each of the 20 foods, four products were selected (branded gluten-free, cheapest gluten-free, branded standard, cheapest standard) resulting in sampling of up to 80 products in each of the 30 stores.

RESULTS

In general, there was limited availability of gluten-free foods, with an average of 8.2 of the 20 (41%) foods being available in a gluten-free version per store. Regular supermarkets had a greater availability (18.0/20, 90%), whereas budget supermarkets (1.8/20, 9%) and corner shops (1.8/20, 9%) had almost no gluten-free versions (P < 0.001). All 10 gluten-free versions of wheat-based foods were more costly than their standard counterparts (76-518% more expensive; P < 0.001). Some gluten-free versions of everyday foods were also more costly than standard counterparts (2-124%).

CONCLUSIONS

There is limited availability of gluten-free foods and they are generally more expensive than their standard counterparts. This may impact on compliance to a gluten-free diet, with potential nutritional and clinical consequences, together with an increased risk of complications.

Limited availability and higher cost of gluten-free foods

BACKGROUND

A gluten-free diet is the only treatment for patients with coeliac disease, although it can be burdensome to follow and result in inadequate nutrient intake. The cost and availability of a gluten-free diet has been cited as a cause of incomplete dietary compliance; however, this has not been extensively investigated. The aim was to investigate the availability and cost of gluten-free foods across a wide range of stores.

METHODS

The availability and cost of 20 foods (both wheat-based and everyday foods) was surveyed at 30 different stores across five different store categories. For each of the 20 foods, four products were selected (branded gluten-free, cheapest gluten-free, branded standard, cheapest standard) resulting in sampling of up to 80 products in each of the 30 stores.

RESULTS

In general, there was limited availability of gluten-free foods, with an average of 8.2 of the 20 (41%) foods being available in a gluten-free version per store. Regular supermarkets had a greater availability (18.0/20, 90%), whereas budget supermarkets (1.8/20, 9%) and corner shops (1.8/20, 9%) had almost no gluten-free versions (P < 0.001). All 10 gluten-free versions of wheat-based foods were more costly than their standard counterparts (76-518% more expensive; P < 0.001). Some gluten-free versions of everyday foods were also more costly than standard counterparts (2-124%).

CONCLUSIONS

There is limited availability of gluten-free foods and they are generally more expensive than their standard counterparts. This may impact on compliance to a gluten-free diet, with potential nutritional and clinical consequences, together with an increased risk of complications.