Effect of wheat bran derived prebiotic supplementation on gastrointestinal transit, gut microbiota, and metabolic health: a randomized controlled trial in healthy adults with a slow gut transit

Acute intake of the wheat bran extract Arabinoxylan-Oligosaccharide (AXOS) modulates the gut microbiota, improves stool characteristics and postprandial glycemia in healthy humans. Yet, little is known on how long-term AXOS intake influences gastrointestinal (GI) functioning, gut microbiota, and metabolic health. In this randomized, placebo-controlled, double-blind study, we evaluated the effects of AXOS intake on GI function and metabolic health in adults with slow GI transit without constipation. Forty-eight normoglycemic adults were included with whole-gut transit time (WGTT) of >35 h receiving either 15 g/day AXOS or placebo (maltodextrin) for 12-wks. The primary outcome was WGTT, and secondary outcomes included stool parameters, gut permeability, short-chain fatty acids (SCFA), microbiota composition, energy expenditure, substrate oxidation, glucose, insulin, lipids, gut hormones, and adipose tissue (AT) function. WGTT was unchanged, but stool consistency softened after AXOS. 12-wks of AXOS intake significantly changed the microbiota by increasing Bifidobacterium and decreasing microbial alpha-diversity. With a good classification accuracy, overall microbiota composition classified responders with decreased WGTT after AXOS. The incretin hormone Glucagon-like protein 1 was reduced after AXOS compared to placebo. Energy expenditure, plasma metabolites, AT parameters, SCFA, and gut permeability were unchanged. In conclusion, intake of wheat bran extract increases fecal Bifidobacterium and softens stool consistency without major effects on energy metabolism in healthy humans with a slow GI transit. We show that overall gut microbiota classified responders with decreased WGTT after AXOS highlighting that GI transit and change thereof were associated with gut microbiota independent of Bifidobacterium. NCT02491125.

Smart Data Collection for the Assessment of Treatment Effects in Irritable Bowel Syndrome: Observational Study

BACKGROUND

End-of-day symptom diaries are recommended by drug regulatory authorities to assess treatment response in patients with irritable bowel syndrome. We developed a smartphone app to measure treatment response.

OBJECTIVE

Because the employment of an app to measure treatment response in irritable bowel syndrome is relatively new, we aimed to explore patients' adherence to diary use and characteristics associated with adherence.

METHODS

A smartphone app was developed to serve as a symptom diary. Patients with irritable bowel syndrome (based on Rome IV criteria) were instructed to fill out end-of-day diary questionnaires during an 8-week treatment. Additional online questionnaires assessed demographics, irritable bowel syndrome symptom severity, and psychosocial comorbidities. Adherence rate to the diary was defined as the percentage of days completed out of total days. Adherence to the additional web-based questionnaires was also assessed.

RESULTS

Overall, 189 patients were included (age: mean 34.0 years, SD 13.3 years; female: 147/189, 77.8%; male: 42/189, 22.2%). The mean adherence rate was 87.9% (SD 9.4%). However, adherence to the diary decreased over time (P<.001). No significant association was found between adherence and gender (P=.84), age (P=.22), or education level (lower education level: P=.58, middle education level: P=.46, versus high education level), while higher anxiety scores were associated with lower adherence (P=.03). Adherence to the online questionnaires was also high (>99%). Missing data due to technical issues were limited.

CONCLUSIONS

The use of a smartphone app as a symptom diary to assess treatment response resulted in high patient adherence. The data-collection framework described led to standardized data collection with excellent completeness and can be used for future randomized controlled trials. Due to the slight decrease in adherence to diary use throughout the study, this method might be less suitable for longer trials.

Abstract A62: Clinical translation of liquid biopsy DNA methylation biomarkers: Lessons from two systematic reviews

Background: Very few (&lt;0.1%) of DNA methylation biomarkers are eventually translated into clinical practice, even though over 5,000 have been published over the last decades. In an attempt to create an overview of the current evidence on these markers, we performed two systematic reviews on diagnostic DNA methylation biomarkers in liquid biopsies, for colorectal cancer (CRC) and renal cell carcinoma (RCC) (1). Here, we present the evidence of these systematic reviews and provide novel recommendations to improve the current clinical translation of DNA methylation biomarkers.

Methods: For CRC, we identified 109 bodily fluid biomarker studies published before January 2019 in PubMed, Embase, Cochrane Library, or Google Scholar. For RCC, we identified 6 liquid biopsy studies up to January 2019 in these databases. Data extraction (study design, patient characteristics, disease stage, tumor location, technical assays, diagnostic measures) was performed on published reports. STARD criteria and Level of Evidence (LoE) were registered to assess reporting quality and strength for clinical translation, and forest plots were generated to summarize diagnostic performance of the biomarkers.

Findings: Our systematic literature search revealed multiple issues that hamper the development of DNA methylation biomarkers for RCC and CRC diagnosis, including methodologic and technical heterogeneity and lack of validation or clinical translation. Among the most important issues were a lack of translation from tissue into liquid biopsy; for CRC 88/389 (23%) CRC markers were studied in liquid biopsies, and for RCC these numbers were 15/44 (34%). In addition, results showed a lack of independent validation, with 37/88 (42%) CRC markers and 9/15 (60%) RCC markers in liquid biopsies studied in more than one study or study population. Also, inappropriate marker identification and primer design, lack of true clinical need definition, and low reporting quality were issues that were recognized in our systematic literature searches. These issues all hamper the development of the field, keep the LoE low, and hinder the translation of DNA methylation biomarkers into clinical tests.

Interpretation: Our systematic literature searches revealed that major requirements to develop clinically relevant diagnostic DNA methylation markers are often lacking. To avoid the resulting research waste, clinical needs, intended biomarker use, and independent validation should be better considered prior to study design. In addition, improved reporting quality would facilitate meta-analysis, thereby increasing LoE and enabling clinical translation.

Reference: 1. Lommen et al. Eur Urol Oncol 2019; https://doi.org/10.1016/j.euo.2019.07.011.

Citation Format: Kim Lommen, Zheng Feng, Cary J.G. Oberije, Alouisa J. P. van de Wetering, Selena Odeh, Alexander Koch, Maureen J. B. Aarts, Joep G. van Roermund, Leo J. Schouten, Egbert Oosterwijk, Nathalie Vaes, Ad A. M. Masclee, Beatriz Carvalho, Gerrit A. Meijer, Maurice P. Zeegers, James G. Herman, Vivianne C. Tjan-Heijnen, Veerle Melotte, Manon van Engeland, Kim Smits. Clinical translation of liquid biopsy DNA methylation biomarkers: Lessons from two systematic reviews [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr A62.

[Nausea; article for education and training purposes]

Nausea is a common presenting symptom in medical care with a broad differential diagnosis. In this teaching article we provide practical information on many aspects of nausea including pathophysiology and differential diagnosis, history and physical examination, and diagnostic tests and treatment. This was done by means of answering several questions from the daily practice of general practitioners, specialists in internal medicine and surgeons. In a patient with nausea a provisional diagnosis can be made based on medical history, careful history-taking and age. Diagnostic testing is only performed on clinical suspicion and depends on the provisional diagnosis and presence of alarm symptoms. Tailored medical treatment of nausea is based on the provisional diagnosis and on the mechanism of action of the intended antiemetic agent.

Implementation of quality controls is essential to prevent batch effects in breathomics data and allow for cross-study comparisons

Exhaled breath analysis has become a promising monitoring tool for various ailments by identifying volatile organic compounds (VOCs) as indicative biomarkers excreted in the human body. Throughout the process of sampling, measuring, and data processing, non-biological variations are introduced in the data leading to batch effects. Algorithmic approaches have been developed to cope with within-study batch effects. Batch differences, however, may occur among different studies too, and up-to-date, ways to correct for cross-study batch effects are lacking; ultimately, cross-study comparisons to verify the uniqueness of found VOC profiles for a specific disease may be challenging. This study applies within-study batch-effect-correction approaches to correct for cross-study batch effects; suggestions are made that may help prevent the introduction of cross-study variations. Three batch-effect-correction algorithms were investigated: zero-centering, combat, and the analysis of covariance framework. The breath samples were collected from inflammatory bowel disease ([Formula: see text]), chronic liver disease ([Formula: see text]), and irritable bowel syndrome ([Formula: see text]) patients at different periods, and they were analysed via gas chromatography-mass spectrometry. Multivariate statistics were used to visualise and verify the results. The visualisation of the data before any batch-effect-correction technique was applied showed a clear distinction due to probable batch effects among the datasets of the three cohorts. The visualisation of the three datasets after implementing all three correction techniques showed that the batch effects were still present in the data. Predictions made using partial least squares discriminant analysis and random forest confirmed this observation. The within-study batch-effect-correction approaches fail to correct for cross-study batch effects present in the data. The present study proposes a framework for systematically standardising future breathomics data by using internal standards or quality control samples at regular analysis intervals. Further knowledge regarding the nature of the unsolicited variations among cross-study batches must be obtained to move the field further.

Distal colonic transit is linked to gut microbiota diversity and microbial fermentation in humans with slow colonic transit

Longer colonic transit time and hard stools are associated with increased gut microbiota diversity. Here, we investigate to what extent quantitative measures of (segmental) colonic transit time were related to gut microbiota composition, microbial metabolites, and gut-related parameters in a human cross-sectional study. Using radiopaque markers, (segmental) colonic transit time (CTT) was measured in 48 lean/overweight participants with long colonic transit but without constipation. Fecal microbiota composition was determined using 16S rRNA gene amplicon sequencing. Associations between gastrointestinal transit (segmental CTT and stool frequency and consistency), microbiota diversity and composition, microbial metabolites [short-chain fatty acids (SCFA), branched-chain fatty acids, and breath hydrogen], habitual diet, and gut-related host parameters [lipopolysaccharide-binding protein (LBP) and fecal calprotectin] were investigated using univariate and multivariate approaches. Long descending (i.e., distal) colonic transit was associated with increased microbial α-diversity but not with stool consistency. Using unweighted and weighted UniFrac distance, microbiota variation was not related to (segmental) CTT but to demographics, diet, plasma LBP, and fecal calprotectin. Bray-Curtis dissimilarity related only to stool consistency. Rectosigmoid and descending colonic transit were negatively associated with fecal SCFA and plasma acetate, respectively. This study suggests that the distal colon transit may affect not only microbiota diversity but also microbial metabolism.NEW & NOTEWORTHY We extend previous findings showing that long distal colonic transit time influences microbial diversification and fermentation, whereas stool consistency is related to microbiota composition in humans with a long colonic transit. This study puts the importance of the (distal) colonic site in microbiota ecology forward, which should be considered in future therapeutic studies targeting, for instance, short-chain fatty acid production to improve metabolic health.

Intestinal barrier function is maintained with aging - a comprehensive study in healthy subjects and irritable bowel syndrome patients

Animal studies have shown that intestinal barrier function is compromised with aging. We aimed to assess the effects of aging on intestinal barrier function in humans in vivo and ex vivo. In this cross-sectional study, healthy subjects and subjects with irritable bowel syndrome (IBS) of older (65–75 years) and young adult age (18–40 years) were compared. In vivo gastrointestinal site-specific permeability was assessed by a multi-sugar test, taking into account potential confounders. Sigmoid biopsies were collected from subgroups of healthy young adults and elderly for ex vivo Ussing chamber experiments, gene transcription of barrier-related genes and staining of junctional proteins. No significant differences between healthy young adults and elderly were found for small intestinal, colonic and whole gut permeability (P ≥ 0.142). In IBS patients, gastroduodenal and colonic permeability did not differ significantly (P ≥ 0.400), but small intestinal and whole gut permeability were higher in elderly versus young adults (P ≤ 0.009), mainly driven by the IBS-diarrhea subtype. Ussing chamber experiments with or without stressor (P ≥ 0.052), and relative expression of intestinal barrier-related genes (P ≥ 0.264) showed no significant differences between healthy elderly and young adults, as confirmed by immunofluorescent stainings. Overall, the functional capacity of the intestinal barrier is maintained in elderly.

Efficacy and Safety of Peppermint Oil in a Randomized, Double-Blind Trial of Patients With Irritable Bowel Syndrome

BACKGROUND & AIMS

Peppermint oil is frequently used to treat irritable bowel syndrome (IBS), despite a lack of evidence for efficacy from high-quality controlled trials. We studied the efficacy and safety of small-intestinal-release peppermint oil in patients with IBS and explored the effects of targeted ileocolonic-release peppermint oil.

METHODS

We performed a double-blind trial of 190 patients with IBS (according to Rome IV criteria) at 4 hospitals in The Netherlands from August 2016 through March 2018; 189 patients were included in the intent-to-treat analysis (mean age, 34.0 years; 77.8% female; 57.7% in primary care), and 178 completed the study. Patients were randomly assigned to groups given 182 mg small-intestinal-release peppermint oil, 182 mg ileocolonic-release peppermint oil, or placebo for 8 weeks. The primary endpoint was abdominal pain response, as defined by the US Food and Drug Administration: at least a 30% decrease in the weekly average of worst daily abdominal pain compared with baseline in at least 4 weeks. The co-primary endpoint was overall relief of IBS symptoms, as defined by the European Medicines Agency. Secondary endpoints included abdominal pain, discomfort, symptom severity, and adverse events.

RESULTS

Abdominal pain response did not differ significantly between the peppermint oil and placebo groups: 29 of 62 patients in the small-intestinal-release peppermint oil group had a response (46.8%, P = .170 vs placebo), 26 of 63 patients in the ileocolonic-release peppermint oil group had a response (41.3%, P = .385 vs placebo), and 22 of 64 patients in the placebo group had a response (34.4%). We did not find differences among the groups in overall relief (9.7%, P = .317 and 1.6%, P = .351 vs 4.7% for placebo). The small intestinal peppermint oil did, however, produce greater improvements than placebo in secondary outcomes of abdominal pain (P = .016), discomfort (P = .020), and IBS severity (P = .020). Adverse events, although mild, were more common in both peppermint oil groups (P < .005).

CONCLUSIONS

In a randomized trial of patients with IBS, we found that neither small-intestinal-release nor ileocolonic-release peppermint oil (8 weeks) produced statistically significant reductions in abdominal pain response or overall symptom relief, when using US Food and Drug Administration/European Medicines Agency recommended endpoints. The small-intestinal-release peppermint oil did, however, significantly reduce abdominal pain, discomfort, and IBS severity. These findings do not support further development of ileocolonic-release peppermint oil for treatment of IBS. Clinicaltrials.gov, Number: NCT02716285.

Ambient air quality as risk factor for microscopic colitis - A geographic information system (GIS) study

BACKGROUND

Microscopic colitis (MC) is considered a multifactorial disease, strongly associated with smoking. However, little is known about the role of environmental factors such as ambient air pollution in MC pathophysiology. There is an overlap in components of cigarette smoke and ambient air pollution. Therefore, the aim of this study was to explore an independent association between ambient air quality and MC.

METHODS

A case-control study was performed. MC cases in South Limburg, the Netherlands, diagnosed between 2000 and 2012, were retrieved from the national pathology registry and matched to non-MC controls from the same area based on age (±2 years) and gender. A stable residential address for ≥3 years was required. Residential land use, proximity to major road, and concentrations of air pollution compounds, were determined using a Geographic Information System (GIS). Univariate and multivariable regression analyses were corrected for age, gender and smoking status.

RESULTS

In total, 345 MC cases (78.6% female) and 583 matched controls (77.2% female) were included. In the univariate analyses, the percentage of urban green within a 500 m buffer and residential proximity to the nearest highway were associated with MC (both p < 0.10). On the multivariable level only a higher age at diagnosis (OR 1.02, 95%-CI 1.01-1.04) and current smoking at index date (OR 4.30; 95%-CI 3.01-6.14) were significantly associated with MC.

CONCLUSION

Based on the current findings, ambient air quality does not seem to be an important risk factor for MC, in contrast to the well-known risk factors age and current smoking.

Percutaneous endoscopic versus radiologic gastrostomy for enteral feeding: a retrospective analysis on outcomes and complications

Background and study aims  Percutaneous endoscopic gastrostomy (PEG) and percutaneous radiologic gastrostomy (PRG) are techniques used for long-term enteral feeding. Our primary aim was to analyze procedure-related and 30-day mortality and complications between PEG and PRG in relation to indications. Patients and methods  A single-center retrospective analysis was performed thath included all adult patients receiving initial PEG (January 2008 until April 2016) and PRG (January 2010 until April 2016). Outcomes were mortality (procedure-related, 30-day), complications (early (≤ 30 days) and late) and success rates. Results  A total of 760 procedures (469 PRG and 291 PEG) were analyzed. Most common indications were head and neck cancer (HNC), cerebrovascular accident (CVA) and amyotrophic lateral sclerosis (ALS). Success rates for placement were 91.2 % for PEG and 97.1 % for PRG ( P  = 0.001). Procedure-related mortality was 1.7 % in PEG and 0.4 % in PRG ( P  = 0.113). The 30-day mortality was 10.7 % in PEG and 5.1 % in PRG ( P  = 0.481 after multivariate logistic regression) CVA was associated with higher 30-day mortality, whereas ALS, higher body weight, and prophylactic placements in HNC were associated with lower rates. Tube-related complications were less frequent in PEG, both early (2.7 % vs. 26.4 %, P  ≤ 0.001) and late (8.6 % vs. 31.5 %, P  ≤ 0.001). The percentage of major complications and infections did not differ. Conclusions  With respect to procedure-related and 30-day mortality, PEG and PRG compare equally. PRG had a higher procedural success rate. Tube-related complications and pain are less frequent after PEG compared to PRG. The choice for either PEG or PRG therefore should primarily be based on local facilities and expertise.

Gut microbiota composition and functional changes in inflammatory bowel disease and irritable bowel syndrome

Changes in the gut microbiota have been associated with two of the most common gastrointestinal diseases, inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). Here, we performed a case-control analysis using shotgun metagenomic sequencing of stool samples from 1792 individuals with IBD and IBS compared with control individuals in the general population. Despite substantial overlap between the gut microbiome of patients with IBD and IBS compared with control individuals, we were able to use gut microbiota composition differences to distinguish patients with IBD from those with IBS. By combining species-level profiles and strain-level profiles with bacterial growth rates, metabolic functions, antibiotic resistance, and virulence factor analyses, we identified key bacterial species that may be involved in two common gastrointestinal diseases.

Normal colonic transit time predicts the outcome of colonic manometry in patients with chronic constipation-an exploratory study

PURPOSE

Colonic manometry (CM) can be of additive value in the diagnostic workup of colonic motility in chronic constipated patients. However, it is claimed that colonic motor disturbances occur in normal-transit constipation (NTC) and slow-transit (STC) constipation, as measured using a radio-opaque marker study, and therefore, the relationship between colonic motor disturbances on CM and colonic transit time (CTT) remains unclear. Our aim was to compare results from colonic marker study with the outcome of CM in patients with treatment-refractory chronic constipation (CC).

METHOD

Eighty-seven CC patients and 12 healthy volunteers, undergoing both a CTT study and a 24-h CM in a Dutch tertiary referral center, were included. CTT was measured using radio-opaque markers (X-ray at day 4 after ingestion of 20 markers at day 0). CM was performed using a catheter with 6 solid-state pressure sensors, endoscopically clipped to the mucosa in the right colon. CM was defined as normal when at least three high-amplitude propagating contractions (HAPCs), i.e., propagating waves with amplitude ≥ 80 mmHg over at least three sensors, were identified.

RESULTS

In total, 70 patients showed STC on CTT, of which 21 (30%) showed normal CM. All 17 NTC patients and healthy volunteers showed normal CM. The negative predictive value of CTT for normal CM was 100%.

CONCLUSION

Colonic manometry should be considered in therapy-refractory STC patients in order to further delineate colonic motility. However, in this exploratory study, for patients presenting with NTC on a radio-opaque marker study, colonic manometry does not appear to have added value.

Anaplastic Large Cell T Cell Lymphoma in a Patient With Severe Therapy-refractory Crohn's Disease on Long-standing Immunosuppressive Medication During Ustekinumab Treatment: A Case Report and Review of the Literature

Use of ustekinumab in Crohn's disease was approved in 2016, and consequently data regarding its real-world safety are still limited. We here present a 29-year-old woman with severe therapy-refractory Crohn's disease, who developed an anaplastic large cell T cell lymphoma during treatment with ustekinumab.

Risk of impaired nutritional status and flare occurrence in IBD outpatients

BACKGROUND

Inflammatory bowel disease (IBD) patients are at risk of an impaired nutritional status. The impact thereof on the IBD relapse risk is clinically relevant, though sparsely investigated.

AIM

The aim was to explore the association between an impaired nutritional status risk and the occurrence of disease flares in IBD outpatients participating in a longitudinal telemedicine study.

METHODS

IBD outpatients were recruited from the myIBDcoach study cohort, with one year clinical follow-up. Through myIBDcoach, a telemedicine tool, patients reported on disease activity and risk of impaired nutritional status (i.e. Short Nutritional Assessment Questionnaire >1 and/or BMI < 18.5 kg/m²) every one to three months. Data was analysed by generalized estimating equation modelling.

RESULTS

In total, 417 patients were included. During follow-up, 49 patients (11.8%) flared after initial clinical remission and 53 patients (12.7%) showed an increased risk of impaired nutritional status. The risk of impaired nutritional status was associated with flare occurrence (OR 2.61 (95% CI 1.02-6.69)).

CONCLUSIONS

The risk of an impaired nutritional status was associated with subsequent flares in IBD outpatients. This emphasizes the importance of monitoring disease activity in IBD patients at risk of impaired nutritional status.

Faecal Microbiota Dynamics and their Relation to Disease Course in Crohn's Disease

BACKGROUND

Microbial shifts have been associated with disease activity in Crohn's disease [CD], but findings on specific taxa are inconsistent. This may be due to differences in applied methods and cross-sectional study designs. We prospectively examined the faecal microbiota in adult CD patients with changing or stable disease course over time.

METHODS

Faeces were collected at two time-points from 15 healthy control individuals [HCs], 35 CD patients who were in remission and who maintained remission [RRs], and 22 CD patients during remission and also during subsequent exacerbation [RAs]. The microbial composition was assessed by 16S rRNA [V4] gene sequencing.

RESULTS

Compared with HCs, patients with CD had a lower microbial richness [p = 0.0002] and diversity [p = 0.005]. Moreover, the microbial community structure of a subset of patients, clustered apart from HCs, was characterized by low microbial diversity and Faecalibacterium abundance. Patients within this cluster did not differ with respect to long-term disease course compared with patients with a 'healthy-appearing' microbiota.Over time, microbial richness and diversity did not change in RR versus RA patients. Although the microbial community structure of both RR and RA patients was less stable over time compared with that of HCs, no differences were observed between the patient groups [p = 0.17]; nor was the stability impacted by Montreal classification, medication use, or surgery.

CONCLUSION

The altered microbiota composition and stability in CD was neither associated with disease activity nor long-term disease course, questioning its involvement in the development of an exacerbation. The aberrant microbiota composition in a subset of CD patients warrants further exploration of a more microbiota-driven etiology in this group.

Reduction in IBS symptom severity is not paralleled by improvement in quality of life in patients with irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a brain-gut disorder, of which the natural course varies between patients and is difficult to predict. This study aimed to evaluate symptom evolution over a 5-year follow-up period and to identify baseline predictors for symptom severity and quality of life (QoL) at follow-up.

METHODS

Maastricht IBS cohort participants completed questionnaires upon inclusion regarding demographics and lifestyle, gastrointestinal (GI) symptoms, anxiety and depression, and QoL. The same questionnaires, in addition to others, were completed after 5 years. Rome criteria were confirmed face-to-face at initial enrollment and through telephonic interviews at follow-up.

KEY RESULTS

At a mean follow-up of 4.7 years, 379 patients were approached of whom 203 (53.7%) responded. Of these, 161 were reached by telephone and analyzed; 49 (30.4%) did not fulfill the Rome III criteria at follow-up and had lower levels of GI symptoms and GI-specific anxiety compared to those remaining Rome III-positive (P < 0.001). However, Rome III-negative patients had comparable levels of QoL and life satisfaction, comorbid anxiety and depression, work absenteeism, and impaired productivity. No baseline predictors were found for being Rome III-positive or Rome III-negative. However, greater age and lower baseline physical QoL predicted lower physical QoL at follow-up (P < 0.005 and P < 0.01, respectively), while lower baseline mental QoL predicted lower mental QoL at follow-up (P = 0.005). Additionally, higher anxiety and depression scores at follow-up were associated with lower QoL and life satisfaction at follow-up (P < 0.001).

CONCLUSIONS AND INFERENCES

Long-term QoL and general well-being might depend on concurrent psychological symptoms, rather than GI symptom improvement.

Therapeutic strategies in gastroparesis: Results of stepwise approach with diet and prokinetics, Gastric Rest, and PEG-J: A retrospective analysis

BACKGROUND

Gastroparesis is characterized by abnormal gastric motor function with delayed gastric emptying in the absence of mechanical obstruction. In our tertiary referral center, patients are treated with a stepwise approach, starting with dietary advice and prokinetics, followed by three months of nasoduodenal tube feeding with "gastric rest." When not successful, a percutaneous endoscopic gastrostomy with jejunal extension (PEG-J) for long-term enteral feeding is placed.

AIM

To evaluate the effect of this stepwise approach on weight and symptoms.

METHODS

Analyses of data of all referred gastroparesis patients between 2008 and 2016.

KEY RESULTS

A total of 86 patients (71% female, 20-87 years [mean 55.8 years]) were analyzed of whom 50 (58%) had adequate symptom responses to diet and prokinetics. The remaining 36 (decompensated gastroparesis) were treated with three months gastric rest. Symptom response rate was 47% (17/36). Significant weight gain was seen in all patients, independent of symptom response. In the remaining 19 symptom non-responders, the enteral feeding was continued through PEG-J. Treatment was effective (symptoms) in 37%, with significant weight gain in all. In 84% of patients, the PEG-J is still in use (mean duration 962 days).

CONCLUSIONS AND INFERENCES

Following a stepwise treatment approach in gastroparesis, adequate symptom response was reached in 86% of all patients. Weight gain was achieved in all patients, independent of symptom response. Diet and prokinetics were effective with regard to symptoms in 58%, temporary gastric rest in 47%, and PEG-J as third step in 37% of patients.

Diabetes mellitus, genetic variants in the insulin-like growth factor pathway and colorectal cancer risk

Genetic variation in the insulin‐like growth factor (IGF) pathway may further increase the risk of colorectal cancer (CRC) associated with type 2 diabetes mellitus (T2DM). Joint effects of T2DM and genetic variation in the IGF pathway on CRC risk can increase mechanistic insights. Participants from the Netherlands Cohort Study (n = 120, 852) completed a baseline questionnaire in 1986 when 55–69 years old (case–cohort, n_subcohort = 5,000, n_cases = 3,441 after 16.3 years follow‐up). Self‐reported DM at baseline with onset at ≥30 years was classified as T2DM. Eighteen single nucleotide polymorphisms (SNPs) from the IGF pathway were aggregated in a genetic risk score (GRS). Cox proportional hazard ratios (HRs) for CRC were estimated according to combinations of T2DM status with GRS tertiles and categories of an IGF1 19‐CA repeat polymorphism. Baseline T2DM prevalence was 3.1% in subcohort members and 3.8% in CRC cases. Comparison of combined categories with non‐T2DM individuals in the lowest GRS tertile as reference showed that those in the highest GRS tertiles with and without T2DM had significantly increased CRC risks, particularly those with T2DM (HR = 2.28, 95% CI: 1.11, 4.66). As compared to IGF1 19‐CA wild‐type carriers without T2DM, carrying two IGF1 19‐CA variant repeat alleles were associated with a significantly decreased CRC risk in those without T2DM (HR = 0.76, 95% CI: 0.63–0.91). This association was absent when T2DM was present. Our study of joint effects indicated that the presence of unfavorable alleles in the IGF pathway may further increase the risk of CRC associated with T2DM.

What's new?

Colorectal cancer (CRC) and type‐2 diabetes mellitus (T2DM) have several risk factors in common (high BMI, physical inactivity, etc.). In this study, the authors identified several SNPs in the insulin‐like growth factor (IGF) pathway that further increase CRC risk, particularly in people with T2DM. These results support the hypothesis that T2DM increases CRC risk by influencing the IGF pathway. Screening for these unfavorable genetic variations in the IGF pathway may also help to improve the assessment of personalized CRC risk.

Development and Validation of a Patient-reported Score to Screen for Mucosal Inflammation in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Patient-reported outcome measures [PROMs] assessing inflammatory bowel disease [IBD] activity are of interest for monitoring in clinical practice, telemedicine systems, or trials. Different PROMs for follow-up of disease activity are available; however, none was developed with endoscopy as gold standard. The objective of this study was to develop and validate a PROM to predict endoscopic disease activity, following the recommendations of the Food and Drug Administration.

METHODS

During development, 178 IBD patients undergoing a colonoscopy were asked to fill out 13 clinical questions derived from the literature. During endoscopy, inflammation was assessed with the simplified endoscopic score for Crohn's disease [CD] and the Mayo endoscopic subscore for ulcerative colitis [UC]. Based on correlation with endoscopic inflammation, questions were reduced to a total of six for CD and five for UC. The newly developed Monitor IBD At Home questionnaire [MIAH] was validated in an independent cohort of 135 CD and 131 UC patients. Additionally, diagnostic accuracy of the MIAH combined with a calprotectin home test [CHT] was assessed.

RESULTS

The MIAH-CD includes questions on rectal bleeding, mucus, stool frequency, urgency, fatigue, and patient-reported disease activity. The MIAH-UC contains items on rectal bleeding, stool frequency, urgency, abdominal pain, and patient-reported disease activity. Both questionnaires showed to be valid, reliable, and responsive to changes. The MIAH and CHT combined had a sensitivity, specificity, negative predictive value [NPV], and positive predicitive value [PPV] of 96.7%, 66.7%, 94.7%, and 76.3% for CD and of 88.2%, 81.4%, 95.6%, and 60.0% for UC, respectively, compared with endoscopy.

CONCLUSIONS

The MIAH is the first PROM developed to predict endoscopic inflammation in IBD patients. A combination of this questionnaire and a CHT shows excellent diagnostic accuracy to screen for patients who need further assessment of disease activity, and can be used in daily practice, telemedicine systems, and trials.

Causal relationships among the gut microbiome, short-chain fatty acids and metabolic diseases

Microbiome-wide association studies on large population cohorts have highlighted associations between the gut microbiome and complex traits, including type 2 diabetes (T2D) and obesity1. However, the causal relationships remain largely unresolved. We leveraged information from 952 normoglycemic individuals for whom genome-wide genotyping, gut metagenomic sequence and fecal short-chain fatty acid (SCFA) levels were available2, then combined this information with genome-wide-association summary statistics for 17 metabolic and anthropometric traits. Using bidirectional Mendelian randomization (MR) analyses to assess causality3, we found that the host-genetic-driven increase in gut production of the SCFA butyrate was associated with improved insulin response after an oral glucose-tolerance test (P = 9.8 × 10-5), whereas abnormalities in the production or absorption of another SCFA, propionate, were causally related to an increased risk of T2D (P = 0.004). These data provide evidence of a causal effect of the gut microbiome on metabolic traits and support the use of MR as a means to elucidate causal relationships from microbiome-wide association findings.

Novel Perceived Stress and Life Events Precede Flares of Inflammatory Bowel Disease: A Prospective 12-Month Follow-Up Study

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD] is characterized by recurrent disease flares. The impact of psychosocial wellbeing on the occurrence of flares is unclear. In this prospective study, we aimed to evaluate the association between patient-reported psychosocial wellbeing and disease flares using continuous monitoring.

METHODS

Consecutive IBD patients were recruited from the myIBDcoach telemedicine study cohort. Over 12 months, participants reported on disease activity together with anxiety, depression, fatigue, perceived stress and life events every 1-3 months. Flares were defined using a combination of clinical disease activity and additional measurements. Generalized estimating equation models were used to assess associations between psychosocial wellbeing and flares over time. The influences of both the presence of psychosocial symptoms in general as well as novel psychosocial symptoms were analysed.

RESULTS

In total, 417 patients were included. Forty-nine patients [11.8%] experienced a flare during the study period. The occurrence of life events in the preceding 3 months was positively associated with flares (odds ratio [OR] = 1.81; 95% confidence interval [CI] = 1.04-3.17), while the presence of anxiety, depression, fatigue and perceived stress in general was not. However, novel perceived stress [OR = 2.92; 95% CI = 1.44-5.90] was associated with flares.

CONCLUSIONS

The occurrence of life events and novel perceived stress are associated with disease flares in the next 3 months, while the presence of perceived stress in general is not. These findings underline the importance of continuous personalized monitoring of IBD patients and may contribute to the prevention of disease flares.

Modulation of Intestinal Epithelial Permeability by Plasma from Patients with Crohn's Disease in a Three-dimensional Cell Culture Model

Intestinal epithelial barrier is affected by multiple factors, such as tumour necrosis factor-α (TNF-α). Plasma concentration of TNF-α is higher in patients with Crohn’s disease (CD) than healthy controls (HC) and correlates positively with disease activity. This study aimed to determine the effect of plasma from active, inactive CD patients on intestinal barrier function and to investigate the underlying mechanism. Plasma samples were collected from CD patients and HC. 3D Caco-2 cysts were treated with plasma or TNF-α, with or without pre-incubation of adalimumab (a monoclonal antibody that antagonizes TNF-α) or JNK inhibitor SP600125. The results demonstrated that exposure of the cysts to plasma from CD patients resulted in enhanced paracellular permeability in a disease activity-dependent manner. Compared to HC, active CD plasma decreased ZO-1 and OCCLUDIN expression on mRNA and protein levels, and led to an increased JNK phosphorylation. Pre-incubation with adalimumab or SP600125 ameliorated TJ disruption and barrier dysfunction induced by plasma from CD patients. These results indicate that plasma from CD patients is able to induce epithelial barrier disruption, in part through TNF-α induced TJs modulation. The data also demonstrate an involvement of MAPK pathway, in particular the JNK isoform, in CD patient plasma-induced barrier dysfunction.

Development of a real-time patient-reported outcome measure for symptom assessment in patients with functional dyspepsia using the experience sampling method

BACKGROUND

Patient-reported outcome measures (PROMs) are used to assess symptoms in patients with functional dyspepsia (FD). Current end-of-day questionnaires have several limitations including sensitivity to recall and ecological bias. The experience sampling method (ESM) is characterized by random and repeated assessments across momentary states in daily life and therefore less sensitive to these limitations. This study describes the development of a novel PROM based on ESM technology.

METHODS

An initial draft of the PROM was developed based on literature. Focus group interviews with FD patients according to Rome IV criteria, and an expert meeting with international opinion leaders in the field of functional gastrointestinal disorders were conducted in order to select items for the PROM. Cognitive interviews were performed to evaluate patients' understanding of the selected items and to create the definitive PROM.

KEY RESULTS

A systematic literature search revealed 59 items across four domains (ie, physical status; mood and psychological factors; context and environment; and nutrition, medication, and substance use). After patient focus group interviews and an international expert meeting, the number of items was reduced to 33. Cognitive interviews resulted in some minor linguistic changes in order to improve patients' understanding.

CONCLUSIONS AND INFERENCES

A novel digital ESM-based PROM for real-time symptom assessment in patients with functional dyspepsia was developed. This novel PROM has the potential to identify individual symptom patterns and specific triggers for dyspeptic symptoms, and optimize treatment strategies.

Impact of early events and lifestyle on the gut microbiota and metabolic phenotypes in young school-age children

BACKGROUND

The gut microbiota evolves from birth and is in early life influenced by events such as birth mode, type of infant feeding, and maternal and infant antibiotics use. However, we still have a gap in our understanding of gut microbiota development in older children, and to what extent early events and pre-school lifestyle modulate the composition of the gut microbiota, and how this impinges on whole body metabolic regulation in school-age children.

RESULTS

Taking advantage of the KOALA Birth Cohort Study, a long-term prospective birth cohort in the Netherlands with extensive collection of high-quality host metadata, we applied shotgun metagenomics sequencing and systematically investigated the gut microbiota of children at 6-9 years of age. We demonstrated an overall adult-like gut microbiota in the 281 Dutch school-age children and identified 3 enterotypes dominated by the genera Bacteroides, Prevotella, and Bifidobacterium, respectively. Importantly, we found that breastfeeding duration in early life and pre-school dietary lifestyle correlated with the composition and functional competences of the gut microbiota in the children at school age. The correlations between pre-school dietary lifestyle and metabolic phenotypes exhibited a striking enterotype dependency. Thus, an inverse correlation between high dietary fiber consumption and low plasma insulin levels was only observed in individuals with the Bacteroides and Prevotella enterotypes, but not in Bifidobacterium enterotype individuals in whom the gut microbiota displayed overall lower microbial gene richness, alpha-diversity, functional potential for complex carbohydrate fermentation, and butyrate and succinate production. High total fat consumption and elevated plasma free fatty acid levels in the Bifidobacterium enterotype are associated with the co-occurrence of Streptococcus.

CONCLUSIONS

Our work highlights the persistent effects of breastfeeding duration and pre-school dietary lifestyle in affecting the gut microbiota in school-age children and reveals distinct compositional and functional potential in children according to enterotypes. The findings underscore enterotype-specific links between the host metabolic phenotypes and dietary patterns, emphasizing the importance of microbiome-based stratification when investigating metabolic responses to diets. Future diet intervention studies are clearly warranted to examine gut microbe-diet-host relationships to promote knowledge-based recommendations in relation to improving metabolic health in children.

The Experience Sampling Method-Evaluation of treatment effect of escitalopram in IBS with comorbid panic disorder

BACKGROUND

Confirming treatment response in clinical trials for irritable bowel syndrome (IBS) is challenging, due to the lack of biomarkers and limitations of the currently available symptom assessment tools. The Experience Sampling Method (ESM) might overcome these limitations by collecting digital assessments randomly and repeatedly during daily life. This study evaluated differences in change in abdominal pain between real-time (ie, ESM) and retrospective (ie, Gastrointestinal Symptom Rating Scale [GSRS] and an end-of-day symptom diary) measurements, using data of an RCT on escitalopram vs placebo in patients with IBS and comorbid panic disorder.

METHODS

Twenty-nine IBS patients with comorbid panic disorder were included in a 6-month RCT. The GSRS, diary, and ESM were completed at baseline (t = 0) and after 3 (t = 3) and 6 months (t = 6). Linear mixed models were used.

KEY RESULTS

Experience Sampling Method analyses revealed a significant interaction between escitalopram and time, and ESM abdominal pain scores were 1.4 points lower in the escitalopram group compared to placebo at t = 6 (on a 1-to-7 scale; P = 0.021). When including the interaction with momentary anxiety, the reduction in abdominal pain scores in escitalopram vs placebo was even more pronounced for higher levels of anxiety. Average GSRS- and end-of-day abdominal pain scores were not significantly different between escitalopram and placebo at t = 3 and 6.

CONCLUSIONS & INFERENCES

Real-time ESM has the potential to capture treatment response more sensitively compared to a retrospective end-of-day GI symptom diary and the GSRS, by taking into account day-to-day symptom variability as well as momentary factors that might moderate treatment effect, such as anxiety.

Age-dependent changes in GI physiology and microbiota: time to reconsider?

Our life expectancy is increasing, leading to a rise in the ageing population. Ageing is associated with a decline in physiological function and adaptive capacity. Altered GI physiology can affect the amount and types of nutrients digested and absorbed as well as impact the intestinal microbiota. The intestinal microbiota is considered a key player in our health, and a variety of studies have reported that microbiota composition is changing during ageing. Since ageing is associated with a decline in GI function and adaptive capacity, it is crucial to obtain insights into this decline and how this is related to the intestinal microbiota in the elderly. Hence, in this review we focus on age-related changes in GI physiology and function, changes of the intestinal microbiota with ageing and frailty, how these are associated and how intestinal microbiota-targeted interventions may counteract these changes.

A Novel Ileocolonic Release Peppermint Oil Capsule for Treatment of Irritable Bowel Syndrome: A Phase I Study in Healthy Volunteers

INTRODUCTION

Peppermint oil (PO) has been shown to reduce abdominal pain in patients with irritable bowel syndrome (IBS). PO is assumed to induce intestinal smooth muscle relaxation and desensitization of nociceptive nerve afferents. To increase colonic PO concentration, an ileocolonic release peppermint oil (IC-PO) capsule has been developed. The aim of this study was to compare pharmacokinetic parameters of the currently available small intestinal release PO (SI-PO) and the novel IC-PO.

METHODS

In this randomized, double-blind, crossover study, subjects received 182 mg of either SI-PO or IC-PO in a crossover design with a washout period of more than 14 days. Blood samples were collected to determine menthol glucuronide concentrations.

RESULTS

Eight healthy volunteers (50% female, median age 22) were included. The time to reach the maximum concentration (T_max) of IC-PO was significantly longer compared to SI-PO with a median (IQR) of 360 (360-405) versus 180 (120-180) min. The lag time (T_lag) was significantly longer with a median (IQR) of 225 (204-284) for IC-PO compared to 37 (6-65) min for SI-PO. The areas under the menthol glucuronide plasma concentration-time curves were significantly smaller with a median (IQR) of 2331 μg h/L (2006-2510) for IC-PO compared to 2623 μg h/L (2471-2920) for SI-PO. No significant differences were found in peak concentrations and elimination half-lives.

CONCLUSION

IC-PO has a significantly delayed peak menthol glucuronide concentration and T_lag, both pointing to the release of PO in the more distal part of the intestine. This may enhance therapeutic efficacy as it results in increased exposure of colonic mucosal afferents to the PO. A randomized controlled trial investigating the efficacy of SI and IC-PO in IBS is currently ongoing.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02291445, EudraCT database 2014-004195-32.

Incidence and Classification of Postcolonoscopy Colorectal Cancers in Inflammatory Bowel Disease: A Dutch Population-Based Cohort Study

BACKGROUND AND AIMS

Patients with inflammatory bowel disease [IBD] colitis are at increased risk for colorectal cancer [CRC]. We examined the proportion and most likely aetiology of potentially preventable postcolonoscopy CRCs [PCCRCs] in a population-based cohort. Furthermore, adherence to IBD surveillance guidelines was evaluated in both PCCRCs and the remainder of prevalent CRCs.

METHODS

All IBD patients diagnosed from 1991 to 2011 in the South Limburg region of The Netherlands [i.e. IBDSL cohort] were included. CRC cases were cross-checked with the Dutch pathology database and cancer registry. PCCRCs were defined as cancers diagnosed within 6-60 months after a colonoscopy and were classified as attributable to 'inappropriate surveillance interval', 'inadequate bowel examination', 'incomplete resection', 'missed lesion' or 'newly developed cancer'.

RESULTS

Twenty CRC cases were identified during 25,931 patient years of follow-up in 2,801 patients. The proportion of PCCRCs was 45.0%. Of these, 55.6% could be considered a 'missed lesion', while other possible aetiologies occurred only once. Considering both PCCRCs [n=9] and prevalent CRCs [n=11], ten were detected after publication of the surveillance guideline, but only three patients were enrolled. Moreover, 6 CRCs [30.0%] were detected before the recommended start of surveillance.

CONCLUSIONS

In the IBDSL cohort, 45.0% of all CRCs were considered to be PCCRCs, mainly classified as missed lesions. Additionally, a large proportion of CRCs in our cohort were observed before a surveillance endoscopy was performed. Therefore, stringent adherence to IBD surveillance guidelines, improving endoscopy techniques and adjusting the surveillance program may lead to a decrease in CRC incidence.

Gastrointestinal cancer incidence in type 2 diabetes mellitus; results from a large population-based cohort study in the UK

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) have been shown to have higher incidences of liver, pancreatic, and colorectal cancer compared to non-diabetic individuals. Current evidence is conflicting for other gastrointestinal (GI) cancers. Therefore, we aimed to determine incidence rates (IRs) of all GI cancers in patients with and without T2DM.

METHODS

A cohort study was performed using the UK Clinical Practice Research Datalink (1988-2012). A cohort of antidiabetic drug users was matched at baseline to a non-diabetic cohort, by age, sex, and practice. Crude IRs and 95% confidence intervals (95% CI) of GI cancers per 100,000 person-years were calculated stratified by age, sex, and calendar year.

RESULTS

333,438 T2DM and 333,438 non-diabetic individuals were analyzed. IRs of liver (IR 26, 95% CI 24-28 vs. 8.9, 95% CI 7.7-10), pancreatic (IR 65, 95% CI 62-69 vs. 31, 95% CI 28-34), and colon cancer (IR 119, 95% CI 114-124 vs. 109, 95% CI 104-114) were significantly higher in the diabetic compared to the non-diabetic cohort, whereas the IR of oesophageal cancer was significantly lower (IR 41, 95% CI 39-44 vs. 47, 95% CI 44-51). Sex-specific IRs of colon cancer remained significantly higher in men with T2DM, and IRs of esophageal cancer remained significantly lower in women with T2DM.

CONCLUSION

In this study, T2DM patients were shown to have higher crude IRs of liver, pancreatic and colon cancer, but not of gastric, biliary, and rectal cancer. Moreover, the lower observed IRs of oesophageal cancer in diabetic patients warrants further investigation.

Percutaneous endoscopic colostomy for adults with chronic constipation: Retrospective case series of 12 patients

BACKGROUND

Percutaneous endoscopic colostomy (PEC) is a technique derived from percutaneous endoscopic gastrostomy. When conservative treatment of chronic obstipation fails, colon irrigation via PEC seems less invasive than surgical interventions. However, previous studies have noted high complication rates of PEC, mostly related to infections. Our aim was to report our experiences with PEC in patients with chronic refractory constipation.

METHODS

Retrospective analysis of all patients who underwent PEC for refractory constipation in our secondary referral hospital between 2009 and 2016.

KEY RESULTS

Twelve patients received a PEC for chronic, refractory constipation. Short-term efficacy for relief of constipation symptoms was good in 8 patients and moderate in 4 patients. Two patients had the PEC removed because of spontaneous improvement of constipation. Three patients, who initially noticed a positive effect, preferred an ileostomy over PEC after 1-5 years. One PEC was removed because of an abscess. Long-term efficacy is 50%: 6 patients still use their PEC after 3.3 years of follow-up. No mortality occurred.

CONCLUSIONS AND INTERFERENCES

PEC offers a technically easily feasible and safe treatment option for patients with chronic constipation not responding to conventional therapy. Long-term efficacy of PEC in our patients is 50%.

Patient-Reported Outcome Measures for Use in Clinical Trials and Clinical Practice in Inflammatory Bowel Diseases: A Systematic Review

BACKGROUND & AIMS

Mucosal inflammation must be carefully monitored to improve the long-term outcomes of patients with inflammatory bowel diseases (IBD). Patient-reported outcome measures (PROMs) are used increasingly to monitor disease activity in clinical practice and as endpoints in clinical trials. We performed a systematic review to provide an overview of the available PROMs on IBD activity and to evaluate their diagnostic value.

METHODS

A systematic search of the PubMed, Medline, Cochrane library, and Embase databases using defined keywords, identified 973 articles. These were screened by 2 independent reviewers, and 37 articles on development or validation of PROMs to assess IBD activity were identified for further analysis. Based on the recommendations of the Food and Drug Administration (FDA), the following measurement properties were evaluated: content, construct, and criterion validity; reliability; and responsiveness to change. In addition, data on ease of use in clinical practice were collected.

RESULTS

Seventeen articles presenting 20 different PROMs were included the final analysis, although none met all the FDA-recommended criteria. Only 2 PROMs (patient-reported Harvey Bradshaw Index and Simple Clinical Colitis Activity Index scores) reported patient involvement during its development. Only 6 PROMs (patient-reported global assessment, patient assessment of disease activity, mobile health index for Crohn's disease, mobile health index for ulcerative colitis, patient-reported outcome derived from the Mayo score, and the 6-point Mayo score) were validated as markers of IBD activity, using findings from endoscopy as the reference standard; these PROMs identified patients with mucosal inflammation with area under the curve values of 0.63-0.82. The mobile health index for CD and UC scores had the best measurement properties for use in clinical practice and in clinical trials.

CONCLUSIONS

In a systematic review, we identified more than 20 PROMS that have been developed and tested for their ability to determine IBD activity. Further studies are needed to determine their accuracy and whether they can be used effectively in routine practice, clinical trials, telemedicine systems, and value-based healthcare programs.

Volatile metabolites in breath strongly correlate with gut microbiome in CD patients

Microbiota composition and its metabolic capacity are very important for host health. Evidence suggests that gut microbiome is involved in the metabolites production by host-microbiome interaction. These metabolites can be absorbed in blood and excreted in exhaled air. Although, profiles of gut microbiota and exhaled metabolites were associated with gastrointestinal diseases, a direct link between them has not yet been investigated. The aim of the study was to investigate the relation between volatiles in breath and gut microbiome in active and quiescent Crohn's disease (CD) via a multivariate statistical approach. Canonical correlation analysis (CCA) was used to assess the relation between exhaled metabolites and faecal bacterial species. From 68 CD patients, 184 repeated faecal and breath samples were collected (92 active and 92 quiescent disease). The microbiota composition was assessed by the pyrosequencing of the 16 S rRNA V1-V3 gene region and breath metabolites by gas chromatography mass spectrometry. In active disease, CCA analysis identified 18 metabolites significantly correlated with 19 faecal bacterial taxa (R = 0.91 p-value 3.5*10-4). In quiescent disease 17 volatile metabolites were correlated with 17 bacterial taxa (R = 0.96 p-value 2.8*10-4). Nine metabolites and three bacteria taxa overlapped in active and inactive CD. This is the first study that shows a significant relation between gut microbiome and exhaled metabolites, and was found to differ between active and quiescent CD, indicating various underlying mechanisms. Unravelling this link is essential to increase our understanding on the functional effects of the microbiome and may provide new leads for microbiome-targeted intervention.

Systematic review: Disease-specific instruments to assess gastrointestinal symptoms in functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a common functional gastrointestinal disorder with incompletely understood pathophysiology and heterogeneous symptom presentation. Assessment of treatment efficacy in FD is a methodological challenge as response to treatment must be assessed primarily by measuring subjective symptoms. Therefore, the use of patient-reported outcome measures (PROMs) is recommended by regulatory authorities to assess gastrointestinal symptoms in clinical trials for FD. In the last decades, a multitude of outcome measures has been developed. However, currently no PROM has been approved by the regulatory authorities, and no consensus has been reached with regard to the most relevant outcome measure in FD.

PURPOSE

This systematic review discusses the available disease-specific outcome measures for assessment of FD symptoms with psychometric validation properties, strengths, and limitations. Moreover, recommendations for use of current available outcome measures are provided, and potential areas of future research are discussed.

Development, content validity, and cross-cultural adaptation of a patient-reported outcome measure for real-time symptom assessment in irritable bowel syndrome

BACKGROUND

End-of-day questionnaires, which are considered the gold standard for assessing abdominal pain and other gastrointestinal (GI) symptoms in irritable bowel syndrome (IBS), are influenced by recall and ecological bias. The experience sampling method (ESM) is characterized by random and repeated assessments in the natural state and environment of a subject, and herewith overcomes these limitations. This report describes the development of a patient-reported outcome measure (PROM) based on the ESM principle, taking into account content validity and cross-cultural adaptation.

METHODS

Focus group interviews with IBS patients and expert meetings with international experts in the fields of neurogastroenterology & motility and pain were performed in order to select the items for the PROM. Forward-and-back translation and cognitive interviews were performed to adapt the instrument for the use in different countries and to assure on patients' understanding with the final items.

KEY RESULTS

Focus group interviews revealed 42 items, categorized into five domains: physical status, defecation, mood and psychological factors, context and environment, and nutrition and drug use. Experts reduced the number of items to 32 and cognitive interviewing after translation resulted in a few slight adjustments regarding linguistic issues, but not regarding content of the items.

CONCLUSIONS AND INFERENCES

An ESM-based PROM, suitable for momentary assessment of IBS symptom patterns was developed, taking into account content validity and cross-cultural adaptation. This PROM will be implemented in a specifically designed smartphone application and further validation in a multicenter setting will follow.

Endoscopic subtypes of colorectal laterally spreading tumors (LSTs) and the risk of submucosal invasion: a meta-analysis

BACKGROUND AND STUDY AIMS

Many studies have reported on laterally spreading tumors (LSTs), but systematic reviews of the data to determine their risk of containing submucosal invasion (SMI) are lacking. We systematically screened and analyzed the available literature to provide a more solid basis for evidence-based treatment.

METHODS

We conducted a systematic search in PubMed, Embase, the Cochrane Library, and Scopus for published articles until July 2017. We estimated pooled prevalence or odds ratios (ORs) with 95 % confidence intervals (CIs), using random-effects models. We classified endoscopic subtypes into granular LST, which comprises the homogeneous and nodular mixed subtypes, and non-granular LST, which comprises the flat elevated and pseudodepressed subtypes.

RESULTS

We identified 2949 studies, of which 48 were included. Overall, 8.5 % (95 %CI 6.5 % - 10.5 %) of LSTs contained SMI. The risk of SMI differed among the LST subtypes: 31.6 % in non-granular pseudodepressed LSTs (95 %CI 19.8 % - 43.4 %), 10.5 % in granular nodular mixed LSTs (95 %CI 5.9 % - 15.1 %), 4.9 % in non-granular flat elevated LSTs (95 %CI 2.1 % - 7.8 %), and 0.5 % in granular homogenous LSTs (95 %CI 0.1 % - 1.0 %). SMI was more common in distally rather than in proximally located LSTs (OR 2.50, 95 %CI 1.24 - 5.02). The proportion of SMI increased with lesion size (10 - 19 mm, 4.6 %; 20 - 29 mm, 9.2 %; ≥ 30 mm, 16.5 %). The pooled prevalence of patients with one or more LSTs in the general colonoscopy population was 0.8 % (95 %CI 0.6 % - 1.1 %).

CONCLUSION

The majority of LSTs are non-invasive at the time of colonoscopic detection and can be treated with (piecemeal) endoscopic mucosal resection. Pretreatment diagnosis of endoscopic subtype, specifying areas of concern (nodule or depression), determines those LSTs at highest risk of containing SMI, where en bloc resection is the preferred therapy.

Rome III vs Rome IV criteria for irritable bowel syndrome: A comparison of clinical characteristics in a large cohort study

BACKGROUND

The Rome criteria for irritable bowel syndrome (IBS) have been revised and are expected to apply only to the subset of Rome III IBS subjects with abdominal pain as predominant symptom, occurring at least once a week. The aim of this study was to determine the percentage of Rome III IBS subjects that fulfills Rome IV criteria and to evaluate differences between Rome IV-positive and Rome IV-negative subjects.

METHODS

Four hundred and four Rome III IBS subjects completed a 14-day end-of-day symptom diary, the Gastrointestinal Symptom Rating Scale (GSRS), Hospital Anxiety and Depression Scale, and RAND 36-item Short-Form Health Survey (SF-36). Diary-based surrogate Rome IV criteria were defined as occurrence of abdominal pain at least 1 day each week with a severity of ≥2 (mild; definition 1) or ≥3 (considerable; definition 2).

KEY RESULTS

Using surrogate Rome IV criteria, 353 (87.4%, definition 1) and 249 (61.6%, definition 2) subjects were defined as Rome IV positive. These patients were more often female, younger, and recruited from secondary/tertiary care compared with Rome IV-negative subjects. They also presented with higher abdominal pain scores and gastrointestinal (GI) symptom severity on both end-of-day diary and GSRS, higher psychological symptom scores, and lower quality of life compared with Rome IV-negative subjects.

CONCLUSIONS AND INFERENCES

The Rome IV IBS population likely reflects a subgroup of Rome III IBS patients with more severe GI symptomatology, psychological comorbidities, and lower quality of life. This implies that results from Rome III IBS studies may not be directly comparable to those from Rome IV IBS populations.

Habitual diet and diet quality in Irritable Bowel Syndrome: A case-control study

BACKGROUND

Diet is considered to be a key factor in symptom generation in Irritable Bowel Syndrome (IBS) and patients tend to exclude food products from their diet in pursue of symptom relief, which may impair diet quality.

METHODS

We evaluated habitual dietary intake in IBS patients with regard to nutrients and food products using an extensive food frequency questionnaire. One hundred ninety-four IBS patients were compared to 186 healthy controls using multiple logistic regression analysis. An overall diet quality score was calculated for each participant based on the criteria of the Dutch Healthy Diet (DHD) index.

KEY RESULTS

A lower DHD-score was found for IBS (mean [SD]: 52.9 [9.6]) vs controls (55.1 [9.2], P=.02). The diet of patients was lower in fibers (21 g vs 25 g per day, P=.002) and fructose (14 g vs 16 g, P=.033), while higher in total fat (37% vs 36% of total energy intake, P=.010) and added sugars (46 g vs 44 g, P=.029). Differences in daily intake of food products included lower consumption of apples (40 g vs 69 g, P<.001), pasta (28 vs 37 g, P=.029) and alcoholic beverages (130 g vs 193 g, P=.024) and higher consumption of processed meat (38 g vs 29 g, P<.001). Some of these findings correlated with gastrointestinal symptoms, showing differences between IBS subtypes.

CONCLUSIONS AND INFERENCES

Differences in habitual diet were described, showing lower diet quality in IBS patients compared to controls, with increased consumption of fat and lower intake of fibers and fructose. Our data support the importance of personalized and professional nutritional guidance of IBS patients.

Biomarkers for visceral hypersensitivity in patients with irritable bowel syndrome

BACKGROUND

Increased visceral sensitivity is observed in up to 60% of patients with Irritable Bowel Syndrome (IBS). Mucosal inflammation, altered neuroendocrine activity and intraluminal metabolic processes may contribute to the development of visceral hypersensitivity. Previously, we demonstrated that biomarkers, indicative for these biological processes, were altered in IBS patients compared to healthy controls. However, how these processes relate to visceral hypersensitivity is unknown.

AIM

The aim of this study was to provide insight in biological processes associated with visceral hypersensitivity. Fecal and plasma biomarkers were measured in normosensitive and hypersensitive IBS patients.

METHODS

A total of 167 IBS patients underwent a rectal barostat procedure to assess visceral sensitivity to pain. Based on the outcome, patients were classified into a normosensitive or hypersensitive group. Calprotectin, human β-defensin 2 (HBD2), chromogranin A (CgA), and short chain fatty acids (SCFAs) were measured in feces, citrulline in plasma, and serotonin and its main metabolite 5-hydroxyindoleacetic acid (5-HIAA) in platelet-poor plasma.

KEY RESULTS

Fecal markers and plasma citrulline were measured in 83 hypersensitive and 84 normosensitive patients, while platelet-poor plasma for the assessment of serotonin and 5-HIAA was available for a subgroup, i.e. 53 hypersensitive and 42 normosensitive patients. No statistically significant differences were found in concentrations of biomarkers between groups. Adjustment of the analyses for potential confounders, such as medication use, did not alter this conclusion.

CONCLUSIONS & INFERENCES

Our findings do not support a role for the biological processes as ascertained by biomarkers in visceral hypersensitivity in IBS patients. This study is registered in the US National Library of Medicine (clinicaltrials.gov, NCT00775060).

Role of short-chain fatty acids in colonic inflammation, carcinogenesis, and mucosal protection and healing

Short-chain fatty acids (SCFAs), mainly acetate, propionate, and butyrate, produced by microbial fermentation of undigested food substances are believed to play a beneficial role in human gut health. Short-chain fatty acids influence colonic health through various mechanisms. In vitro and ex vivo studies show that SCFAs have anti-inflammatory and anticarcinogenic effects, play an important role in maintaining metabolic homeostasis in colonocytes, and protect colonocytes from external harm. Animal studies have found substantial positive effects of SCFAs or dietary fiber on colonic disease, but convincing evidence in humans is lacking. Most human intervention trials have been conducted in the context of inflammatory bowel disease. Only a limited number of those trials are of high quality, showing little or no favorable effect of SCFA treatment over placebo. Opportunities for future research include exploring the use of combination therapies with anti-inflammatory drugs, prebiotics, or probiotics; the use of prodrugs in the setting of carcinogenesis; or the direct application of SCFAs to improve mucosal healing after colonic surgery.

Review article: transient receptor potential channels as possible therapeutic targets in irritable bowel syndrome

BACKGROUND

Abdominal pain in irritable bowel syndrome (IBS) remains challenging to treat effectively. Researchers have attempted to elucidate visceral nociceptive processes in order to guide treatment development. Transient receptor potential (TRP) channels have been implied in the generation (TRPV1, TRPV4, TRPA1) and inhibition (TRPM8) of visceral pain signals. Pathological changes in their functioning have been demonstrated in inflammatory conditions, and appear to be present in IBS as well.

AIM

To provide a comprehensive review of the current literature on TRP channels involved in visceral nociception. In particular, we emphasise the clinical implications of these nociceptors in the treatment of IBS.

METHODS

Evidence to support this review was obtained from an electronic database search via PubMed using the search terms "visceral nociception," "visceral hypersensitivity," "irritable bowel syndrome" and "transient receptor potential channels." After screening the abstracts the articles deemed relevant were cross-referenced for additional manuscripts.

RESULTS

Recent studies have resulted in significant advances in our understanding of TRP channel mediated visceral nociception. The diversity of TRP channel sensitization pathways is increasingly recognised. Endogenous TRP agonists, including poly-unsaturated fatty acid metabolites and hydrogen sulphide, have been implied in augmented visceral pain generation in IBS. New potential targets for treatment development have been identified (TRPA1 and TRPV4,) and alternative means of affecting TRP channel signalling (partial antagonists, downstream targeting and RNA-based therapy) are currently being explored.

CONCLUSIONS

The improved understanding of mechanisms involved in visceral nociception provides a solid basis for the development of new treatment strategies for abdominal pain in IBS.

A 20-Year Temporal Change Analysis in Incidence, Presenting Phenotype and Mortality, in the Dutch IBDSL Cohort-Can Diagnostic Factors Explain the Increase in IBD Incidence?

BACKGROUND

The aim was to study temporal changes in incidence, disease phenotype at diagnosis, and mortality of adult inflammatory bowel disease [IBD] patients in South Limburg, The Netherlands, diagnosed between 1991 and 2010. In addition, the 2010 IBD prevalence was estimated.

METHODS

A multi-faceted approach including hospital administrations, the national pathology registry [PALGA], and general practitioners led to the identification of 1162 patients with Crohn's disease [CD], 1663 with ulcerative colitis [UC], and 84 with unclassified IBD [IBD-U]. Temporal changes in incidence, disease phenotype, and mortality were studied using linear, multinomial regression analyses, and standardised mortality rates [SMR], respectively.

RESULTS

The annual incidences increased from 17.90/100000 in 1991 to 40.36/100000 in 2010 for IBD, from 5.84/100000 to 17.49/100000 for CD, and from 11.67/100000 to 21.47/100000 for UC [p < 0.01 for all]. A shift towards milder disease at diagnosis was observed over time [eg decrease of complicated disease in CD, increase of proctitis in UC]. IBD mortality was similar to that in the general population (SMR 0.92; 95% confidence interval [CI] 0.81-1.05), and did not change over time. The estimated IBD prevalence was 830/100000.

CONCLUSIONS

The IBD incidence in South Limburg increased significantly between 1991 and 2010. The shift towards milder disease at diagnosis in parallel with the improved diagnostics and ability to detect low-grade inflammation was suggestive of an important role of diagnostic factors in this increase. Environmental factors probably played a role as well. The mortality was low and, together with the increasing incidence, led to the high prevalence of IBD in South Limburg.

Lactobacillus plantarum Strains Can Enhance Human Mucosal and Systemic Immunity and Prevent Non-steroidal Anti-inflammatory Drug Induced Reduction in T Regulatory Cells

Orally ingested bacteria interact with intestinal mucosa and may impact immunity. However, insights in mechanisms involved are limited. In this randomized placebo-controlled cross-over trial, healthy human subjects were given Lactobacillus plantarum supplementation (strain TIFN101, CIP104448, or WCFS1) or placebo for 7 days. To determine whether L. plantarum can enhance immune response, we compared the effects of three stains on systemic and gut mucosal immunity, by among others assessing memory responses against tetanus toxoid (TT)-antigen, and mucosal gene transcription, in human volunteers during induction of mild immune stressor in the intestine, by giving a commonly used enteropathic drug, indomethacin [non-steroidal anti-inflammatory drug (NSAID)]. Systemic effects of the interventions were studies in peripheral blood samples. NSAID was found to induce a reduction in serum CD4⁺/Foxp3 regulatory cells, which was prevented by L. plantarum TIFN101. T-cell polarization experiments showed L. plantarum TIFN101 to enhance responses against TT-antigen, which indicates stimulation of memory responses by this strain. Cell extracts of the specific L. plantarum strains provoked responses after WCFS1 and TIFN101 consumption, indicating stimulation of immune responses against the specific bacteria. Mucosal immunomodulatory effects were studied in duodenal biopsies. In small intestinal mucosa, TIFN101 upregulated genes associated with maintenance of T- and B-cell function and antigen presentation. Furthermore, L. plantarum TIFN101 and WCFS1 downregulated immunological pathways involved in antigen presentation and shared downregulation of snoRNAs, which may suggest cellular destabilization, but may also be an indicator of tissue repair. Full sequencing of the L. plantarum strains revealed possible gene clusters that might be responsible for the differential biological effects of the bacteria on host immunity. In conclusion, the impact of oral consumption L. plantarum on host immunity is strain dependent and involves responses against bacterial cell components. Some strains may enhance specific responses against pathogens by enhancing antigen presentation and leukocyte maintenance in mucosa. In future studies and clinical settings, caution should be taken in selecting beneficial bacteria as closely related strains can have different effects. Our data show that specific bacterial strains can prevent immune stress induced by commonly consumed painkillers such as NSAID and can have enhancing beneficial effects on immunity of consumers by stimulating antigen presentation and memory responses.

The potential of volatile organic compounds for the detection of active disease in patients with ulcerative colitis

BACKGROUND

To optimise treatment of ulcerative colitis (UC), patients need repeated assessment of mucosal inflammation. Current non-invasive biomarkers and clinical activity indices do not accurately reflect disease activity in all patients and cannot discriminate UC from non-UC colitis. Volatile organic compounds (VOCs) in exhaled air could be predictive of active disease or remission in Crohn's disease.

AIM

To investigate whether VOCs are able to differentiate between active UC, UC in remission and non-UC colitis.

METHODS

UC patients participated in a 1-year study. Clinical activity index, blood, faecal and breath samples were collected at each out-patient visit. Patients with clear defined active faecal calprotectin >250 μg/g and inactive disease (Simple Clinical Colitis Activity Index <3, C-reactive protein <5 mg/L and faecal calprotectin <100 μg/g) were included for cross-sectional analysis. Non-UC colitis was confirmed by stool culture or radiological evaluation. Breath samples were analysed by gas chromatography time-of-flight mass spectrometry and kernel-based method to identify discriminating VOCs.

RESULTS

In total, 72 UC (132 breath samples; 62 active; 70 remission) and 22 non-UC-colitis patients (22 samples) were included. Eleven VOCs predicted active vs. inactive UC in an independent internal validation set with 92% sensitivity and 77% specificity (AUC 0.94). Non-UC colitis patients could be clearly separated from active and inactive UC patients with principal component analysis.

CONCLUSIONS

Volatile organic compounds can accurately distinguish active disease from remission in UC and profiles in UC are clearly different from profiles in non-UC colitis patients. VOCs have demonstrated potential as new non-invasive biomarker to monitor inflammation in UC.

Is intestinal oxidative stress involved in patients with compensated liver cirrhosis?

BACKGROUND

Liver cirrhosis is associated with intestinal epithelial barrier dysfunction, which may be affected by oxidative stress. Studies in cirrhotic rats provided evidence for intestinal oxidative stress, but studies in cirrhotic patients are scarce. We have shown intestinal barrier dysfunction in patients with compensated cirrhosis.

AIM

The present study aimed to investigate whether oxidative stress occurs in the intestinal mucosa of compensated cirrhotic patients and may contribute to barrier dysfunction.

MATERIAL AND METHODS

Oxidative stress was studied in duodenal and sigmoid biopsies from 15 cirrhotic patients and 22 controls by analyzing transcription of genes involved in glutathione and uric acid metabolism using quantitative real-time polymerase chain reaction. Protein levels of glutathione and glutathione disulphide were measured and the glutathione/glutathione disulphide ratio was calculated as marker of oxidative stress. In addition, intestinal myeloperoxidase and fecal calprotectin were determined.

RESULTS

Gene transcription of glutathione synthetase and glutathione reductase were significantly different in duodenal and sigmoid biopsies of cirrhotic patients vs. controls, but no alterations were found for other genes nor for glutathione, glutathione disulphide, glutathione/glutathione disulphide ratio and intestinal myeloperoxidase and fecal calprotectin concentrations.

CONCLUSION

This study did not find indications for oxidative stress and low-grade inflammation in the small and large intestine of stable compensated cirrhotic patients. Although these preliminary findings need further validation, we found intestinal oxidative stress not to be a major mechanism contributing to epithelial barrier dysfunction in patients with compensated cirrhosis.

[Changes in the treatment of Crohn's disease: fewer hospitalizations, less surgery, and reduced glucocorticoid use]

OBJECTIVE

To study changes in treatment and disease course in patients with Crohn's disease (CD) in the South Limburg region of the Netherlands between 1991 and 2014.

DESIGN

Population-based cohort study.

METHODS

All 1162 CD patients in the 'IBD South Limburg cohort' were divided across three subcohorts on the basis of year of diagnosis: 1991-1998 (N = 316), 1999-2005 (N = 387) and 2006-2011 (N = 459). We compared the risk of hospitalization, bowel resection and the development of strictures and/or fistulas across the subcohorts. We also compared cumulative corticosteroid use and the relationship between the outcome measures and maintenance medication.

RESULTS

In the period 1991-2014 there was an increase in the number of patients treated within 5 years with immunomodulators from 30.6% to 70.8%. For treatment with biologicals there was an increase from 3.1% to 41.2%. In parallel, the risk of hospitalization decreased from 65.9% to 44.2% and the risk of bowel resection decreased from 42.9% to 17.4%. The risk of developing strictures or fistulas remained stable (21.2%). There was no significant association between the outcome measures and the use of immunomodulators or biologicals. Furthermore, corticosteroid use decreased over time; this was linked to use of immunomodulators and biologicals.

CONCLUSION

Treatment of Crohn's disease has changed over the past two decades, and the disease course has improved. We found no association between changes in maintenance medication and disease course.