What impact has the Centre of Research Excellence in Digestive Health made in the field of gastrointestinal health in Australia and internationally? Study protocol for impact evaluation using the FAIT framework

INTRODUCTION

The need for public research funding to be more accountable and demonstrate impact beyond typical academic outputs is increasing. This is particularly challenging and the science behind this form of research is in its infancy when applied to collaborative research funding such as that provided by the Australian National Health and Medical Research Council to the Centre for Research Excellence in Digestive Health (CRE-DH).

METHODS AND ANALYSIS

In this paper, we describe the protocol for applying the Framework to Assess the Impact from Translational health research to the CRE-DH. The study design involves a five-stage sequential mixed-method approach. In phase I, we developed an impact programme logic model to map the pathway to impact and establish key domains of benefit such as knowledge advancement, capacity building, clinical implementation, policy and legislation, community and economic impacts. In phase 2, we have identified and selected appropriate, measurable and timely impact indicators for each of these domains and established a data plan to capture the necessary data. Phase 3 will develop a model for cost-consequence analysis and identification of relevant data for microcosting and valuation of consequences. In phase 4, we will determine selected case studies to include in the narrative whereas phase 5 involves collation, data analysis and completion of the reporting of impact.We expect this impact evaluation to comprehensively describe the contribution of the CRE-DH for intentional activity over the CRE-DH lifespan and beyond to improve outcomes for people suffering with chronic and debilitating digestive disorders.

ETHICS AND DISSEMINATION

This impact evaluation study has been registered with the Hunter New England Human Research Ethics Committee as project 2024/PID00336 and ethics application 2024/ETH00290. Results of this study will be disseminated via medical conferences, peer-reviewed publications, policy submissions, direct communication with relevant stakeholders, media and social media channels such as X (formely Twitter).

Healthcare Utilization Patterns: Irritable Bowel Syndrome, Inflammatory Bowel Disease, and Gastroesophageal Reflux Disease

BACKGROUND

Limited information is available about patterns of healthcare utilization for prevalent gastrointestinal conditions and their link to symptom burden.

AIM

To identify patterns of healthcare utilization among outpatients with highly prevalent gastrointestinal conditions and define the link between healthcare utilization, symptom burden, and disease group.

METHODS

We randomly selected patients from the gastroenterology outpatient clinic at Princess Alexandra Hospital who had chronic gastrointestinal conditions such as constipation-predominant irritable bowel syndrome (IBS-C, n = 101), diarrhea-predominant IBS (IBS-D, n = 101), mixed IBS (n = 103), inflammatory bowel disease with acute flare (n = 113), IBD in remission (n = 103), and gastroesophageal reflux disease (n = 102). All had presented at least 12 months before and had a 12-month follow-up after the index consultation. Healthcare utilization data were obtained from state-wide electronic medical records over a 24-month period. Intensity of gastrointestinal symptoms was measured using the validated Structured Assessment of Gastrointestinal Symptoms (SAGIS) Scale. Latent class analyses (LCA) based on healthcare utilization were used to identify distinct patterns of healthcare utilization among these patients.

RESULTS

LCA revealed four distinct healthcare utilization patterns across all diagnostic groups: Group A: Emergency department utilizers, Group B: Outpatient focused care utilizers, Group C: Inpatient care utilizers and Group D: Inpatient care and emergency department utilizers. LCA groups with high emergency utilization were characterized by high gastrointestinal symptom burden at index consultation regardless of condition (Mean (standard deviation)) SAGIS score Group A: 24.63 (± 14.11), Group B: 19.18 (± 15.77), Group C: 22.48 (± 17.42), and Group D: 17.59 (± 13.74, p < 0.05).

CONCLUSION

Distinct healthcare utilization patterns across highly prevalent gastrointestinal conditions exist. Symptom severity rather than diagnosis, likely reflecting unmet clinical need, defines healthcare utilization.

Social determinants and participation in fecal occult blood test based colorectal cancer screening: A qualitative systematic review and meta-synthesis

ISSUE ADDRESSED

Colorectal cancer (CRC) screening through fecal occult blood testing (FOBT) has saved thousands of lives globally with multiple countries adopting comprehensive population wide screening programs. Participation rates in FOBT based CRC screening for the socially and economically disadvantaged remains low. The aim of this systematic review is to explore empirical evidence that will guide targeted interventions to improve participation rates within priority populations.

METHODS

PubMed, Embase, Scopus, Cinahl and PsycInfo were systematically searched from inception to 22 June 2022. Eligible studies contained qualitative evidence identifying barriers to FOBT based CRC screening for populations impacted by the social determinants of health. An inductive thematic synthesis approach was applied using grounded theory methodology, to explore descriptive themes and interpret these into higher order analytical constructs and theories.

RESULTS

A total of 8,501 publications were identified and screened. A total of 48 studies from 10 countries were eligible for inclusion, representing 2,232 subjects. Coding within included studies resulted in 30 key descriptive themes with a thematic frequency greater than 10%. Coded themes applied to four overarching, interconnected barriers driving inequality for priority populations: social, behavioural, economic and technical/interfaces. SO WHAT?: This study has highlighted the need for stronger patient/provider relationships to mitigate barriers to FOBT screening participation for diverse groups. Findings can assist health professionals and policy makers address the systemic exclusion of priority populations in cancer screening by moving beyond the responsibility of the individual to a focus on addressing the information asymmetry driving low value perceptions.

TRAV26-2 T-Cell Receptor Expression Is Associated With Mucosal Lymphocyte Response to Wheat Proteins in Patients With Functional Dyspepsia

INTRODUCTION

An association between functional dyspepsia (FD) and wheat-containing foods has been reported in observational studies; however, an adaptive response has not been demonstrated. We examined whether antigens present in wheat could provoke a response from FD duodenal lymphocytes.

METHODS

Lamina propria mononuclear cells (LPMCs) were isolated from duodenal biopsies from 50 patients with FD and 23 controls. LPMCs were exposed to gluten (0.2 mg/mL) or gliadin (0.2 mg/mL) for 24 hours. Flow cytometry was performed to phenotype lymphocytes. Quantitative PCR was used to measure the expression of gliadin-associated T-cell receptor alpha variant ( TRAV ) 26-2.

RESULTS

In response to gliadin (but not gluten) stimulation, the effector Th2-like population was increased in FD LPMCs compared with that in controls and unstimulated FD LPMCs. Duodenal gene expression of TRAV26- 2 was decreased in patients with FD compared with that in controls. We identified a positive association between gene expression of this T-cell receptor variant and LPMC effector Th17-like cell populations in patients with FD, but not controls after exposure to gluten, but not gliadin.

DISCUSSION

Our findings suggest that gliadin exposure provokes a duodenal effector Th2-like response in patients with FD, supporting the notion that food antigens drive responses in some patients. Furthermore, these findings suggest that altered lymphocyte responses to wheat proteins play a role in FD pathogenesis.

Overlap of disorders of gut-brain interaction: a systematic review and meta-analysis

BACKGROUND

Rome criteria differentiate distinct types of disorders of gut-brain interaction (DGBI); also known as functional gastrointestinal disorders. Overlap of symptom categories frequently occurs. This systematic review and meta-analysis aimed to define the prevalence of DGBI overlap and compare overlap in population-based, primary care or tertiary care health settings. Furthermore, we aimed to compare symptom severity of psychological comorbidities in DGBI with and without overlap.

METHODS

For this systematic review and meta-analysis we searched MEDLINE (PubMed) and Embase electronic databases from inception until March 1, 2022, for original articles and conference abstracts of observational cross-sectional, case-controlled, or cohort design studies that reported the prevalence of DGBI overlap in adult participants (aged ≥18 years). We included only those studies where the diagnosis of DGBI was based on clinical assessment, questionnaire data, or specific symptom-based criteria. Studies were excluded if reporting on mixed populations of DGBI and organic diseases. Aggregate patient data were extracted from eligible published studies. The prevalence of DGBI overlap in all studies was pooled using the DerSimonian and Laird random effects model, and further analysis stratified by subgroups (care setting, diagnostic criteria, geographic region, and gross domestic product per capita). We also assessed the relationship between DGBI overlap with anxiety, depression, and quality of life symptom scores. This study was registered with PROSPERO (CRD42022311101).

FINDINGS

46 of 1268 screened studies, reporting on 75 682 adult DGBI participants, were eligible for inclusion in this systematic review and meta-analysis. Overall, 24 424 (pooled prevalence 36·5% [95% CI 30·7 to 42·6]) participants had a DGBI overlap, with considerable between-study heterogeneity (I²=99·51, p=0·0001). In the tertiary health-care setting, overlap among participants with DGBI was more prevalent (8373 of 22 617, pooled prevalence 47·3% [95% CI 33·2 to 61·7]) compared with population-based cohorts (11 332 of 39 749, pooled prevalence 26·5% [95% CI 20·5 to 33·4]; odds ratio 2·50 [95% CI 1·28 to 4·87]; p=0·0084). Quality of life physical component scores were significantly lower in participants with DGBI overlap compared with participants without overlap (standardised mean difference -0·47 [95% CI -0·80 to -0·14]; p=0·025). Participants with DGBI overlap had both increased symptom scores for anxiety (0·39 [95% CI 0·24 to 0·54]; p=0·0001) and depression (0·41 [0·30 to 0·51]; p=0·0001).

INTERPRETATION

Overlap of DGBI subtypes is frequent, and is more prevalent in tertiary care settings and associated with more severe symptom manifestations or psychological comorbidities. Despite the large sample size, the comparative analyses revealed substantial heterogeneity, and the results should be interpreted with caution.

FUNDING

National Health and Medical Research Council and Centre for Research Excellence.

Development and Validation of a Patient-Reported Experience Measure for Gastrointestinal Endoscopy: The Comprehensive Endoscopy Satisfaction Tool (CEST)

GOALS

We aimed to develop and validate a patient-reported experience measure for gastrointestinal (GI) endoscopy, the Comprehensive Endoscopy Satisfaction Tool that captures relevant domains that influence the patient's experience and identify factors that shape satisfaction.

BACKGROUND

Patient-reported experience measures are used to capture specific quality aspects of health care services. GI endoscopic services are high-volume services, and there is a lack of specific, validated instruments to capture various domains that shape the patients' experience with routine clinical endoscopic services.

STUDY

After an environmental scan and structured literature review, focus groups with patients were conducted to identify relevant factors influencing the patient experience with GI endoscopic services. After an initial validation in 101 patients undergoing routine GI endoscopies, the instrument was tested in 7800 patients. In addition, the influence of sociodemographic factors on global satisfaction was explored.

RESULTS

The final version included 26 specific items plus 4 global ratings for preprocedure, experience on day of procedure, postprocedure care, and infrastructure. In addition, a global rating of the overall experience was included. Patient satisfaction was significantly higher in older patients (P<0.001) but not influenced by gender, nationality, marital status, education, or employment status. Interestingly, during periods of coronavirus disease-19-related service interruptions, the Net Promoter Score was significantly reduced (P<0.0001) providing evidence for the responsiveness of the instrument.

CONCLUSIONS

The Comprehensive Endoscopy Satisfaction Tool is a valid measure for the patient experience with the various components of endoscopic services, allows for the identification of domains that impact on the patient experience and is a practical tool to compare patient satisfaction over time and across facilities.

Utilising lipid and, arginine and proline metabolism in blood plasma to differentiate the biochemical expression in functional dyspepsia (FD) and irritable bowel syndrome (IBS)

Functional gastrointestinal disorders (FGID) such as functional dyspepsia (FD) and irritable bowel syndrome (IBS) are highly prevalent and debilitating attributed to altered gut function and gut-brain interactions. FGID can be reliably diagnosed based upon the symptom pattern; but in the clinical setting FD or IBS a frequent diagnoses of exclusion after relevant structural causes of symptoms have been ruled out by appropriate testing. Thus far, there is no established biomarker for FGIDs. To address this limitation, we utilised multi-omics and chemometrics integration to characterise the blood plasma biochemistry in patients with IBS, FD, an overlap of FD/IBS, and controls using liquid chromatography-mass spectrometry (LC-MS) techniques.Cholesterol metabolism products Cholest-5,24-dien-3β-ol, 3-O-β-D-glucopyranoside, energy pathway metabolites, immunoglobulin-γ2 and immunoglobulin-κ, and carbonic anhydrase-1 proteins were particularly elevated in IBS. Furthermore, arginine and proline metabolisms, thyroid hormone synthesis, ferroptosis and, complementary and coagulation cascades were particularly upregulated in patients with IBS. Cer(d18:1/26:1(17Z)) and PI(14:0/22:1(11Z)) lipids were elevated in FD and FD-IBS but were depleted in IBS. Markers of central carbon metabolism and lipidome profiles allowed better discrimination and model predictability than metaproteome profile in healthy and FGID conditions.Overall, the multi-omics integration allowed the discrimination of healthy controls and FGID patients. It also effectively differentiated the biochemistry of FGID subtypes including FD, IBS and FD-IBS co-occurrence. This study points towards the possibility of multi-omics integration for rapid and high throughput analysis of plasma samples to support clinicians screen and diagnose patients with suspected FGIDs.

Defects in NLRP6, autophagy and goblet cell homeostasis are associated with reduced duodenal CRH receptor 2 expression in patients with functional dyspepsia

Functional dyspepsia (FD) affects up to 15% of the population and is characterised by recurring upper gastrointestinal (GI) symptoms occurring in the absence of clinically identifiable pathology. Psychological stress is a key factor associated with the onset of FD and locally acting hypothalamic-pituitary-adrenal (HPA) axis hormones have been implicated in GI motility and barrier dysfunction. Recent pre-clinical work has identified mechanistic pathways linking corticotropin-releasing hormone (CRH) with the innate epithelial immune protein NLRP6, an inflammasome that has been shown to regulate GI mucus secretion. We recruited twelve FD patients and twelve healthy individuals to examine whether dysregulation of hypothalamic-pituitary adrenal (HPA) axis hormones and altered NLRP6 pathways were evident in the duodenal mucosa. Protein expression was assessed by immunoblot and immunohistochemistry in D2 duodenal biopsies. Plasma HPA axis hormones were assayed by ELISA and enteroid and colorectal cancer cell line cultures were used to verify function. FD patients exhibited reduced duodenal CRH-receptor 2, compared to non-GI disease controls, indicating a dysregulation of duodenal HPA signalling. The loss of CRH-receptor 2 correlated with reduced NLRP6 expression and autophagy function, processes critical for maintaining goblet cell homeostasis. In accordance, duodenal goblet cell numbers and mucin exocytosis was reduced in FD patients compared to controls. In vitro studies demonstrated that CRH could reduce NLRP6 in duodenal spheroids and promote mucus secretion in the HT29-MTX-E12 cell line. In conclusion, FD patients exhibit defects in the NLRP6-autophagy axis with decreased goblet cell function that may drive symptoms of disease. These features correlated with loss of CRH receptor 2 and may be driven by dysregulation of HPA signalling in the duodenum of FD patients.

Methane positive small intestinal bacterial overgrowth in inflammatory bowel disease and irritable bowel syndrome: A systematic review and meta-analysis

Several studies reported a potential role of methane producing archaea in the pathophysiology of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). We conducted a systematic review and meta-analysis to assess the prevalence of methane positive small intestinal bacterial overgrowth (SIBO) in IBS and IBD compared with controls. MEDLINE (PubMed) and Embase electronic databases were searched from inception until March 2021 for case-control and prevalence studies reporting SIBO in IBS and IBD. We extracted data from published studies and calculated pooled prevalence of SIBO in IBS or IBD, odds ratios (OR), and 95% CIs, utilizing a random effects model. The final dataset included 17 independent studies assessing the prevalence of methane positive SIBO in 1,653 IBS-patients and 713 controls, and 7 studies assessing the prevalence of methane positive SIBO in 626 IBD-patients and 497 controls, all utilizing breath test for SIBO diagnosis. Prevalence of methane positive SIBO in IBS and IBD was 25.0% (95% CI 18.8-32.4) and 5.6% (95% CI 2.6-11.8), respectively. Methane positive SIBO in IBS was not increased compared to controls (OR = 1.2, 95% CI 0.8-1.7, P = .37) but was significantly more prevalent in IBS-C as compared to IBS-D (OR = 3.1, 95% CI 1.7-5.6, P = .0001). The prevalence of methane-positive SIBO in patients with IBD was 3-fold lower at 7.4% (95% CI 5.4-9.8) compared to 23.5% (95% CI 19.8-27.5) in controls. The prevalence of methane positive SIBO was significantly lower in Crohn's disease as compared to ulcerative colitis, (5.3%, 95% CI 3.0-8.5 vs. 20.2%, 95% CI 12.8-29.4). This systematic review and meta-analysis suggests methane positivity on breath testing is positively associated with IBS-C and inversely with IBD. However, the quality of evidence is low largely due to clinical heterogeneity of the studies. Thus, causality is uncertain and further studies are required.

How frequent are vancomycin-resistant enterococci in patients with primary sclerosing cholangitis and ulcerative colitis treated with oral vancomycin?

In patients with primary sclerosing cholangitis (PSC), antimicrobial therapy with oral vancomycin (OV) is increasingly used to prevent progression of the liver disease and control concomitant ulcerative colitis (UC); however, there are concerns regarding the risk of development of vancomycin-resistant enterococci (VRE). Thus, we aimed to determine the incidence of VRE in PSC-UC patients. We conducted a retrospective study of PSC-UC patients, treated with OV at the Department of Gastroenterology at the Princess Alexandra Hospital. VRE testing was performed utilizing rectal swabs. We included 7 PSC-UC patients (age 22-53 years, 2 females) treated with OV with daily dose ranging from 250 to 1500 mg. All patients were treated for at least 6 months with OV (range 9-31 months, mean 32.1 months). All patients achieved complete clinical remission of the UC, with mean reduction of fecal calprotectin by 634 μg/mg (87.3%), mean reduction in the C-reactive protein by 21.9 mg/L (74.2%), and mean reduction in the total Mayo score by 9.3 (93.3%). With regard to the liver parameters, mean improvement in alkaline phosphatase enzyme and total bilirubin was -48.7 U/L (-19.7%) and -2.7 mg/dL (-19.6%), respectively. No patient treated with OV developed VRE or reported any adverse events. This cohort study including PSC-UC patients did not provide evidence for development of VRE, while treatment with vancomycin was associated with clinical and endoscopic remission of the UC. Larger, prospective trials are required to define the efficacy and safety of antimicrobial therapy in PSC-UC, while the risk of VRE appears small.

Is there a causal link between psychological disorders and functional gastrointestinal disorders?

INTRODUCTION

Psychological distress is associated with functional gastrointestinal disorders (FGIDs) including irritable bowel syndrome (IBS) and functional dyspepsia (FD) but only evidence from prospective longitudinal and treatment studies can indicate whether the link between FGIDs and psychological distress is causal. Emerging evidence suggests underlying biological mechanisms may explain the association of psychological distress with FGIDs.

AREAS COVERED

This review critically evaluates whether anxiety and/or depression and FGIDs are causally related including evidence for a temporal sequence, strength and specificity of the association, biological gradient, and biological plausibility.

EXPERT OPINION

Accumulating evidence suggests that psychological factors are causal for symptoms in a subset of FGID patients and not explained by health care seeking behavior (brain-gut disorder). In other cases, psychological factors may arise secondary to intestinal disease (gut-brain disorder). Prospective population-based studies are needed in FGIDs other than IBS and FD to determine if a similar brain-gut and gut-brain syndrome exists. Treatment studies have not phenotyped FGIDs according to brain-gut versus gut-brain origins which may be important in understanding true treatment efficacy. Future research needs to unravel biological mechanisms that may explain the link between psychological factors and FGIDs but promising data in the area of the brain-gut-immune-microbe axis is emerging.

Duodenal bacterial load as determined by quantitative polymerase chain reaction in asymptomatic controls, functional gastrointestinal disorders and inflammatory bowel disease

BACKGROUND

Small intestinal bacterial overgrowth may play a role in gastrointestinal and non-gastrointestinal diseases.

AIMS

To use quantitative polymerase chain reaction (qPCR) to determine and compare bacterial loads of duodenal biopsies in asymptomatic controls, and patients with functional gastrointestinal disorders (FGIDs) and inflammatory bowel disease (IBD) including ulcerative colitis (UC) and Crohn's disease (CD). To define effects of gastric acid inhibition on bacterial load, explore links of bacterial load and gastrointestinal symptoms in response to a standardised nutrient challenge and compare bacterial load with glucose breath test results.

METHODS

In 237 patients (63 controls, 84 FGID and 90 IBD), we collected mucosal samples under aseptic conditions during endoscopy extracted and total DNA. Bacterial load metric was calculated utilising qPCR measurements of the bacterial 16S rRNA gene, normalised to human beta-actin expression. Standard glucose breath test and nutrient challenge test were performed.

RESULTS

The duodenal microbial load was higher in patients with FGID (0.22 ± 0.03) than controls (0.07 ± 0.05; P = 0.007) and patients with UC (0.01 ± 0.05) or CD (0.02 ± 0.09), (P = 0.0001). While patients treated with proton pump inhibitors (PPI) had significantly higher bacterial loads than non-users (P < 0.05), this did not explain differences between patient groups and controls. Bacterial load was significantly (r = 0.21, P < 0.016) associated with the symptom response to standardised nutrient challenge test. Methane, but not hydrogen values on glucose breath test were associated with bacterial load measured utilising qPCR.

CONCLUSIONS

Utilising qPCR, a diagnosis of FGID and treatment with PPI were independently associated with increased bacterial loads. Increased bacterial loads are associated with an augmented symptom response to a standardised nutrient challenge.

Systematic review with meta-analysis: the prevalence of small intestinal bacterial overgrowth in inflammatory bowel disease

BACKGROUND

Current data on small intestinal bacterial overgrowth (SIBO) in patients with inflammatory bowel diseases (IBD) are controversial.

AIM

To conduct a systematic review and meta-analysis to determine the prevalence of SIBO in patients with ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

Electronic databases were searched up to May 2018 for studies reporting prevalence of SIBO in IBD patients. The prevalence rate of SIBO among IBD patients and the odds ratio (OR) and 95% CI of SIBO in IBD patients compared with controls were calculated.

RESULTS

The final dataset included 11 studies (1175 adult patients with IBD and 407 controls), all utilising breath test for diagnosis of SIBO. The proportion of SIBO in IBD patients was 22.3% (95% CI 19.92-24.68). The OR for SIBO in IBD patients was 9.51 (95% CI 3.39-26.68) compared to non-IBD controls, and high in both CD (OR = 10.86; 95% CI 2.76-42.69) and UC (OR = 7.96; 95% CI 1.66-38.35). In patients with CD, subgroup analysis showed the presence of fibrostenosing disease (OR = 7.47; 95% CI 2.51-22.20) and prior bowel surgery (OR = 2.38; 95% CI 1.65-3.44), especially resection of the ileocecal valve, increased the odds of SIBO. Individual studies suggest that combined small and large bowel disease but not disease activity may be associated with SIBO.

CONCLUSIONS

Overall, there is a substantial increase in the prevalence of SIBO in IBD patients compared to controls. Prior surgery and the presence of fibrostenosing disease are risk factors for SIBO in IBD.

Population based study: atopy and autoimmune diseases are associated with functional dyspepsia and irritable bowel syndrome, independent of psychological distress

BACKGROUND

The pathogenesis of functional GI disorders (FGIDs) is uncertain. However, underlying immune activation and psychological distress has been documented in irritable bowel syndrome (IBS) and functional dyspepsia (FD). Epidemiological data from the UK suggest that FGIDs are linked to atopy and certain autoimmune diseases but this has not been confirmed.

AIM

To test if allergic or autoimmune diseases are independently associated with FGIDs, irrespective of psychological distress in a large population based study.

METHODS

A total of 3542 people (mean age 57.9 years and 52.7% females) randomly selected from the Australian population, returned a mail survey (response rate = 43%). The survey asked about a physician diagnosis of autoimmune disease (scleroderma, psoriasis, rheumatoid arthritis and diabetes mellitus) or allergic conditions (asthma, food, pollen and/or animal allergy). The questionnaire assessed psychological distress and Rome III criteria for FD and IBS.

RESULTS

Asthma, food, pollen and animal allergies, psoriasis and rheumatoid arthritis were univariately significantly associated with IBS and FD. Food allergy (OR = 1.66; 95% CI = 1.15-2.40, P = 0.007), psoriasis (OR = 1.81; 95% CI = 1.19-2.74, P = 0.006) and rheumatoid arthritis (OR = 1.68; 95% CI = 1.15-2.4, P = 0.007) were independent risk factors for IBS, controlling for age, gender and psychological distress. In FD, asthma (OR = 1.32; 95% CI = 1.04-1.68, P = 0.025) and food allergy (OR = 1.78; 95% CI = 1.28-2.49, P = 0.001) were independent predictors, controlling for age, sex and psychological distress.

CONCLUSIONS

There is evidence that both atopic and autoimmune diseases are risk factors for FGIDs, independent of psychological distress, differing in IBS and FD. This provides evidence that different peripheral pathways may be involved in the pathogenesis of certain FGIDs.

Overlap of Irritable Bowel Syndrome and Functional Dyspepsia in the Clinical Setting: Prevalence and Risk Factors

BACKGROUND

According to Rome IV criteria, functional dyspepsia (FD) and irritable bowel syndrome (IBS) are distinct functional gastrointestinal disorders (FGID); however, overlap of these conditions is common in population-based studies, but clinical data are lacking.

AIMS

To determine the overlap of FD and IBS in the clinical setting and define risk factors for the overlap of FD/IBS.

METHODS

A total of 1127 consecutive gastroenterology outpatients of a tertiary center were recruited and symptoms assessed with a standardized validated questionnaire. Patients without evidence for structural or biochemical abnormalities as a cause of symptoms were then categorized based upon the symptom pattern as having FD, IBS or FD/IBS overlap. Additionally, this categorization was compared with the clinical diagnosis documented in the integrated electronic medical records system.

RESULTS

A total of 120 patients had a clinical diagnosis of a FGID. Based upon standardized assessment with a questionnaire, 64% of patients had FD/IBS overlap as compared to 23% based upon the routine clinical documentation. In patients with severe IBS or FD symptoms (defined as symptoms affecting quality of life), the likelihood of FD/IBS overlap was substantially increased (OR = 3.1; 95%CI 1.9-5.0) and (OR = 9.0; 95%CI 3.5-22.7), respectively. Thus, symptom severity for IBS- or FD symptoms were significantly higher for patients with FD/IBS overlap as compared to patients with FD or IBS alone (p all < 0.01). Age, gender and IBS-subtype were not associated with overlap.

CONCLUSION

In the clinical setting, overlap of FD and IBS is the norm rather than the exception. FD/IBS overlap is associated with a more severe manifestation of a FGID.

Influence of cigarette smoking on the human duodenal mucosa-associated microbiota

BACKGROUND

Cigarette smoking is a known risk factor in a number of gastrointestinal (GI) diseases in which the microbiota is implicated, including duodenal ulcer and Crohn's disease. Smoking has the potential to alter the microbiota; however, to date, the impact of smoking on the mucosa-associated microbiota (MAM), and particularly that of the upper GI tract, remains very poorly characterised. Thus, we investigated the impact of smoking on the upper small intestinal MAM. A total of 102 patients undergoing upper GI endoscopy for the assessment of GI symptoms, iron deficiency, or Crohn's disease, but without identifiable lesions in the duodenum, were recruited. Smoking status was determined during clinical assessment and patients classified as current (n = 21), previous smokers (n = 40), or having never smoked (n = 41). The duodenal (D2) MAM was profiled via 16S rRNA gene amplicon sequencing.

RESULTS

Smoking, both current and previous, is associated with significantly reduced bacterial diversity in the upper small intestinal mucosa, as compared to patients who had never smoked. This was accompanied by higher relative abundance of Firmicutes, specifically Streptococcus and Veillonella spp. The relative abundance of the genus Rothia was also observed to be greater in current smokers; while in contrast, levels of Prevotella and Neisseria were lower. The MAM profiles and diversity of previous smokers were observed to be intermediate between current and never smokers. Smoking did not impact the total density of bacteria present on the mucosa.

CONCLUSIONS

These data indicate the duodenal MAM of current smokers is characterised by reduced bacterial diversity, which is partially but not completely restored in previous smokers. While the precise mechanisms remain to be elucidated, these microbiota changes may in some part explain the adverse effects of smoking on mucosa-associated diseases of the GI tract. Smoking status requires consideration when interpreting MAM data.

A randomized placebo-controlled trial on the effects of Menthacarin, a proprietary peppermint- and caraway-oil-preparation, on symptoms and quality of life in patients with functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a very common condition affecting more than 10% of the population. While there is no cure, a few drugs have been found to be effective for the relief of symptoms, although most are only effective in a subgroup of patients. We assess and compare the efficacy of a fixed peppermint/caraway-oil-combination (Menthacarin) on symptoms and quality of life (QoL) in patients with FD symptoms consistent with epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS).

METHODS

In a prospective, double-blind, multicenter trial, 114 outpatients with chronic or recurrent FD were randomized and treated for 4 weeks with the proprietary peppermint- and caraway-oil-preparation Menthacarin or placebo (2×1 capsule/day). Improvement of abdominal pain and discomfort were used as co-primary efficacy measures (scores measured with the validated Nepean Dyspepsia Index).

KEY RESULTS

After 2 and 4 weeks, active treatment was superior to placebo in alleviating symptoms consistent with PDS and EPS (P all <.001). After 4 weeks of treatment, pain and discomfort scores improved by 7.6±4.8 and 3.6±2.5 points (full analysis set; mean±SD) for Menthacarin and by 3.4±4.3 and 1.3±2.1 points for placebo, respectively. All secondary efficacy measures showed advantages for Menthacarin.

CONCLUSIONS & INFERENCES

Menthacarin is an effective therapy for the relief of pain and discomfort and improvement of disease-specific QoL in patients with FD and significantly improves symptoms consistent with EPS and PDS.

Undiagnosed pancreatic exocrine insufficiency and chronic pancreatitis in functional GI disorder patients with diarrhea or abdominal pain

BACKGROUND AND AIM

A previous UK study showed that 6.1% of patients with diarrhea-predominant irritable bowel syndrome (IBS-D) had evidence of severe pancreatic exocrine insufficiency (PEI), but these findings need replication. We aimed to identify the prevalence of PEI based on fecal elastase stool testing in consecutive outpatients presenting with chronic unexplained abdominal pain and/or diarrhea and/or IBS-D.

METHODS

Patients aged over 40 years presenting to hospital outpatient clinics from six sites within Australia with unexplained abdominal pain and/or diarrhea for at least 3 months and/or IBS-D were studied. Patients completed validated questionnaires and donated a stool sample in which elastase concentration was measured by ELISA. A concentration of < 100 mcg/g stool represented severe and < 200 mcg/g mild to moderate PEI. Patients whose fecal elastase was < 200 mcg/g underwent testing for pancreatic pathology with an endoscopic ultrasound or abdominal CT.

RESULTS

Two hundred eighteen patients (mean age of 60 years, 29.4% male) were studied. PEI was found in 4.6% (95% CI 2.2-8.3%) (n = 10), with five patients (2.3% (95% CI 0.8-5.3%) having severe PEI. Only male sex and heavy alcohol use were significantly associated with abnormal versus normal pancreatic functioning. Of seven patients who underwent endoscopic ultrasound or CT, two had features indicative of chronic pancreatitis.

CONCLUSION

One in 50 patients with IBS-D or otherwise unexplained abdominal pain or diarrhea have an abnormal fecal elastase, but unexpected pancreatic insufficiency was detected in only a minority of these. This study failed to confirm the high prevalence of PEI among patients with unexplained GI symptoms previously reported.

Is There a Link Between H. Pylori and the Epidemiology of Crohn's Disease?

INTRODUCTION

Case control studies suggest an inverse association between Helicobacter pylori (H. pylori) and Crohn's disease (CD). It is possible this could be accounted for by confounders such as antibiotic therapy. Analyzing the geographic distribution of H. pylori and the links with the incidence and prevalence of CD would be an alternative approach to circumvent these confounders.

METHODS

The literature was searched for studies published between 1990 and 2016 that reported incidence or prevalence data for CD in random population samples in developed countries (GDP per capita >20,000 USD/year). Corresponding prevalence studies for H. pylori in these same regions were then sought matched to the same time period (±6 years). The association between the incidence and prevalence of CD and H. pylori prevalence rates were assessed before and after adjusting for GDP and life expectancy.

RESULTS

A total of 19 CD prevalence and 22 CD incidence studies from 10 European countries, Japan, USA, and Australia with date-matched H. pylori prevalence data were identified. The mean H. pylori prevalence rate was 43.4% (range 15.5-85%), and the mean rates for incidence and prevalence for CD were 6.9 and 91.0/100,000 respectively. The incidence (r = -0.469, p < 0.03) and prevalence (r = -0.527, p = 0.02) of CD was inversely and significantly associated with prevalence of H. pylori infection.

CONCLUSIONS

Our data demonstrate a significant inverse association between geographic distribution of H. pylori and CD. Thus, it is highly unlikely that the findings of previous case control studies were simply due to confounding factors such as concomitant antibiotic use in CD patients.

Abdominal migraine

Background

Abdominal migraine (AM) is a syndrome usually recognised in childhood. The syndrome is characterised by episodic attacks of severe abdominal pain and vasomotor symptoms, nausea and vomiting. It is a poorly understood disorder largely due to a limited recognition of this condition by the medical community. However, the publication of AM diagnostic guidelines by the International Headache Society a decade ago and the recognition of AM in the Rome Classification of functional gastrointestinal disorders have helped to legitimise this disorder and facilitate research.

Overview

AM is relatively common, affecting up to 4% of the paediatric population. Whilst AM is not believed to continue into adulthood for the majority of children, it has the propensity to develop into probable migraine and recurrent abdominal pain in adulthood. The pathophysiology of this condition remains unclear and as a result treatment for this condition is suboptimal with avoidance of triggers and prophylactic treatment currently recommended when an episode begins.

Conclusion

The recognition of AM by the IHS and the Rome Foundation should help facilitate future research into the pathophysiology of this debilitating condition and as a result better treatments for AM should emerge. Randomised controlled trials should be a priority.

Women and functional dyspepsia

Functional dyspepsia is relatively common yet poorly understood. The best accepted diagnostic criteria are the Rome III criteria. The epidemiology, healthcare seeking rates, impact and pathophysiology are reviewed with a focus on women. Treatment is limited with no clearly established regimen currently recommended. Duodenal eosinophilia may be found in a subset. Proton pump inhibitors and prokinetic agents represent the standard therapeutic regimen after Helicobacter pylori infection has been eliminated. Some novel agents such as the prokinetic acotiamide appear promising; however, the need for a safe and efficacious treatment remains largely unmet. This review also describes the currently available management options for functional dyspepsia.

Early life factors initiate a 'vicious circle' of affective and gastrointestinal symptoms: A longitudinal study

OBJECTIVE

Functional gastrointestinal disorders (FGID) have been shown to be associated with both comorbid mood disorders and traumatic events such as abuse earlier in life. In a longitudinal study, we tested a model that hypothesized: (i) childhood abuse was associated with subsequent mood disorder and pain or interference in life by bowel symptoms both directly and indirectly via neurotic personality; and (ii) an ongoing cycle of mood disorder impacts on bowel symptoms.

DESIGN

Subjects from the general population classified as irritable bowel syndrome and/or functional dyspepsia (IBS/FD, n = 207) or free of FGID (n = 100) were prospectively studied every 6 months over 18 months. In addition to bowel symptom interference and abdominal pain, measures of personality (neuroticism), childhood abuse history, depression, and anxiety were obtained. The hypothesized model was tested via Path Modelling.

RESULTS

Childhood abuse was found to be directly associated with neuroticism but only indirectly associated with baseline interference and mood disorders (via neuroticism). The data further supported an ongoing cycle of elevations in mood disorders and pain/interference by bowel symptoms. The data supported direct effects of interference at one time point on interference at the subsequent time point in addition to indirect effects of prior anxiety and depression. Repeating the model with pain frequency as the outcome yielded almost identical findings which suggests the findings are generalized across domains of symptoms and quality-of-life.

CONCLUSION

Our data provide support for a model characterized by a 'vicious circle' between mood disorders and FGID symptoms in adulthood, with initial input from early life factors.

Pathways connecting cognitive behavioral therapy and change in bowel symptoms of IBS

OBJECTIVE

A single previous paper on this topic found a direct pathway between cognitive behavioral therapy (CBT) and an irritable bowel syndrome (IBS) global symptom score. This is controversial since under the biopsychosocial model, the expectation is that CBT's effect would be mediated by mood. Using more sensitive bowel symptom scales and measurements at additional time points, we aimed to compare the relative strengths of direct pathways between CBT and change in IBS symptoms and indirect pathways that operate via mood state using structural equation modeling.

METHODS

Our data set included 105 people with Rome I IBS randomized to individual CBT (n=34), relaxation therapy (n=36), and usual medical care (n=35). The primary outcome was defined as adequate relief of IBS symptoms in terms of the distress, frequency, and impairment according to the Bowel Symptom Severity Scale. Outcomes in functional status (according to the 36-item Short-Form Health Survey) and psychological status (Hospital Anxiety and Depression Scale) were secondary outcomes.

RESULTS

Our data suggest indirect pathways that operate via mood, most clearly anxiety but to a lesser extent depression. Statistically significant pathways were identified that lead from CBT to change in mood state thence to change in bowel symptoms, followed by further changes in mood then changes in bowel symptoms. Our data provide no evidence of direct effect of CBT on bowel symptoms.

CONCLUSIONS

The present study suggests that CBT may operate via changes in mood state while not ruling out the possibility of direct effects. Our findings do not directly support, but are consistent with, a biopsychosocial model.

Development and validation of the Geriatric Anxiety Inventory

BACKGROUND

Anxiety symptoms and anxiety disorders are highly prevalent among elderly people, although infrequently the subject of systematic research in this age group. One important limitation is the lack of a widely accepted instrument to measure dimensional anxiety in both normal old people and old people with mental health problems seen in various settings. Accordingly, we developed and tested of a short scale to measure anxiety in older people.

METHODS

We generated a large number of potential items de novo and by reference to existing anxiety scales, and then reduced the number of items to 60 through consultation with a reference group consisting of psychologists, psychiatrists and normal elderly people. We then tested the psychometric properties of these 60 items in 452 normal old people and 46 patients attending a psychogeriatric service. We were able to reduce the number of items to 20. We chose a 1-week perspective and a dichotomous response scale.

RESULTS

Cronbach's alpha for the 20-item Geriatric Anxiety Inventory (GAI) was 0.91 among normal elderly people and 0.93 in the psychogeriatric sample. Concurrent validity with a variety of other measures was demonstrated in both the normal sample and the psychogeriatric sample. Inter-rater and test-retest reliability were found to be excellent. Receiver operating characteristic analysis indicated a cut-point of 10/11 for the detection of DSM-IV Generalized Anxiety Disorder (GAD) in the psychogeriatric sample, with 83% of patients correctly classified with a specificity of 84% and a sensitivity of 75%.

CONCLUSIONS

The GAI is a new 20-item self-report or nurse-administered scale that measures dimensional anxiety in elderly people. It has sound psychometric properties. Initial clinical testing indicates that it is able to discriminate between those with and without any anxiety disorder and between those with and without DSM-IV GAD.