Effect of Brain-Gut Behavioral Treatments on Abdominal Pain in Irritable Bowel Syndrome: Systematic Review and Network Meta-analysis.

BACKGROUND & AIMS: Some brain-gut behavioral treatments (BGBTs) are beneficial for global symptoms in irritable bowel syndrome (IBS). United States management guidelines suggest their use in patients with persistent abdominal pain, but their specific effect on this symptom has not been assessed systematically. METHODS: We searched the literature through December 16, 2023, for randomized controlled trials (RCTs) assessing efficacy of BGBTs for adults with IBS, compared with each other or a control intervention. Trials provided an assessment of abdominal pain resolution or improvement at treatment completion. We extracted data as intention-to-treat analyses, assuming dropouts to be treatment failures and reporting pooled relative risks (RRs) of abdominal pain not improving with 95% confidence intervals (CIs), ranking therapies according to the P score. RESULTS: We identified 42 eligible randomized controlled trials comprising 5220 participants. After treatment completion, the BGBTs with the largest numbers of trials and patients recruited demonstrating efficacy for abdominal pain, specifically, included self-guided/minimal contact cognitive behavioral therapy (CBT) (RR, 0.71; 95% CI, 0.54-0.95; P score, 0.58), face-to-face multicomponent behavioral therapy (RR, 0.72; 95% CI, 0.54-0.97; P score, 0.56), and face-to-face gut-directed hypnotherapy (RR, 0.77; 95% CI, 0.61-0.96; P score, 0.49). Among trials recruiting only patients with refractory global IBS symptoms, group CBT was more efficacious than routine care for abdominal pain, but no other significant differences were detected. No trials were low risk of bias across all domains, and there was evidence of funnel plot asymmetry. CONCLUSIONS: Several BGBTs, including self-guided/minimal contact CBT, face-to-face multicomponent behavioral therapy, and face-to-face gut-directed hypnotherapy may be efficacious for abdominal pain in IBS, although none was superior to another.

Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Some probiotics may be beneficial in irritable bowel syndrome (IBS), but differences in species and strains used, as well as endpoints reported, have hampered attempts to make specific recommendations as to which should be preferred. We updated our previous meta-analysis examining this issue. METHODS: MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (up to March 2023). Randomized controlled trials (RCTs) recruiting adults with IBS, comparing probiotics with placebo were eligible. Dichotomous symptom data were pooled to obtain a relative risk of global symptoms, abdominal pain, or abdominal bloating or distension persisting after therapy, with a 95% confidence interval (CI). Continuous data were pooled using a standardized mean difference with a 95% CI. Adverse events data were also pooled. RESULTS: We identified 82 eligible trials, containing 10,332 patients. Only 24 RCTs were at low risk of bias across all domains. For global symptoms, there was moderate certainty in the evidence for a benefit of Escherichia strains, low certainty for Lactobacillus strains and Lactobacillus plantarum 299V, and very low certainty for combination probiotics, LacClean Gold S, Duolac 7s, and Bacillus strains. For abdominal pain, there was low certainty in the evidence for a benefit of Saccharomyces cerevisae I-3856 and Bifidobacterium strains, and very low certainty for combination probiotics, Lactobacillus, Saccharomyces, and Bacillus strains. For abdominal bloating or distension there was very low certainty in the evidence for a benefit of combination probiotics and Bacillus strains. The relative risk of experiencing any adverse event, in 55 trials, including more than 7000 patients, was not significantly higher with probiotics. CONCLUSIONS: Some combinations of probiotics or strains may be beneficial in IBS. However, certainty in the evidence for efficacy by GRADE criteria was low to very low across almost all of our analyses.

Gut Microbiome Composition Is Associated With Future Onset of Crohn's Disease in Healthy First-Degree Relatives.

BACKGROUND & AIMS: The cause of Crohn's disease (CD) is unknown, but the current hypothesis is that microbial or environmental factors induce gut inflammation in genetically susceptible individuals, leading to chronic intestinal inflammation. Case-control studies of patients with CD have cataloged alterations in the gut microbiome composition; however, these studies fail to distinguish whether the altered gut microbiome composition is associated with initiation of CD or is the result of inflammation or drug treatment. METHODS: In this prospective cohort study, 3483 healthy first-degree relatives (FDRs) of patients with CD were recruited to identify the gut microbiome composition that precedes the onset of CD and to what extent this composition predicts the risk of developing CD. We applied a machine learning approach to the analysis of the gut microbiome composition (based on 16S ribosomal RNA sequencing) to define a microbial signature that associates with future development of CD. The performance of the model was assessed in an independent validation cohort. RESULTS: In the validation cohort, the microbiome risk score (MRS) model yielded a hazard ratio of 2.24 (95% confidence interval, 1.03-4.84; P = .04), using the median of the MRS from the discovery cohort as the threshold. The MRS demonstrated a temporal validity by capturing individuals that developed CD up to 5 years before disease onset (area under the curve > 0.65). The 5 most important taxa contributing to the MRS included Ruminococcus torques, Blautia, Colidextribacter, an uncultured genus-level group from Oscillospiraceae, and Roseburia. CONCLUSION: This study is the first to demonstrate that gut microbiome composition is associated with future onset of CD and suggests that gut microbiome is a contributor in the pathogenesis of CD.

Environmental Factors Associated with Risk of Crohn's Disease Development in the Crohn's and Colitis Canada - Genetic, Environmental, Microbial Project.

BACKGROUND & AIMS: To date, it is unclear how environmental factors influence Crohn's disease (CD) risk and how they interact with biological processes. This study investigates the association between environmental exposures and CD risk and evaluates their association with pre-disease biomarkers. METHODS: We studied 4289 healthy first-degree relatives (FDRs) of patients with CD from the Crohn's and Colitis Canada - Genetic, Environmental, Microbial (CCC-GEM) project. Regression models identified environmental factors associated with future CD onset and their association with pre-disease biological factors, including altered intestinal permeability measured by urinary fractional excretion of lactulose to mannitol ratio (LMR); gut inflammation via fecal calprotectin (FCP) levels; and fecal microbiome composition through 16S rRNA sequencing. RESULTS: Over a 5.62-year median follow-up, 86 FDRs developed CD. Living with a dog between ages 5 and 15 (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.40-0.96; P = .034), and living with a large family size in the first year of life (HR, 0.43; 95% CI, 0.21-0.85; P = .016) were associated with decreased CD risk, whereas having a bird at the time of recruitment (HR, 2.78; 95% CI, 1.36-5.68; P = .005) was associated with an increased CD risk. Furthermore, living with a dog was associated with reduced LMR, altered relative abundance of multiple bacterial genera, and increased Chao1 diversity, whereas bird owners had higher FCP levels. Large family during participants' first year of life was associated with altered microbiota composition without affecting FCP or LMR. CONCLUSION: This study identifies environmental variables associated with CD risk. These variables were also associated with altered barrier function, subclinical inflammation, and gut microbiome composition shifts, suggesting potential roles in CD pathogenesis.

Immune response and barrier dysfunction-related proteomic signatures in preclinical phase of Crohn's disease highlight earliest events of pathogenesis.

OBJECTIVE: The measure of serum proteome in the preclinical state of Crohn's disease (CD) may provide insight into biological pathways involved in CD pathogenesis. We aimed to assess associations of serum proteins with future CD onset and with other biomarkers predicting CD risk in a healthy at-risk cohort. DESIGN: In a nested case-control study within the Crohn's and Colitis Canada Genetics Environment Microbial Project (CCC-GEM) cohort, which prospectively follows healthy first-degree relatives (FDRs), subjects who developed CD (n=71) were matched with four FDRs remaining healthy (n=284). Using samples at recruitment, serum protein profiles using the Olink Proximity Extension Assay platform was assessed for association with future development of CD and with other baseline biomarkers as follows: serum antimicrobial antibodies (AS: positive antibody sum) (Prometheus); faecal calprotectin (FCP); gut barrier function using the fractional excretion of lactulose-to-mannitol ratio (LMR) assay. RESULTS: We identified 25 of 446 serum proteins significantly associated with future development of CD. C-X-C motif chemokine 9 (CXCL9) had the highest OR with future risk of CD (OR=2.07 per SD, 95% CI 1.58 to 2.73, q=7.9e-5), whereas matrix extracellular phosphoglycoprotein had the lowest OR (OR 0.44, 95% CI 0.29 to 0.66, q=0.02). Notably, CXCL9 was the only analyte significantly associated with all other CD-risk biomarkers with consistent direction of effect (FCP: OR=2.21; LMR: OR=1.67; AS: OR=1.59) (q<0.05 for all). CONCLUSION: We identified serum proteomic signatures associated with future CD development, reflecting potential early biological processes of immune and barrier dysfunction.

What is the Prevalence of Clinically Significant Endoscopic Findings in Subjects With Dyspepsia? Updated Systematic Review and Meta-analysis.

BACKGROUND & AIMS: The prevalence of clinically significant endoscopic findings in people with dyspepsia and understanding how symptoms can predict endoscopic pathology can help inform dyspepsia guidelines. We evaluated this in an updated systematic review and meta-analysis. METHODS: We searched MEDLINE, EMBASE, Cochrane CENTRAL, and the Cochrane Database of Systematic Reviews from 2010 through to January 2022 to identify relevant articles. Eligible studies enrolled adults from the community, workplace, blood donation or screening clinics, family physician offices, or internal medicine clinics. Studies were required to report prevalence of dyspepsia and perform esophagogastroduodenoscopy (EGD). Prevalence of clinically significant endoscopic findings in subjects with and without dyspepsia was pooled for all studies and compared using odds ratios and 95% confidence intervals (CIs). The data were pooled with those of the 9 studies included in the prior review. RESULTS: Of 511 papers evaluated, 184 reported prevalence of dyspepsia. Fifteen reported prevalence of endoscopic findings among 41,763 participants (40.4% with dyspepsia). Erosive esophagitis was the most common abnormality (pooled prevalence, 11.0%; 95% CI, 8.9%-13.2%) followed by peptic ulcer (pooled prevalence, 4.4%; 95% CI, 2.5%-6.7%). The only finding encountered more frequently in individuals with dyspepsia, compared with those without, was peptic ulcer (odds ratio, 1.61; 95% CI, 1.08-2.39). More than 85% of EGDs were completely normal. Gastroesophageal cancer was rare (<0.4%) and equally prevalent among those with and without dyspepsia. CONCLUSIONS: Erosive esophagitis was the most common clinically significant finding at EGD, whereas gastroesophageal cancers were rare. Most pathology, including esophagitis and cancer, were found in similar proportions in both groups. These findings support noninvasive approaches to managing dyspepsia in the community, with EGD reserved for those at high risk of malignancy.

Altered Gut Microbiome Composition and Function Are Associated With Gut Barrier Dysfunction in Healthy Relatives of Patients With Crohn's Disease.

BACKGROUND & AIMS: The gut microbiome has been suggested to play a role in gut barrier hemostasis, but data are scarce and limited to animal studies. We therefore aimed to assess whether alterations in gut microbial composition and functional pathways are associated with gut barrier function in a cohort of healthy first-degree relatives of patients with Crohn's disease. METHODS: We used the Crohn's and Colitis Canada Genetic Environmental Microbial (CCC-GEM) cohort of healthy first-degree relatives of patients with Crohn's disease. Gut barrier function was assessed using the urinary fractional excretion of lactulose-to-mannitol ratio (LMR). Microbiome composition was assessed by sequencing fecal 16S ribosomal RNA. The cohort was divided into a discovery cohort (n = 2472) and a validation cohort (n = 655). A regression model was used to assess microbial associations with the LMR. A random forest classifier algorithm was performed to assess microbial community contribution to barrier function. RESULTS: Individuals with impaired barrier function (LMR >0.025) had reduced alpha-diversity (Chao1 index, P = 4.0e-4) and altered beta-diversity (Bray-Curtis dissimilarity index, R2 = 0.001, P = 1.0e-3) compared with individuals with an LMR ≤0.025. When taxa were assessed individually, we identified 8 genera and 52 microbial pathways associated with an LMR >0.025 (q < 0.05). Four genera (decreased prevalence of Adlercreutzia, Clostridia UCG 014, and Clostridium sensu stricto 1 and increased abundance of Colidextribacter) and 8 pathways (including decreased biosynthesis of glutamate, tryptophan, and threonine) were replicated in the validation cohort. The random forest approach revealed that the bacterial community is associated with gut barrier function (area under the curve, 0.63; P = 1.4e-6). CONCLUSIONS: The gut microbiome community and pathways are associated with changes in gut barrier function. These findings may identify potential microbial targets to modulate gut barrier.

Mediterranean-Like Dietary Pattern Associations With Gut Microbiome Composition and Subclinical Gastrointestinal Inflammation.

BACKGROUND & AIMS: Case-control studies have shown that patients with Crohn's disease (CD) have a microbial composition different from healthy individuals. Although the causes of CD are unknown, epidemiologic studies suggest that diet is an important contributor to CD risk, potentially via modulation of bacterial composition and gut inflammation. We hypothesized that long-term dietary clusters (DCs) are associated with gut microbiome compositions and gut inflammation. Our objectives were to identify dietary patterns and assess whether they are associated with alterations in specific gut microbial compositions and subclinical levels of gut inflammation in a cohort of healthy first-degree relatives (FDRs) of patients with CD. METHODS: As part of the Genetic, Environmental, Microbial (GEM) Project, we recruited a cohort of 2289 healthy FDRs of patients with CD. Individuals provided stool samples and answered a validated food frequency questionnaire reflecting their habitual diet during the year before sample collection. Unsupervised analysis identified 3 dietary and 3 microbial composition clusters. RESULTS: DC3, resembling the Mediterranean diet, was strongly associated with a defined microbial composition, with an increased abundance of fiber-degrading bacteria, such as Ruminococcus, as well as taxa such as Faecalibacterium. The DC3 diet was also significantly associated with lower levels of subclinical gut inflammation, defined by fecal calprotectin, compared with other dietary patterns. No significant associations were found between individual food items and fecal calprotectin, suggesting that long-term dietary patterns rather than individual food items contribute to subclinical gut inflammation. Additionally, mediation analysis demonstrated that DC3 had a direct effect on subclinical inflammation that was partially mediated by the microbiota. CONCLUSIONS: Overall, these results indicated that Mediterranean-like dietary patterns are associated with microbiome and lower intestinal inflammation. This study will help guide future dietary strategies that affect microbial composition and host gut inflammation to prevent diseases.

Associations of Antibiotics, Hormonal Therapies, Oral Contraceptives, and Long-Term NSAIDS With Inflammatory Bowel Disease: Results From the Prospective Urban Rural Epidemiology (PURE) Study.

BACKGROUND & AIMS: Several medications have been suspected to contribute to the etiology of inflammatory bowel disease (IBD). This study assessed the association between medication use and the risk of developing IBD using the Prospective Urban Rural Epidemiology cohort. METHODS: This was a prospective cohort study of 133,137 individuals between the ages of 20 and 80 from 24 countries. Country-specific validated questionnaires documented baseline and follow-up medication use. Participants were followed up prospectively at least every 3 years. The main outcome was the development of IBD, including Crohn's disease (CD) and ulcerative colitis (UC). Short-term (baseline but not follow-up use) and long-term use (baseline and subsequent follow-up use) were evaluated. Results are presented as adjusted odds ratios (aORs) with 95% CIs. RESULTS: During a median follow-up period of 11.0 years (interquartile range, 9.2-12.2 y), there were 571 incident IBD cases (143 CD and 428 UC). Incident IBD was associated significantly with baseline antibiotic (aOR, 2.81; 95% CI, 1.67-4.73; P = .0001) and hormonal medication use (aOR, 4.43; 95% CI, 1.78-11.01; P = .001). Among females, previous or current oral contraceptive use also was associated with IBD development (aOR, 2.17; 95% CI, 1.70-2.77; P < .001). Nonsteroidal anti-inflammatory drug users also were observed to have increased odds of IBD (aOR, 1.80; 95% CI, 1.23-2.64; P = .002), which was driven by long-term use (aOR, 5.58; 95% CI, 2.26-13.80; P < .001). All significant results were consistent in direction for CD and UC with low heterogeneity. CONCLUSIONS: Antibiotics, hormonal medications, oral contraceptives, and long-term nonsteroidal anti-inflammatory drug use were associated with increased odds of incident IBD after adjustment for covariates.

Working to Answer the Effectiveness of Nutrition in IBD: Still a Ways to Go.

ABSTRACT: The Specific Carbohydrate diet (SCD) is an exclusion diet widely popular among patients with IBD, which restricts carbohydrates and processed foods. Two recently concluded controlled studies PRODUCE (Personalized Research on Diet in Ulcerative Colitis (UC) and Crohn's Disease) and DINE-CD (The Diet to Induce Remission in Crohn's disease) confirm efficacy of SCD on symptom control but fail to demonstrate a sustained anti-inflammatory response. These dietary studies are a welcome addition to a poorly understood field of dietary management of IBD, we explore some practical challenges including trial designs, recruitment, and retention in long term dietary intervention studies. Future dietary intervention studies should, therefore, incorporate endoscopic end points to establish a true anti-inflammatory response to elimination diets, preferably with detailed multi-omics analysis to understand mechanism of action.

Microbiota signatures and mucosal healing in the use of enteral nutrition therapy v. corticosteroids for the treatment of children with Crohn's disease: a systematic review and meta-analysis.

Corticosteroids (CS) and exclusive and partial enteral nutrition (EEN and PEN) are effective therapies in paediatric Crohn's disease (CD). This systematic review of randomised controlled trials (RCT) and cohort studies analyses the impact of EEN/PEN v. CS on intestinal microbiota, mucosal healing as well as other clinically important outcomes, including clinical remission, relapse, adherence, adverse events and health-related quality of life (HRQL) in paediatric CD. Three RCT (n 76) and sixteen cohort studies (n 1104) compared EEN v. CS. With limited available data (one RCT), the effect on intestinal microbiome indicated a trend towards EEN regarding Shannon diversity. Based on two RCT, EEN achieved higher mucosal healing than CS (risk ratio (RR) 2·36, 95 % CI (1·22, 4·57), low certainty). Compared with CS, patients on EEN were less likely to experience adverse events based on two RCT (RR 0·32, 95 % CI (0·13, 0·80), low certainty). For HRQL, there was a trend in favour of CS based on data from two published abstracts of cohort studies. Based on thirteen cohort studies, EEN achieved higher clinical remission than CS (RR 1·18, 95 % CI (1·02, 1·38), very low certainty). Studies also reported no important differences in relapse and adherence. Compared with CS, EEN may improve mucosal healing with fewer adverse events based on RCT data. While limited data indicate the need for further trials, this is the first systematic review to comprehensively summarise the data on intestinal microbiome, mucosal healing and HRQOL when comparing enteral nutrition and CS in paediatric CD.

Psychosocial factors associated with j-pouch surgery for patients with IBD: a scoping review.

BACKGROUND: Ulcerative colitis and Crohn's disease are subtypes of inflammatory bowel disease: a chronic condition of unclear etiology characterized by inflammation of the small and large intestine. Inflammatory bowel disease is managed with diet, medications, and surgeries, with the most common surgery, recommended to ulcerative colitis patients being j-pouch surgery. PURPOSE: To assess the current literature concerning psychosocial factors associated with j-pouch surgery for patients with inflammatory bowel disease. METHODS: A systematic scoping review of the empirical and grey literature was conducted for original research on j-pouch surgery and psychosocial variables. Eight databases were searched: Medline, PsychInfo, CINAHL, EBM Reviews, ProQuest Dissertations and Theses Global, ResearchGate, Prospero, and PrePubMed. RESULTS: Thirty-nine articles were identified. Many studies (n = 18) adopted a case-series design, and none examined psychosocial interventions. The most popular psychosocial variables assessed were quality of life (n = 34) and those associated with sexual health and functioning (n = 9). CONCLUSIONS: Despite being an established surgical procedure, little research has examined the psychosocial implications of j-pouch surgery. As such, clinicians lack a robust understanding of how this procedure affects patients' psychiatric and social status and adaptive abilities. There is a need for high-quality research utilizing validated measures and rigorous design methodologies with control populations.

Efficacy of Helicobacter pylori eradication therapy for functional dyspepsia: updated systematic review and meta-analysis.

OBJECTIVE: Functional dyspepsia (FD) is a chronic disorder that is difficult to treat. Helicobacter pylori may contribute to its pathophysiology. A Cochrane review from 2006 suggested that eradication therapy was beneficial, but there have been numerous randomised controlled trials (RCTs) published since. We evaluated impact of eradication therapy on both cure and improvement of FD, as well as whether any benefit was likely to arise from eradication of H. pylori. DESIGN: We searched the medical literature through October 2021 to identify RCTs examining efficacy of eradication therapy in H. pylori-positive adults with FD. The control arm received antisecretory therapy or prokinetics, with or without placebo antibiotics, or placebo alone. Follow-up was for ≥3 months. We pooled dichotomous data to obtain a relative risk (RR) of symptoms not being cured or symptoms not improving with a 95% CI. We estimated the number needed to treat (NNT). RESULTS: Twenty-nine RCTs recruited 6781 H. pylori-positive patients with FD. Eradication therapy was superior to control for symptom cure (RR of symptoms not being cured=0.91; 95% CI 0.88 to 0.94, NNT=14; 95% CI 11 to 21) and improvement (RR of symptoms not improving=0.84; 95% CI 0.78 to 0.91, NNT=9; 95% CI 7 to 17). There was no significant correlation between eradication rate and RR of FD improving or being cured (Pearson correlation coefficient=-0.23, p=0.907), but the effect was larger in patients with successful eradication of H. pylori than with unsuccessful eradication (RR=0.65; 95% CI 0.52 to 0.82, NNT=4.5, 95% CI 3 to 9). Adverse events (RR=2.19; 95% 1.10 to 4.37) and adverse events leading to withdrawal (RR=2.60; 95% CI 1.47 to 4.58) were more common with eradication therapy. CONCLUSION: There is high quality evidence to suggest that H. pylori eradication therapy leads to both cure and improvement in FD symptoms, although the benefit is modest.

Anti-Microbial Antibody Response is Associated With Future Onset of Crohn's Disease Independent of Biomarkers of Altered Gut Barrier Function, Subclinical Inflammation, and Genetic Risk.

BACKGROUND AND AIMS: Altered host immune reactivity to microbial antigens is hypothesized to trigger the onset of Crohn's disease (CD). We aimed to assess whether increased serum anti-microbial antibody response in asymptomatic first-degree relatives (FDRs) of CD patients is an independent risk factor for future CD development. METHODS: We measured host serum antibody response to 6 microbial antigens at enrollment (Prometheus enzyme-linked immunosorbent assay test: anti-Saccharomyces cerevisiae antibodies immunoglobulin A/immunoglobulin G, anti-OmpC, anti-A4-Fla2, anti-FlaX, anti-CBir1) and derived the sum of positive antibodies (AS). We used samples at enrollment of prospectively followed healthy FDRs from a nested case-control cohort of the Crohn's and Colitis Canada Genetics Environment Microbial Project. Those who later developed CD (n = 77) were matched 1:4 by age, sex, follow-up duration, and geographic location with control FDRs remaining healthy (n = 307). To address our research aims, we fitted a multivariable conditional logistic regression model and performed causal mediation analysis. RESULTS: High baseline AS (≥2) (43% of cases, 11% of controls) was associated with higher risk of developing CD (adjusted odds ratio, 6.5; 95% confidence interval, 3.4-12.7; P < .001). Importantly, this association remained significant when adjusted for markers of gut barrier function, fecal calprotectin, C-reactive protein, and CD-polygenic risk score, and in subjects recruited more than 3 years before diagnosis. Causal mediation analysis showed that the effect of high AS on future CD development is partially mediated (42%) via preclinical gut inflammation. CONCLUSIONS: Our results suggest that increased anti-microbial antibody responses are associated with risk of future development of CD, independent of biomarkers of abnormal gut barrier function, subclinical inflammation, and CD-related genetic risks. This suggests that anti-microbial antibody responses are an early predisease event in the development of CD.

Guidewire-assisted cannulation of the common bile duct for the prevention of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis.

BACKGROUND: Cannulation techniques have been recognized as being important in causing post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). However, considerable controversy exists about the usefulness of the guidewire-assisted cannulation technique for the prevention of PEP. OBJECTIVES: To assess the effectiveness and safety of the guidewire-assisted cannulation technique compared to the conventional contrast-assisted cannulation technique for the prevention of PEP in people undergoing diagnostic or therapeutic ERCP for biliary or pancreatic diseases. SEARCH METHODS: For the previous version of this review, we searched CENTRAL (the Cochrane Library), MEDLINE, Embase, CINAHL and major conference proceedings, up to February 2012, with no language restrictions. An updated search was performed on 26 February 2021 for the current version of this review. Two clinical trial registries, clinicaltrials.gov and WHO ICTRP, were also searched in this update. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing the guidewire-assisted cannulation technique versus the contrast-assisted cannulation technique in people undergoing ERCP. DATA COLLECTION AND ANALYSIS: Two review authors conducted study selection, data extraction, and methodological quality assessment independently. Using intention-to-treat analysis with random-effects models, we combined dichotomous data to obtain risk ratios (RR) with 95% confidence intervals (CI). We assessed heterogeneity using the Chi² test (P < 0.10) and I² statistic (> 50%). To explore sources of heterogeneity, we conducted a priori subgroup analyses according to trial design, publication type, risk of bias, use of precut sphincterotomy, inadvertent guidewire insertion or contrast injection of the pancreatic duct (PD), use of a PD stent, cannulation device, and trainee involvement in cannulation. To assess the robustness of our results, we carried out sensitivity analyses using different summary statistics (RR versus odds ratio (OR)) and meta-analytic models (fixed-effect versus random-effects) and per-protocol analysis. MAIN RESULTS: 15 RCTs comprising 4426 participants were included. There was moderate heterogeneity among trials for the outcome of PEP (P = 0.08, I² = 36%). Meta-analyses suggest that the guidewire-assisted cannulation technique probably reduces the risk of PEP compared to the contrast-assisted cannulation technique (RR 0.51, 95% CI 0.36 to 0.72, 15 studies, moderate-certainty evidence). In addition, the guidewire-assisted cannulation technique may result in an increase in primary cannulation success (RR 1.06, 95% CI 1.01 to 1.12, 13 studies, low-certainty evidence), and probably reduces the need for precut sphincterotomy (RR 0.79, 95% CI 0.64 to 0.96, 10 studies, moderate-certainty evidence). Compared to the contrast-assisted cannulation technique, the guidewire-assisted cannulation technique may result in little to no difference in the risk of post-sphincterotomy bleeding (RR 0.87, 95% CI 0.49 to 1.54, 7 studies, low-certainty evidence) and perforation (RR 0.93, 95% CI 0.11 to 8.23, 8 studies, very low-certainty evidence). Procedure-related mortality was reported by eight studies, and there were no cases of deaths in both arms (moderate-certainty evidence). Subgroup analyses suggest that the heterogeneity for the outcome of PEP could be explained by differences in trial design. The results were robust in sensitivity analyses. AUTHORS' CONCLUSIONS: There is moderate-certainty evidence that the guidewire-assisted cannulation technique probably reduces the risk of PEP compared to the contrast-assisted cannulation technique. There is low-certainty evidence that the guidewire-assisted cannulation technique may result in an increase in primary cannulation success. There is low- and very low-certainty evidence that the guidewire-assisted cannulation technique may result in little to no difference in the risk of bleeding and perforation. No procedure-related deaths were reported. Therefore, the guidewire-assisted cannulation technique appears to be superior to the contrast-assisted cannulation technique considering the certainty of evidence and the balance of benefits and harms. However, the routine use of guidewires in biliary cannulation will be dependent on local expertise, availability, and cost. Future research should assess the effectiveness and safety of the guidewire-assisted cannulation technique in the context of other pharmacologic or non-pharmacologic interventions for the prevention of PEP.

Proton pump inhibitor treatment initiated prior to endoscopic diagnosis in upper gastrointestinal bleeding.

BACKGROUND: Upper gastrointestinal (GI) bleeding is a common reason for emergency hospital admission. Proton pump inhibitors (PPIs) reduce gastric acid production and are used to manage upper GI bleeding. However, there is conflicting evidence regarding the clinical efficacy of proton pump inhibitors initiated before endoscopy in people with upper gastrointestinal bleeding. OBJECTIVES: To assess the effects of PPI treatment initiated prior to endoscopy in people with acute upper GI bleeding. SEARCH METHODS: We searched the CENTRAL, MEDLINE, Embase and CINAHL databases and major conference proceedings to October 2008, for the previous versions of this review, and in April 2018, October 2019, and 3 June 2021 for this update. We also contacted experts in the field and searched trial registries and references of trials for any additional trials. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) that compared treatment with a PPI (oral or intravenous) versus control treatment with either placebo, histamine-2 receptor antagonist (H2RA) or no treatment, prior to endoscopy in hospitalised people with uninvestigated upper GI bleeding. DATA COLLECTION AND ANALYSIS: At least two review authors independently assessed study eligibility, extracted study data and assessed risk of bias. Outcomes assessed at 30 days were: mortality (our primary outcome), rebleeding, surgery, high-risk stigmata of recent haemorrhage (active bleeding, non-bleeding visible vessel or adherent clot) at index endoscopy, endoscopic haemostatic treatment at index endoscopy, time to discharge, blood transfusion requirements and adverse effects. We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included six RCTs comprising 2223 participants. No new studies have been published after the literature search performed in 2008 for the previous version of this review. Of the included studies, we considered one to be at low risk of bias, two to be at unclear risk of bias, and three at high risk of bias. Our meta-analyses suggest that pre-endoscopic PPI use may not reduce mortality (OR 1.14, 95% CI 0.76 to 1.70; 5 studies; low-certainty evidence), and may reduce rebleeding (OR 0.81, 95% CI 0.62 to 1.06; 5 studies; low-certainty evidence). In addition, pre-endoscopic PPI use may not reduce the need for surgery (OR 0.91, 95% CI 0.65 to 1.26; 6 studies; low-certainty evidence), and may not reduce the proportion of participants with high-risk stigmata of recent haemorrhage at index endoscopy (OR 0.80, 95% CI 0.52 to 1.21; 4 studies; low-certainty evidence). Pre-endoscopic PPI use likely reduces the need for endoscopic haemostatic treatment at index endoscopy (OR 0.68, 95% CI 0.50 to 0.93; 3 studies; moderate-certainty evidence). There were insufficient data to determine the effect of pre-endoscopic PPI use on blood transfusions (2 studies; meta-analysis not possible; very low-certainty evidence) and time to discharge (1 study; very low-certainty evidence). There was no substantial heterogeneity amongst trials in any analysis. AUTHORS' CONCLUSIONS: There is moderate-certainty evidence that PPI treatment initiated before endoscopy for upper GI bleeding likely reduces the requirement for endoscopic haemostatic treatment at index endoscopy. However, there is insufficient evidence to conclude whether pre-endoscopic PPI treatment increases, reduces or has no effect on other clinical outcomes, including mortality, rebleeding and need for surgery. Further well-designed RCTs that conform to current standards for endoscopic haemostatic treatment and appropriate co-interventions, and that ensure high-dose PPIs are only given to people who received endoscopic haemostatic treatment, regardless of initial randomisation, are warranted. However, as it may be unrealistic to achieve the optimal information size, pragmatic multicentre trials may provide valuable evidence on this topic.

A patient-led, peer-to-peer qualitative study on the psychosocial relationship between young adults with inflammatory bowel disease and food.

BACKGROUND: Inflammatory bowel diseases (IBDs) are chronic gastrointestinal diseases that negatively affect the enjoyment of food and engagement in social and cultural gatherings. Such experiences may promote psychosocial challenges, an aspect of IBD often overlooked and under-supported in clinical settings and research. OBJECTIVES: This study explored the psychosocial experiences that young adults with IBD have with food via a qualitative patient-led research process. METHODS: Trained patient researchers conducted this study by engaging peers via semi-structured interviews and focus groups in a three-step co-design process. Participants (n = 9) identified the research topic (SET), explored the topic and identified emerging themes (COLLECT), refined themes and made recommendations for healthcare system change (REFLECT). RESULTS: Themes that emerged included: 'Experimenting with Food', 'Evolution Over Time', 'Diet Changes are Emotional' and 'Role of Stigma'. Participants identified the significance and frustrations of repeated testing and experimenting with food compatibility, and noted nuances in food relationships as they gain knowledge and experience over time. They emphasized the importance of maintaining a sense of hope throughout and wished to impart this to newly diagnosed patients. CONCLUSION: Participants experience numerous psychosocial challenges as they strive to manage their diet, noting gaps in support available from IBD practitioners. Participants made practical recommendations for healthcare system change to improve patient outcomes, highlighting the importance of sharing stories and collaboratively including patients in the development of new services and protocols. Authors recommend further research in this area to build a body of knowledge and support that helps IBD patients maintain hope while navigating challenges with food. PATIENT OR PUBLIC CONTRIBUTION: The first four authors on this paper were the lead researchers in this study's design and analysis and identify as patients; they conducted the research with this identity at the forefront following a peer-to-peer research model. These authors were mentored by patient researchers who also contributed to the manuscript, and the research process itself was co-lead and directed by other patient participants and consultants. Results and recommendations coming from this paper came directly from patient participants.

Germline variation in the insulin-like growth factor pathway and risk of Barrett's esophagus and esophageal adenocarcinoma.

Genome-wide association studies (GWAS) of esophageal adenocarcinoma (EAC) and its precursor, Barrett's esophagus (BE), have uncovered significant genetic components of risk, but most heritability remains unexplained. Targeted assessment of genetic variation in biologically relevant pathways using novel analytical approaches may identify missed susceptibility signals. Central obesity, a key BE/EAC risk factor, is linked to systemic inflammation, altered hormonal signaling and insulin-like growth factor (IGF) axis dysfunction. Here, we assessed IGF-related genetic variation and risk of BE and EAC. Principal component analysis was employed to evaluate pathway-level and gene-level associations with BE/EAC, using genotypes for 270 single-nucleotide polymorphisms (SNPs) in or near 12 IGF-related genes, ascertained from 3295 BE cases, 2515 EAC cases and 3207 controls in the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON) GWAS. Gene-level signals were assessed using Multi-marker Analysis of GenoMic Annotation (MAGMA) and SNP summary statistics from BEACON and an expanded GWAS meta-analysis (6167 BE cases, 4112 EAC cases, 17 159 controls). Global variation in the IGF pathway was associated with risk of BE (P = 0.0015). Gene-level associations with BE were observed for GHR (growth hormone receptor; P = 0.00046, false discovery rate q = 0.0056) and IGF1R (IGF1 receptor; P = 0.0090, q = 0.0542). These gene-level signals remained significant at q < 0.1 when assessed using data from the largest available BE/EAC GWAS meta-analysis. No significant associations were observed for EAC. This study represents the most comprehensive evaluation to date of inherited genetic variation in the IGF pathway and BE/EAC risk, providing novel evidence that variation in two genes encoding cell-surface receptors, GHR and IGF1R, may influence risk of BE.

Differences in Gut Microbiota in Patients With vs Without Inflammatory Bowel Diseases: A Systematic Review.

BACKGROUND & AIMS: Altering the intestinal microbiota has been proposed as a treatment for inflammatory bowel diseases (IBDs), but there are no established associations between specific microbes and IBD. We performed a systematic review to identify frequent associations. METHODS: We searched the MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials databases, through April 2, 2018 for studies that compared intestinal microbiota (from fecal or colonic or ileal tissue samples) among patients (adult or pediatric) with IBD vs healthy individuals (controls). The primary outcome was difference in specific taxa in fecal or intestinal tissue samples from patients with IBD vs controls. We used the Newcastle-Ottawa scale to assess the quality of studies included in the review. RESULTS: We identified 2631 citations; 48 studies from 45 articles were included in the analysis. Most studies evaluated adults with Crohn's disease or ulcerative colitis. All 3 studies of Christensenellaceae and Coriobacteriaceae and 6 of 11 studies of Faecalibacterium prausnitzii reported a decreased amount of those organisms compared with controls, whereas 2 studies each of Actinomyces, Veillonella, and Escherichia coli revealed an increased amount in patients with Crohn's disease. For patients with ulcerative colitis, Eubacterium rectale and Akkermansia were decreased in all 3 studies, whereas E coli was increased in 4 of 9 studies. The microbiota diversity was either decreased or not different in patients with IBD vs controls. Fewer than 50% of the studies stated comparable sexes and ages of cases and controls. CONCLUSIONS: In a systematic review, we found evidence for differences in abundances of some bacteria in patients with IBD vs controls, but we cannot make conclusions due to inconsistent results and methods among studies. Further large-scale studies, with better methods of assessing microbe populations, are needed.

Association Between Inflammatory Bowel Diseases and Celiac Disease: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: There is controversy over the association between celiac disease (CeD) and inflammatory bowel diseases (IBD). We performed a systematic review and meta-analysis to assess evidence for an association between CeD and IBD. METHODS: We searched databases including MEDLINE, EMBASE, CENTRAL, Web of Science, CINAHL, DARE, and SIGLE through June 25, 2019 for studies assessing the risk of CeD in patients with IBD, and IBD in patients with CeD, compared with controls of any type. We used the Newcastle-Ottawa Scale to evaluate the risk of bias and GRADE to assess the certainty of the evidence. RESULTS: We identified 9791 studies and included 65 studies in our analysis. Moderate certainty evidence found an increased risk of CeD in patients with IBD vs controls (risk ratio [RR] 3.96; 95% confidence interval [CI] 2.23-7.02) and increased risk of IBD in patients with CeD vs controls (RR 9.88; 95% CI 4.03-24.21). There was low-certainty evidence for the risk of anti-Saccharomyces antibodies, a serologic marker of IBD, in patients with CeD vs controls (RR 6.22; 95% CI 2.44-15.84). There was low-certainty evidence for no difference in risk of HLA-DQ2 or DQ8 in patients with IBD vs controls (RR 1.04; 95% CI 0.42-2.56), and very low-certainty evidence for an increased risk of anti-tissue transglutaminase in patients with IBD vs controls (RR 1.52; 95% CI 0.52-4.40). Patients with IBD had a slight decrease in risk of anti-endomysial antibodies vs controls (RR 0.70; 95% CI 0.18-2.74), but these results are uncertain. CONCLUSIONS: In a systematic review and meta-analysis, we found an increased risk of IBD in patients with CeD and increased risk of CeD in patients with IBD, compared with other patient populations. High-quality prospective cohort studies are needed to assess the risk of CeD-specific and IBD-specific biomarkers in patients with IBD and CeD.