Oral tryptophan activates duodenal aryl hydrocarbon receptor in healthy subjects: a crossover randomized controlled trial.

Tryptophan is an essential amino acid transformed by host and gut microbial enzymes into metabolites that regulate mucosal homeostasis through aryl hydrocarbon receptor (AhR) activation. Alteration of tryptophan metabolism has been associated with chronic inflammation; however, whether tryptophan supplementation affects the metabolite repertoire and AhR activation under physiological conditions in humans is unknown. We performed a randomized, double blind, placebo-controlled, crossover study in 20 healthy volunteers. Subjects on a low tryptophan background diet were randomly assigned to a 3-wk l-tryptophan supplementation (3 g/day) or placebo, and after a 2-wk washout switched to opposite interventions. We assessed gastrointestinal and psychological symptoms by validated questionnaires, AhR activation by cell reporter assay, tryptophan metabolites by liquid chromatography and high-resolution mass spectrometry, cytokine production in isolated monocytes by ELISA, and microbiota profile by 16S rRNA Illumina technique. Oral tryptophan supplementation was well tolerated, with no changes in gastrointestinal or psychological scores. Compared with placebo, tryptophan increased AhR activation capacity by duodenal contents, but not by feces. This was paralleled by higher urinary and plasma kynurenine metabolites and indoles. Tryptophan had a modest impact on fecal microbiome profiles and no significant effect on cytokine production. At the doses used in this study, oral tryptophan supplementation in humans induces microbial indole and host kynurenine metabolic pathways in the small intestine, known to be immunomodulatory. The results should prompt tryptophan intervention strategies in inflammatory conditions of the small intestine where the AhR pathway is impaired.NEW & NOTEWORTHY We demonstrate that in healthy subjects, orally administered tryptophan activates microbial indole and host kynurenine pathways in the small intestine, the primary metabolic site for dietary components, and the richest source of immune cells along the gut. This study provides novel insights in how to optimally activate immunomodulatory AhR pathways and indole metabolism in the small intestine, serving as basis for future therapeutic trials using l-tryptophan supplementation in chronic inflammatory conditions affecting the small intestine.

Biogeographic Variation and Functional Pathways of the Gut Microbiota in Celiac Disease.

BACKGROUND & AIMS: Genes and gluten are necessary but insufficient to cause celiac disease (CeD). Altered gut microbiota has been implicated as an additional risk factor. Variability in sampling site may confound interpretation and mechanistic insight, as CeD primarily affects the small intestine. Thus, we characterized CeD microbiota along the duodenum and in feces and verified functional impact in gnotobiotic mice. METHODS: We used 16S rRNA gene sequencing (Illumina) and predicted gene function (PICRUSt2) in duodenal biopsies (D1, D2 and D3), aspirates, and stool from patients with active CeD and controls. CeD alleles were determined in consented participants. A subset of duodenal samples stratified according to similar CeD risk genotypes (controls DQ2-/- or DQ2+/- and CeD DQ2+/-) were used for further analysis and to colonize germ-free mice for gluten metabolism studies. RESULTS: Microbiota composition and predicted function in CeD was largely determined by intestinal location. In the duodenum, but not stool, there was higher abundance of Escherichia coli (D1), Prevotella salivae (D2), and Neisseria (D3) in CeD vs controls. Predicted bacterial protease and peptidase genes were altered in CeD and impaired gluten degradation was detected only in mice colonized with CeD microbiota. CONCLUSIONS: Our results showed luminal and mucosal microbial niches along the gut in CeD. We identified novel microbial proteolytic pathways involved in gluten detoxification that are impaired in CeD but not in controls carrying DQ2, suggesting an association with active duodenal inflammation. Sampling site should be considered a confounding factor in microbiome studies in CeD.

Association of Celiac Disease and Inflammatory Bowel Disease: A Nationwide Register-Based Cohort Study.

INTRODUCTION: To determine the risk of inflammatory bowel disease (IBD) in patients with celiac disease (CeD) (and vice versa ) compared with general-population comparators. METHODS: Using Swedish histopathology and healthcare register data, we identified 48,551 patients with CeD and 83,529 with IBD diagnosed in 1969-2016. Each patient was compared with age- and sex-matched general-population comparators (CeD: n = 240,136; IBD: n = 408,195). Cox regression estimated hazard ratios (HRs) for IBD in patients with CeD and vice versa . Our main analyses were limited to events beyond the first year of follow-up to reduce potential surveillance bias. RESULTS: During follow-up, 784 (1.6%) patients with CeD were diagnosed with IBD compared with 1,015 (0.4%) matched comparators. In patients with CeD, the HR for IBD was 3.91 (95% confidence interval [CI] 3.56-4.31), with largely similar HRs for Crohn's disease (4.36; 3.72-5.11) and ulcerative colitis (3.40; 3.00-3.85). During follow-up, 644 (0.8%) patients with IBD and 597 (0.1%) comparators were diagnosed with CeD. The HR for CeD in patients with IBD was 5.49 (95% CI 4.90-6.16), with the highest risk estimates seen in ulcerative colitis (HR = 6.99; 6.07-8.05), and the HR for Crohn's disease was 3.31 (2.69-4.06). In patients with CeD and IBD, the diagnostic interval was usually <1 year; however, HRs of 3-4 were seen even after 10 years of follow-up. During 20 years of follow-up, 2.5% of patients with CeD developed incident IBD, and 1.3% of patients with IBD developed CeD. DISCUSSION: The bidirectional association between CeD diagnosis and IBD warrants attention in the initial assessment and follow-up of these conditions. Their co-occurrence, independent of temporal sequence, suggests shared etiology.

Real-World Gluten Exposure in Patients With Celiac Disease on Gluten-Free Diets, Determined From Gliadin Immunogenic Peptides in Urine and Fecal Samples.

BACKGROUND & AIMS: It is not clear how often patients who are on gluten-free diets (GFDs) for treatment of celiac disease still are exposed to gluten. We studied levels of gluten immunogenic peptides (GIP) in fecal and urine samples, collected over 4 weeks, from patients with celiac disease on a long-term GFD. METHODS: We performed a prospective study of 53 adults with celiac disease who had been on a GFD for more than 2 years (median duration, 8 y; interquartile range, 5-12 y) in Argentina. At baseline, symptoms were assessed by the celiac symptom index questionnaire. Patients collected stool each Friday and Saturday and urine samples each Sunday for 4 weeks. We used a commercial enzyme-linked immunosorbent assay to measure GIP in stool and point-of-care tests to measure GIP in urine samples. RESULTS: Overall, 159 of 420 stool and urine samples (37.9%) were positive for GIP; 88.7% of patients had at least 1 fecal or urine sample that was positive for GIP (median, 3 excretions). On weekends (urine samples), 69.8% of patients excreted GIP at least once, compared with 62.3% during weekdays (stool). The number of patients with a sample that was positive for GIP increased over the 4-week study period (urine samples in week 1 vs week 4: P < .05). Patients with symptoms had more weeks in which GIP was detected in stool than patients without symptoms (P < .05). The number of samples that were positive for GIP correlated with titers of deamidated gliadin peptide IgA in patients' blood samples, but not with levels of tissue transglutaminase. CONCLUSIONS: Patients with celiac disease on a long-term GFD still frequently are exposed to gluten. Assays to detect GIP in stool and urine might be used to assist dietitians in assessment of GFD compliance.

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.

Gluten-Free Diet Reduces Symptoms, Particularly Diarrhea, in Patients With Irritable Bowel Syndrome and Antigliadin IgG.

BACKGROUND & AIMS: Many patients with irritable bowel syndrome (IBS) perceive that their symptoms are triggered by wheat-containing foods. We assessed symptoms and gastrointestinal transit before and after a gluten-free diet (GFD) in unselected patients with IBS and investigated biomarkers associated with symptoms. METHODS: We performed a prospective study of 50 patients with IBS (ROME III, all subtypes), with and without serologic reactivity to gluten (antigliadin IgG and IgA), and 25 healthy subjects (controls) at a university hospital in Hamilton, Ontario, Canada, between 2012 and 2016. Gastrointestinal transit, gut symptoms, anxiety, depression, somatization, dietary habits, and microbiota composition were studied before and after 4 weeks of a GFD. HLA-DQ2/DQ8 status was determined. GFD compliance was assessed by a dietitian and by measuring gluten peptides in stool. RESULTS: There was no difference in symptoms among patients at baseline, but after the GFD, patients with antigliadin IgG and IgA reported less diarrhea than patients without these antibodies (P = .03). Compared with baseline, IBS symptoms improved in 18 of 24 patients (75%) with antigliadin IgG and IgA and in 8 of 21 patients (38%) without the antibodies. Although constipation, diarrhea, and abdominal pain were reduced in patients with antigliadin IgG and IgA, only pain decreased in patients without these antibodies. Gastrointestinal transit normalized in a higher proportion of patients with antigliadin IgG and IgA. Anxiety, depression, somatization, and well-being increased in both groups. The presence of antigliadin IgG was associated with overall reductions in symptoms (adjusted odds ratio compared with patients without this antibody, 128.9; 95% CI, 1.16-1427.8; P = .04). Symptoms were reduced even in patients with antigliadin IgG and IgA who reduced gluten intake but were not strictly compliant with the GFD. In controls, a GFD had no effect on gastrointestinal symptoms or gut function. CONCLUSIONS: Antigliadin IgG can be used as a biomarker to identify patients with IBS who might have reductions in symptoms, particularly diarrhea, on a GFD. Larger studies are needed to validate these findings. ClinicalTrials.gov: NCT03492333.

The Risk of Contracting COVID-19 Is Not Increased in Patients With Celiac Disease.

The World Health Organization declared coronavirus disease-2019 (COVID-19) a global pandemic in March 2020. Since then, there are more than 34 million cases of COVID-19 leading to more than 1 million deaths worldwide. Numerous studies suggest that celiac disease (CeD), a chronic immune-mediated gastrointestinal condition triggered by gluten, is associated with an increased risk of respiratory infections.1-3 However, how it relates to the risk of COVID-19 is unknown. To address this gap, we conducted a cross-sectional study to evaluate whether patients with self-reported CeD are at an increased risk of contracting COVID-19.

Probiotics for Celiac Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

INTRODUCTION: Many patients with celiac disease (CD) experience persistent symptoms despite adhering to the gluten-free diet. Different studies have assessed the use of probiotics as an adjuvant treatment for CD. We performed a systematic review and meta-analysis to evaluate the efficacy of probiotics in improving gastrointestinal (GI) symptoms and quality of life (QOL) in patients with CD. METHODS: We searched EMBASE, MEDLINE, CINAHL, Web of Science, CENTRAL, and DARE databases up to February 2019 for randomized controlled trials (RCTs) evaluating probiotics compared with placebo for treating CD. We collected data on GI symptoms, QOL, adverse events, serum tumor necrosis factor-α, intestinal permeability, and microbiota composition. RESULTS: We screened 2,831 records and found that 7 articles describing 6 RCTs (n = 279 participants) were eligible for quantitative analysis. Probiotics improved GI symptoms when assessed by the GI Symptoms Rating Scale (mean difference symptom reduction: -28.7%; 95% confidence interval [CI] -43.96 to -13.52; P = 0.0002). There was no difference in GI symptoms after probiotics when different questionnaires were pooled. The levels of Bifidobacteria increased after probiotics (mean difference: 0.85 log colony-forming units (CFU) per gram; 95% CI 0.38-1.32 log CFU per gram; P = 0.0003). There were insufficient data on tumor necrosis factor-a levels or QOL for probiotics compared with placebo. No difference in adverse events was observed between probiotics and placebo. The overall certainty of the evidence ranged from very low to low. DISCUSSION: Probiotics may improve GI symptoms in patients with CD. High-quality clinical trials are needed to improve the certainty in the evidence (see Visual abstract, Supplementary Digital Content 2, http://links.lww.com/AJG/B595).

Metabolomics reveals elevated urinary excretion of collagen degradation and epithelial cell turnover products in irritable bowel syndrome patients.

INTRODUCTION: Irritable bowel syndrome (IBS), the most commonly diagnosed functional gastrointestinal (GI) disorder in developed countries, is characterized by chronic abdominal pain, and altered bowel habits. OBJECTIVES: Accurate and timely diagnosis is challenging as it relies on symptoms and an evolving set of exclusion criteria to distinguish it from other related GI disorders reflecting a complex etiology that remains poorly understood. Herein, nontargeted metabolite profiling of repeat urine specimens collected from a cohort of IBS patients (n = 42) was compared to healthy controls (n = 20) to gain insights into the underlying pathophysiology. METHODS: An integrated data workflow for characterization of the urine metabolome with stringent quality control was developed to authenticate reliably measured (CV < 30%) and frequently detected (> 75%) metabolites using multisegment injection-capillary electrophoresis-mass spectrometry. Complementary statistical methods were then used to rank differentially excreted urinary metabolites after normalization to osmolality that were subsequently identified by high resolution tandem mass spectrometry and their electrophoretic migration behavior. RESULTS: Our work revealed ten consistently elevated urinary metabolites in repeat samples collected from IBS patients at two different time points (q < 0.05 after age and Benjamini-Hochberg/FDR adjustment), which were associated with greater collagen degradation and intestinal mucosal turn-over processes likely due to low-grade inflammation. IBS-specific metabolites identified in urine included a series of hydroxylysine metabolites (O-glycosylgalactosyl-hydroxylysine, O-galactosyl-hydroxylysine, lysine), mannopyranosy-L-tryptophan, imidazole propionate, glutamine, serine, ornithine, dimethylglycine and dimethylguanosine. A major limitation in this retrospective case-control study was significant co-morbidity of IBS patients with other illnesses, including depression and prescribed medications as compared to healthy controls. CONCLUSION: This work provides new mechanistic insights into the pathophysiology of IBS while also offering a convenient way to monitor patient disease progression and treatment responses to therapy based on a panel of urinary metabolites that avoids invasive blood sampling, colonoscopy and/or tissue biopsies.

Safety of Adding Oats to a Gluten-Free Diet for Patients With Celiac Disease: Systematic Review and Meta-analysis of Clinical and Observational Studies.

BACKGROUND & AIMS: Patients with celiac disease should maintain a gluten-free diet (GFD), excluding wheat, rye, and barley. Oats might increase the nutritional value of a GFD, but their inclusion is controversial. We performed a systematic review and meta-analysis to evaluate the safety of oats as part of a GFD in patients with celiac disease. METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE databases for clinical trials and observational studies of the effects of including oats in GFD of patients with celiac disease. The studies reported patients' symptoms, results from serology tests, and findings from histologic analyses. We used the GRADE approach to assess the quality of evidence. RESULTS: We identified 433 studies; 28 were eligible for analysis. Of these, 6 were randomized and 2 were not randomized controlled trials comprising a total of 661 patients-the remaining studies were observational. All randomized controlled trials used pure/uncontaminated oats. Oat consumption for 12 months did not affect symptoms (standardized mean difference: reduction in symptom scores in patients who did and did not consume oats, -0.22; 95% CI, -0.56 to 0.13; P = .22), histologic scores (relative risk for histologic findings in patients who consumed oats, 0.24; 95% CI, 0.01-4.8; P = .35), intraepithelial lymphocyte counts (standardized mean difference, 0.21; 95% CI, reduction of 1.44 to increase in 1.86), or results from serologic tests. Subgroup analyses of adults vs children did not reveal differences. The overall quality of evidence was low. CONCLUSIONS: In a systematic review and meta-analysis, we found no evidence that addition of oats to a GFD affects symptoms, histology, immunity, or serologic features of patients with celiac disease. However, there were few studies for many endpoints, as well as limited geographic distribution and low quality of evidence. Rigorous double-blind, placebo-controlled, randomized controlled trials, using commonly available oats sourced from different regions, are needed.

Probiotic Bifidobacterium longum NCC3001 Reduces Depression Scores and Alters Brain Activity: A Pilot Study in Patients With Irritable Bowel Syndrome.

BACKGROUND & AIMS: Probiotics can reduce symptoms of irritable bowel syndrome (IBS), but little is known about their effects on psychiatric comorbidities. We performed a prospective study to evaluate the effects of Bifidobacterium longum NCC3001 (BL) on anxiety and depression in patients with IBS. METHODS: We performed a randomized, double-blind, placebo-controlled study of 44 adults with IBS and diarrhea or a mixed-stool pattern (based on Rome III criteria) and mild to moderate anxiety and/or depression (based on the Hospital Anxiety and Depression scale) at McMaster University in Canada, from March 2011 to May 2014. At the screening visit, clinical history and symptoms were assessed and blood samples were collected. Patients were then randomly assigned to groups and given daily BL (n = 22) or placebo (n = 22) for 6 weeks. At weeks 0, 6, and 10, we determined patients' levels of anxiety and depression, IBS symptoms, quality of life, and somatization using validated questionnaires. At weeks 0 and 6, stool, urine and blood samples were collected, and functional magnetic resonance imaging (fMRI) test was performed. We assessed brain activation patterns, fecal microbiota, urine metabolome profiles, serum markers of inflammation, neurotransmitters, and neurotrophin levels. RESULTS: At week 6, 14 of 22 patients in the BL group had reduction in depression scores of 2 points or more on the Hospital Anxiety and Depression scale, vs 7 of 22 patients in the placebo group (P = .04). BL had no significant effect on anxiety or IBS symptoms. Patients in the BL group had a mean increase in quality of life score compared with the placebo group. The fMRI analysis showed that BL reduced responses to negative emotional stimuli in multiple brain areas, including amygdala and fronto-limbic regions, compared with placebo. The groups had similar fecal microbiota profiles, serum markers of inflammation, and levels of neurotrophins and neurotransmitters, but the BL group had reduced urine levels of methylamines and aromatic amino acids metabolites. At week 10, depression scores were reduced in patients given BL vs placebo. CONCLUSION: In a placebo-controlled trial, we found that the probiotic BL reduces depression but not anxiety scores and increases quality of life in patients with IBS. These improvements were associated with changes in brain activation patterns that indicate that this probiotic reduces limbic reactivity. ClinicalTrials.gov no. NCT01276626.

Management of bone health in patients with celiac disease: Practical guide for clinicians.

OBJECTIVE: To describe clinical issues related to bone health in patients with celiac disease (CD) and to provide guidance on monitoring bone health in these patients. SOURCES OF INFORMATION: A PubMed search was conducted to review literature relevant to CD and bone health, including guidelines published by professional gastroenterological organizations. MAIN MESSAGE: Bone health can be negatively affected in both adults and children with CD owing to the inflammatory process and malabsorption of calcium and vitamin D. Most adults with symptomatic CD at diagnosis have low bone mass. Bone mineral density should be tested at diagnosis and at follow-up, especially in adult patients. Vitamin D levels should be measured at diagnosis and annually until they are normal. In addition to a strict gluten-free diet, supplementation with calcium and vitamin D should be provided and weight-bearing exercises encouraged. CONCLUSION: Bone health can be adversely affected in patients with CD. These patients require adequate calcium and vitamin D supplementation, as well as monitoring of vitamin D levels and bone mineral density with regular follow-up to help prevent osteoporosis and fractures.

Minimal differences in prevalence and spectrum of organic disease at upper gastrointestinal endoscopy between selected secondary care patients with symptoms of gastro-oesophageal reflux or dyspepsia.

OBJECTIVES: Gastro-oesophageal reflux and dyspepsia are felt to be separate upper gastrointestinal (GI) conditions. We aimed to measure the degree of overlap between them, and assess whether endoscopic findings differed. MATERIAL AND METHODS: Demographic, symptom, upper GI endoscopy and histology data were collected from consecutive adults in secondary care. Patients were categorised according to whether they reported gastro-oesophageal reflux alone, dyspepsia alone or both, and patient demographics and endoscopic findings were compared. RESULTS: Of 1167 patients, 97 (8.3%) had gastro-oesophageal reflux alone, 571 (48.9%) dyspepsia alone, and 499 (42.8%) overlap. Patients with overlap symptoms were more likely to smoke, compared with those with gastro-oesophageal reflux alone, or dyspepsia alone (p = .009), but there were no other differences. Patients with gastro-oesophageal reflux alone or overlap had a higher prevalence of erosive oesophagitis (18.6% and 15.4% respectively, p < .001), but this was still the commonest diagnosis among those with dyspepsia alone (7.2%). No significant differences were seen in prevalence of other endoscopic findings. CONCLUSIONS: Gastro-oesophageal reflux and dyspepsia symptoms commonly overlap. There were minimal differences in demographics or spectrum of underlying organic disease between various symptom groups, suggesting that restrictive classifications according to predominant symptom may not be clinically useful.

Proton pump inhibitors for functional dyspepsia.

BACKGROUND: Functional dyspepsia (FD or non-ulcer dyspepsia) is defined as continuous or frequently recurring epigastric pain or discomfort for which no organic cause can be found. Acid suppressive therapy, including proton pump inhibitors (PPIs), has been proposed as a therapeutic option in FD, but its efficacy remains controversial. While PPIs are generally considered safe and well tolerated, they have been associated with adverse events, especially in the long term. For this reason, decisions on whether to initiate or continue PPI therapy should be made based on an appropriate clinical indication. Therefore, we conducted a systematic review to evaluate whether PPI therapy provides symptomatic relief in FD. OBJECTIVES: To determine the efficacy of proton pump inhibitors in the improvement of global symptoms of dyspepsia and quality of life compared to placebo, H2 receptor antagonists or prokinetics, in people with functional dyspepsia. SEARCH METHODS: We searched in the following electronic databases: the Cochrane Library (to January 2016), MEDLINE (OvidSP; to February 2016), Embase (OvidSP; to February 2016), and SIGLE grey literature (up to February 2016) and clinical trial registries; we handsearched abstracts from conferences up to February 2016. We screened non-systematic reviews, systematic reviews and guidelines to identify any additional trials. We contacted trialists to obtain missing information. SELECTION CRITERIA: All randomized controlled trials (RCTs) comparing any PPI with placebo, H2 receptor antagonists (H2RAs) or prokinetics for the treatment of FD. Participants were adults (aged 16 years or greater) with an adequate diagnosis of FD (any validated criteria such as Rome I, II, III or Lancet Working Group). DATA COLLECTION AND ANALYSIS: Two review authors independently assessed eligibility, trial quality and extracted data. We collected data on dyspeptic symptoms, quality of life and number of overall adverse events. Specific adverse events were beyond the scope of this review. MAIN RESULTS: We identified 23 RCTs from 22 papers (with 8759 participants) studying the effect of PPIs versus placebo, H2RAs or prokinetics for improvement of global symptoms of dyspepsia and quality of life in people with FD. Low-dose PPIs had similar efficacy as standard-dose PPIs, therefore we combined these subgroups for the analysis. Two to eight weeks of therapy with PPI was slightly more effective than placebo at relieving overall dyspepsia symptoms in people with FD (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.82 to 0.94; participants = 5968; studies = 16; number needed to treat for an additional beneficial outcome (NNTB) 13; moderate quality evidence). PPIs may be slightly more effective than H2RAs (RR 0.88, 95% CI 0.74 to 1.04; participants = 740; studies = 2, NNTB 13; low quality evidence), and slightly more effective than prokinetics (RR 0.90, 95% CI 0.81 to 1.00; participants = 892; studies = 4; NNTB 20; low quality evidence) at relieving overall dyspepsia symptoms in people with FD. PPIs plus prokinetics were possibly slightly more effective than PPIs alone at relieving overall dyspepsia symptoms (RR 0.85, 95% CI 0.68 to 1.08; participants = 407; studies = 2; NNTB 18; moderate quality evidence).The was no difference when subgrouped by Helicobacter pylori status, country of origin, or presence of reflux or Rome III subtypes. There were no differences in the number of adverse events observed between PPIs and any of the other treatments. AUTHORS' CONCLUSIONS: There is evidence that PPIs are effective for the treatment of FD, independent of the dose and duration of treatment compared with placebo. PPIs may be slightly more effective than H2RAs for the treatment of FD; however, the evidence is scarce. The trials evaluating PPIs versus prokinetics are difficult to interpret as they are at risk of bias. Although the effect of these drugs seems to be small, the drugs are well tolerated.

Proton pump inhibitors for functional dyspepsia.

BACKGROUND: Functional dyspepsia (FD or non-ulcer dyspepsia) is defined as continuous or frequently recurring epigastric pain or discomfort for which no organic cause can be found. Acid suppressive therapy, including proton pump inhibitors (PPIs), has been proposed as a therapeutic option in FD, but its efficacy remains controversial. While PPIs are generally considered safe and well tolerated, they have been associated with adverse events, especially in the long term. For this reason, decisions on whether to initiate or continue PPI therapy should be made based on an appropriate clinical indication. Therefore, we conducted a systematic review to evaluate whether PPI therapy provides symptomatic relief in FD. OBJECTIVES: To determine the efficacy of proton pump inhibitors in the improvement of global symptoms of dyspepsia and quality of life compared to placebo, H2 receptor antagonists or prokinetics, in people with functional dyspepsia. SEARCH METHODS: We searched in the following electronic databases: the Cochrane Library (to May 2017), MEDLINE (OvidSP; to May 2017), Embase (OvidSP; to May 2017), and SIGLE grey literature (up to May 2017) and clinical trial registries; we handsearched abstracts from conferences up to May 2017. We screened non-systematic reviews, systematic reviews and guidelines to identify any additional trials. We contacted trialists to obtain missing information. SELECTION CRITERIA: All randomized controlled trials (RCTs) comparing any PPI with placebo, H2 receptor antagonists (H2RAs) or prokinetics for the treatment of FD of at least two weeks' duration. Participants were adults (aged 16 years or greater) with an adequate diagnosis of FD (any validated criteria such as Rome I, II, III or Lancet Working Group). DATA COLLECTION AND ANALYSIS: Two review authors independently assessed eligibility and trial quality, and extracted data. We collected data on dyspeptic symptoms, quality of life and number of overall adverse events. Specific adverse events were beyond the scope of this review. MAIN RESULTS: We identified 25 RCTs from 27 papers (with 8453 participants) studying the effect of PPIs versus placebo, H2RAs or prokinetics for improvement of global symptoms of dyspepsia and quality of life in people with FD. Low-dose PPIs had similar efficacy as standard-dose PPIs, therefore we combined these subgroups for the analysis. PPI was more effective than placebo at relieving overall dyspepsia symptoms in people with FD (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.82 to 0.94; participants = 6172; studies = 18; number needed to treat for an additional beneficial outcome (NNTB) 11; moderate quality evidence). PPIs may have little or no effect compared with H2RAs (RR 0.88, 95% CI 0.74 to 1.04; participants = 740; studies = 2; low quality evidence), and may be slightly more effective than prokinetics (RR 0.89, 95% CI 0.81 to 0.99; participants = 1033; studies = 5; NNTB 16; low quality evidence) at relieving overall dyspepsia symptoms in people with FD. PPIs plus prokinetics have probably little or no effect compared with PPIs alone at relieving overall dyspepsia symptoms (RR 0.85, 95% CI 0.68 to 1.08; participants = 407; studies = 2; moderate quality evidence).There was no difference when subgrouped by Helicobacter pylori status, country of origin, or presence of reflux or Rome III subtypes. There were no differences in the number of adverse events observed between PPIs and any of the other treatments. There were fewer adverse events in the combination of PPI plus prokinetics compared to prokinetics alone (RR 0.60, 95% CI 0.39 to 0.93; participants = 407; studies = 2; moderate quality evidence). AUTHORS' CONCLUSIONS: There is evidence that PPIs are effective for the treatment of FD, independent of the dose and duration of treatment compared with placebo. PPIs may be slightly more effective than prokinetics for the treatment of FD; however, the evidence is scarce. The trials evaluating PPIs versus prokinetics are difficult to interpret as they are at risk of bias. Although the effect of these drugs seems to be small, the drugs are well tolerated.

Gluten Introduction to Infant Feeding and Risk of Celiac Disease: Systematic Review and Meta-Analysis.

OBJECTIVE: To assess the evidence regarding the effect of time of gluten introduction and breastfeeding on the risk of developing celiac disease (CD). STUDY DESIGN: We included randomized controlled trials and observational studies evaluating the proper timing for introducing gluten to the infant diet, the appropriate quantity of gluten consumption at weaning, and the effect of breastfeeding on CD risk. Studies were located through the electronic databases Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), EMBASE (Ovid), and System for Information on Grey Literature in Europe (SIGLE). Two independent authors collected the data. RESULTS: A total of 1982 studies were identified, 15 of which were eligible for data extraction. A meta-analysis was performed on 2 randomized controlled trials, 10 cohort studies, and 1 case-control study. There was a 25% increase in CD risk with late (>6 months) vs recommended (4-6 months) gluten introduction (risk ratio [RR], 1.25; 95% CI, 1.08-1.45). There was no significant effect of breastfeeding vs no breastfeeding on CD risk (OR, 0.55; 95% CI, 0.28-1.10), with substantial heterogeneity (I(2) = 92%) among studies. CONCLUSION: There is currently no evidence to support that early introduction of gluten to the infant diet increases the risk of CD; however, late introduction of gluten may be associated with increased risk of CD. More studies are needed that control for potential confounders and that evaluate environmental factors in low-risk families.

Anxiety and Depression Increase in a Stepwise Manner in Parallel With Multiple FGIDs and Symptom Severity and Frequency.

OBJECTIVES: Anxiety and depression occur frequently in patients with functional gastrointestinal disorders (FGIDs), but their precise prevalence is unknown. We addressed this issue in a large cohort of adult patients and determined the underlying factors. METHODS: In total, 4,217 new outpatients attending 2 hospitals in Hamilton, Ontario, Canada completed questionnaires evaluating FGIDs and anxiety and depression (Hospital Anxiety and Depression scale). Chart review was performed in a random sample of 2,400 patients. RESULTS: Seventy-six percent of patients fulfilled Rome III criteria for FGIDs, but only 57% were diagnosed with FGIDs after excluding organic diseases, and the latter group was considered for the analysis. Compared with patients not meeting the criteria, prevalence of anxiety (odds ratio (OR) 2.66, 95% confidence interval (CI): 1.62-4.37) or depression (OR 2.04, 95% CI: 1.03-4.02) was increased in patients with FGIDs. The risk was comparable to patients with organic disease (anxiety: OR 2.12, 95% CI: 1.24-3.61; depression: OR 2.48, 95% CI: 1.21-5.09). The lowest prevalence was observed in asymptomatic patients (OR 1.37; 95% CI 0.58-3.23 and 0.51; 95% CI 0.10-2.48; for both conditions, respectively). The prevalence of anxiety and depression increased in a stepwise manner with the number of co-existing FGIDs and frequency and/or severity of gastrointestinal (GI) symptoms. Psychiatric comorbidity was more common in females with FGIDs compared with males (anxiety OR 1.73; 95% CI 1.35-2.28; depression OR 1.52; 95% CI 1.04-2.21). Anxiety and depression were formally diagnosed by the consulting physician in only 22% and 9% of patients, respectively. CONCLUSIONS: Psychiatric comorbidity is common in patients referred to a secondary care center but is often unrecognized. The prevalence of both anxiety and depression is influenced by gender, presence of organic diseases, and FGIDs, and it increases with the number of coexistent FGIDs and frequency and severity of GI symptoms.

Motility alterations in celiac disease and non-celiac gluten sensitivity.

Regulation of gut motility is complex and involves neuromuscular, immune and environmental mechanisms. It is well established that patients with celiac disease (CD) often display gut dysmotility. Studies have shown the presence of disturbed esophageal motility, altered gastric emptying, and dysmotility of the small intestine, gallbladder and colon in untreated CD. Most of these motor abnormalities resolve after a strict gluten-free diet, suggesting that mechanisms related to the inflammatory condition and disease process are responsible for the motor dysfunction. Motility abnormalities are also a hallmark of functional bowel disorders such as irritable bowel syndrome (IBS), where it has been proposed as underlying mechanism for symptom generation (diarrhea, constipation, bloating). Non-celiac gluten sensitivity (NCGS) is a poorly defined entity, mostly self-diagnosed, that presents clinically with IBS symptoms in the absence of specific celiac markers. Patients with NCGS are believed to react symptomatically to wheat components, and some studies have proposed the presence of low-grade inflammation in these patients. There is little information regarding the functional characterization of these patients before and after a gluten-free diet. A study suggested the presence of altered gastrointestinal transit in NCGS patients who also have a high prevalence of nonspecific anti-gliadin antibodies. Results of an ongoing clinical study in NCGS patients with positive anti-gliadin antibodies before and after a gluten-free diet will be discussed. Elucidating the mechanisms for symptom generation in NCGS patients is important to find new therapeutic alternatives to the burden of imposing a strict gluten-free diet in patients who do not have CD.