Bitter-tasting drugs tune GDF15 and GLP-1 expression via bitter taste or motilin receptors in the intestine of patients with obesity.

OBJECTIVE: Growth differentiation factor 15 (GDF15), a stress related cytokine, was recently identified as a novel satiety signal acting via the GFRAL receptor located in the hindbrain. Bitter compounds are known to induce satiety via the release of glucagon-like peptide 1 (GLP-1) through activation of bitter taste receptors (TAS2Rs, 25 subtypes) on enteroendocrine cells in the gut. This study aimed to investigate whether and how bitter compounds induce a stress response in intestinal epithelial cells to affect GDF15 expression in patients with obesity, thereby facilitating satiety signaling from the gut. METHODS: The acute effect of oral intake of the bitter-containing medication Plaquenil (hydroxychloroquine sulfate) on plasma GDF15 levels was evaluated in a placebo-controlled, double-blind, randomized, two-visit crossover study in healthy volunteers. Primary crypts isolated from the jejunal mucosa from patients with obesity were stimulated with vehicle or bitter compounds, and the effect on GDF15 expression was evaluated using RT-qPCR or ELISA. Immunofluorescence colocalization studies were performed between GDF15, epithelial cell type markers and TAS2Rs. The role of TAS2Rs was tested by 1) pretreatment with a TAS2R antagonist, GIV3727; 2) determining TAS2R4/43 polymorphisms that affect taste sensitivity to TAS2R4/43 agonists. RESULTS: Acute intake of hydroxychloroquine sulfate increased GDF15 plasma levels, which correlated with reduced hunger scores and plasma ghrelin levels in healthy volunteers. This effect was mimicked in primary jejunal cultures from patients with obesity. GDF15 was expressed in enteroendocrine and goblet cells with higher expression levels in patients with obesity. Various bitter-tasting compounds (medicinal, plant extracts, bacterial) either increased or decreased GDF15 expression, with some also affecting GLP-1. The effect was mediated by specific intestinal TAS2R subtypes and the unfolded protein response pathway. The bitter-induced effect on GDF15/GLP-1 expression was influenced by the existence of TAS2R4 amino acid polymorphisms and TAS2R43 deletion polymorphisms that may predict patient's therapeutic responsiveness. However, the effect of the bitter-tasting antibiotic azithromycin on GDF15 release was mediated via the motilin receptor, possibly explaining some of its aversive side effects. CONCLUSIONS: Bitter chemosensory and pharmacological receptors regulate the release of GDF15 from human gut epithelial cells and represent potential targets for modulating metabolic disorders or cachexia.

Symptom profiles compatible with disorders of gut-brain interaction (DGBI) in organic gastrointestinal diseases: A global population-based study.

BACKGROUND: Patients with organic gastrointestinal (GI) diseases and diabetes mellitus (DM) can have concomitant disorders of gut-brain interaction (DGBI). OBJECTIVE: This study aimed to compare the global prevalence of DGBI-compatible symptom profiles in adults with and without self-reported organic GI diseases or DM. METHODS: Data were collected in a population-based internet survey in 26 countries, the Rome Foundation Global Epidemiology Study (n = 54,127). Individuals were asked if they had been diagnosed by a doctor with gastroesophageal reflux disease, peptic ulcer, coeliac disease, inflammatory bowel disease (IBD), diverticulitis, GI cancer or DM. Individuals not reporting the organic diagnosis of interest were included in the reference group. DGBI-compatible symptom profiles were based on Rome IV diagnostic questions. Odds ratios (ORs [95% confidence interval]) were calculated using mixed logistic regression models. RESULTS: Having one of the investigated organic GI diseases was linked to having any DGBI-compatible symptom profile ranging from OR 1.64 [1.33, 2.02] in GI cancer to OR 3.22 [2.80, 3.69] in IBD. Those associations were stronger than for DM, OR 1.26 [1.18, 1.35]. Strong links between organic GI diseases and DGBI-compatible symptom profiles were seen for corresponding (e.g., IBD and bowel DGBI) and non-corresponding (e.g., IBD and esophageal DGBI) anatomical regions. The strongest link was seen between fecal incontinence and coeliac disease, OR 6.94 [4.95, 9.73]. After adjusting for confounding factors, associations diminished, but persisted. CONCLUSION: DGBI-compatible symptom profiles are more common in individuals with self-reported organic GI diseases and DM compared to the general population. The presence of these concomitant DGBIs should be considered in the management of organic (GI) diseases.

The combination of L-menthol and caraway oil does not affect gastric function but increases hunger in healthy subjects.

BACKGROUND: The heterogeneous character of functional gastrointestinal disorders, recently renamed into disorders of gut-brain interaction, makes finding effective treatment options challenging. Compared to synthetic drugs, phytotherapy can have broader pharmacological effects and is often better tolerated. This study aimed to investigate the effect of peppermint oil and caraway oil (POCO) on gastric function and symptom levels in 32 healthy subjects in a single-blinded, placebo-controlled, randomized, parallel design. METHODS: Gastric emptying rate was assessed using a 13C-breath test. Intragastric pressure was measured using high-resolution manometry in fasted state and during intragastric infusion of a nutrient drink (350 mL or until full satiation). GI symptoms were rated on a 100 mm VAS. Data were analyzed using linear mixed models. KEY RESULTS: POCO had no effect on intragastric pressure in fasted or fed state (p > 0.08 for all). No significant differences in gastric emptying rate were observed (p = 0.54). In the fasted state, a stronger increase in hunger and decrease in satiety were observed following POCO (p = 0.016 and p = 0.008, respectively). No differences in hunger and satiety were observed in the fed state (p > 0.31 for all). POCO induced less epigastric burning, bloating, and fullness (p < 0.05 for all). CONCLUSIONS: Acute POCO administration did not affect gastric function in healthy subjects, but increased fasted hunger ratings. The effects of POCO on gastric function and hunger sensations in patients with disorders of gut-brain interaction, and the contribution to symptom improvement, needs to be elucidated in future studies.

10-year follow-up results of the European Achalasia Trial: a multicentre randomised controlled trial comparing pneumatic dilation with laparoscopic Heller myotomy.

OBJECTIVE: As achalasia is a chronic disorder, long-term follow-up data comparing different treatments are essential to select optimal clinical management. Here, we report on the 10-year follow-up of the European Achalasia Trial comparing endoscopic pneumodilation (PD) with laparoscopic Heller myotomy (LHM). DESIGN: A total of 201 newly diagnosed patients with achalasia were randomised to either a series of PDs (n=96) or LHM (n=105). Patients completed symptom (Eckardt score) and quality-of-life questionnaires, underwent functional tests and upper endoscopy. Primary outcome was therapeutic success defined as Eckardt score <3 at yearly follow-up. Secondary outcomes were the need for retreatment, lower oesophageal sphincter pressure, oesophageal emptying, gastro-oesophageal reflux and the rate of complications. RESULTS: After 10 years of follow-up, LHM (n=40) and PD (n=36) were equally effective in both the full analysis set (74% vs 74%, p=0.84) and the per protocol set (74% vs 86%, respectively, p=0.07). Subgroup analysis revealed that PD was superior to LHM for type 2 achalasia (p=0.03) while there was a trend, although not significant (p=0.05), that LHM performed better for type 3 achalasia. Barium column height after 5 min at timed barium oesophagram was significantly higher for patients treated with PD compared with LHM, while other parameters, including gastro-oesophageal reflux, were not different. CONCLUSIONS: PD and LHM are equally effective even after 10 years of follow-up with limited risk to develop gastro-oesophageal reflux. Based on these data, we conclude that PD and LHM can both be proposed as initial treatment of achalasia.

The Use of Peppermint Oil in Gastroenterology.

BACKGROUND: For decades, mint has been used worldwide for its relieving effects against gastrointestinal disturbances. Peppermint is a perennial herb common in Europe and North America. The active ingredient of peppermint oil is menthol and has various gastroenterological and non-gastroenterological uses, especially in the context of functional gastrointestinal disorders (FGIDs). METHODS: We conducted a literature search on the main medical databases for original articles, reviews, meta-analyses, randomized clinical trials, and case series using the following keywords and acronyms and their associations: peppermint oil, gastro-intestinal motility, irritable bowel syndrome, functional dyspepsia, gastrointestinal sensitivity and gastrointestinal endoscopy. RESULTS: Peppermint oil and its constituents exert smooth muscle relaxant and anti-spasmodic effects on the lower esophageal sphincter, stomach, duodenum, and large bowel. Moreover, peppermint oil can modulate visceral and central nervous system sensitivity. Taken together, these effects suggest using peppermint oil both for improved endoscopic performance and for treating functional dyspepsia and irritable bowel syndrome. Importantly, peppermint oil has an attractive safety profile compared to classical pharmacological treatments, especially in FGIDs. CONCLUSION: Peppermint oil is a safe herbal medicine therapy for application in gastroenterology, with promising scientific perspectives and rapidly expanding use in clinical practice.

The Efficacy of Peroral Endoscopic Myotomy vs Pneumatic Dilation as Treatment for Patients With Achalasia Suffering From Persistent or Recurrent Symptoms After Laparoscopic Heller Myotomy: A Randomized Clinical Trial.

BACKGROUND & AIMS: For patients with achalasia experiencing persistent or recurrent symptoms after laparoscopic Heller myotomy (LHM), pneumatic dilation (PD) is the most frequently used treatment. Per-oral endoscopic myotomy (POEM) is increasingly being investigated as rescue therapy. This study aimed to determine the efficacy of POEM vs PD for patients with persistent or recurrent symptoms after LHM. METHODS: This randomized multicenter controlled trial included patients after LHM with an Eckardt score >3 and substantial stasis (≥2 cm) on timed barium esophagogram and randomized to POEM or PD. The primary outcome was treatment success, defined as an Eckardt score of ≤3 and without unscheduled re-treatment. Secondary outcomes included the presence of reflux esophagitis, high-resolution manometry, and timed barium esophagogram findings. Follow-up duration was 1 year after initial treatment. RESULTS: Ninety patients were included. POEM had a higher success rate (28 of 45 patients [62.2%]) than PD (12 of 45 patients [26.7%]; absolute difference, 35.6%; 95% CI, 16.4%-54.7%; P = .001; odds ratio, 0.22; 95% CI, 0.09-0.54; relative risk for success, 2.33; 95% CI, 1.37-3.99). Reflux esophagitis was not significantly different between POEM (12 of 35 [34.3%]) and PD (6 of 40 [15%]). Basal lower esophageal sphincter pressure and integrated relaxation pressure (IRP-4) were significantly lower in the POEM group (P = .034; P = .002). Barium column height after 2 and 5 minutes was significantly less in patients treated with POEM (P = .005; P = .015). CONCLUSIONS: Among patients with achalasia experiencing persistent or recurrent symptoms after LHM, POEM resulted in a significantly higher success rate than PD, with a numerically higher incidence of grade A-B reflux esophagitis. NETHERLANDS TRIAL REGISTRY: NL4361 (NTR4501), https://trialsearch.who.int/Trial2.aspx?TrialID = NTR4501.

Using high resolution manometry impedance to diagnose upper esophageal sphincter and pharyngeal motor disorders.

BACKGROUND: Oro-pharyngeal pathophysiology, including upper esophageal sphincter (UES) and pharyngeal disorders, can be assessed by pharyngeal high-resolution manometry impedance (P-HRM-I). We aimed to establish methodology to diagnose disorders utilizing P-HRM-I, hypothesizing that the objective measures could be used to diagnose disordered deglutition evidenced by greater aspiration scores. METHODS: Patients (n = 509, 18-91 years) were compared to controls (n = 120, 20-94 years). Variables measuring UES relaxation, UES opening extent, intrabolus pressure, and pharyngeal contractile strength were derived for 10 ml liquid swallows. Three associated pharyngeal pressurization patterns, which may be indicative of obstructed flow, were characterized: pan-pressurization (Type 1), distal compartmentalized pressurization (Type 2), and transient pressurization (Type 3). Deglutitive aspiration was determined from video fluoroscopy. RESULTS: UES relaxation pressure was best able to differentiate patients from controls (T 6.528, p < 0.0001). Patients with abnormal relaxation pressure (>8 mmHg) more frequently exhibited pharyngeal pressurization patterns and had adjunct evidence of reduced luminal distensibility (high intrabolus pressure and/or reduced UES opening). Utilizing this information, a diagnostic scheme was devised identifying 138 patients with UES disorder. A further 96 patients without evidence of UES disorder had abnormally weak pharyngeal pressures, confirming propulsive disorder. Amongst a sub-sample of 320 patients undergoing video fluoroscopy, those with pharyngeal pressurizations and adjunct evidence of reduced UES relaxation and/or distensibility had higher aspiration scores (Chi-square 60.169, p < 0.0001). CONCLUSION: P-HRM-I can provide evidence for UES disorder based on pharyngeal pressurization patterns and abnormal findings for UES relaxation pressure, UES opening, and intrabolus pressure. Measuring pharyngeal contractility requires further optimization.

Fecal Microbiota Transplantation in NAFLD Treatment.

Introduction: Gut microbiota is not only a taxonomic biologic ecosystem but is also involved in human intestinal and extra-intestinal functions such as immune system modulation, nutrient absorption and digestion, as well as metabolism regulation. The latter is strictly linked to non-alcoholic fatty liver disease (NAFLD) pathophysiology. Materials and methods: We reviewed the literature on the definition of gut microbiota, the concepts of "dysbiosis" and "eubiosis", their role in NAFLD pathogenesis, and the data on fecal microbiota transplantation (FMT) in these patients. We consulted the main medical databases using the following keywords, acronyms, and their associations: gut microbiota, eubiosis, dysbiosis, bile acids, NAFLD, and FMT. Results: Gut microbiota qualitative and quantitative composition is different in healthy subjects vs. NALFD patients. This dysbiosis is associated with and involved in NAFLD pathogenesis and evolution to non-acoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma (HCC). In detail, microbial-driven metabolism of bile acids (BAs) and interaction with hepatic and intestinal farnesoid nuclear X receptor (FXR) have shown a determinant role in liver fat deposition and the development of fibrosis. Over the use of pre- or probiotics, FMT has shown preclinical and initial clinical promising results in NAFLD treatment through re-modulation of microbial dysbiosis. Conclusions: Promising clinical data support a larger investigation of gut microbiota dysbiosis reversion through FMT in NAFLD using randomized clinical trials to design precision-medicine treatments for these patients at different disease stages.

Concise Review: Applicability of High-resolution Manometry in Gastroesophageal Reflux Disease.

Manometry, particularly high-resolution manometry is the preferred diagnostic tool used to evaluate esophageal motor function. This investigation is strongly indicated in the setting of dysphagia, but is also useful in gastroesophageal reflux disease (GERD), especially in case of failure of conventional treatment to exclude alternative diagnoses and prior to anti-reflux surgery. Moreover, ineffective esophagogastric junction barrier function and esophageal motor dysfunction are pathophysiological mechanisms in GERD and can be identified by manometry. The recent international guidelines have positioned high-resolution manometry as an important part of functional diagnostic work up in GERD in order to identify the GERD phenotype to guide specific treatment. The proposed manometric identification and measurement is based on the Chicago classification version 4.0 adding with new established metrics for GERD evaluation.

Exploring the pathophysiology of LARS after low anterior resection for rectal cancer with high-resolution colon manometry.

BACKGROUND: A total mesorectal excision for rectal cancer-although nerve- and sphincter-sparing-can give rise to significant bowel symptoms, commonly referred to as low anterior resection syndrome (LARS). The exact pathophysiology of this syndrome still remains largely unknown, and the impact of radical surgery on colonic motility has only been scarcely investigated. METHODS: High-resolution colon manometry was performed in patients, 12-24 months after restoration of transit. Patients were divided into two groups: patients with major LARS and no/minor LARS, according to the LARS-score. Colonic motor patterns were compared, and the relationship of these patterns with the LARS-scores was investigated. KEY RESULTS: Data were analyzed in 18 patients (9 no/minor LARS, 9 major LARS). Cyclic short antegrade motor patterns did occur more in patients with major LARS (total: p = 0.022; post-bisacodyl: p = 0.004) and were strongly correlated to LARS-scores after administering bisacodyl (p < 0.001). High amplitude propagating contractions (HAPC's) that started in the proximal colon and ended in the mid-section of the colon occurred significantly less in patients with major LARS compared with patients with no/minor LARS (p = 0.015). CONCLUSIONS AND INFERENCES: The occurrence of more cyclic short antegrade motor patterns and less HAPC's (from the proximal to the mid-colon) is more prevalent in patients with major LARS. These findings help to understand the differences in pathophysiology in patients developing major versus no/minor bowel complaints after TME for rectal cancer.

Functional bowel disorders with diarrhoea: Clinical guidelines of the United European Gastroenterology and European Society for Neurogastroenterology and Motility.

Irritable bowel syndrome with diarrhoea (IBS-D) and functional diarrhoea (FDr) are the two major functional bowel disorders characterized by diarrhoea. In spite of their high prevalence, IBS-D and FDr are associated with major uncertainties, especially regarding their optimal diagnostic work-up and management. A Delphi consensus was performed with experts from 10 European countries who conducted a literature summary and voting process on 31 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation criteria. Consensus (defined as >80% agreement) was reached for all the statements. The panel agreed with the potential overlapping of IBS-D and FDr. In terms of diagnosis, the consensus supports a symptom-based approach also with the exclusion of alarm symptoms, recommending the evaluation of full blood count, C-reactive protein, serology for coeliac disease, and faecal calprotectin, and consideration of diagnosing bile acid diarrhoea. Colonoscopy with random biopsies in both the right and left colon is recommended in patients older than 50 years and in presence of alarm features. Regarding treatment, a strong consensus was achieved for the use of a diet low fermentable oligo-, di-, monosaccharides and polyols, gut-directed psychological therapies, rifaximin, loperamide, and eluxadoline. A weak or conditional recommendation was achieved for antispasmodics, probiotics, tryciclic antidepressants, bile acid sequestrants, 5-hydroxytryptamine-3 antagonists (i.e. alosetron, ondansetron, or ramosetron). A multinational group of European experts summarized the current state of consensus on the definition, diagnosis, and management of IBS-D and FDr.

Achalasia.

Achalasia is a rare disorder of the oesophageal smooth muscle characterized by impaired relaxation of the lower oesophageal sphincter (LES) and absent or spastic contractions in the oesophageal body. The key pathophysiological mechanism is loss of inhibitory nerve function that probably results from an autoimmune attack targeting oesophageal myenteric nerves through cell-mediated and, possibly, antibody-mediated mechanisms. Achalasia incidence and prevalence increase with age, but the disorder can affect all ages and both sexes. Cardinal symptoms consist of dysphagia, regurgitation, chest pain and weight loss. Several years can pass between symptom onset and an achalasia diagnosis. Evaluation starts with endoscopy to rule out structural causes, followed by high-resolution manometry and/or barium radiography. Functional lumen imaging probe can provide complementary evidence. Achalasia subtypes have management and prognostic implications. Although symptom questionnaires are not useful for diagnosis, the Eckardt score is a simple symptom scoring scale that helps to quantify symptom response to therapy. Oral pharmacotherapy is not particularly effective. Botulinum toxin injection into the LES can temporize symptoms and function as a bridge to definitive therapy. Pneumatic dilation, per-oral endoscopic myotomy and laparoscopic Heller myotomy can provide durable symptom benefit. End-stage achalasia with a dilated, non-functioning oesophagus may require oesophagectomy or enteral feeding into the stomach. Long-term complications can, rarely, include oesophageal cancer, but surveillance recommendations have not been established.

Endoscopic pyloromyotomy for the treatment of severe and refractory gastroparesis: a pilot, randomised, sham-controlled trial.

OBJECTIVE: Endoscopic pyloromyotomy (G-POEM) is a minimally invasive treatment option with promising uncontrolled outcome results in patients with gastroparesis. DESIGN: In this prospective randomised trial, we compared G-POEM with a sham procedure in patients with severe gastroparesis. The primary outcome was the proportion of patients with treatment success (defined as a decrease in the Gastroparesis Cardinal Symptom Index (GCSI) by at least 50%) at 6 months. Patients randomised to the sham group with persistent symptoms were offered cross-over G-POEM. RESULTS: The enrolment was stopped after the interim analysis by the Data and Safety Monitoring Board prior to reaching the planned sample of 86 patients. A total of 41 patients (17 diabetic, 13 postsurgical, 11 idiopathic; 46% male) were randomised (21 G-POEM, 20-sham). Treatment success rate was 71% (95% CI 50 to 86) after G-POEM versus 22% (8-47) after sham (p=0.005). Treatment success in patients with diabetic, postsurgical and idiopathic gastroparesis was 89% (95% CI 56 to 98), 50% (18-82) and 67% (30-90) after G-POEM; the corresponding rates in the sham group were 17% (3-57), 29% (7-67) and 20% (3-67).Median gastric retention at 4 hours decreased from 22% (95% CI 17 to 31) to 12% (5-22) after G-POEM and did not change after sham: 26% (18-39) versus 24% (11-35). Twelve patients crossed over to G-POEM with 9 of them (75%) achieving treatment success. CONCLUSION: In severe gastroparesis, G-POEM is superior to a sham procedure for improving both symptoms and gastric emptying 6 months after the procedure. These results are not entirely conclusive in patients with idiopathic and postsurgical aetiologies. TRIAL REGISTRATION NUMBER: NCT03356067; ClinicalTrials.gov.

Estrogens Play a Critical Role in Stress-Related Gastrointestinal Dysfunction in a Spontaneous Model of Disorders of Gut-Brain Interaction.

BACKGROUND: Disorders of the gut-brain interaction (DGBI), such as irritable bowel syndrome and functional dyspepsia, are more prevalent in women than in men, with a ratio of 2:1. Furthermore, stressful life events have been reported as one of the triggers for symptoms in DGBI patients. METHODS: Here, we studied the effect of an early-life stressor (maternal separation (MS)) on jejunal and colonic alterations, including colonic sensitivity and immune cells infiltration and activation in a validated spontaneous model of DGBI (BBDP-N), and investigated the involvement of ß-estradiol on stress-worsened intestinal alterations. RESULTS: We found that maternal separation exacerbated colonic sensitivity and mast cell and eosinophil infiltration and activation in females only. Ovariectomy partially rescued the stress phenotype by decreasing colonic sensitivity, which was restored by ß-estradiol injections and did not impact immune cells infiltration and activation. Stressed males exposed to ß-estradiol demonstrated similar intestinal alterations as MS females. CONCLUSION: Estrogen plays a direct critical role in colonic hypersensitivity in a spontaneous animal model of DGBI, while for immune activation, estrogen seems to be involved in the first step of their recruitment and activation. Our data point towards a complex interaction between stress and ß-estradiol in DGBI.

A Prospective, Real-World, Multinational Study of Naloxegol for Patients with Cancer Pain Diagnosed with Opioid-Induced Constipation-The NACASY Study.

The Naloxegol Cancer Study (NACASY) was a multinational European study aimed to evaluate the 4-week safety and efficacy of naloxegol in a real-world setting in patients with cancer pain diagnosed with opioid-induced constipation. The primary safety endpoint was the incidence of adverse events leading to study discontinuation. We recruited 170 patients who received at least one dose of naloxegol (i.e., safety population). Out of 170 patients, 20 (11.8%, 95%CI 6.9-16.6) discontinued the study due to adverse events, and, of them, 12 (7.1%, 95%CI 3.2-10.9%) were study discontinuations due to naloxegol-related adverse events. From 76 patients subjects who had completed both 4 weeks of treatment and 28 days of the diary, 55 patients (72.4%, 95% CI 62.3-82.4%) were regarded as responders (i.e., showed ≥3 bowel-movements per week and an increase of ≥1 bowel-movement over baseline) to naloxegol treatment. The Patient Assessment of Constipation-Quality of Life Questionnaire total score and all its subscales improved from baseline to 4 weeks of follow up. Our findings support and provide new evidence about the beneficial effect of naloxegol in terms of improvement of constipation and quality-of-life in patients with cancer-related pain and opioid-induced constipation and show a safety profile consistent with previous pivotal and real-world studies.

Gut-brain axis dysfunction underlies FODMAP-induced symptom generation in irritable bowel syndrome.

BACKGROUND: FODMAPs produce similar small bowel water and colonic gas in patients with irritable bowel syndrome (IBS) and healthy controls (HCs), despite IBS patients reporting increased gastrointestinal (GI) symptoms. AIM: To unravel the mechanisms underlying FODMAP-induced symptom reporting, we investigated gut and brain responses to fructan administration in IBS patients and HC. METHODS: This randomised, double-blind, cross-over study consisted of three visits where fructans (40 g/500 mL saline), glucose (40 g/500 mL saline) or saline (500 mL) were infused intragastrically during 1 h MR brain scanning; abdominal MRI was performed before, 1 h, and 2 h post-infusion. Symptoms were rated using validated scales. RESULTS: In IBS (n = 13), fructans induced more cramps, pain, flatulence and nausea compared to glucose (P = 0.03, 0.001, 0.009 and <0.001 respectively), contrary to HC (n = 13) (all P > 0.14), with between-group differences for cramps and nausea (P = 0.004 and 0.023). Fructans increased small bowel motility and ascending colonic gas and volume equally in IBS and HC (between-group P > 0.25). The difference in colonic gas between fructans and saline covaried with differences in bloating and cramps in IBS (P = 0.008 and 0.035 respectively). Pain-related brain regions responded differentially to fructans in IBS compared to HC, including the cerebellum, supramarginal gyrus, anterior and midcingulate cortex, insula and thalamus (pFWE-corrected  < 0.05); these brain responses covaried with symptom responses in IBS. CONCLUSIONS: Fructans increase small bowel motility and colon gas and volume similarly in IBS patients and HC. Increased symptom responses to fructans in IBS covary with altered brain responses in pain-related regions, indicating that gut-brain axis dysregulation may drive FODMAP-induced symptom generation in IBS.

Pneumatic dilation for persistent dysphagia after antireflux surgery, a multicentre single-blind randomised sham-controlled clinical trial.

OBJECTIVE: There is no evidence-based treatment for persistent dysphagia after laparoscopic fundoplication. The aim of this study was to evaluate the effect of pneumatic dilation on persistent dysphagia after laparoscopic fundoplication. DESIGN: We performed a multicentre, single-blind, randomised sham-controlled trial of patients with persistent dysphagia (>3 months) after laparoscopic fundoplication. Patients with an Eckardt symptom score ≥4 were randomly assigned to pneumatic dilation (PD) using a 35 mm balloon or sham dilation. Primary outcome was treatment success, defined as an Eckardt score <4 and a minimal reduction of 2 points in the Eckardt score after 30 days. Secondary outcomes included change in stasis on timed barium oesophagogram, change in high-resolution manometry parameters and questionnaires on quality of life, reflux and dysphagia symptoms. RESULTS: Forty-two patients were randomised. In the intention-to-treat analysis, the success rates of PD (7/21 patients (33%)) and sham dilation (8/21 patients (38%)) were similar after 30 days (risk difference -4.7% (95% CI (-33.7% to 24.2%) p=0.747). There was no significant difference in change of stasis on the timed barium oesophagogram after 2 min (PD vs sham: median 0.0 cm, p25-p75 range 0.0-4.3 cm vs median 0.0 cm, p25-p75 range 0.0-0.0; p=0.122) or change in lower oesophageal sphincter relaxation pressure (PD vs sham: 10.54±6.25 vs 14.60±6.17 mm Hg; p=0.052). Quality of life, reflux and dysphagia symptoms were not significantly different between the two groups. CONCLUSION: Pneumatic dilation with a 35 mm balloon is not superior to sham dilation for the treatment of persistent dysphagia after fundoplication.

High-resolution colonic manometry interobserver analysis trial.

INTRODUCTION: Colonic high-resolution manometry (HRM) is a novel, not widely used diagnostic method used in the final workup of chronic constipation before surgery. Since its introduction, different motor patterns have been defined. However, it remains to be established whether these patterns are easily and reproducibly identified by different investigators. METHODS: The primary aim of this study was to determine agreement for motor pattern identification with HRM. To calculate the interobserver agreement (IOA), the Fleiss's kappa statistic for multiple observers was used. Seven participants analyzed 106 one-min time frames, derived from five measurements in healthy volunteers and five in patients with chronic constipation. The time frames were chosen to show a variety and combination of motor patterns consisting of short antegrade, short retrograde, cyclic anterograde, cyclic retrograde, long antegrade, long retrograde, slow retrograde motor pattern, high-amplitude propagating motor patterns, and pancolonic pressurizations. All of the measurements were performed with a solid-state colonic HRM catheter, comprising 40 pressure sensors spaced 2.5 cm apart. RESULTS: A median of 10.25 h (range 6-20) were required to analyze all time frames. High-amplitude propagating contractions achieved an almost perfect level of agreement (k = 0.91). Several motor patterns achieved substantial agreement; these included the short antegrade (k = 0.63), long antegrade (k = 0.68), cyclic retrograde (k = 0.70), slow retrograde motor pattern (k = 0.80), and abdominal pressure or movement artifacts (k = 0.67). Moderate agreement was found for short retrograde (k = 0.57), cyclic anterograde (k = 0.59), long retrograde motor patterns (k = 0.59) and simultaneous pressure waves (k = 0.59). CONCLUSION: For the majority of motor patterns, the overall IOA for colonic manometry was substantial or high. This high level of agreement supports the use of colonic manometry application in clinical and research settings. Harmonization has the potential to improve agreement for long anterograde motor patterns with high amplitudes and for mixed direction patterns.

Human intestinal bitter taste receptors regulate innate immune responses and metabolic regulators in obesity.

Bitter taste receptors (taste 2 receptors, TAS2Rs) serve as warning sensors in the lingual system against the ingestion of potentially poisonous food. Here, we investigated the functional role of TAS2Rs in the human gut and focused on their potential to trigger an additional host defense pathway in the intestine. Human jejunal crypts, especially those from individuals with obesity, responded to bitter agonists by inducing the release of antimicrobial peptides (α-defensin 5 and regenerating islet-derived protein 3 α [REG3A]) but also regulated the expression of other innate immune factors (mucins, chemokines) that affected E. coli growth. We found that the effect of aloin on E. coli growth and on the release of the mucus glycoprotein CLCA1, identified via proteomics, was affected by TAS2R43 deletion polymorphisms and thus confirmed a role for TAS2R43. RNA-Seq revealed that denatonium benzoate induced an NRF2-mediated nutrient stress response and an unfolded protein response that increased the expression of the mitokine GDF15 but also ADM2 and LDLR, genes that are involved in anorectic signaling and lipid homeostasis. In conclusion, TAS2Rs in the intestine constitute a promising target for treating diseases that involve disturbances in the innate immune system and body weight control. TAS2R polymorphisms may be valuable genetic markers to predict therapeutic responses.