Jan Tack

• Doctor of Medicine
• Professor at KU Leuven

Introduction The daily prevalence, impact, and associated personal and health factors of gas‐related gastrointestinal (GI) symptoms in the general population are poorly understood and were investigated in a multi‐national sample in this study. Methods Adults (18+ years) were surveyed nationwide via the Internet in the United States (USA), the Unit...

The Rome Foundation embarked on an ambitious multi‐year, multinational population‐based study to evaluate the prevalence of Rome IV‐defined DGBI and their biopsychosocial impact on a worldwide scale. The consistency of the study findings attests to the scientific rigor of this effort, as evident in the publications that resulted from this internati...

Background: In Europe, IBS is commonly treated with musculotropic spasmolytics (eg, otilonium bromide, OB). In tertiary care, a low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet provides significant improvement. Yet, dietary treatment remains to be explored in primary care. We evaluated the effect of a smar...

Food ingestion is a major symptom trigger in functional esophageal and functional gastroduodenal disorders, as well as gastroparesis. This review summarizes current knowledge and identifies areas of research on the role of food factors and the opportunities for dietary innervation in these disorders. While many patients suffering from functional es...

Background and Aims: Breathing exercises, such as slow deep breathing (SDB), are commonly being used for pain management. However, the underlying physiological mechanisms are not completely understood. Here we explored whether the respiratory phase modulates visceral pain perception and associated autonomic responses during SDB. Methods: 57 partic...

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...

Background Itopride, a mixed D2 antagonist and cholinesterase inhibitor, has prokinetic effects on gastric motility. The Leuven Postprandial Distress Scale is a validated patient‐reported outcome instrument for functional dyspepsia (FD) postprandial distress syndrome (PDS). We aimed to use the LPDS to assess treatment outcome in PDS and PDS/EPS (ep...

Patients with functional dyspepsia (FD) complain of epigastric symptoms with no identifiable cause. Increased intestinal permeability has been described in these patients, especially in the proximal small bowel or duodenum, and was associated with mucosal immune activation and symptoms. In this review, we discuss duodenal barrier function, includin...

Simple Summary Prescription opioid pain medications help ease pain, but they also cause some unwanted side effects such as constipation. In this study we evaluated the safety and efficacy of naloxegol used to treat constipation that is caused by opioids. We found that naloxegol improved constipation and quality of life in patients with cancer-relat...

Background Patients with disorders of gut-brain interaction (DGBI) report meal intake to be associated with symptoms. DGBI patients with meal-related symptoms may have more severe symptoms overall and worse health outcomes, but this subgroup has not been well characterized. We aimed to describe the global prevalence of meal-related abdominal pain a...

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 admin...

Psychological stress negatively affects the intestinal barrier function in animals and humans. We aimed to study the effect of Lactobacillus rhamnosus CNCM I-3690 on intestinal permeability and stress-markers during public speech. Healthy students were randomized to L. rhamnosus-containing (test) or acidified (placebo) milk consumed twice daily for...

Irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) are common gastrointestinal disorders imposing considerable impact on the quality of life and well-being of affected individuals. A paucity of evidence-based treatment options exist for CIC and IBS-C sufferers. Tegaserod, a 5-HT4 agonist, has a substantial...

Background: Functional dyspepsia (FD) is differentiated into two subgroups: the postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). Acute gastroenteritis and Helicobacter pylori (HP) infection have been identified as risk factors for FD. It is unclear how these risk factors relate to Rome IV subgroups and their clinical impact...

Purpose of review: In this review, we evaluate recent findings related to the association between gastrointestinal hormones and regulation of gastric emptying. Recent findings: Motilin and ghrelin, which act during fasting, promote gastric motility, whereas most of the hormones secreted after a meal inhibit gastric motility. Serotonin has differ...

(1) Background: Predictors of dietary treatment response in irritable bowel syndrome (IBS) remain understudied. We aimed to investigate predictors of symptom improvement during the low FODMAP and the traditional IBS diet for four weeks. (2) Methods: Baseline measures included faecal Dysbiosis Index, food diaries with daily energy and FODMAP intake,...

Proton pump inhibitors (PPI) may improve symptoms in functional dyspepsia (FD) through duodenal eosinophil-reducing effects. However, the contribution of the microbiome to FD symptoms and its interaction with PPI remains elusive. Aseptic duodenal brushings and biopsies were performed before and after PPI intake (4 weeks Pantoprazole 40 mg daily, FD...

Disorders of gastric motor and sensory function affect 10%-20% of the world's population and adversely impact nutrition, quality of life, work productivity, and health care costs. Classifying these disorders can be challenging given the heterogeneity of symptom presentation, the presence of symptoms unexplained by endoscopic, radiographic and/or la...

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 inves...

Bitter taste receptors (TAS2R) serve as warning sensors in the lingual system against ingestion of potential 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 from obese subjects, respond...

Tissue cryopreservation provides a convenient solution for tackling one of the major problems in neuroscience research, namely, the scarce availability of human nerve tissues, especially if needed alive. While brain tissue can be used only postmortem, live nerve tissue can reasonably well be harvested from the periphery. A valuable source of primar...

La Clasificación de Chicago v4.0 (CCv4.0) es el esquema actualizado para clasificar las alteraciones de la motilidad esofágica utilizando la métrica de la manometría de alta resolución (HRM). Para desarrollar la CCv4.0, 52 expertos internacionales diversos separados en siete subgrupos de trabajo utilizaron una metodología formalmente validada, en u...

Background and aims Rumination syndrome is a Disorder of Gut-Brain Interaction (DGBI) of unknown etiology. We aimed to assess its global prevalence and potential associations with other medical conditions. Methods Data were collected via the Internet in 26 countries. Subjects were evenly distributed by country, sex and age groups and were invited...

The Rome criteria, which define Disorders of Gut-Brain Interaction (DGBIs), are extensively applied in epidemiological research, pathophysiological studies, treatment trials, and clinical practice. The requirement for long periods of symptom presence and high symptom frequencies facilitated the use of the Rome criteria in epidemiology studies and t...

Introduction In oropharyngeal dysphagia, impaired pharyngoesophageal junction (PEJ) opening is reflected by an elevated hypopharyngeal intrabolus pressure (IBP), quantifiable using pharyngeal high‐resolution manometry with impedance (P‐HRM‐I). Transient intrabolus pressurization (TP) phenomena are not sustained and last for only a brief period. We...

Small single center study comparing the B1 mouthpiece (Fujifilm) for upper GI endoscopy to a conventional mouthpiece for upper GI endoscopy

Description Delayed gastric emptying on objective testing defines gastroparesis, but symptoms overlap with functional dyspepsia, and do not correlate well with gastric emptying delay. This review outlines a strategy for defining, diagnosing and managing refractory gastroparesis. Methods The Best Practice Advice statements presented here were devel...

Background Functional dyspepsia (FD) is one of the most common conditions in clinical practice. In spite of its prevalence, FD is associated with major uncertainties in terms of its definition, underlying pathophysiology, diagnosis, treatment, and prognosis. Methods A Delphi consensus was initiated with 41 experts from 22 European countries who co...

Background Spasmolytic agents are an attractive first line treatment option for irritable bowel syndrome (IBS). Pinaverium bromide (pinaverium) has antispasmodic effects on gastrointestinal smooth muscle and can relieve major IBS symptoms, but an up-to-date meta-analysis comparing the efficacy of pinaverium with placebo is lacking. The aim is to pe...

Background Functional gastroduodenal disorders include functional dyspepsia, chronic nausea and vomiting syndromes, and gastroparesis. These disorders are common, but their overlapping symptomatology poses challenges to diagnosis, research, and therapy. This study aimed to introduce and validate a standardized patient symptom-logging system and App...

Pancreatic polypeptide (PP) is known to affect food intake. In this exploratory study, we set out to investigate its supraphysiological effect on food tolerance, gastric accommodation, and emptying. In 12 healthy volunteers, 0, 3, or 10 pmol*kg⁻¹*min⁻¹ PP was administered intravenously (PP0, PP3 or PP10). Thirty minutes thereafter, nutrient drink i...

An increased intestinal permeability has been described in various gastrointestinal and non-gastrointestinal disorders. Nevertheless, the concept and definition of intestinal permeability is relatively broad and includes not only an altered paracellular route, regulated by tight junction proteins, but also the transcellular route involving membrane...

Background Gastroparesis is a condition characterized by epigastric symptoms and delayed gastric emptying (GE) rate in the absence of any mechanical obstruction. The condition is challenging in clinical practice by the lack of guidance concerning diagnosis and management of gastroparesis. Methods A Delphi consensus was undertaken by 40 experts fro...

Background Functional dyspepsia (FD) is a common gastrointestinal condition of poorly understood pathophysiology. While symptoms’ overlap with other conditions may indicate common pathogenetic mechanisms, genetic predisposition is suspected but has not been adequately investigated. Methods Using healthcare, questionnaire, and genetic data from thr...

Background Studies using somatic pain models have shown the hypoalgesic effects of slow, deep breathing. We evaluated the effect of slow, deep breathing on visceral pain and explored putative mediating mechanisms including autonomic and emotional responses. Methods Fifty‐seven healthy volunteers (36 females, mean age = 22.0 years) performed contro...

Background Aerosol spread is key to interpret the risk of viral contamination during clinical procedures such as esophageal high‐resolution manometry (HRM). Installing an air purifier seems a legitimate strategy, but this has recently been questioned. Methods Patients undergoing an HRM procedure at the Leuven University Hospital were included in t...

Background Current treatments for functional dyspepsia have limited efficacy or present safety issues. We aimed to assess spore-forming probiotics in functional dyspepsia as monotherapy or add-on therapy to long-term treatment with proton-pump inhibitors. Methods In this single-centre, randomised, double-blind, placebo-controlled pilot trial that...

Background Two studies demonstrated the efficacy and safety of naldemedine in adult patients with chronic non-cancer pain and opioid-induced constipation (OIC). However, no studies have compared the efficacy of peripherally acting µ-opioid receptor antagonists in patients with adequate and inadequate responses to prior OIC therapy with laxatives. T...

Background: Functional dyspepsia (FD) is one of the most common functional gastrointestinal disorders. Based on the various symptoms present in patients with functional dyspepsia-postprandial distress syndrome (FD-PDS), routine agents such as acid suppressants, prokinetic drugs, and centrally acting drugs, offer limited treatment choice with potent...

Background The prevalence of duodenogastroesophageal reflux (DGER) and its effect on symptoms and oesophageal lesions in gastroesophageal reflux disease (GERD) is unclear. Aims To conduct a systematic review to determine the prevalence of DGER among patients with GERD, the effect of DGER on symptoms and oesophageal lesions, and the treatment of DG...

Although gasotransmitters nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) receive a bad connotation; in low concentrations these play a major governing role in local and systemic blood flow, stomach acid release, smooth muscles relaxations, anti-inflammatory behavior, protective effect and more. Many of these physiological proces...

Objective Opioid-induced constipation is among the most common side effects associated with opioid use in patients with chronic non-cancer pain, and it can have a significant negative impact on health-related quality of life (QOL). This analysis evaluated the effect of naldemedine 0.2 mg on patient-reported outcomes in three phase 3 clinical studie...

Background Different peripheral pathways are implicated in the regulation of the food ingestion-digestion cycle. Methods Narrative review on gastrointestinal mechanisms involved in satiety and hunger signalling. Results Combined mechano- and chemoreceptors, peripherally released peptide hormones and neural pathways provide feedback to the brain t...

Background Gastrointestinal (GI) function is critically dependent on the control of the enteric nervous system (ENS), which is situated within the gut wall and organized into two ganglionated nerve plexuses: the submucosal and myenteric plexus. The ENS is optimally positioned and together with the intestinal epithelium, is well‐equipped to monitor...

Esophageal hypomotility in general and especially ineffective esophageal motility according to the Chicago criteria of primary motility disorders of the esophagus, is one of the most frequently diagnosed motility disorders on high resolution manometry and results in a large number of patients visiting gastroenterologists. Most patients with esophag...

Bitter tastants are recently introduced as potential hunger-suppressive compounds, the so-called "Bitter pill". However, the literature about bitter administration lacks consistency in methods and findings. We want to test whether hunger ratings and hormone plasma levels are affected by: 1) the site of administration: intragastrically (IG) or intra...

Background & aims: Opioids have a role in chronic pain management. However, opioid-induced constipation (OIC) may cause patients to skip or reduce opioid doses, leading to inadequate pain relief and negatively impacting quality of life (QOL). We sought to establish a minimal clinically important difference (MCID) to understand whether changes in Q...

Introduction: Functional dyspepsia (FD) is a prevalent condition with multifactorial pathophysiology, including impaired gastric accommodation (GA), hypersensitivity to gastric distention, and delayed gastric emptying. Drink tests (DT) have been proposed as a potential biomarker for the presence and severity of gastric sensorimotor dysfunction. Th...

Background Due to important biases, conventional end‐of‐day and end‐of‐week assessment methods of gastrointestinal symptoms in functional dyspepsia (FD) are considered suboptimal. Real‐time symptom assessment based on the experience sampling method (ESM) could be a more accurate measurement method. This study aimed to evaluate validity and reliabil...

O In primary care, IBS is a condition that generates high diagnostic and therapeutic uncertainty for general practitioners (GPs), and the efficacy of currently available therapeutic modalities is limited. In Europe, musculotropic agents (eg otilonium bromide, OB) are commonly used. Recently, at the level of specialist care, the low FODMAP diet supe...

Background and aims Conditions such as irritable bowel syndrome (IBS), functional dyspepsia and functional constipation are among the prevalent gastrointestinal disorders classified as disorders of gut brain interaction (DGBI), which can adversely affect the lives of sufferers. This study aimed to assess the degree and consequences of overlapping D...

Background & Aims Enteral nutrition with polymeric intact protein formula is the preferred medical nutrition strategy in critically ill patients when oral intake is insufficient. Enteral nutrition formulas are often rich in casein protein, which has coagulating properties. Coagulation in the stomach impedes gastric emptying and might result in high...

Background Gastroparesis is a condition characterized by epigastric symptoms and delayed gastric emptying (GE) rate in the absence of any mechanical obstruction. The condition is challenging in clinical practice by the lack of guidance concerning diagnosis and management of gastroparesis. Methods A Delphi consensus was undertaken by 40 experts fro...

Background Functional dyspepsia (FD) is one of the most common conditions in clinical practice. In spite of its prevalence, FD is associated with major uncertainties in terms of its definition, underlying pathophysiology, diagnosis, treatment, and prognosis. Methods A Delphi consensus was initiated with 41 experts from 22 European countries who co...

The Chicago Classification v4.0 (CCv4.0) is the updated classification scheme for esophageal motility disorders using metrics from high‐resolution manometry (HRM). A key feature of CCv.4.0 is the more rigorous and expansive protocol that incorporates single wet swallows acquired in different positions (supine, upright) and provocative testing, incl...

Linked to the growing obesity epidemic, demand for bariatric and metabolic surgery has increased, the most common procedures being sleeve gastrectomy and Roux-en-Y gastric bypass. Originally, bariatric procedures were described as purely restrictive, malabsorptive, or combined restrictive–malabsorptive procedures limiting food intake, nutrient abso...

The relevance of gastric emptying (GE) rate to symptom generation in functional dyspepsia and idiopathic gastroparesis is a matter of controversy. We aimed to evaluate the relationship between symptom severity and GE when simultaneously assessed, avoiding biases of recall symptom severity questionnaires and single-time-point GE measurements. Metho...

Background Clinical trials in irritable bowel syndrome are associated with high placebo response rates. We aimed to identify the magnitude of the placebo response and the contributing factors to this occurrence. Methods We did a systematic review and meta-analysis with a search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Tr...

Aim To determine whether a dose‐dependent effect in the stimulation of gut hormone release (plasma cholecystokinin [CCK], active glucagon‐like peptide‐1 [aGLP‐1] and peptide tyrosine tyrosine [PYY]) is found for the natural sweetener erythritol. Materials and Methods Twelve healthy, lean volunteers received solutions with 10, 25 or 50 g erythritol...

Background An isovolumetric intragastric balloon to continuously measure gastric phasic contractility was recently developed by us. We aimed to investigate the readout of this technique in relation to gastric content and gastric emptying. Methods In this crossover investigation, the VIPUNTM Gastric Monitoring System, which comprises a double lumen...

Functional dyspepsia (FD) is defined as the presence of gastroduodenal symptoms in the absence of organic disease that is likely to explain the symptoms. Joint hypermobility (JH) refers to the increased passive or active movement of a joint beyond its normal range and is characteristically present in patients with joint hypermobility syndrome (JHS)...

Background Gastric motor function alterations have been implicated in the pathogenesis of functional dyspepsia with postprandial distress syndrome (PDS). Prucalopride, a 5‐TH4 agonist, is known to stimulate gastrointestinal motility. We aimed to evaluate the effect of prucalopride on gastric sensorimotor function in healthy subjects (HV). Methods...

Magnesium oxide has been widely used as a laxative for many years in East Asia, yet its prescription has largely been based on empirical knowledge. In recent years, several new laxatives have been developed, which has led to a resurgence in interest and increased scientific evidence surrounding the use of magnesium oxide, which is convenient to adm...

Nutrient signals sensed by enteroendocrine cells are conveyed to the enteric nervous system (ENS) to initiate intestinal reflexes. We addressed whether there are specific enteric pathways dedicated to detecting different luminal nutrients. Calcium imaging was performed on intact jejunal preparations from Wnt1-cre;R26R-GCaMP3 and Villin-cre;R26R-GCa...

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 dy...

Sugar consumption is associated with a whole range of negative health effects and should be reduced and the natural sweetener xylitol might be helpful in achieving this goal. The present study was conducted as a randomized, placebo-controlled, double-blind, cross-over trial. Twelve healthy, lean volunteers received intragastric solutions with 7, 17...

Gastroparesis occurs commonly as a complication of long-standing diabetes, but the in the largest group of patients no cause can be established and these are referred to as idiopatic gastroparesis patients. While delayed gastric emptying is a defining feature of gastroparesis, gastric emptying rate is inconsistently linked with symptoms and choice...

Chicago Classification v4.0 (CCv4.0) is the updated classification scheme for esophageal motility disorders using metrics from high‐resolution manometry (HRM). Fifty‐two diverse international experts separated into seven working subgroups utilized formal validated methodologies over two‐years to develop CCv4.0. Key updates in CCv.4.0 consist of a m...

Background Administration of a bitter compound can alter the intragastric pressure (IGP) after a meal. Additionally, a negative correlation between IGP and the number of transient lower esophageal sphincter relaxations (TLESRs) has been demonstrated. However, the effect of a bitter tastant on the number of TLESRs and subsequent reflux episodes has...

Background Rumination is defined as the repetitive, effortless regurgitation of recently ingested food into the mouth. These episodes are preceded by a rise in intragastric pressure (IGP) and mainly occur postprandially. IGP peaks >30 mmHg have been proposed as a cutoff to differentiate rumination from reflux events. In clinical practice, we observ...

In this article, we report on the development of a catheter-based, biomimetic sensor as a step toward a minimally invasive diagnostic instrument in the context of functional bowel disorders. Histamine is a key mediator in allergic and inflammatory processes in the small intestines; however, it is a challenge to determine histamine levels at the duo...

Background Polyethylene glycol (PEG), bisacodyl, and prucalopride have been reported to be more effective than placebo in treating patients with constipation but about 50% of the patients still do not respond to these medications. Only bisacodyl and prucalopride are expected to directly stimulate the colonic motility in humans in vivo. As no previo...

For up to 2 decades, pathophysiological research in functional dyspepsia focused on gastric sensorimotor dysfunction underlying symptom generation. Recent pathophysiological research has focused on low-grade inflammation in the duodenal mucosa. Emerging evidence confirms a loss of mucosal integrity in the duodenum in functional dyspepsia, and this...

Background Esophageal hypersensitivity is considered an important pathophysiological mechanism in refractory gastroesophageal reflux disease (GERD) patients. Serotonin (5‐HT) plays an important role in the regulation of GI (gastrointestinal) secretion, motility and sensitivity. Previous studies found that altered 5‐HT availability has no clear effe...

Background Several patients in gastroenterology practice present with esophageal symptoms, and in case of normal endoscopy with biopsies, high‐resolution manometry (HRM) is often the next step. Our aim was to develop a European consensus on the clinical application of esophageal HRM, to offer the clinician guidance in selecting patients for HRM and...