Postprandial symptoms originating from the stomach in functional dyspepsia

Double-blind, randomized, 8-week multicenter study of the efficacy and safety of STW 5-IIversus placebo in functional dyspepsia

Background and Aim

Herbal products are widely used to treat patients with disorders of gut brain interaction but clinical efficacy and safety data for treatments lasting >4 weeks are widely lacking. We evaluated the efficacy and safety of 8 weeks of treatment with the herbal combination product STW 5-II for patients with functional dyspepsia (FD) meeting Rome II criteria. We also conducted a post hoc analysis including patients meeting Rome IV criteria for FD and evaluated the effect of the G-protein beta 3 (GNB3) subunit polymorphism (C825T) on therapeutic response.

Methods

This multicenter, placebo-controlled, double-blind study included 272 FD patients meeting Rome II criteria in the intention-to-treat cohort and 266 meeting Rome IV criteria. We used the validated Gastrointestinal Symptom Score (GIS) to assess GI symptoms, defining response rate as the proportion of patients with ≥50% GIS improvement in at least three of four assessments.

Results

After 8 weeks, the response rate was significantly higher in the STW 5-II group versus placebo (61.2% vs 45.1%, P = 0.008). Mean GIS non-significantly improved with STW 5-II treatment (7.9 ± 4.41 vs 6.7 ± 4.91 with placebo; P = 0.07). In the Rome IV subgroup analysis, STW 5-II yielded a better response rate (P = 0.01) versus placebo and greater postprandial distress symptom improvement (P = 0.04) versus placebo. Safety parameters did not differ between groups, and GNB3 status was not linked with therapeutic response.

Conclusion

STW 5-II is efficacious, with no observed safety signals at up to 8 weeks of treatment in patients with FD meeting Rome II or IV criteria.

Gastric Alimetry Expands Patient Phenotyping in Gastroduodenal Disorders Compared with Gastric Emptying Scintigraphy

INTRODUCTION

Gastric emptying testing (GET) assesses gastric motility, however, is nonspecific and insensitive for neuromuscular disorders. Gastric Alimetry (GA) is a new medical device combining noninvasive gastric electrophysiological mapping and validated symptom profiling. This study assessed patient-specific phenotyping using GA compared with GET.

METHODS

Patients with chronic gastroduodenal symptoms underwent simultaneous GET and GA, comprising a 30-minute baseline, 99m TC-labelled egg meal, and 4-hour postprandial recording. Results were referenced to normative ranges. Symptoms were profiled in the validated GA App and phenotyped using rule-based criteria based on their relationships to the meal and gastric activity: (i) sensorimotor, (ii) continuous, and (iii) other.

RESULTS

Seventy-five patients were assessed, 77% female. Motility abnormality detection rates were as follows: GET 22.7% (14 delayed, 3 rapid), GA spectral analysis 33.3% (14 low rhythm stability/low amplitude, 5 high amplitude, and 6 abnormal frequency), and combined yield 42.7%. In patients with normal spectral analysis, GA symptom phenotypes included sensorimotor 17% (where symptoms strongly paired with gastric amplitude, median r = 0.61), continuous 30%, and other 53%. GA phenotypes showed superior correlations with Gastroparesis Cardinal Symptom Index, Patient Assessment of Upper Gastrointestinal Symptom Severity Index, and anxiety scales, whereas Rome IV Criteria did not correlate with psychometric scores ( P > 0.05). Delayed emptying was not predictive of specific GA phenotypes.

DISCUSSION

GA improves patient phenotyping in chronic gastroduodenal disorders in the presence and absence of motility abnormalities with increased correlation with symptoms and psychometrics compared with gastric emptying status and Rome IV criteria. These findings have implications for the diagnostic profiling and personalized management of gastroduodenal disorders.

Gastric Alimetry® Test Interpretation in Gastroduodenal Disorders: Review and Recommendations

Chronic gastroduodenal symptoms are prevalent worldwide, and there is a need for new diagnostic and treatment approaches. Several overlapping processes may contribute to these symptoms, including gastric dysmotility, hypersensitivity, gut-brain axis disorders, gastric outflow resistance, and duodenal inflammation. Gastric Alimetry® (Alimetry, New Zealand) is a non-invasive test for evaluating gastric function that combines body surface gastric mapping (high-resolution electrophysiology) with validated symptom profiling. Together, these complementary data streams enable important new clinical insights into gastric disorders and their symptom correlations, with emerging therapeutic implications. A comprehensive database has been established, currently comprising > 2000 Gastric Alimetry tests, including both controls and patients with various gastroduodenal disorders. From studies employing this database, this paper presents a systematic methodology for Gastric Alimetry test interpretation, together with an extensive supporting literature review. Reporting is grouped into four sections: Test Quality, Spectral Analysis, Symptoms, and Conclusions. This review compiles, assesses, and evaluates each of these aspects of test assessment, with discussion of relevant evidence, example cases, limitations, and areas for future work. The resultant interpretation methodology is recommended for use in clinical practice and research to assist clinicians in their use of Gastric Alimetry as a diagnostic aid and is expected to continue to evolve with further development.

Principles and clinical methods of body surface gastric mapping: Technical review

BACKGROUND AND PURPOSE

Chronic gastric symptoms are common, however differentiating specific contributing mechanisms in individual patients remains challenging. Abnormal gastric motility is present in a significant subgroup, but reliable methods for assessing gastric motor function in clinical practice are lacking. Body surface gastric mapping (BSGM) is a new diagnostic aid, employs multi-electrode arrays to measure and map gastric myoelectrical activity non-invasively in high resolution. Clinical adoption of BSGM is currently expanding following studies demonstrating the ability to achieve specific patient subgrouping, and subsequent regulatory clearances. An international working group was formed in order to standardize clinical BSGM methods, encompassing a technical group developing BSGM methods and a clinical advisory group. The working group performed a technical literature review and synthesis focusing on the rationale, principles, methods, and clinical applications of BSGM, with secondary review by the clinical group. The principles and validation of BSGM were evaluated, including key advances achieved over legacy electrogastrography (EGG). Methods for BSGM were reviewed, including device design considerations, patient preparation, test conduct, and data processing steps. Recent advances in BSGM test metrics and reference intervals are discussed, including four novel metrics, being the 'principal gastric frequency', BMI-adjusted amplitude, Gastric Alimetry Rhythm Index™, and fed: fasted amplitude ratio. An additional essential element of BSGM has been the introduction of validated digital tools for standardized symptom profiling, performed simultaneously during testing. Specific phenotypes identifiable by BSGM and the associated symptom profiles were codified with reference to pathophysiology. Finally, knowledge gaps and priority areas for future BSGM research were also identified by the working group.

Gastric Alimetry ® improves patient phenotyping in gastroduodenal disorders compared to gastric emptying scintigraphy alone

Objectives

Gastric emptying testing (GET) assesses gastric motility, however is non-specific and insensitive for neuromuscular disorders. Gastric Alimetry® (GA) is a new medical device combining non-invasive gastric electrophysiological mapping and validated symptom profiling. This study assessed patient-specific phenotyping using GA compared to GET.

Methods

Patients with chronic gastroduodenal symptoms underwent simultaneous GET and GA, comprising a 30-minute baseline, 99m TC-labelled egg meal, and 4-hour postprandial recording. Results were referenced to normative ranges. Symptoms were profiled in the validated GA App and phenotyped using rule-based criteria based on their relationships to the meal and gastric activity: i) sensorimotor; ii) continuous; and iii) other.

Results

75 patients were assessed; 77% female. Motility abnormality detection rates were: GET 22.7% (14 delayed, 3 rapid); GA spectral analysis 33.3% (14 low rhythm stability / low amplitude; 5 high amplitude; 6 abnormal frequency); combined yield 42.7%. In patients with normal spectral analysis, GA symptom phenotypes included: sensorimotor 17% (where symptoms strongly paired with gastric amplitude; median r=0.61); continuous 30%; other 53%. GA phenotypes showed superior correlations with GCSI, PAGI-SYM, and anxiety scales, whereas Rome IV Criteria did not correlate with psychometric scores (p>0.05). Delayed emptying was not predictive of specific GA phenotypes.

Conclusions

GA improves patient phenotyping in chronic gastroduodenal disorders in the presence and absence of motility abnormalities with improved correlation with symptoms and psychometrics compared to gastric emptying status and Rome IV criteria. These findings have implications for the diagnostic profiling and personalized management of gastroduodenal disorders.

Study Highlights

1) WHAT IS KNOWN Chronic gastroduodenal symptoms are common, costly and greatly impact on quality of lifeThere is a poor correlation between gastric emptying testing (GET) and symptomsGastric Alimetry® is a new medical device combining non-invasive gastric electrophysiological mapping and validated symptom profiling 2) WHAT IS NEW HERE Gastric Alimetry generates a 1.5x higher yield for motility abnormalities than GETWith symptom profiling, Gastric Alimetry identified 2.7x more specific patient categories than GETGastric Alimetry improves clinical phenotyping, with improved correlation with symptoms and psychometrics compared to GET.

Evidence-Based and Emerging Dietary Approaches to Upper Disorders of Gut-Brain Interaction

Food ingestion is a major symptom trigger in functional esophageal and gastroduodenal disorders and gastroparesis. This review summarizes current knowledge and identifies areas of research on the role of food factors and the opportunities for dietary intervention in these disorders. While many patients experiencing functional esophageal and gastroduodenal disorders identify specific food items as symptom triggers, available data do not allow the identification of specific nutrient groups that are more likely to induce symptoms. In functional dyspepsia (FD), recent studies have shown the potential efficacy of a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, although the underlying mechanism of action is unclear. Reports of favorable responses to gluten elimination in patients with FD are confounded by the concomitant benefit of reduced intake of fructans, fermentable oligosaccharides, disaccharides, monosaccharides, and polyols present in wheat. Emerging data based on a 6-food elimination diet and confocal laser endomicroscopic evaluation of mucosal responses to food proteins suggest a role for duodenal allergic reactions in FD symptom generation. In patients with gastroparesis, a low-residue diet has been shown to improve symptoms. Novel dietary approaches under evaluation are the Mediterranean diet and the heating/cooling diet approach.

Effects of Rome IV Definitions of Functional Dyspepsia Subgroups in Secondary Care

BACKGROUND & AIMS

Functional dyspepsia (FD) is subdivided into postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) according to the Rome III consensus. In clinical practice, there is a major overlap between these subgroups. The Rome IV criteria included postprandially occurring symptoms in the PDS subgroup. We aimed to analyze the effects of the Rome IV criteria, compared with Rome III, on FD subgroups in patients recruited from secondary care.

METHODS

Patients with FD (n = 224; mean age, 43 ± 1 y; 77% women) were recruited from secondary-care units in Belgium and filled out symptom questionnaires, allowing subdivision according to Rome III and Rome IV criteria and identification of postprandial symptoms. Symptom patterns and demographics were compared between the subgroups. Statistical analysis was performed using the t test and the Fisher exact test.

RESULTS

According to the Rome III criteria, 25% of participants had PDS, 8% had EPS, and 67% had an overlap. Postprandial fullness, early satiation, and bloating were present in significantly more patients in the PDS and overlap groups than the EPS group (P < .0001). A higher proportion of patients in the overlap group showed symptoms such as postprandial epigastric pain and nausea than in the EPS group (both P ≤ .02). With the Rome IV criteria, the overlap group was reduced to 35%; 57% of patients were considered to have PDS and 8% to have EPS. Postprandial pain was significantly more prevalent in the PDS than in the EPS group (P ≤ .002), and postprandial nausea was significantly more prevalent in the PDS group than the overlap group (P = .007).

CONCLUSIONS

Compared with Rome III criteria, the Rome IV criteria significantly reduces the overlap between PDS and EPS groups. Studies are needed to determine if Rome IV subgroups are associated differently with psychological comorbidities and treatment responses.

The effect of prucalopride on gastric sensorimotor function and satiation in healthy volunteers

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

Barostat and intragastric pressure (IGP) measurements were performed in 17 HV (59% females, age 29.4 ± 2.7 y) after treatment with placebo or prucalopride (2 mg) (single-blind cross-over). Isobaric stepwise distensions and gastric sensations were assessed to determine gastric compliance and sensitivity. Gastric accommodation (GA) with the barostat was quantified before and after ingestion of 200 ml of a nutrient drink (ND). GA measured by IGP was quantified as the drop of IGP from baseline during the intragastric infusion of ND until maximal satiation (60 ml/min).

KEY RESULTS

Prucalopride did not affect barostat assessed gastric compliance or sensitivity. No differences were observed in GA after prucalopride. During the barostat study, 10 min after the meal, 7 HVs reported significantly higher ratings for nausea after prucalopride (p < 0.001), and vomiting was induced in 4 of the HVs. A positive correlation was observed between the delta mean perception of nausea with the delta mean increase of intra-balloon volume before and after meal ingestion (r = 0.37, p = 0.03). During IGP measurements, no effect on nutrient tolerance was observed and increased cramp severity scores were observed which were associated with a significant increase of distal IGP (r = 0.78, p < 0.0001).

CONCLUSIONS & INFERENCES

Prucalopride does not enhances gastric accommodation but it might increase sensitivity to gastric distention. Furthermore, the increase in sensitivity seems to be related to an increase in nausea with distension. Clinicaltrials.gov: NCT04429802.

Developing a Scale for the Evaluation of People With Post-prandial Distress Syndrome

Background: Functional dyspepsia (FD) is one of the most critical health problems worldwide. Although there has been an increased intervention to improve FD symptoms, it is difficult to compare the effect of intervention measures with the existing methods of reporting the outcome, and it is a lack of clinical evaluation tools that can be used to evaluate patients' symptoms and treatment. One way of potentially addressing this way is to offer a patient-reported symptom scoring scales, which can be self-reported by patients to highlight interventions' authenticity and reliability. Nevertheless, there is still a lack of validated patient-reported outcome instruments for post-prandial distress syndrome (PDS). This study aims to establish a symptom scoring scale to evaluate the effectiveness of interventions for PDS.

Methods: The study consists of two steps. The first step was to formulate the scale. Through a systematic literature review and group discussion, an item pool and scale framework were formed. Then, through the expert consultation and pre-investigation, the formal version of the scale was formed. The second step is to test the reliability and validity of the scale. The scale is tested in the target population to determine whether the reliability and validity of the scale.

Discussion: The improvement in patients' self-reported symptoms had a significant impact on the researchers' evaluation of the intervention's authenticity. Therefore, we develop a symptom scoring scale for reporting studies evaluating the effectiveness of PDS interventions. The scale will be used for a more significant comparison to evaluate PDS interventions' effectiveness. The scale also improves trial reporting, reducing research waste by prioritizing the collection and reporting of critical results for all relevant stakeholders.

Clinical Trial Registration: ChiCTR, ChiCTR2100044489. Registered on March 22, 2021.

International Union of Basic and Clinical Pharmacology. CX. Classification of Receptors for 5-hydroxytryptamine; Pharmacology and Function

5-HT receptors expressed throughout the human body are targets for established therapeutics and various drugs in development. Their diversity of structure and function reflects the important role 5-HT receptors play in physiologic and pathophysiological processes. The present review offers a framework for the official receptor nomenclature and a detailed understanding of each of the 14 5-HT receptor subtypes, their roles in the systems of the body, and, where appropriate, the (potential) utility of therapeutics targeting these receptors. SIGNIFICANCE STATEMENT: This review provides a comprehensive account of the classification and function of 5-hydroxytryptamine receptors, including how they are targeted for therapeutic benefit.

Analysis of Postprandial Symptom Patterns in Subgroups of Patients With Rome III or Rome IV Functional Dyspepsia

BACKGROUND & AIMS

Among patients with functional dyspepsia (FD), there is overlap in symptoms between those in the Rome III subgroups of postprandial distress syndrome (PDS) and those with epigastric pain syndrome (EPS). The Rome IV consensus proposed to incorporate all patients with postprandial symptoms into the PDS group. We aimed to evaluate the assessment of meal-related dyspepsia symptoms in patients with FD according to the Rome III vs Rome IV subdivisions.

METHODS

Consecutive patients with FD referred for a gastric emptying test (n = 96) were asked to fill out the Rome III gastroduodenal questionnaire, with questions on meal-related occurrence. Study participants underwent a gastric emptying breath test, during which the intensity of dyspeptic symptoms (fullness, bloating, belching, nausea, epigastric pain, and burning) was scored before and up to 4 hours after a meal. We analyzed the association between the Rome subdivision and symptom severity and pattern during the breath test.

RESULTS

According to Rome III, 10% had EPS alone, 29% PDS alone, and 61% overlapping EPS and PDS. The frequency of the symptoms reported in the Rome questionnaire associated with the intensity of the symptoms during the breath test in the PDS group and in the groups with PDS and EPS overlap, but not in the group with EPS. We adapted the definition of the PDS subgroup to include patients with meal-related non-PDS symptoms (Rome IV); this reduced the proportion of patients with overlap of EPS and PDS symptoms from 61% to 18% and in this group the association of symptoms with the meal was reduced.

CONCLUSIONS

In an analysis of patients with FD, a meal induced or exacerbated symptoms in most patients. The Rome IV criteria for PDS reduce the proportions categorized as having both PDS and EPS and identify a patient group whose symptoms are associated with the meals. University hospital of Leuven study no: S55426.

Gastric motor and sensory function in health assessed by magnetic resonance imaging: Establishment of reference intervals for the Nottingham test meal in healthy subjects

BACKGROUND

Current investigations of gastric emptying rarely identify the cause of symptoms or provide a definitive diagnosis in patients with dyspepsia. This study assessed gastric function by magnetic resonance imaging (MRI) using the modular "Nottingham test meal" (NTM) in healthy volunteers (HVs).

METHODS

The NTM comprises (a) 400 mL liquid nutrient (0.75 kcal/mL) labeled with Gadolinium-DOTA and (b) an optional solid component (12 agar-beads [0 kcal]). Filling sensations were documented. MRI measurements of gastric volume, emptying, contraction wave frequency, and secretion were obtained using validated methods.

KEY RESULTS

Gastric function was measured in a population of 73 HVs stratified for age and sex. NTM induced moderate satiety and fullness. Labeled fluid was observed in the small bowel in all subjects after meal ingestion ("early-phase" GE). Secretion was rapid such that postprandial gastric content volume was often greater than meal volume (GCV0 > 400 mL), and there was increasing dilution of the meal during the study (P < 0.001). Gastric half-time was median 66-minutes (95% reference interval 35 to 161-minutes ["late-phase" GE]). The number of intact agar beads in the stomach was 7/12 (58%) at 60-minutes and 1/12 (8%) at 120-minutes. Age, bodyweight and sex had measurable effects on gastric function; however, these were small compared to inter-individual variation for most metrics.

CONCLUSIONS AND INFERENCES

Reference intervals are presented for MRI measurements of gastric function assessed for the mixed liquid/solid NTM. Studies in patients will determine which metrics are of clinical value and also whether the reference intervals presented here offer optimal diagnostic sensitivity and specificity.

Plausibility criteria for putative pathophysiological mechanisms in functional gastrointestinal disorders: a consensus of experts

BACKGROUND AND AIMS

The functional gastrointestinal disorders (FGIDs) are extremely common conditions associated with a considerable personal, social and health economic burden. Managing FGIDs in clinical practice is challenging because of the uncertainty of symptom-based diagnosis, the high frequency of overlap between these conditions and the limited efficacy of available therapies. It has often been argued that successful drug development and management of FGIDs requires knowledge of the underlying pathophysiology. Numerous and highly variable candidate pathophysiological mechanisms have been implicated in the generation of FGID symptoms, but there is no current consensus on how to best define the relevance of these disturbances.

METHODS

A group of international experts on FGIDs developed plausibility criteria that should be fulfilled by relevant pathophysiological mechanisms in FGIDs.

RESULTS

Five criteria are proposed: (1) the presence of the abnormality in a subset of patients, (2) temporal association between proposed mechanism and symptom(s), (3) correlation between the level of impairment of the mechanism and symptom(s), (4) induction of the symptom(s) by provoking the pathophysiological abnormality in healthy subjects and (5) treatment response by a therapy specifically correcting the underlying disorder or congruent natural history of symptoms and dysfunction in the absence of specific therapy. Based on strength of evidence for these five criteria according to the Grading of Recommendations Assessment, Development and Evaluation system, a plausibility score can be calculated for each mechanism.

CONCLUSION

Evaluation of the strength of evidence for candidate pathophysiological abnormalities fulfilling these five plausibility criteria will help to identify the most relevant mechanisms to target for novel diagnostic approaches and for the development of new therapies.

Clinical assessment of gastric emptying and sensory function utilizing gamma scintigraphy: Establishment of reference intervals for the liquid and solid components of the Nottingham test meal in healthy subjects

BACKGROUND

Current investigations of stomach function are based on small test meals that do not reliably induce symptoms and analysis techniques that rarely detect clinically relevant dysfunction. This study presents the reference intervals of the modular "Nottingham test meal" (NTM) for assessment of gastric function by gamma scintigraphy (GSc) in a representative population of healthy volunteers (HVs) stratified for age and sex.

METHODS

The NTM comprises 400 mL liquid nutrient (0.75 kcal/mL) and an optional solid component (12 solid agar-beads (0 kcal). Filling and dyspeptic sensations were documented by 100 mm visual analogue scale (VAS). Gamma scintigraphy parameters that describe early and late phase Gastric emptying (GE) were calculated from validated models.

KEY RESULTS

Gastric emptying (GE) of the liquid component was measured in 73 HVs (male 34; aged 45±20). The NTM produced normal postprandial fullness (VAS ≥30 in 41/74 subjects). Dyspeptic symptoms were rare (VAS ≥30 in 2/74 subjects). Gastric emptying half-time with the Liquid- and Solid-component -NTM was median 44 (95% reference interval 28-78) minutes and 162 (144-193) minutes, respectively. Gastric accommodation was assessed by the ratio of the liquid-NTM retained in the proximal:total stomach and by Early phase emptying assessed by gastric volume after completing the meal (GCV0). No consistent effect of anthropometric measures on GE parameters was present.

CONCLUSIONS AND INFERENCES

Reference intervals are presented for GSc measurements of gastric motor and sensory function assessed by the NTM. Studies involving patients are required to determine whether the reference interval range offers optimal diagnostic sensitivity and specificity.

The Role of Duodenal Inflammation in Functional Dyspepsia

Functional dyspepsia (FD) is common and significantly impairs quality of life. Symptoms of FD are considered to originate from the gastroduodenal region, classified by the Rome criteria as disorders of brain-gut interaction without structural alteration. However, it is now apparent that FD is a number of syndromes, the epigastric pain syndrome (bothersome epigastric pain or epigastric burning) and the postprandial distress syndrome (with bothersome postprandial fullness or early satiation) and there are wide-ranging symptoms and severity. The origin of these troublesome symptoms is now considered to be a result of disrupted gastroduodenal neuropathophysiology. The complexity of the syndrome indicates that there must be different triggers, supported by the limited efficacy of the many treatments available. Current research based on evidence by association suggests that duodenal contents, including the duodenal microbiome, pathogens, and allergy may be triggers of FD. Recent studies have also shown that systemic responses of increased circulating lymphocytes and elevated proinflammatory cytokines and subtle inflammation in the duodenum may accompany the onset and persistence of symptoms. This inflammatory phenotype is characterized by innate inflammation, an eosinophil infiltrate in the duodenum in FD in those with postprandial distress syndrome. Routine histopathology practice does not quantify these cells so the status of FD is not yet appreciated as an inflammatory condition. Thus functional is becoming inflammatory and this breakthrough in understanding that functional does not necessarily mean no, but subtle pathology, may improve therapeutic options, which are currently aimed at symptom relief rather than targeted at underlying pathology.

Impaired Interoception in a Preclinical Model of Functional Dyspepsia

INTRODUCTION

The etiologies of functional dyspepsia symptoms, including postprandial distress syndrome, remain unknown. We tested the hypothesis that neonatal colon inflammation induces postprandial distress syndrome-like symptoms in adult life that associate with increased activation of vagal afferent pathways and forebrain limbic regions.

RESULTS

These rats showed a significant decrease in nutrient meal consumption to satiety after an overnight fast, decrease in gastric emptying, decrease in total distance traveled, and decrease in percent distance traveled in midfield versus control rats in open field test, indicating postprandial anxiety- and depression-like behaviors. Adult naïve rats treated with oral iodoacetamide to induce H. pylori-like mild gastritis demonstrated similar postprandial effects as the above rats.

CONCLUSIONS

We concluded that neonatal colon inflammation is a risk factor for the development of postprandial distress syndrome-like symptoms. While mild gastritis can induce symptoms similar to those of neonatal colon inflammation, gastritis in these rats does not worsen the symptoms.

Validation of the Leuven Postprandial Distress Scale, a questionnaire for symptom assessment in the functional dyspepsia/postprandial distress syndrome

BACKGROUND

A validated patient-reported outcome instrument is lacking for the functional dyspepsia/postprandial distress syndrome.

AIM

To validate the Leuven Postprandial Distress Scale (LPDS).

METHODS

The LPDS diary, comprising eight symptoms with verbal descriptors rated for severity (0-4), was derived from focus groups and cognitive debriefing. It was used in a 2-week run-in, 8-week double-blind placebo-controlled trial of itopride 100 mg t.d.s. Results in 60 patients, with concealed treatment allocation, were used to analyse LPDS content validity, consistency, reliability and responsiveness. Patients also filled out Patient Assessment of Gastrointestinal Symptoms (PAGI-SYM), Nepean Dyspepsia Index, overall treatment evaluation and overall symptom severity questionnaires. Construct validity was evaluated by known-group analyses and by correlating LPDS with these additional questionnaires. Minimum Clinically Important Difference was determined from threshold changes in anchor questionnaires.

RESULTS

Symptom patterns and factor analysis identified three cardinal symptoms of postprandial distress syndrome (early satiation, postprandial fullness, upper abdominal bloating), whose mean intensities generate weekly LPDS scores. Known-groups analysis showed large-effect-size differences in LPDS scores (Cohen's d = 2.16). Strong correlations (r > 0.57) between LPDS scores and relevant anchors at baseline indicate good convergent validity. Internal consistency of LPDS was good (α > 0.85) with high inter-item correlations (0.67-0.76), and test-retest reliability (r = 0.85). Changes in LPDS scores were highly convergent with changes in overall treatment evaluation, overall symptom severity and PAGI-SYM (r > 0.52). minimum clinically important difference analysis generated thresholds of 0.4-0.6.

CONCLUSIONS

The Leuven Postprandial Distress Scale, which is supported by the European Medicines Agency, is a sensitive and reliable patient-reported outcome instrument to assess symptoms in the functional dyspepsia/postprandial distress syndrome.

The latent structure of the functional dyspepsia symptom complex: a taxometric analysis

OBJECTIVES

Rome III introduced a subdivision of functional dyspepsia (FD) into postprandial distress syndrome and epigastric pain syndrome, characterized by early satiation/postprandial fullness, and epigastric pain/burning, respectively. However, evidence on their degree of overlap is mixed. We aimed to investigate the latent structure of FD to test whether distinguishable symptom-based subgroups exist.

METHODS

Consecutive tertiary care Rome II FD patients completed the dyspepsia symptom severity scale. Confirmatory factor analysis (CFA) was used to compare the fit of a single factor model, a correlated three-factor model based on Rome III subgroups and a bifactor model consisting of a general FD factor and orthogonal subgroup factors. Taxometric analyses were subsequently used to investigate the latent structure of FD.

KEY RESULTS

Nine hundred and fifty-seven FD patients (71.1% women, age 41 ± 14.8) participated. In CFA, the bifactor model yielded a significantly better fit than the two other models (χ² difference tests both p < 0.001). All symptoms had significant loadings on both the general and the subgroup-specific factors (all p < 0.05). Somatization was associated with the general (r = 0.72, p < 0.01), but not the subgroup-specific factors (all r < 0.13, p > 0.05). Taxometric analyses supported a dimensional structure of FD (all CCFI<0.38).

CONCLUSIONS AND INFERENCES

We found a dimensional rather than categorical latent structure of the FD symptom complex in tertiary care. A combination of a general dyspepsia symptom reporting factor, which was associated with somatization, and symptom-specific factors reflecting the Rome III subdivision fitted the data best. This has implications for classification, pathophysiology, and treatment of FD.

Changes in patients’ symptoms and gastric emptying after Helicobacter pylori treatment

AIM: To investigate the changes in clinical symptoms and gastric emptying and their association in functional dyspepsia (FD) patients.

METHODS: Seventy FD patients were enrolled and divided into 2 groups Helicobacter pylori (H. pylori)-negative group (28 patients), and H. pylori-positive group (42 patients). Patients in the H. pylori-positive group were further randomly divided into groups: H. pylori-treatment group (21 patients) and conventional treatment group (21 patients). Seventy two healthy subjects were selected as the control group. The proximal and distal stomach area was measured by ultrasound immediately after patients took the test meal, and at 20, 40, 60 and 90 min; then, gastric half-emptying time was calculated. The incidence of symptoms and gastric half-emptying time between the FD and control groups were compared. The H. pylori-negative and conventional treatment groups were given conventional treatment: domperidone 0.6 mg/(kg/d) for 1 mo. The H. pylori-treatment group was given H. pylori eradication treatment + conventional treatment: lansoprazole 30 mg once daily, clarithromycin 0.5 g twice daily and amoxicillin 1.0 g twice daily for 1 wk, then domperidone 0.6 mg/(kg/d) for 1 mo. The incidence of symptoms and gastric emptying were compared between the FD and control groups. The relationship between dyspeptic symptoms and gastric half-emptying time in the FD and control groups were analyzed. Then total symptom scores before and after treatment and gastric half-emptying time were compared among the 3 groups.

RESULTS: The incidence of abdominal pain, epigastric burning sensation, abdominal distension, nausea, belching, and early satiety symptoms in the FD group were significantly higher than in the control group (50.0% vs 20.8%; 37.1% vs 12.5%; 78.6% vs 44.4%; 45.7% vs 22.2%; 52.9% vs 15.3%; 57.1% vs 19.4%; all P < 0.05). The gastric half-emptying times of the proximal end, distal end, and the whole stomach in the FD group were slower than in the control group (93.7 ± 26.2 vs 72.0 ± 14.3; 102.2 ± 26.4 vs 87.5 ± 18.2; 102.1 ± 28.6 vs 78.3 ± 14.1; all P < 0.05). Abdominal distension, belching and early satiety had an effect on distal gastric half-emptying time (P < 0.05). Abdominal distension and abdominal pain had an effect on the gastric half-emptying time of the whole stomach (P < 0.05). All were risk factors (odds ratio > 1). The total symptom score of the 3 groups after treatment was lower than before treatment (P < 0.05). Total symptom scores after treatment in the H. pylori-treatment group and H. pylori-negative group were lower than in the conventional treatment group (5.15 ± 2.27 vs 7.02 ± 3.04, 4.93 ± 3.22 vs 7.02 ± 3.04, All P < 0.05). The gastric half-emptying times of the proximal end, distal end, and the whole stomach in the H. pylori-negative and H. pylori-treatment groups were shorter than in the conventional treatment group (P < 0.05).

CONCLUSION: FD patients have delayed gastric emptying. H. pylori infection treatment helps to improve symptoms of dyspepsia and is a reasonable choice for treatment in clinical practice.

Development and validation of a large, modular test meal with liquid and solid components for assessment of gastric motor and sensory function by non-invasive imaging

BACKGROUND

Current investigations of stomach function are based on small test meals that do not reliably induce symptoms and analysis techniques that rarely detect clinically relevant dysfunction. This study introduces the large 'Nottingham Test Meal' (NTM) for assessment of gastric motor and sensory function by non-invasive imaging.

METHODS

NTM comprises 400 mL liquid nutrient (0.75 kcal/mL) and 12 solid agar-beads (0 kcal) with known breaking strength. Gastric fullness and dyspeptic sensations were documented by 100 mm visual analogue scale (VAS). Gastric emptying (GE) were measured in 24 healthy volunteers (HVs) by gastric scintigraphy (GS) and magnetic resonance imaging (MRI). The contribution of secretion to gastric volume was assessed. Parameters that describe GE were calculated from validated models. Inter-observer agreement and reproducibility were assessed.

KEY RESULTS

NTM produced moderate fullness (VAS ≥30) but no more than mild dyspeptic symptoms (VAS <30) in 24 HVs. Stable binding of meal components to labels in gastric conditions was confirmed. Distinct early and late-phase GE were detected by both modalities. Liquid GE half-time was median 49 (95% CI: 36-62) min and 68 (57-71) min for GS and MRI, respectively. Differences between GS and MRI measurements were explained by the contribution of gastric secretion. Breaking strength for agar-beads was 0.8 N/m(2) such that median 25 (8-50) % intact agar-beads and 65 (47-74) % solid material remained at 120 min on MRI and GS, respectively. Good reproducibility for liquid GE parameters was present and GE was not altered by agar-beads.

CONCLUSIONS & INFERENCES

The NTM provided an objective assessment of gastric motor and sensory function. The results were reproducible and liquid emptying was not affected by non-nutrient agar-beads. The method is potentially suitable for clinical practice.

Upper gastrointestinal sensitivity to meal-related signals in adult humans - relevance to appetite regulation and gut symptoms in health, obesity and functional dyspepsia

Both the stomach and small intestine play important roles in sensing the arrival of a meal, and its physico-chemical characteristics, in the gastrointestinal lumen. The presence of a meal in the stomach provides a distension stimulus, and, as the meal empties into the small intestine, nutrients interact with small intestinal receptors, initiating the release of gut hormones, associated with feedback regulation of gastrointestinal functions, including gut motility, and signaling to the central nervous system, modulating eating behaviours, including energy intake. Lipid appears to have particularly potent effects, also in close interaction with, and modulating the effects of, gastric distension, and involving the action of gut hormones, particularly cholecystokinin (CCK). These findings have not only provided important, and novel, insights into how gastrointestinal signals interact to modulate subjective appetite perceptions, including fullness, but also laid the foundation for an increasing appreciation of the role of altered gastrointestinal sensitivities, e.g. as a consequence of excess dietary intake in obesity, or underlying the induction of gastrointestinal symptoms in functional dyspepsia (a condition characterized by symptoms, including bloating, nausea and early fullness, amongst others, after meals, particularly those high in fat, in the absence of any structural or functional abnormalities in the gastrointestinal tract). This paper will review the effects of dietary nutrients, particularly lipid, on gastrointestinal function, and associated effects on appetite perceptions and energy intake, effects of interactions of gastrointestinal stimuli, as well as the role of altered gastrointestinal sensitivities (exaggerated, or reduced) in eating-related disorders, particularly obesity and functional dyspepsia.

Functional Nausea in Children

Chronic nausea is a highly prevalent, bothersome, and difficult-to-treat symptom among adolescents. When chronic nausea presents as the predominant symptom and is not associated with any underlying disease, it may be considered a functional gastrointestinal disorder and named "functional nausea." The clinical features of functional nausea and its association with comorbid conditions provide clues to the underlying pathophysiological mechanisms. These may include gastrointestinal motor and sensory disturbances, autonomic imbalance, altered central nervous system pathways, or a combination of these. This review summarizes the current knowledge on mechanisms and treatment strategies for chronic, functional nausea in children.

Cellular and Molecular Mechanisms of Phenotypic Switch in Gastrointestinal Smooth Muscle

As a general rule, smooth muscle cells (SMC) are able to switch from a contractile phenotype to a less mature synthetic phenotype. This switch is accompanied by a loss of differentiation with decreased expression of contractile markers, increased proliferation as well as the synthesis and the release of several signaling molecules such as pro-inflammatory cytokines, chemotaxis-associated molecules, and growth factors. This SMC phenotypic plasticity has extensively been investigated in vascular diseases, but interest is also emerging in the field of gastroenterology. It has in fact been postulated that altered microenvironmental conditions, including the composition of microbiota, could trigger the remodeling of the enteric SMC, with phenotype changes and consequent alterations of contraction and impairment of gut motility. Several molecular actors participate in this phenotype remodeling. These include extracellular molecules such as cytokines and extracellular matrix proteins, as well as intracellular proteins, for example, transcription factors. Epigenetic control mechanisms and miRNA have also been suggested to participate. In this review key roles and actors of smooth muscle phenotypic switch, mainly in GI tissue, are described and discussed in the light of literature data available so far. J. Cell. Physiol. 231: 295-302, 2016. © 2015 Wiley Periodicals, Inc.

Rome III functional dyspepsia subdivision in PDS and EPS: recognizing postprandial symptoms reduces overlap

BACKGROUND

The Rome III consensus proposed to subdivide functional dyspepsia (FD) into two groups: meal-related dyspepsia or postprandial distress syndrome (PDS), and meal-unrelated dyspepsia or epigastric pain syndrome (EPS). However, in clinical practice, overlap between both has been reported to be as high as 50%, thereby hampering clinical applicability. Although EPS is referred to as meal-unrelated dyspepsia, relationship of symptoms to meal ingestion in this category is not formally addressed in the Rome III criteria. The aim of our study was to investigate whether taking into account the relationship of epigastric pain and nausea to meal ingestion may help to improve separation between EPS and PDS.

METHODS

Consecutive ambulatory tertiary-care patients with epigastric symptoms filled out Rome III gastro-duodenal questionnaires with supplementary questions. Those fulfilling Rome III FD criteria and a negative endoscopy were identified and subdivided into 'pure' PDS patients (i.e., meeting criteria for PDS without EPS symptoms), 'pure' EPS (i.e., meeting criteria for EPS without PDS symptoms), and overlapping PDS-EPS (i.e., symptoms of both PDS and EPS).

KEY RESULTS

Out of 1029 patients coming to endoscopy, 199 patients (73% females, 45.9 ± 1.0 years, BMI: 23.7 ± 0.35) fulfilled Rome III FD diagnostic criteria, and could be subdivided into pure PDS (69% females, 49 ± 2 years, BMI: 24.2 ± 0.61), pure EPS (59% females, 47.4 ± 2 years, BMI: 23.2 ± 0.97) and overlapping PDS-EPS (64% females, age 43 ± 5 years, BMI: 26 ± 0.46). Compared with pure EPS patients, the overlap PDS-EPS patients were characterized by a higher occurrence of postprandial epigastric pain (70% vs 31%, p < 0.0001), while the occurrence of epigastric pain in between meals was borderline (48% vs 38%, p = 0.05). In addition, the overlap PDS-EPS patients reported a higher occurrence of postprandial nausea (23% vs 0%, p < 0.0001), and bloating (79% vs 28%, p = 0.0001). When postprandial epigastric pain and postprandial nausea were considered as PDS symptoms, the 'adapted' subdivision identified 48% pure PDS, 16% pure EPS, and 36% overlapping PDS-EPS patients.

CONCLUSIONS & INFERENCES

EPS and PDS symptoms frequently coexist in FD patients, with postprandial symptoms substantially contributing to the overlap. A more rigorous linking of postprandially occurring symptoms to PDS, regardless of their qualitative nature, may improve the separation between PDS and EPS.

Novel sequential stress model for functional dyspepsia: Efficacy of the herbal preparation STW5

BACKGROUND

Many screening procedures for agents with potential usefulness in functional dyspepsia (FD) rely on animals exposed to stress early in life (neonatal maternal separation, NMS) or in adulthood (restraint stress, RS).

PURPOSE

Since many clinical cases of FD have been associated with stress in early life followed by stress in adulthood, a sequential model simulating the clinical situation is described. To explore the validity of the model, the efficacy of STW5, a multicomponent herbal preparation of proven usefulness in FD, was tested.

STUDY DESIGN/METHODS

A sequential stress model established where rats are exposed to NMS after birth followed later by RS in adulthood. Stress hormones and ghrelin were measured in plasma, while responsiveness of stomach fundus strips to smooth muscle stimulants and relaxants was assessed ex-vivo. The effectiveness of treatment with STW5 a few days before and during exposure to RS in preventing changes induced by the stress model is reported and compared to its efficacy when used in animals subjected to RS alone.

RESULTS

Responses to both stimulants and relaxants were reduced to various extents in the studied models, but treatment with STW5 tended to normalize gastric responsiveness. Plasma levels of ghrelin, corticosterone releasing factor, and corticosterone were raised by RS as well as the sequential model. Treatment with STW5 tended to prevent the deranged parameters.

CONCLUSION

The sequential stress model has a place in drug screening for potential usefulness in FD as it simulates more the clinical setting. Furthermore, the findings shed more light on the mechanisms of action of STW5 in FD.

Effect of acotiamide on gastric emptying in healthy adult humans

BACKGROUND

Acotiamide is a first-in-class drug that is used to treat functional dyspepsia (FD). It is considered that acotiamide acts as an antagonist on muscarinic autoreceptors in the enteric nervous system and inhibits acetylcholinesterase activity. We examined the effect of acotiamide on gastric emptying in healthy adult humans.

MATERIALS AND METHODS

Twelve healthy adult males were enrolled in this double-blind crossover study. Acotiamide or placebo was administered orally in the 12 subjects 30 min before ingestion of a nutritional liquid meal (400 Kcal/400 mL). Six of the 12 participants took 100 mg of acotiamide or placebo, and six of the 12 participants took 300 mg of acotiamide or placebo in a double-blind crossover fashion. All subjects underwent measurement of gastric emptying by the (13) C breath test.

RESULTS

After the meal with placebo was ingested, the %dose/h curve ascended. The %dose/h curve after a meal with 100 or 300 mg of acotiamide ascended in an identical manner compared with the results with placebo. No significant differences were observed at any studied time point, and there were no significant changes in gastric emptying parameters (gastric emptying coefficient, t-1/2ex and t-lag ex).

CONCLUSIONS

A single administration of 100 or 300 mg of acotiamide did not affect gastric emptying after a liquid meal in healthy adult humans. Acotiamide has profound effects on restoring delayed gastric emptying and impaired accommodation in patients with FD but may have no effect on gastric emptying in healthy subjects. Such pharmacological actions have not been observed in previous gastroprokinetic studies.

Radionuclide gastric emptying scintigraphy in patients with functional dyspepsia

AIM: To assess the use of gastric emptying scintigraphy with solid test meal in patients with functional dyspepsia (FD) and normal subjects.

METHODS: Forty-two patients with FD and 30 normal subjects underwent gastric emptying scintigraphy with 99mTc-DTPA labeling egg solid meal. The standard curve of gastric emptying was plotted to figure out the half-time of gastric emptying and emptying rate at 60 and 120 min by three different methods: method 1 with the radioactivity of the anterior view, method 2 with the mean value of and method 3 with the geometric mean of the radioactivity of the anterior and pastier views as the y-axis of the standard curve of gastric emptying, respectively. The differences in half-times and gastric emptying rates at 60 and 120 min figured out by the three different methods were compared between patients with FD and normal subjects.

RESULTS: One-way analysis of variance was performed to compare the differences in half-times. The half-time figured out by method 1 did not differ significantly from that by method 2 (P = 0.808, P = 0.243, P > 0.05), but the half-time figured out by method 3 differed significantly from those by methods 1 and 2 (1 vs 3: P = 0.007, P = 0.000; 2 vs 3: P = 0.035, P = 0.023; P < 0.05 for all). The half-time and gastric emptying rates at 60 and 120 min differed significantly between FD patients and normal subjects (P = 0.000). Method 1 figured out 80.9%, method 2 figured out 71.4% and method 3 figured out 90.5% of FD patients had longer half-time than normal subjects.

CONCLUSION: Radionuclide 99mTc-DTPA gastric emptying scintigraphy with solid meal is a simple, accurate, quantitative and physiologic method for measuring gastric motility in FD patients.