Gastric Emptying Breath Test Research Articles

Short- and long-term reproducibility of body surface gastric mapping using the Gastric Alimetry® system.

Many diagnostic tests for gastroduodenal symptoms, such as gastric emptying scintigraphy (GES), gastric emptying breath tests (GEBT), and electrogastrography (EGG) show variable intra-individual reproducibility over time. This study investigated the short- and long-term reproducibility of body surface gastric mapping (BSGM), a non-invasive test for assessing gastric function, in controls and patients with chronic gastroduodenal disorders. Participants completed three standardized BSGM tests using Gastric Alimetry® (Alimetry, New Zealand). The test encompassed a fasting baseline (30 min), a 482 kCal standard meal, and a 4 h postprandial recording. The first two tests were >6 months apart and the last occurred ~1 week after the second test, to evaluate long and short-term reproducibility. Fourteen patients with upper gastrointestinal symptoms and 14 healthy controls were recruited. There were no significant differences in any BSGM metrics between the tests at short and long term (all p > 0.180). Lin's concordance correlation coefficients (CCC) for the primary metrics were high, ranging from 0.58 to 0.96, with intra-individual coefficients of variance (CVintra) ranging from 0.2% to 1.9%. Reproducibility was higher, and intra-individual variation lower, than in previous studies of GES (CCC = 0.54-0.83, CVintra = 3%-77%), GEBT (CVintra = 8%-11%), and EGG (CVintra = 3%-78%). BSGM spectral metrics demonstrate high reproducibility and low intra-individual variation at both short and long term, with superior results to comparable tests. The high reproducibility of Gastric Alimetry supports its role as a diagnostic aid for gastric dysfunction and a reliable tool for evaluating treatment outcomes and disease progression over time.

Diabetic Gastroparesis: Navigating Pathophysiology and Nutritional Interventions

Diabetic gastroparesis (DGP) delays gastric emptying in diabetes patients, notably impacting those with type 1 and long-standing type 2 diabetes. Symptoms include early satiety, fullness, appetite loss, bloating, abdominal pain, and vomiting, arising from slow stomach-to-intestine food movement. DGP’s unpredictable nature complicates diagnosis and blood glucose management, leading to severe complications like dehydration, malnutrition, and bezoar formation. Understanding DGP’s mechanisms is crucial for effective management. Vagal dysfunction, disturbances in the interstitial cells of Cajal, reduced neural nitric oxide synthase, and increased oxidative stress contribute to the complex pathophysiology. Accurate diagnosis demands a comprehensive approach, utilizing tools like gastric scintigraphy and the Gastric Emptying Breath Test. Considering the complex relationship between DGP and glycemia, managing blood glucose levels becomes paramount. Nutritional interventions, tailored to each patient, address malnutrition risks, emphasizing smaller, more frequent meals and liquid consistency. DGP’s complex nature necessitates collaborative efforts for enhanced diagnostic strategies, improved pathophysiological understanding, and compassionate management approaches. This comprehensive approach offers hope for a future where individuals with DGP can experience improved well-being and quality of life.

Physiological characterization of gastric emptying using high-resolution antropyloroduodenal manometry.

Delayed gastric emptying (GE) has been associated with antral and pyloric dysmotility. We aimed to characterize differences in the antral, duodenal, and pyloric motility profiles associated with delayed GE, using high-resolution antropyloroduodenal manometry (HR-ADM). Patients referred for HR-ADM for dyspeptic symptoms performed a concurrent GE breath test (NCT01519180 and NCT04918329). HR-ADM involved 36 sensors 1 cm apart, placed across the pylorus. Interdigestive and postprandial periods were identified. Antral, pyloric, and duodenal motor profiles were analyzed recording the frequency, amplitude, and propagative nature of contractions for each period. Plots of patients with normal and delayed GE were compared. Sixty patients underwent both HR-ADM and GE tests. Twenty-five and 35 patients had delayed and normal GE, respectively. Antral and duodenal motor profiles were not different between the two groups during the interdigestive period. During the postprandial period, a lower frequency of antral contractions was associated with delayed GE (2.22 vs. 1.39 contractions/min; P = 0.002), but no difference in mean contraction amplitude was observed. The pyloric region was identified in all the patients and pylorospasms, defined as 3 min of repeated isolated pyloric contractions, were more frequent in patients with delayed GE (32.0% vs. 5.7%; P = 0.02) during the postprandial period. No difference in duodenal contraction profiles was observed. Manometric profile alterations were observed in 72% of the patients with delayed GE, with 56% having a low frequency of antral contractions. Using HR-ADM, patients with delayed GE displayed different postprandial antropyloric motility as compared with patients with normal GE.NEW & NOTEWORTHY High-resolution antropyloroduodenal manometry (HR-ADM) allows precise characterization of antral, pyloric, and duodenal motility, although its association with gastric emptying (GE) has been poorly investigated. Concurrent HR-ADM with GE measurement showed a lower frequency of antral postprandial contractions and an increased frequency of postprandial pylorospasms in patients with delayed GE. HR-ADM could, therefore, be useful in the future to better select patients for treatments targeting the pylorus.

Nausea is the only symptom associated with delayed gastric emptying in pediatric functional dyspepsia patients.

Functional dyspepsia (FD) is a heterogeneous functional gastrointestinal disorder (FGID) with a highly prevalent symptom complex. The aim of our study is to investigate the relation between symptoms of FD and results of gastric emptying (GE) breath test in children. This study included patients (6-17 years old) presented at the general gastroenterology outpatient clinic with dyspeptic symptoms (Rome IV criteria) and underwent careful history taking with clinical examination. A GE breath test with a 13 C-octanoic acid labeled (250 kcal) solid meal was performed and dyspepsia symptom scores, clarified using pictograms for postprandial fullness, bloating, belching, nausea, vomiting, epigastric pain and burning, were obtained every 15 min ranging from 0 to 4 for a total of 240 min. The severity of the complaints (overall and individual symptoms) as displayed by the symptom questionnaire was compared between normal and delayed GE groups. The relationship between GE time and the severity of FD symptoms was assessed using Mann-Whitney test. Thirty nine FD patients (55% girls; mean age: 11.9 ± 3.3 years) participated in the study. Of these, 43% had delayed GE. The overall symptom severity in patients with delayed GE was similar to the symptoms of patients with a normal GE rate (149.5 ± 12.7 points vs. 123.9 ± 9.0; p = 0.19). Individual symptoms scores showed only nausea to be significantly increased in the group with delayed GE (21.5 ± 1.9 points vs. 33.2 ± 4.6; p = 0.048, p < 0.1). Especially in children with nausea as presenting symptom of FD, a low threshold should be withheld to perform a GE breath test.

Bariatric endoscopic antral myotomy: first-in-human proof of concept of a novel therapeutic method to delay gastric emptying and induce weight loss

Bariatric endoscopic antral myotomy: first-in-human proof of concept of a novel therapeutic method to delay gastric emptying and induce weight loss

IBCOx-12 The Endoscopic Sleeve Gastroplasty Produces Durable Physiologic Changes: Results from a Randomized US Clinical Trial

Abstract Background Obesity is associated with faster gastric emptying and altered appetite. Endoscopic sleeve gastroplasty (ESG) has gained global adaptation, but our understanding of its physiologic mechanism of action and durability is limited. We sought to determine changes in gastric emptying, weight loss, and eating behaviors after ESG when compared to moderate-intensity lifestyle interventions (LS) in the short and long-term. Methods This is an a priori designed sub-study of a large ongoing multicenter US RCT (MERIT trial), where adults with BMI 30-40 kg/m2 were randomized to ESG versus moderate-intensity LS alone. We measured gastric emptying (T1/2) using a 4- hour gastric emptying breath test at baseline, 3 and 12 months into the study. We reported weight loss outcomes as percent total body weight lost (%TBWL). Changes in three eating behaviour domains (Cognitive Restraint [CR], Emotional Eating [EE], Uncontrolled Eating [UE]) were assessed using the Three-Factor Eating Questionnaire (TFEQ) at 6 months. The primary outcome was the change in T1/2 (minutes) at 3 months, and secondary outcomes were changes in T1/2 at 12 months, %TBWL, and eating behaviours. We used the t-test for the analyses. Linear regression was performed to determine the association between gastric emptying and weight loss. Results 46 patients were randomized in the study (ESG n=26; LS n=20). Baseline characteristics were similar between the two groups. Out of n=46, n=43, and n=31 subjects have reached 3 and 12 months, respectively. Three patients dropped out of the study. At 3 months, T1/2 (minutes) was delayed in the ESG group (n=24) compared to the LS group (n=19) (170.8 vs. 87.5; p&amp;lt;0.0001). At 12 months, T1/2 was still delayed in the ESG group (n=17) vs. control group (n=14) (133.4 vs. 87.6; p=0.0005), and delayed compared to baseline. %TBWL in the ESG group was 12.3%, 15.1% and 15.7% at 3, 6 and 12 months (p &amp;lt;0.01 compared to baseline), while it was 2.3%, 2.2% and 0.3% (p&amp;gt;0.05 compared to baseline) in the LS group. Greater delays in gastric emptying at 3 months correlated with weight loss at all time points. (Figure 1) At 6 months, significant improvements in the EE and UE domains were seen in both groups, but for CR, only significant improvements were seen in the ESG group. Percent total fasting ghrelin, GLP-1, and PYY increased at 12 months in the ESG group compared to LS control (51%, 51%, 6.3% vs. -9%, 4%, -10.5%). Only 1 SAE managed endoscopically with full recovery was reported in the ESG group. Conclusions ESG produces sustained physiologic alterations in appetite regulatory pathways and durable weight-loss. This provides further evidence supporting the clinical adoption of the technique as a durable and effective obesity therapy.

Effects on physiologic measures of appetite from intragastric balloon and endoscopic sleeve gastroplasty: results of a prospective study.

Background:Endoscopic bariatric therapies can help address widening management gaps in obesity. Their ability to facilitate weight loss is largely tied to influences on appetite through perturbations of gastric emptying and accommodation. As these tools gain traction in obesity therapy, their physiologic underpinnings require exploration, which may enhance efficacy, tolerance, and patient-tailored care.Methods:We prospectively assessed consecutive subjects with fluid-filled intragastric balloons (IGBs) (n = 18) placed between October 2016 and June 2017 or underwent endoscopic sleeve gastroplasty (ESG) (n = 23) from March 2018 to June 2018. Patients underwent physiologic appraisal at 3 months with 13C-spirulina-based gastric emptying breath test to determine time to half emptying (T50), as well as maximum tolerated volume (MTV) of a standard nutrient drink test. Changes in T50 and MTV at 3 months were compared with percent total body weight loss (%TBWL) at 3 and 6 months using best-fit linear regression.Results:The change in T50 at 3 months correlated with %TBWL at 3 months for IGB (P = 0.01) and ESG (P = 0.01) but with greater impact on %TBWL in IGB compared to ESG (R2 = 0.42 vs. 0.26). Change in T50 at 3 months was predictive of weight loss at 6 months for IGB (P = 0.01) but not ESG (P = 0.11). ESG was associated with greater decrease in MTV compared to IGB (340.25 ± 297.97 mL vs. 183.00 ± 217.13 mL, P = 0.08), indicting an enhanced effect on satiation through decreased gastric accommodation. Changes in MTV at 3 months did not correlate with %TBWL for either IGB (P = 0.26) or ESG (P = 0.49) but trended toward significance for predicting %TBWL at 6 months for ESG (P = 0.06) but not IGB (P = 0.19).Conclusion:IGB and ESG both induce weight loss but likely through distinct gastric motor function phenotypes, and gastric emptying may predict future weight loss in patients with IGB.

Plasma GLP-1 Response to Oral and Intraduodenal Nutrients in Health and Type 2 Diabetes-Impact on Gastric Emptying.

Both gastric emptying and the secretion of glucagon-like peptide-1 (GLP-1) are major determinants of postprandial glycemia in health and type 2 diabetes (T2D). GLP-1 secretion after a meal is dependent on the entry of nutrients into the small intestine, which, in turn, slows gastric emptying. To define the relationship between gastric emptying and the GLP-1 response to both oral and small intestinal nutrients in subjects with and without T2D. We evaluated: (i) the relationship between gastric emptying (breath test) and postprandial GLP-1 levels after a mashed potato meal in 73 individuals with T2D; (ii) inter-individual variations in GLP-1 response to (a) intraduodenal glucose (4 kcal/min) during euglycemia and hyperglycemia in 11 healthy and 12 T2D, subjects, (b) intraduodenal fat (2 kcal/min) in 15 T2D subjects, and (c) intraduodenal protein (3 kcal/min) in 10 healthy subjects; and (iii) the relationship between gastric emptying (breath test) of 75 g oral glucose and the GLP-1 response to intraduodenal glucose (4 kcal/min) in 21 subjects (9 healthy, 12 T2D). The GLP-1 response to the mashed potato meal was unrelated to the gastric half-emptying time (T50). The GLP-1 responses to intraduodenal glucose, fat, and protein varied substantially between individuals, but intra-individual variation to glucose was modest. The T50 of oral glucose was related directly to the GLP-1 response to intraduodenal glucose (r = 0.65, P = 0.002). In a given individual, gastric emptying is not a determinant of the postprandial GLP-1 response. However, the intrinsic gastric emptying rate is determined in part by the responsiveness of GLP-1 to intestinal nutrients.

Administration of a standard dose of vonoprazan fumarate delays gastric emptying in Japanese healthy adults: a prospective clinical trial.

There is no established view of how gastric acid suppression affects the time for gastric emptying. Vonoprazan fumarate shows potent and durable gastric acid inhibitory effects, but its effects on gastric emptying have not been studied widely. We investigated the effects of vonoprazan fumarate on gastric emptying and measured serum gastrin and plasma ghrelin levels in healthy adults. Ten participants were administered 10mg vonoprazan fumarate daily for 14days, then 20mg vonoprazan fumarate daily for 14days. The gastric emptying breath test was performed and serum gastrin levels were measured at baseline and after each medication administration period. The protocol was then repeated, with the gastric emptying breath test and serum gastrin and plasma desacyl-ghrelin levels measured at baseline and the end of the medication trial. Mean serum gastrin levels increased in a dose-dependent manner [baseline: 104.7 ± 50.4, after 10mg protocol: 328 ± 123.8, after 20mg protocol: 555 ± 378.8 (pg/mL, mean ± standard deviation), p = 0.0008]. There was a significant difference between the gastric emptying breath test Tmax at baseline and just after the 20mg protocol (baseline: 45.5 ± 15.3, after 20mg protocol: 60.5 ± 19.6min, p = 0.0418). Plasma desacyl-ghrelin levels increased significantly just after the 20mg protocol compared to those at baseline [baseline: 222.3 ± 106.4, after 20mg protocol: 366.2 ± 178.6 (fmol/mL), p = 0.0008]. In healthy adults, 14days of vonoprazan fumarate administration at 20mg/day delayed gastric emptying. This clinical trial was registered in the University hospital Medical Information Network Clinical Trial Registry (Trial No. UMIN000039199 and UMIN000042969).

The Effect of Continuous Intake of Lactobacillus gasseri OLL2716 on Mild to Moderate Delayed Gastric Emptying: A Randomized Controlled Study.

Probiotics have been suggested to be effective for functional dyspepsia, but their effect on gastric motility is not clear. We evaluated the effect of Lactobacillus gasseri OLL2716 (LG21 strain) on mild to moderate delayed gastric emptying by a double-blind, parallel-group, placebo-controlled, randomized trial. Participants (n = 28) were randomly assigned to ingest LG21 strain-containing yogurt (LG21 strain group) or LG21 strain-free yogurt (placebo group) for 12 weeks. The 13C gastric emptying breath test was performed to measure the gastric emptying rate over time following ingestion of a liquid meal, and the time to reach the peak (Tmax) was used as an indicator of gastric emptying. We also measured the salivary amylase concentration, an indicator of autonomic dysfunction under stress. The per-protocol population (n = 27, male n = 4, female n = 23) was evaluated for efficacy. When a ≥30% reduction in the difference between participant’s Tmax and the Japanese mean Tmax was defined as an improvement, the odds ratio of improvement in delayed gastric emptying compared to placebo after 12 weeks was 4.1 (95% confidence interval, 0.8 to 20.2). Moreover, salivary amylase concentrations were significantly lower than in the placebo group, indicating an improvement in autonomic function. The present data were not enough to support the beneficial effects of the LG21 strain on delayed gastric emptying. However, if we define the odds ratio in further study investigated with a larger number of participants, LG21 strain might be expected to have some impact on delayed gastric emptying.

Relationship between symptoms during a gastric emptying study, daily symptoms and quality of life in patients with diabetes mellitus.

Gastric emptying is of limited utility for predicting the severity of symptoms in patients with diabetes mellitus and gastrointestinal symptoms. We evaluated the extent to which symptoms recorded during a 13 C-spirulina-based gastric emptying breath test (GEBT) or scintigraphy predicting the severity of daily symptoms in diabetes mellitus. Gastric emptying, symptoms during a gastric emptying study, either scintigraphy (n=38) or GEBT (n=111), and daily gastrointestinal symptoms were evaluated in 149 patients with diabetes mellitus and variably severe gastrointestinal symptoms. Gastric emptying was normal, delayed, and rapid in 37%, 52%, and 9% measured with the GEBT and 55%, 34%, and 11% of patients measured with scintigraphy; differences between GEBT and scintigraphy were not significant. Daily symptoms were moderately severe or more intense in 58% and 21% of patients undergoing scintigraphy and GEBT (P<0.0001). Symptoms during the GEBT (46%) and emptying thalf (3%) explained 50% of the variance in daily symptoms in the GEBT group. In the scintigraphy group, symptoms explained 29% of this variance; the thalf was insignificant. Patients who reported that one or more symptoms were more severe than the others during the GE study were more likely (OR 3.98, 95% CI 2.16, 7.33) to report the same symptom(s) as being the most severe in the daily diary. Symptoms during a GEBT and to a lesser extent during scintigraphy, but not gastric emptying predict the severity of daily symptoms and may serve as a biomarker in patients with diabetes mellitus.

Gastric peroral endoscopic pyloromyotomy for decompensated gastroparesis: comprehensive motility analysis in relation to treatment outcomes.

Background and study aims There are no reliable data to predict which patients with gastroparesis (GP) would benefit the most from gastric peroral endoscopic pyloromyotomy (G-POEM). The aim of the present study was to assess whether antro-duodenal motility patterns and pyloric distensibility can predict the outcome of G-POEM in patients with decompensated GP. Patients and methods In an open-label study, patients with GP and refractory symptoms were eligible for treatment with G-POEM if treatment attempts according to a standardized stepwise protocol had failed. Baseline assessment included Gastroparesis Cardinal Symptom Index (GCSI), C13-octanoic gastric emptying breath test and high-resolution antro-duodenal manometry. Pyloric distensibility using EndoFlip measurements was assessed at baseline and 3 months after the procedure. Explorative analyses were performed on potential predictors of response using logistic regression analyses. Results Twenty-four patients with decompensated GP underwent G-POEM. At baseline, 78.3 % and 61.9 % of patients showed antral hypomotility and neuropathic motor patterns, respectively. The technical success rate was 100 % (24/24). Mean GCSI improved significantly at 3, 6, and 12 months after G-POEM ( P = 0.01). Median distensibility index (DI) improved significantly as compared with baseline (7.5 [6.9;11.7] vs. 5.3[3.1;8.1], P = 0.004). A significant correlation was found between clinical response at 6 months and pyloric DI improvement ( P = 0.003). No potential predictors of clinical response after G-POEM could be identified in an explorative analysis. Conclusions G-POEM improved pyloric distensibility patterns in patients with decompensated GP. Clinical response at 6 months after G-POEM was associated with pyloric distensibility improvement. However, no potential predictors of response could be identified from either antro-duodenal motility patterns or pyloric distensibility.

Gastric emptying in healthy children using the Spirulina breath test: The impact of gender, body size, and pubertal development

AbstractBackgroundThere are no pediatric norms for gastric emptying (GE) measured by nuclear scintigraphy. The 13C‐labeled, stable isotope GE breath test (GEBT) is a non‐radioactive alternative. We aimed to determine normative GEBT ranges in a cohort of healthy children and examine the influence of age, gender, puberty, and body surface area (BSA).MethodsHealthy children ages 8–18 years completed the [13C]‐Spirulina platensis GEBT after an overnight fast. Breath samples were collected at baseline, every 15 min × 1 h, then every 30 min for 4 h total. The 13CO2 excretion rate was determined by the change in 13CO2/12CO2 over time in each breath sample, expressed as kPCD (Percent 13C Dose excreted/min). A mixed model with random time was used for multivariable analysis and outcome fit into a quadratic model.Key ResultsThe 100 subjects completed the test meal within allotted time. Median (IQR) age was 13.5 (11.3–15.5) years; 51% were female. Females had lower 13CO2 excretion rates (slower GE) than males across time (p &lt; 0.001) while decreased excretion rates correlated with higher BSA (p = 0.015). Gender differences were also noted within pubertal stages with females showing slower GE. Multivariable analysis suggested that pre‐pubertal children have faster GE than both peri‐ and post‐pubertal groups (p &lt; 0.0001).Conclusions &amp; InferencesGender, puberty, and BSA influence GE rates in healthy children more than age. Although further data are needed, pubertal stage and hormonal influences may be unique factors to consider when assessing GE in children.

Gastric emptying in health and type 2 diabetes: An evaluation using a 75 g oral glucose drink

AimGastric emptying is a major determinant of the glycaemic response to carbohydrate and is frequently abnormal in type 2 diabetes (T2DM). There is little information about how chronic glycaemic control affects gastric emptying in T2DM. We evaluated gastric emptying of a 75 g glucose drink in community-based patients with T2DM of short duration with good or poor glycaemic control, and compared this to young and older controls. MethodsT2DM patients managed by diet and/or metformin, either well-controlled or poorly-controlled, together with young and age-matched older controls without diabetes, consumed a 75 g oral glucose drink containing 150 mg 13C-acetate for evaluation of gastric emptying (breath test) and blood glucose over 180 min. ResultsThe gastric half-emptying time (T50) was longer in the older than the young non-diabetic subjects (P = 0.041), but shorter in well-controlled T2DM patients than age-matched older controls (P = 0.043). The T50 in poorly-controlled T2DM patients was shorter than in older controls (P = 0.006), but similar to young non-diabetic subjects. ConclusionsGastric emptying of a glucose drink is delayed with ageing, but more rapid in patients with T2DM of relatively short duration, regardless of their glycaemic status. These observations support interventions that slow gastric emptying to improve postprandial glycaemia in these patients with T2DM.

Joint Hypermobility Syndrome in Patients With Functional Dyspepsia.

INTRODUCTION:The pathophysiology underlying functional dyspepsia (FD) is multifactorial and focuses on gastric sensorimotor dysfunction. Recent studies demonstrated that joint hypermobility syndrome (JHS) is strongly associated with unexplained dyspeptic symptoms in patients attending gastrointestinal clinics. We aimed to study the relationship between symptoms, gastric sensorimotor function, and JHS in FD patients.METHODS:Tertiary care FD patients who underwent a gastric barostat study and a gastric emptying breath test with 13C-octanoic acid were recruited for assessment of JHS. The presence of JHS was evaluated by a 2-phase interview and clinical examination that included major and minor criteria of the Brighton classification.RESULTS:A total of 62 FD patients (68% women, age 44 ± 1.8 years, and body mass index: 21.7 ± 0.7 kg/m2) accepted to participate in the study. JHS was diagnosed in 55% of FD patients. Assessed symptom profiles during the visit did not differ between the groups. Delayed gastric emptying was not significantly more common in JHS group compared with non-JHS group (JHS group 32% vs non-JHS group 16%, P = 0.31). Prevalence of hypersensitivity to distention (JHS group 24% vs non-JHS group 29%, P = 0.76) and impaired gastric accommodation (JHS group 38% vs non-JHS group 42%, P = 0.79) was similar in patients with or without JHS. No correlations were found between the Beighton hypermobility score and gastric compliance (r = 0.09).DISCUSSION:A large subset of this study cohort of tertiary care FD patients has coexisting JHS. We did not identify any specific differences in gastric sensorimotor function between patients with and without JHS. Further prospective research will be required to elucidate the relationship between JHS, a multisystemic disorder with widespread manifestations, and FD symptoms.

The Effect of Isoleucine Supplementation on Body Weight Gain and Blood Glucose Response in Lean and Obese Mice.

Chronic isoleucine supplementation prevents diet-induced weight gain in rodents. Acute-isoleucine administration improves glucose tolerance in rodents and reduces postprandial glucose levels in humans. However, the effect of chronic-isoleucine supplementation on body weight and glucose tolerance in obesity is unknown. This study aimed to investigate the impact of chronic isoleucine on body weight gain and glucose tolerance in lean and high-fat-diet (HFD) induced-obese mice. Male C57BL/6-mice, fed a standard-laboratory-diet (SLD) or HFD for 12 weeks, were randomly allocated to: (1) Control: Drinking water; (2) Acute: Drinking water with a gavage of isoleucine (300 mg/kg) prior to the oral-glucose-tolerance-test (OGTT) or gastric-emptying-breath-test (GEBT); (3) Chronic: Drinking water with 1.5% isoleucine, for a further six weeks. At 16 weeks, an OGTT and GEBT was performed and at 17 weeks metabolic monitoring. In SLD- and HFD-mice, there was no difference in body weight, fat mass, and plasma lipid profiles between isoleucine treatment groups. Acute-isoleucine did not improve glucose tolerance in SLD- or HFD-mice. Chronic-isoleucine impaired glucose tolerance in SLD-mice. There was no difference in gastric emptying between any groups. Chronic-isoleucine did not alter energy intake, energy expenditure, or respiratory quotient in SLD- or HFD-mice. In conclusion, chronic isoleucine supplementation may not be an effective treatment for obesity or glucose intolerance.

In memory of Gaston Vantrappen, 1927‐2020

Gaston Vantrappen passed away on February 11, 2020, in the presence of his wife and family. As the youngest of his mentees, I want to reflect on the significance of his life for the field of Neurogastroenterology and Motiliy. With the passing away of Gaston Vantrappen, the world lost a truly remarkable clinician, mentor and researcher, and a man with great leadership qualities. His dedication to Gastrointestinal Motility, as it was called in his pioneering days, and the way he led the field with innovative concepts, techniques, and approaches continue to resonate up to this day. His passion remains a source of inspiration to all those who had the privilege of working with him. Gaston Vantrappen was born in Welle, Belgium, on October 27, 1927. After obtaining his Medical Doctor Degree at Leuven University in 1953, he specialized in internal medicine at Leuven University Hospital Saint Raphael and Northwestern University Medical School in Chicago. He was appointed staff member in Internal Medicine at Leuven University Hospitals in 1962 and professor of Medicine in 1965 at Leuven University. In 1978, he became chief of the newly created service of Gastroenterology, and in 1979 he became chairman of Internal Medicine in the Leuven University Hospitals. Gaston Vantrappen was a true pioneer of motility research. He was among the first to perform esophageal manometry, and he set the standard for achalasia therapy using pneumatic dilations. In the 1970s and 1980s, achalasia patients came from all over the world to be treated by Prof. Vantrappen. He was also the first to describe the migrating motor complex in man and to demonstrate that its absence was associated with small intestinal bacterial overgrowth. His team unraveled the role of motilin as a trigger for human interdigestive motility and also pioneered ambulatory esophageal manometry and intestinal luminal EMG recording, developed, and validated the first gastric emptying breath test in the 1990s and established erythromycin and other macrolides as prokinetics acting through the motilin receptor. He was internationally very active, contributing with multiple abstracts and presentations to European and International Motility meetings and to Digestive Disease Week of the American Gastroenterology Association. He organized international motility meetings in Leuven in 1975 and 1986, and in Bruges in 1992. He founded the European Society of Neurogastroenterology and Motility in Leuven in 1982, together with Martin Wienbeck, David Wingate, and others. His legacy comprises not only the European Motility Society and his accomplishments in clinical research, but also large numbers of national and international internists and gastroenterologists who trained with him, and the very successful gastroenterology clinical and research unit he created in Leuven. In the motility field, he mentored several researchers who made significant contributions, such as Jan Hellemans, Jozef Janssens, Theo Peeters, Yvo Ghoos, Karel Geboes, Georges Coremans, Gilbert Ghillebert and Inge Depoortere in Belgium, and Salvatore Cucchiara, Raymond Jian, Jiande Chen, Anna Accarino, Daniel Sifrim, Apostolos Mantides, and Vito Annese, among others, internationally. We now had to say goodbye to an exceptional clinician and academic, who is one of the true big contributors to our field. His impact is perpetuated through his research, through the gastrointestinal motility bastion which the Leuven group continues to be, and through the large numbers of privileged clinicians, gastroenterologists and researchers who trained with him.

Gastroparesis in the 2020s: New Treatments, New Paradigms.

This review highlights recent work that will lead to near-term advances in the understanding and treatment of gastroparesis (Gp). Major current advancements in the pathophysiology of Gp, include recognition of the SIP syncytium as the pacemaking unit rather than ICC alone and that Gp may be part of a pan-enteric autoimmune and/or autonomic disorder with macrophage imbalance. The development of newer techniques to assess gastric emptying (gastric emptying breath test and wireless motility capsule) and pyloric distensibility (EndoFLIP®) are allowing clinicians better characterization of their patients. In addition to pharmaceutical compounds in the pipeline, neuromodulation and endosurgical techniques, such as G-POEM, may help address refractory Gp. We expect that the 2020 decade will witness exciting developments. Treatments targeting gastrointestinal motility, immunological dysfunction, and inflammatory mediators will be evaluated. We anticipate future studies will be guided by biomarkers correlated with patient outcomes and therapeutic efficacy to establish new paradigms in the management of Gp.

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

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. 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. 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. 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.

Comparing radiopaque markers and 13C-labelled breath test in diabetic gastroparesis diagnostics.

Purpose: Determining gastric emptying is mandatory in the diagnosis of diabetic gastroparesis. Several methods of investigation exist, but none has proven reliable, inexpensive and accessible. In this study, we aimed to compare gastric emptying of radiopaque markers (ROM) and 13carbon-labelled gastric emptying breath tests for solids (GEBT). We also aimed to determine any association between gastric emptying and patient-reported symptoms, glycemic control and the patients’ age, diabetes duration and occurrence of other late complications.Patients and methods: Forty-five patients (30 women, 15 men) with diabetes mellitus types 1 or 2 (40, 5) and symptoms of gastroparesis were examined with ROM and GEBT. All were interviewed, filled out symptom questionnaires and had HbA1c levels measured.Results: Forty percent of patients had delayed gastric emptying of ROM, while 55% had delayed gastric emptying of GEBT. Correlation between ROM and GEBT was not significant. Compared to GEBT, sensitivity for a positive ROM test was 0.52, while specificity was 0.74. In women, we found a higher specificity of 0.92, sensitivity 0.47. Difference in HbA1c between patients with positive and negative results was of borderline significance for both tests. GEBT (r=0.41, P=0.008) correlated with HbA1c. Patients with any late complications of diabetes had higher gastric retention of ROM (P=0.028), while patients with polyneuropathy (P=0.014) and diabetic wounds (P=0.004) had slower emptying with GEBT. None of the methods identified significant associations between gastric emptying and symptom scores, age or diabetes duration.Conclusions: As a measure of gastric emptying, the ROM test has benefits of being affordable and available. Compared to GEBT, the method has low diagnostic reliability. Before continued use, we recommend additional studies validating the test in diabetes patients.