Search

In this review, we evaluate recent findings related to the association between gastrointestinal hormones and regulation of gastric emptying.Motilin and ghrelin, which act during fasting, promote gastric motility, whereas most of the hormones secreted after a meal inhibit gastric motility. Serotonin has different progastric or antigastric motility effects depending on the receptor subtype. Serotonin receptor agonists have been used clinically to treat dyspepsia symptoms but other hormone receptor agonists or antagonists are still under development. Glucagon-like peptide 1 agonists, which have gastric motility and appetite-suppressing effects are used as a treatment for obesity and diabetes.Gastrointestinal hormones play an important role in the regulation of gastric motility. Various drugs have been developed to treat delayed gastric emptying by targeting gastrointestinal hormones or their receptors but few have been commercialized.

Motilin is a gastrointestinal hormone secreted by the duodenum. This peptide regulates a characteristic gastrointestinal contraction pattern, called the migrating motor complex, during the fasting state. Motilin also affects the pressure of the lower esophageal sphincter, gastric motility and gastric accommodation in the gastrointestinal tract. Furthermore, motilin induces bile discharge into the duodenum by promoting gallbladder contraction, pepsin secretion in the stomach, pancreatic juice and insulin secretion from the pancreas. In recent years, it has been shown that motilin is associated with appetite, and clinical applications are expected for diseases affected by food intake, e.g. obesity, by regulating motilin levels. Gastric acid and bile are the two major physiological regulators for motilin release. Caloric foods have varying effects on motilin levels, depending on their composition. Among non-caloric foods, bitter substances reduce motilin levels and are therefore expected to have an appetite-suppressing effect. Various motilin receptor agonists and antagonists have been developed but have yet to reach clinical use.

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 this clinical study. All subjects had to wear a surgical mask which was only lowered beneath the nose during the placement and removal of the nasogastric catheter. The number of aerosol particles was measured by a Lasair® II Particle Counter to obtain data about different particles sizes: 0.3; 0.5; 1.0; 3.0; 5.0; and 10.0 µm. Measurements were done immediately before the placement and the removal of the HRM catheter, and one and 5 min after. A portable air purifier with high‐efficiency particle air filters was installed in the hospital room. Key Results Thirteen patients underwent a manometry examination. The amount of 0.3 µm‐sized particles was unaffected during the whole procedure. The larger particle sizes (1.0; 3.0; 5.0; and 10.0 µm) decreased when the catheter was positioned, but not 0.5 µm. During the HRM measurements itself, these numbers decreased further. Yet, 1 min after catheter removal a significant elevation of particles was seen, which did not recover within 5 min. Conclusions & Interferences Based on this study, there is no evidence that filtration systems reduce aerosol particles properly during a clinical investigation.

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 processes are upstream regulated by gut peptides, for instance gastrin, cholecystokinin, secretin, motilin, ghrelin, glucagon-like peptide 1 and 2. The relationship between gasotransmitters and gut hormones is poorly understood. In this review, we discuss the role of NO, CO and H2S on gut peptide release and functioning, and whether manipulation by gasotransmitter substrates or specific blockers leads to physiological alterations. ispartof: FRONTIERS IN PHARMACOLOGY vol:12 ispartof: location:Switzerland status: published

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 or 35 g xylitol or tap water on four separate days. We examined effects on: gut hormones, glucose, insulin, glucagon, uric acid, lipid profile, as well as gastric emptying rates, appetite-related sensations and gastrointestinal symptoms. We found: (i) a dose-dependent stimulation of cholecystokinin (CCK), active glucagon-like peptide-1 (aGLP-1), peptide tyrosine tyrosine (PYY)-release, and decelerated gastric emptying rates, (ii) a dose-dependent increase in blood glucose and insulin, (iii) no effect on motilin, glucagon, or glucose-dependent insulinotropic peptide (GIP)-release, (iv) no effect on blood lipids, but a rise in uric acid, and (v) increased bowel sounds as only side effects. In conclusion, low doses of xylitol stimulate the secretion of gut hormones and induce a deceleration in gastric emptying rates. There is no effect on blood lipids and only little effect on plasma glucose and insulin. This combination of properties (low-glycemic sweetener which stimulates satiation hormone release) makes xylitol an attractive candidate for sugar replacement. ispartof: NUTRIENTS vol:13 issue:1 ispartof: location:Switzerland status: published

We read with interest the recent article by Repici et al who reported that gastrointestinal (GI) endoscopy seems relatively safe for medical staff wearing adequate protective measures, with 4.3% of 968 healthcare workers (HCW) in the endoscopy setting infected with COVID-19.1 Similar to GI endoscopy, oesophageal motility studies are common practice and potentially also high-risk medical procedures as COVID-19 may spread through generation of aerosols and droplets during insertion and removal of oesophageal high resolution manometry (HRM) and 24 hours multichannel intraluminal impedance-pH monitoring (pH-MII) probes.2 Current guidelines recommend high-level protection with N95 mask, Filtering FacePiece (FFP)2 or FFP3, double gloves, face shield and gown for HCW during oesophageal physiologic procedures to minimise the risk of transmission.3 4 However, there is a lack of scientific evidence on the spread of aerosols and droplets during nasogastric intubation. Therefore, we performed a prospective study, addressing these concerns. Patients with a negative COVID-19 test by PCR undergoing nasogastric intubation for HRM or pH-MII were included. During the procedures, patients wore a mask over the mouth and were seated in a lowered position in front of the …

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 to determine sensations of hunger (increase energy intake) or satiation (cessation of energy intake) and regulate the human metabolism. The gastric accommodation reflex, which consists of a transient relaxation of the proximal stomach during food intake, has been identified as a major determinant of meal volume, through activation of tension-sensitive gastric mechanoreceptors. Motilin, whose release is the trigger of gastric Phase 3, has been identified as the major determinant of return of hunger after a meal. In addition, the release of several peptide hormones such as glucagon-like peptide 1 (GLP-1), cholecystokinin as well as motilin and ghrelin contributes to gut-brain signalling with relevance to control of hunger and satiety. A number of nutrients, such as bitter tastants, as well as pharmacological agents, such as endocannabinoid receptor antagonists and GLP-1 analogues act on these pathways to influence hunger, satiation and food intake. CONCLUSION: Gastrointestinal mechanisms such as gastric accommodation and motilin release are key determinants of satiety and hunger. ispartof: UNITED EUROPEAN GASTROENTEROLOGY JOURNAL vol:9 issue:6 pages:727-734 ispartof: location:England status: published

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 never been investigated and it is unclear whether bitter food items should be avoided in gastro-esophageal reflux disease. We hypothesize that bitter administration in healthy volunteers (HVs) will lead to an increase in the number of TLESRs. METHODS After an overnight fast, 20 female HVs (36 years [21-63]) underwent a high-resolution impedance manometry (HRiM) measurement. After placement of the HRiM probe, 0.1 ml/kg of a 10 mM denatonium benzoate solution (bitter) or an identical volume of water (placebo) was administered directly into the stomach. The number of TLESRs and reflux episodes was quantified 30 min before and 2 h after consumption of a high caloric meal. KEY RESULTS There was no significant difference in the number of TLESRs or reflux episodes between the bitter and placebo condition. Additionally, no differences were observed in the nature (gas or liquid) and extent of reflux events. Lower esophageal sphincter pressures dropped significantly in the first postprandial hour to start recovering slowly back to baseline values during the second postprandial hour (p

BACKGROUND: The COVID-19 pandemic, declared by WHO on March 13, 2020, had a major global impact on the healthcare system and services. In the acute phase, the presence of the SARS-CoV-2 virus in the aerodigestive tract limited activities in the gastroenterology clinic and procedures to emergencies only. Motility and function testing was interrupted and as we enter the recovery phase, restarting these procedures requires a safety-focused approach with adequate infection prevention for patients and healthcare professionals. METHODS: We summarized knowledge on the presence of the SARS-CoV-2 virus in the aerodigestive tract and the risk of spread with motility and functional testing. We surveyed 39 European centers documenting how the pandemic affected activities and which measures they are considering for restarting these measurements. We propose recommendations based on current knowledge as applied in our center. RESULTS: Positioning of catheters for gastrointestinal motility tests carries a concern for aerosol-borne infection of healthcare workers. The risk is low with breath tests. The surveyed centers stopped almost all motility and function tests from the second half of March. The speed of restarting and the safety measures taken varied highly. CONCLUSIONS AND INFERENCES: Based on these findings, we provided recommendations and practical relevant information for motility and function test procedures in the COVID-19 pandemic era, to guarantee a high-quality patient care with adequate infection prevention. ispartof: NEUROGASTROENTEROLOGY AND MOTILITY vol:32 issue:7 ispartof: location:England status: published

Functional dyspepsia (FD) and gastroparesis (GP) are common disorders of the upper gastrointestinal tract. The pathophysiology of these conditions is likely to be heterogenous, and factors such as altered motility, sensitivity and response to nutrition have been identified as putative underlying mechanisms. Motility, sensitivity as well as responses to nutrition can be influenced or mediated by peptide hormones and serotonin released from the gastrointestinal mucosa. This review summarizes the role of GI peptides in functional dyspepsia and gastroparesis. In most studies, the levels of somatostatin, ghrelin, and motilin did not differ between healthy volunteers and FD or GP patients, but higher symptom burden was often correlated with higher peptide levels. Ghrelin and motilin receptor agonists showed promising results in improvement of the gastric emptying, but the link with improvement of symptoms is less predictable. Serotonin agonists have a potential to improve symptoms in both FD and idiopathic gastroparesis. Drugs acting on the GLP-1 and on the PYY receptors deserve further investigation. There is a need for systematic large scale studies. ispartof: FRONTIERS IN PSYCHIATRY vol:11 ispartof: location:Switzerland status: published

After the discovery of motilin in 1972, motilin and the motilin receptor were studied intensely for their role in the control of gastrointestinal motility and as targets for treating hypomotility disorders. The genetic revolution - with the use of knockout models - sparked novel insights into the role of multiple peptides but contributed to a decline in interest in motilin, as this peptide and its receptor exist only as pseudogenes in rodents. The past 5 years have seen a major surge in interest in motilin, as a series of studies have shown its relevance in the control of hunger and regulation of food intake in humans in both health and disease. Luminal stimuli, such as bitter tastants, have been identified as modulators of motilin release, with effects on hunger and food intake. The current state of knowledge and potential implications for therapy are summarized in this Review. ispartof: NATURE REVIEWS ENDOCRINOLOGY vol:15 issue:4 pages:238-250 ispartof: location:England status: published

Background: Dipeptidyl peptidase‐4 (DPP‐4) inactivates glucagon‐like peptide‐1 (GLP‐1). Whether DPP‐4 inhibition affects GLP‐1 metabolism and/or food intake in humans remains unknown. Aims: To evaluate the effect of vildagliptin (DPP‐4 inhibitor) on gastric accommodation and ad libitum food intake in healthy volunteers (HVs) Methods: The effects of acute oral vildagliptin administration (50 mg) were evaluated in two randomised, placebo‐controlled, single‐blinded trials. Protocol 1 (n = 10, 32.3 ± 3 years, 23.4 ± 0.7 kg/m2 ): 60 min after treatment, a nutrient drink (270 kcal) was infused intragastrically and intragastric pressure (IGP) was measured for 1 h. Protocol 2 (n = 10, 24.3 ± 0.8 years, 22.3 ± 0.9 kg/m2 ): 60 min after treatment, HVs consumed one nutrient drink (300 kcal). Thirty minutes thereafter, HVs ate ad libitum from a free‐choice buffet for 30 min. Blood was collected at several time points to measure active GLP‐1 plasma levels. Results: During the first 20 min after nutrient infusion, the drop in IGP was smaller after vildagliptin compared to placebo (treatment‐by‐time interaction effect: P = 0.008). No differences were seen on epigastric symptom scores. Planned contrast analysis showed that active GLP‐1 levels were higher after vildagliptin compared to placebo (P = 0.018) only after nutrient ingestion. Total food intake (316.38 ± 58.89 g vs 399.58 ± 63.02 g, P = 0.359) and total caloric intake (594.77 ± 115.17 kcal vs 742.77 ± 107.10 kcal, P = 0.371) did not differ between treatments. Conclusions: Vildagliptin inhibits gastric accommodation without affecting epigastric symptom scoring in HVs. Active GLP‐1 plasma levels were increased after vildagliptin treatment, but the increase was not sufficient to affect ad libitum food intake ispartof: ALIMENTARY PHARMACOLOGY & THERAPEUTICS vol:49 issue:8 pages:997-1004 ispartof: location:England status: published