Charlotte Broers

Shifting the Circadian Rhythm of Feeding in Mice Induces Gastrointestinal, Metabolic and Immune Alterations Which Are Influenced by Ghrelin and the Core Clock Gene Bmal1

Background In our 24-hour society, an increasing number of people are required to be awake and active at night. As a result, the circadian rhythm of feeding is seriously compromised. To mimic this, we subjected mice to restricted feeding (RF), a paradigm in which food availability is limited to short and unusual times of day. RF induces a food-anticipatory increase in the levels of the hunger hormone ghrelin. We aimed to investigate whether ghrelin triggers the changes in body weight and gastric emptying that occur during RF. Moreover, the effect of genetic deletion of the core clock gene Bmal1 on these physiological adaptations was studied. Methods Wild-type, ghrelin receptor knockout and Bmal1 knockout mice were fed ad libitum or put on RF with a normal or high-fat diet (HFD). Plasma ghrelin levels were measured by radioimmunoassay. Gastric contractility was studied in vitro in muscle strips and in vivo (13C breath test). Cytokine mRNA expression was quantified and infiltration of immune cells was assessed histologically. Results The food-anticipatory increase in plasma ghrelin levels induced by RF with normal chow was abolished in HFD-fed mice. During RF, body weight restoration was facilitated by ghrelin and Bmal1. RF altered cytokine mRNA expression levels and triggered contractility changes resulting in an accelerated gastric emptying, independent from ghrelin signaling. During RF with a HFD, Bmal1 enhanced neutrophil recruitment to the stomach, increased gastric IL-1α expression and promoted gastric contractility changes. Conclusions This is the first study demonstrating that ghrelin and Bmal1 regulate the extent of body weight restoration during RF, whereas Bmal1 controls the type of inflammatory infiltrate and contractility changes in the stomach. Disrupting the circadian rhythm of feeding induces a variety of diet-dependent metabolic, immune and gastrointestinal alterations, which may explain the higher prevalence of obesity and immune-related gastrointestinal disorders among shift workers.

The effect of intravenous corticotropin-releasing hormone administration on esophageal sensitivity and motility in health

Esophageal hypersensitivity is important in gastroesophageal reflux disease (GERD) patients who are refractory to acid-suppressive therapy. Stress affects visceral sensitivity and exacerbates heartburn in GERD. Peripheral CRH is a key mediator of the gut stress response. We hypothesize that CRH increases esophageal sensitivity and alters esophageal motility in health. Esophageal sensitivity to thermal, mechanical, electrical, and chemical stimuli was assessed in 14 healthy subjects after administration of placebo or CRH (100 μg iv). Perception scores were assessed for first perception, pain perception threshold (PPT), and pain tolerance threshold (PTT). Esophageal motility was investigated by high-resolution impedance manometry, before and after CRH and evaluated by distal contractile integral (DCI) and intrabolus pressure (IBP). Pressure flow analysis assessed bolus clearance (impedance ratio), degree of pressurization needed to propel bolus onward (IBP slope), and pressure flow (pressure flow index, PFI). Stress and mood were assessed during the study. Sensitivity to mechanical distention was increased after CRH compared with placebo (PPT: P = 0.0023; PTT: P = 0.0253). CRH had no influence on the other stimulations. DCI was increased for all boluses (liquid, P = 0.0012; semisolid, P = 0.0017; solid, P = 0.0107). Impedance ratio for liquid (P < 0.0001) and semisolid swallows (P = 0.0327) decreased after CRH. IBP slope increased after CRH for semisolid (P = 0.0041) and solid (P = 0.0003) swallows. PFI increased for semisolid (P = 0.0017) and solid swallows (P = 0.0031). CRH increased esophageal sensitivity to mechanical distention, not to the other stimulation modalities. CRH increased esophageal contractility and tone, decreased LES relaxation, increased esophageal bolus pressurization, improved esophageal bolus clearance, and increased pressure flow.NEW & NOTEWORTHY This is the first study to address the effect of corticotropin-releasing hormone (CRH) on esophageal sensitivity and alterations in motility in health. CRH administration increased esophageal sensitivity to mechanical distention. This effect is accompanied by an increase in esophageal contractility and tone and a decrease in lower esophageal sphincter relaxation. CRH increased esophageal bolus pressurization, improved esophageal bolus clearance, and increased pressure flow. The changes in esophageal contractile properties may underlie the increased sensitivity to mechanical distention after CRH.

A Randomized Double-Blind, Placebo-Controlled, Cross-Over Study Using Baclofen in the Treatment of Rumination Syndrome

Objectives:Both rumination syndrome and supra-gastric belching (SGB) have limited treatment options. We demonstrated (open-label) that baclofen reduces pressure flow events in these patients. We aimed to study the effect of baclofen in a placebo-controlled, double-blind, cross-over study in patients with clinically suspected rumination and/or SGB.Methods:Twenty tertiary-care patients (mean age 42 years (range 18–61), 13f) with clinically suspected rumination and/or SGB were randomized to receive baclofen (10 mg, t.i.d) or placebo for 2 weeks with cross-over to the alternative intervention after a 1 week wash-out period. At the end of each treatment period, patients underwent a solid-state high-resolution impedance manometry measurement, during which they registered symptoms. Patients received a solid meal and recordings continued for 1 h. They scored overall treatment evaluation (OTE) on a −3 to +3 scale.Results:Both the number of regurgitation event markers and rumination episodes were significantly decreased after baclofen (6 (0–19) vs. 4 (0–14), P=0.04; 13 (8–22) vs. 8 (3–11), P=0.004). The number of SGB episodes was similar in both groups. Lower esophageal sphincter (LES) pressure was significantly higher and the number of transient LES relaxations was significantly lower after baclofen (17.8 (12.7–22.7) vs. 13.1 (7.2–16.9) mm Hg, P=0.0002; 4(1–8) vs. 7(3–12), P=0.17). The number of reflux events decreased in the baclofen condition (4 (1–9) vs. 3 (0–6), P=0.03). Straining episodes were similar in both arms, but the rumination/straining ratio was significantly lower in the baclofen arm (0.06 (0–0.32) vs. 0.33 (0–0.51), P=0.0012). OTE was superior after baclofen compared to placebo (P=0.03).Conclusions:Baclofen is an effective treatment option for patients with rumination syndrome, probably through its effect on LES pressure.

Review article: gastro-oesophageal reflux disease in asthma and chronic obstructive pulmonary disease

When gastro‐oesophageal reflux is causing symptoms or lesions in the oesophagus, this is referred to as gastro‐oesophageal reflux disease (GERD). GERD can manifest itself through typical symptoms (heartburn, regurgitation) or may lead to extra‐oesophageal symptoms. Extra‐oesophageal manifestations of GERD gained increasing attention over the last decade, especially respiratory disorders, because of the prevalent co‐occurrence with GERD. The role of GERD in the pathogenesis of respiratory disorders has become a topic of intense discussion.

Severely impaired gastric accommodation is a hallmark of post-Nissen functional dyspepsia symptoms

Laparoscopic Nissen fundoplication is a commonly performed antireflux surgery, after which reflux symptoms are well controlled, however, complications such as inability to belch or dyspeptic symptoms (mimicking those of functional dyspepsia [FD]) might occur. The aim of the study was to prospectively evaluate symptom pattern and underlying pathophysiological mechanisms in patients with post‐Nissen dyspepsia.

The optimal order of stimulation modalities and reproducibility of the multimodal esophageal stimulation paradigm

Esophageal hypersensitivity can be triggered by different stimuli. We use a multimodal stimulation model to study esophageal sensitivity to four sensory modalities: thermal, mechanical, electrical, and chemical stimulation. The optimal order of these stimulations needs further validation.