Between GERD and NERD: the relevance of weakly acidic reflux

Climate Change and the Esophagus: Speculations on Changing Disease Patterns as the World Warms

PURPOSE OF REVIEW

Esophageal disorders, including gastroesophageal reflux disease (GERD), eosinophilic esophagitis (EoE), and esophageal cancer, may be affected by climate change. Our review describes the impact of climate change on risk factors associated with esophageal diseases and speculates how these climate-related factors impacted esophageal disorders and their management.

RECENT FINDINGS

Climate change is responsible for extreme weather conditions (shifts in rainfall, floods, droughts, and forest fires) and global warming. These consequences affect basic human needs of water and food, causing changes in population dynamics and pose significant threats to digestive health, including common esophageal disorders like GERD, EoE, and esophageal cancers. The changing patterns of esophageal diseases with climate change are likely mediated through risk factors, including nutrition, pollutants, microplastics, and the microbiota-gut-brain axis. The healthcare process itself, including GI endoscopy practices commonly employed in diagnosing and therapeutics of esophageal diseases, may, in turn, contribute to climate change through plastic wastage and greenhouse gas emissions, thus creating the climate change lifecycle. Breaking the cycle would involve changes at the individual level, community level, and national policy level. Prevention is key, with individuals identifying and remediating risk factors and reducing carbon footprints. The ABC (Advocacy, Broadcast, and Collaborate) activities would help enhance awareness at the community level. Higher-level programs such as the Bracing Resilience Against Climate Effects (BRACE) would lead to broader and larger-scale adoption of public health adaptation strategies at the national level. The impact of climate change on esophageal disorders is likely real, mediated by several risk factors, and creates a climate change lifecycle that may only break if changes are made at individual, community, and national levels.

Towards a better diagnosis of gastro esophageal reflux disease

INTRODUCTION

GERD is a common disorder and is characterized by the presence of typical or atypical symptoms. In GERD patients, the presence of mucosal alterations in endoscopy is detected in up to 30% of individuals. The clinical presentation of GERD patients may be complex and their management is challenging, due to the heterogeneous clinical presentation. The present review has been performed searching all relevant articles in this field, over the past years, using PubMed database.

AREAS COVERED

The diagnosis and management of GERD have been significantly improved in the last years due to the increasing availability of reflux monitoring techniques and the implementation of new procedures in the therapeutic armamentarium. Beside traditional impedance-pH variables, new metrics have been developed, increasing the diagnostic yield of reflux monitoring and better predicting the treatment response. Traditional pharmacological treatments include acid-suppressive-therapy and/or anti-acid. On the other hand, surgical treatment and, more recently, endoscopic procedures represent a promising field in the therapeutic approach.

EXPERT OPINION

Diagnosis and treatment of GERD still represent a challenging area. However, we believe that an accurate upfront evaluation is, nowadays, necessary in addressing patients with GERD to a more accurate diagnosis as well as to the best treatment options.

Traditional Chinese medicine based on Tongjiang methodology combined with proton pump inhibitor (PPI) step-down in treating non-erosive reflux disease: a study protocol for a multicentered, randomized controlled clinical trial

BACKGROUND

Non-erosive reflux disease (NERD) is characterized by typical gastroesophageal reflux symptoms, such as heartburn and regurgitation but an absence of esophageal mucosal damage during upper gastrointestinal endoscopy. Although proton pump inhibitors (PPIs) are the first line therapy, almost 50% of patients with NERD fail to respond to this treatment. Traditional Chinese medicine (TCM) can better relieve the symptoms of NERD. Therefore, a randomized controlled trial (RCT) was designed to investigate the efficiency of TCM granules based on Tongjiang (TJ) methodology combined with PPI step-down therapy for NERD patients who did not respond to PPIs alone.

METHOD

This multicentered, double-blinded, RCT with two parallel groups will recruit 174 participants who will be randomized into the TCM granules combined with PPI step-down group (n = 87) and the TCM granules placebo combined with PPI step-down group (n = 87). Both groups of participants will receive 6 weeks of treatment and 4 weeks of follow-up, and all participants will be assessed for related symptoms, mental health status, and quality of life at each visit. The primary outcome measurements include visual analog scale (VAS) for heartburn and regurgitation and the major symptoms scale. The secondary outcome measurements include PPI withdrawal rate, symptom recurrence rate, minor symptoms scale, SF-36, PRO, SAS, SDS, GERD-HRQL, and TCM syndromes scales.

DISCUSSION

Previous research has shown that TCM is capable to alleviate NERD symptoms. This trial will help to provide a better understanding of the synergistic efficiency of the combination of TCM and PPIs, to explore whether the dosage of PPIs can be reduced after the supplement of TCM granules and to provide a feasible plan to reduce dependencies or withdraw NERD patients from PPIs. The outcome of this trial is expected to reduce the symptom recurrence rates, lessen patients' physical and psychological burdens, and achieve good social benefits.

TRIAL REGISTRATION

Clinicaltrials.gov NCT04340297. Registered on April 9, 2020.

Identification of Unique Transcriptomic Signatures and Hub Genes Through RNA Sequencing and Integrated WGCNA and PPI Network Analysis in Nonerosive Reflux Disease

Purpose

Transcriptomic studies on gastroesophageal reflux disease are scarce, and gene expression signatures in nonerosive reflux disease (NERD) remain elusive. The aim of the study was to identify gene expression profiles and potential hub genes in NERD.

Patients and Methods

We performed RNA sequencing on biopsy samples from nine consecutive patients with NERD and six healthy controls. Differentially expressed genes (DEGs) were analysed with the DESeq2 R package. A DEG-based protein-protein interaction (PPI) network was constructed to filter hub genes using Cytoscape. Weighted gene coexpression network analysis (WGCNA) was conducted to identify the coexpression relationships of all modules and explore the relationship between gene sets and clinical traits.

Results

In total, 1195 DEGs were identified, including 649 upregulated and 546 downregulated genes involved in regulating the inflammatory response and epithelial cell differentiation. Overlap of the PPI and WGCNA networks identified five shared genes, namely, THY1, BMP2, LOX, KDR and MMP9, as candidate hub genes in NERD. Quantitative PCR analysis of the expression of these five genes confirmed the sequencing results. Receiver operating characteristic analyses indicated that these hub genes had diagnostic potential for NERD patients. Gene set enrichment analysis confirmed that each hub gene was closely associated with the pathophysiological processes of NERD. In addition, a regulatory network comprising 42 transcription factors (TFs), 28 miRNAs and 5 hub genes was established.

Conclusion

The five core genes may be promising biomarkers of NERD. The TF/miRNA/hub gene network can improve the understanding of the molecular mechanisms underlying disease progression.

Refractory Gastroesophageal Reflux Disease: A Management Update

Gastroesophageal reflux disease (GERD) is one of the most frequent gastrointestinal disorders. Proton pump inhibitors (PPIs) are effective in healing lesions and improving symptoms in most cases, although up to 40% of GERD patients do not respond adequately to PPI therapy. Refractory GERD (rGERD) is one of the most challenging problems, given its impact on the quality of life and consumption of health care resources. The definition of rGERD is a controversial topic as it has not been unequivocally established. Indeed, some patients unresponsive to PPIs who experience symptoms potentially related to GERD may not have GERD; in this case the definition could be replaced with “reflux-like PPI-refractory symptoms.” Patients with persistent reflux-like symptoms should undergo a diagnostic workup aimed at finding objective evidence of GERD through endoscopic and pH-impedance investigations. The management strategies regarding rGERD, apart from a careful check of patient's compliance with PPIs, a possible change in the timing of their administration and the choice of a PPI with a different metabolic pathway, include other pharmacologic treatments. These include histamine-2 receptor antagonists (H2RAs), alginates, antacids and mucosal protective agents, potassium competitive acid blockers (PCABs), prokinetics, gamma aminobutyric acid-B (GABA-B) receptor agonists and metabotropic glutamate receptor-5 (mGluR5) antagonists, and pain modulators. If there is no benefit from medical therapy, but there is objective evidence of GERD, invasive antireflux options should be evaluated after having carefully explained the risks and benefits to the patient. The most widely performed invasive antireflux option remains laparoscopic antireflux surgery (LARS), even if other, less invasive, interventions have been suggested in the last few decades, including endoscopic transoral incisionless fundoplication (TIF), magnetic sphincter augmentation (LINX) or radiofrequency therapy (Stretta). Due to the different mechanisms underlying rGERD, the most effective strategy can vary, and it should be tailored to each patient. The aim of this paper is to review the different management options available to successfully deal with rGERD.

Weak acids induce PGE2 production in human oesophageal cells: novel mechanisms underlying GERD symptoms

The role of weak acids with pH values in the range of 4–7 has been implicated in the symptoms of gastroesophageal reflux disease (GERD). Prostaglandin E₂ (PGE₂) is associated with heartburn symptom in GERD patients; however, the precise productive mechanisms remain unclear. In this study, we revealed that exposure to weak acids increases PGE₂ production with a peak at pH 4–5, slightly in human normal oesophageal cells (Het-1A), and robustly in oesophageal squamous carcinoma cells (KYSE-270). Release of PGE₂ from the oesophageal mucosa was augmented by weak acid treatment in rat. Chenodeoxycholic acid (CDCA), a bile acid, upregulated cyclooxygenase-2 (COX-2) expression in Het-1A and KYSE-270 and induced PGE₂ production in KYSE-270 cells. Weak acid-induced PGE₂ production was significantly inhibited by cytosolic phospholipase A2 (cPLA2), ERK, and transient receptor potential cation channel subfamily V member 4 (TRPV4), a pH-sensing ion channel, inhibitors. Hangeshashinto, a potent inhibitor of COX-2, strongly decreased weak acid- and CDCA-induced PGE₂ levels in KYSE-270. These results indicated that weak acids induce PGE₂ production via TRPV4/ERK/cPLA2 in oesophageal epithelial cells, suggesting a role in GERD symptoms like heartburn. Interventions targeting pH values up to 5 may be necessary for the treatment of GERD.

Protective and regenerative effects of a novel medical device against esophageal mucosal damage using in vitro and ex vivo models

Gastroesophageal reflux disease (GERD) is a common digestive disorder that causes esophagitis and injuries to the esophageal mucosa. GERD symptoms are recurrent during pregnancy and their treatment is focused on lifestyle changes and nonprescription medicines. The aim of this study was to characterize the mechanism of action of a new patented medical device, an oral formulation containing hyaluronic acid, rice extract, and amino acids dispersed in a bioadhesive polymer matrix, by assessing its protective effects in in vitro and ex vivo models of esophageal mucosa damage. Acidic bile salts and pepsin cocktail (BSC) added to CP-A and COLO-680 N esophagus cells were used as an in vitro GERD model to evaluate the binding capacities, anti-inflammatory effects and reparative properties of the investigational product (IP) in comparison to a viscous control. Our results showed that the IP prevents cell permeability and tight junction dysfunction induced by BSC. Furthermore, the IP was also able to down-regulate IL-6 and IL-8 mRNA expression induced by BSC stimulation and to promote tissue repair and wound healing. The results were confirmed by ex vivo experiments in excised rat esophagi through the quantification of Evans Blue permeability assay. These experiments provided evidence that the IP is able to bind to the human esophagus cells, preventing the damage caused by gastroesophageal reflux, showing potential anti-irritative, soothing, and reparative properties.

A SIGE-SINGEM-AIGO technical review on the clinical use of esophageal reflux monitoring

Patients with esophageal symptoms potentially associated with gastroesophageal reflux disease such as heartburn, regurgitation, chest pain, or cough represent one of the most frequent reasons for referral to gastroenterological evaluation. The utility of esophageal reflux monitoring in clinical practice is: (1) to accurately define reflux burden, (2) to segregate patients according to reflux monitoring results as true GERD, reflux hypersensitivity and functional heartburn, and (3) to establish a treatment plan. With this in mind, in the last decade, investigations and technical advances, with the introduction of impedance-pH monitoring and wireless pH capsule, have enhanced our understanding and management of GERD. The following recommendations were discussed and approved after a comprehensive review of the medical literature pertaining to reflux testing techniques and their recent application. This review created under the auspices of the Società Italiana di Gastroenterologia ed Endoscopia Digestiva (SIGE), Società Italiana di Neuro-Gastro-Enterologia e Motilità (SINGEM) and Associazione Italiana Gastroenterologi ed Endoscopisti Digestivi Ospedalieri (AIGO) is intended to help clinicians in applying reflux studies in the most fruitful manner within the context of their patients with esophageal symptoms.

Clinical outcome after laparoscopic Nissen fundoplication in patients with GERD and PPI refractory heartburn

Typical reflux symptoms that respond well to proton pump inhibitor (PPI) therapy are key factors predictive of an excellent outcome with antireflux surgery for gastroesophageal reflux disease (GERD). Our aim was to evaluate whether poor preoperative heartburn (HB) relief with PPIs was associated with a worse outcome after Nissen fundoplication. Patients with a main symptom of HB and a positive pH-test who had a laparoscopic Nissen fundoplication between January 2008 and December 2014 were included. Prior to surgery, patients graded how effectively their HB symptoms were relieved by PPIs. Three groups were defined: good response (76-100% relief), partial response (26-75% relief) and poor response (0-25% relief). Outcomes and satisfaction were assessed at a minimum of 1 year after fundoplication. There were 129 patients who met inclusion criteria and 75 agreed to participate. The median follow-up was 48 months. Prior to Nissen fundoplication 13 patients had a good HB response to PPI-therapy, 36 had a partial response and 26 had a poor response. All patients were satisfied with their HB relief after fundoplication (mean satisfaction score: 9.5/10) and there was no difference in satisfaction score or heartburn relief between groups. Heartburn symptoms that respond poorly to PPI therapy are reliably relieved with a Nissen fundoplication in patients with objectively confirmed GERD. Patient satisfaction after Nissen fundoplication was excellent and was similar in patients with poor versus excellent HB relief with preoperative PPI therapy. Therefore, antireflux surgery is an option for patients with HB and confirmed GERD regardless of the degree of relief of HB symptoms provided by PPI medications.

Survey of nocturnal reflux in patients with gastroesophageal reflux disease in China

To evaluate current diagnosis and treatment of patients with nocturnal gastroesophageal reflux (nGER).

METHODS

This multicenter observational study was conducted in 44 hospitals in China from May 2017 to February 2018. Outpatients with nGER were recruited and their relevant data were collected using a questionnaire, including age, gender, body mass index, history of smoking and alcohol consumption, comorbid diseases, lifestyle, self-reported health status, medical history, nGER symptoms and severity, Hospital Anxiety Depression Scale, Pittsburgh Sleep Quality Index, diagnosis and treatment choices. The study was registered on the Chinese Clinical Trial Registry (no. ChiCTR1800017525).

RESULTS

The study included 4978 individuals, with valid questionnaires collected from 4448 patients (89.4%). The symptoms of heartburn and regurgitation were more severe at night than during the day (P < 0.05). Age and body mass index were positively correlated with reflux severity at night and during the day (P < 0.05). The severity of nGER was positively associated with lifestyle factors such as smoking, a high-fat diet, carbonated beverage consumption, late supper (later than 9 pm), and snoring (all P < 0.05). Night-time heartburn and regurgitation were related with sleep disorder.

CONCLUSIONS

Lifestyle factors are associated with nGER severity, and nGER affects sleep quality. It will be beneficial to popularize and strengthen the diagnosis and treatment of nGER.

Validation in China of a non-invasive salivary pepsin biomarker containing two unique human pepsin monoclonal antibodies to diagnose gastroesophageal reflux disease

OBJECTIVES

Peptest is a new non-invasive reflux diagnostic test based on lateral flow technology that containing two highly specific human pepsin monoclonal antibodies for detecting pepsin, a biomarker for reflux disease. The primary aim of this multicenter clinical study was to validate the efficacy of Peptest in patients diagnosed with gastroesophageal reflux and healthy controls in China.

METHODS

Patients with suspected gastroesophageal reflux underwent an endoscopy and were classified into non-erosive reflux disease and erosive esophagitis subgroups. A healthy control group was also recruited. All participants were given a reflux disease questionnaire-patients scoring greater than 12 and controls scoring zero. All participants provided a postprandial saliva sample and most patients gave an additional post-symptom sample for pepsin analysis.

RESULTS

Altogether 1032 participants aged between 19 and 78 years were recruited. They consisted of 488 patients with non-erosive reflux disease, 221 with erosive esophagitis and 323 healthy controls. The number of postprandial and post-symptom samples analyzed totaled 1031 and 692, respectively. The results across all centers showed an overall pepsin-positive sensitivity of 85%, a specificity of 60%, a positive predictive value of 82%, a negative predictive value of 65% and a positive likelihood ratio of 2.12.

CONCLUSION

The sensitivity of Peptest was high, but the specificity achieved in some centers was low, resulting overall in only a moderate specificity. Further diagnostic investigative studies are warranted.

Individualized medicine of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disease worldwide, and its prevalence is increasing in both developed and developing countries. GERD is divided into three subtypes, namely, erosive esophagitis, nonerosive reflux disease (NERD), and Barrett's esophagus. The etiology, pathogenesis, clinical manifestations, and response to treatment of GERD invariably show high heterogeneity or significant individual difference, especially NERD and refractory GERD. On the other hand, advanced technology has currently provided a wide range of methods for the diagnosis and treatment of GERD patients; however, the long-term efficacy and quality of life of some patients are unsatisfactory. Therefore, each GERD patient needs a specialized management strategy aiming at his/her own condition, which is known as individualized medicine or personalized medicine. The goal of GERD treatment is to relieve the symptoms, while symptomatic remission is directly related to the quality of life. In other words, health-related quality of life and patient satisfaction may be reasonable criteria for GERD. In this paper, we will discuss the individualized medicine of GERD.

Gastroesophageal reflux disease, functional dyspepsia and irritable bowel syndrome: common overlapping gastrointestinal disorders

Several studies have indicated an overlap between gastroesophageal reflux disease (GERD) and various functional gastrointestinal disorders (FGIDs). The overlapping conditions reported have mainly been functional dyspepsia (FD) and irritable bowel syndrome (IBS). The available literature is frequently based on symptomatic questionnaires or endoscopic procedures to diagnose GERD. Rarely, among patients with heartburn, pathophysiological evaluations have been considered to differentiate those with proven GERD from those without. Moreover, both GERD and IBS or FD showed enormous heterogeneity in terms of the criteria and diagnostic procedures used. The GERD-IBS overlap ranges from 3-79% in questionnaire-based studies and from 10-74% when GERD has been diagnosed endoscopically. The prevalence of functional dyspepsia (after normal upper endoscopy) is 12-15% and an overlap with GERD has been reported frequently. Only a few studies have considered a potential overlap between functional heartburn (FH) and IBS using a 24-h pH-metry or impedance-pH evaluation. Similar data has been reported for an overlap between FH and FD. Recently, a revision of the Rome criteria for esophageal FGIDs identified both FH and hypersensitive esophagus (HE) as potential functional esophageal disorders. This might increase the potential overlap between different FGIDs, with FH and HE rather than with GERD. The aim of the present review article was to appraise and discuss the current evidence supporting the possible concomitance of GERD with IBS and FD in the same patients and to evaluate how various GERD treatments could impact on the quality of life of these patients.

Gastroesophageal reflux symptoms among Italian university students: epidemiology and dietary correlates using automatically recorded transactions

BACKGROUND

Gastroesophageal reflux disease (GERD) is one of the most common gastrointestinal disorders worldwide, with relevant impact on the quality of life and health care costs.The aim of our study is to assess the prevalence of GERD based on self-reported symptoms among university students in central Italy. The secondary aim is to evaluate lifestyle correlates, particularly eating habits, in GERD students using automatically recorded transactions through cashiers at university canteen.

METHODS

A web-survey was created and launched through an app, ad-hoc developed for an interactive exchange of information with students, including anthropometric data and lifestyle habits. Moreover, the web-survey allowed users a self-diagnosis of GERD through a simple questionnaire. As regard eating habits, detailed collection of meals consumed, including number and type of dishes, were automatically recorded through cashiers at the university canteen equipped with an automatic registration system.

RESULTS

We collected 3012 questionnaires. A total of 792 students (26.2% of the respondents) reported typical GERD symptoms occurring at least weekly. Female sex was more prevalent than male sex. In the set of students with GERD, the percentage of smokers was higher, and our results showed that when BMI tends to higher values the percentage of students with GERD tends to increase. When evaluating correlates with diet, we found, among all users, a lower frequency of legumes choice in GERD students and, among frequent users, a lower frequency of choice of pasta and rice in GERD students.

DISCUSSION

The results of our study are in line with the values reported in the literature. Nowadays, GERD is a common problem in our communities, and can potentially lead to serious medical complications; the economic burden involved in the diagnostic and therapeutic management of the disease has a relevant impact on healthcare costs.

CONCLUSIONS

To our knowledge, this is the first study evaluating the prevalence of typical GERD-related symptoms in a young population of University students in Italy. Considering the young age of enrolled subjects, our prevalence rate, relatively high compared to the usual estimates, could represent a further negative factor for the future economic sustainability of the healthcare system.

Drugs for improving esophageal mucosa defense: where are we now and where are we going?

In the past, the attention of physiologists and doctors has been mainly focused on the key role of acid in the pathogenesis of gastroesophageal reflux disease (GERD), but increasing evidence that 20-40% of reflux patients respond not at all or only partially to proton pump inhibitors (PPIs) has underlined the concept that factors other than acid are implicated in its development and the elicitation of symptoms. Among these, impaired mucosal integrity, particularly in most patients with non-erosive reflux disease, has recently been reincluded and the reinforcement of defensive mechanisms and/or its protection has been reappointed as a renewed therapeutic target for the management of GERD patients. In this review we will summarize the existing knowledge of the old and novel compounds able to produce this therapeutic effect, including sucralfate, alginate-based drugs, and a new medical device consisting of hyaluronic acid and chondroitin sulfate dispersed in a bioadhesive carrier, together with the potential indications for their use. It is to be stressed, however, that, although these compounds may represent a real alternative to PPI therapy in GERD, the combination of mucosal protection with acid suppression may help manage many cases with a partial or unsatisfactory response to PPIs alone.

A review of pharmacotherapy for treating gastroesophageal reflux disease (GERD)

INTRODUCTION

Medical therapy of gastroesophageal reflux disease (GERD) is based on the use of proton pump inhibitors (PPIs) as first choice treatment. Despite their effectiveness, about 20-30% of patients report an inadequate response and alternative drugs are required. Areas covered: This review provides an overview of current pharmacotherapy for treating GERD by showing the results of PPIs, reflux inhibitors, antidepressants and mucosa protective medications. Expert opinion: Medical therapy of GERD does not definitely cure the disease, because even PPIs are not able to change the key factors responsible for it. However, they remain the mainstay of medical treatment, allowing us to alleviate symptoms, heal esophagitis and prevent complications in the majority of cases. Nevertheless, many patients do not respond, because acid does not play any pathogenetic role. Prokinetics and reflux inhibitors have the potential to control motor abnormalities, but the results of clinical trials are inconsistent. Antidepressant drugs are effective in specific subgroups of NERD patients with visceral hypersensitivity, but larger, controlled clinical studies are necessary. Protective drugs or medical devices have been recently adopted to reinforce mucosal resistance and preliminary trials have confirmed their efficacy either combined with or as add-on medication to PPIs in refractory patients.

A novel murine model of esophageal nonerosive reflux disease: from inflammation to impairment in mucosal integrity

Nonerosive reflux disease (NERD) is a highly prevalent phenotype of the gastroesophageal reflux disease. In this study, we developed a novel murine model of NERD in mice with microscopic inflammation and impairment in the epithelial esophageal barrier. Female Swiss mice were subjected to the following surgical procedure: the transitional region between the forestomach and the glandular portion of the stomach was ligated, and a nontoxic ring was placed around the duodenum near the pylorus. The control group underwent sham surgery. The animals were euthanized at 1, 3, 7, and 14 days after surgery. Survival and body weight were monitored daily. Esophageal wet weight, macroscopic lesion, histopathological alterations, myeloperoxidase (MPO) activity, cytokine levels, transepithelial electrical resistance (TEER), and mucosal permeability were evaluated. The survival rate was 78% at 14 days, with mild loss in body weight. Surgery did not induce erosive esophagitis but instead induced microscopic inflammation and increased esophageal wet weight, IL-6, keratinocyte-derived cytokine (KC) levels, and MPO activity with maximal peak between 3 and 7 days and resolution at 14 days postsurgery. Epithelial esophageal barrier was evaluated in operated mice at 7 and 14 days postsurgery; a decrease in TEER and increase in the esophageal epithelial permeability were observed compared with the sham-operated group. In addition, the inhibition of acid secretion with omeprazole significantly prevented the esophageal inflammation and impairment of barrier function at 7 days postsurgery. Thus we established a novel experimental model of NERD in mice, which can contribute to understanding the pathophysiological events associated with NERD.NEW & NOTEWORTHY In this study, we standardized an experimental model of nonerosive reflux disease (NERD) in mice. This model involves an acute inflammatory response followed by impaired esophageal mucosal integrity, even in the absence of inflammation. Thus this model can serve for evaluation of pathophysiological aspects of NERD and open new perspectives for therapeutic strategies for patients with this disorder.