Mucosal pathogenesis in gastro-esophageal reflux disease

Molecular and Functional Recovery of Esophageal Barrier Integrity After Laparoscopic Anti-reflux Surgery

BACKGROUND

Patients undergoing laparoscopic anti-reflux surgery (LARS) often experience improved quality of life and reduced gastroesophageal reflux disease (GERD) symptoms. This study aimed to assess the impact of LARS on epithelial remodeling and repair in the esophageal mucosa.

METHODS

Upper gastrointestinal (GI) endoscopy was performed once on healthy controls (HC) and twice on GERD patients before and approximately 6 month after surgery, with esophageal biopsies collected. The expressions of E-cadherin (ECAD), Occludin (OCLN), Claudin 1 (CLDN1), Claudin 4 (CLDN4), Zonula Occludens -1 (ZO-1), and ZO-2 were analyzed in the biopsies, and dilated intercellular spaces (DIS) were examined under light microscopy.

RESULTS

The study included 22 GERD patients who were underwent for LARS, and 20 HCs. All patients had pathological reflux episodes. In the Post-LARS group, TEER increased significantly compared to Pre-LARS and HC (p < 0.05), while mucosal permeability decreased (p < 0.05). A significant negative correlation was found between TEER and permeability (p = 0.0002). DIS remained dilated in both Pre- and Post-LARS patients compared to HC (p < 0.05). Gene expression analysis revealed significant increases in ZO-1, OCLN, and ZO-2 Post-LARS (p < 0.05).

CONCLUSION

LARS improves mucosal integrity by enhancing TEER and reducing permeability in GERD patients, although DIS remains unchanged. The upregulation of tight junction genes such as ZO-1 and OCLN Post-LARS suggests that surgical intervention may support epithelial barrier restoration. DIS remains dilated after LARS; this might be reason that it is not an early marker in GERD pathogenesis. These findings enhance our understanding of GERD nature and may inform future target therapeutic strategies.

Research progress of MUC family in esophageal mucosal barrier of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a prevalent chronic digestive disorder with a rising incidence rate, profoundly affecting patients' quality of life. The condition is marked by recurrent episodes of acid reflux and heartburn, which can compromise the esophageal mucosal barrier and trigger inflammatory responses in the esophagus. Mucins (MUC), essential components of the mucus gel layer, play a vital role in protecting the esophageal mucosa and may serve as potential biomarkers for GERD diagnosis and treatment. This review provides a comprehensive overview of the MUC family's structure, types, and physiological functions, highlighting their significance in maintaining the esophageal mucosal barrier. By exploring the role of MUC in GERD, this paper aims to contribute to a deeper understanding of the disease's pathophysiological mechanisms and inform advancements in its diagnosis and treatment.

Untangling immune cell contributions in the progression from GERD to Barrett's esophagus and esophageal cancer: Insights from genetic causal analysis

BACKGROUND

Esophageal adenocarcinoma (EAC) is a rapidly increasing malignancy with significant morbidity and mortality. The progression from gastroesophageal reflux disease (GERD) to Barrett's esophagus (BE) and ultimately to EAC is thought to be influenced by chronic inflammation and immune cell dynamics. Despite the observed correlations in observational studies, the causal relationships between immune cell phenotypes and this disease continuum remain unclear.

METHODS

This study utilized a two-sample Mendelian Randomization (MR) approach to investigate the causal roles of 731 distinct immune cell phenotypes in the GERD-BE-EAC continuum. The analysis leveraged genome-wide association study (GWAS) data for immune phenotypes from a Sardinian cohort and data for GERD, BE, and EAC from the FinnGen and Open GWAS databases. A comprehensive set of MR methods, including inverse variance weighted (IVW), MR-Egger, and weighted median estimators, was employed to assess causality. Sensitivity analyses were conducted to evaluate heterogeneity and pleiotropy, ensuring the robustness of the findings.

RESULTS

The study revealed complex and multifaceted roles of immune cells across the GERD-BE-EAC continuum. In GERD, 34 immune phenotypes were found to be causally associated with either increased or decreased risk. Protective effects were observed in phenotypes such as Unswitched Memory B cells, while others like CD45RA- CD4+ T cells were linked to an elevated risk. In the context of BE, 28 immune phenotypes demonstrated significant causal associations, with the majority being protective, including Unswitched Memory B cells and CD62L on Granulocytes. Conversely, certain phenotypes, such as CD24 on Transitional B cells, were identified as risk factors for BE. For EAC, 34 immune phenotypes were implicated, with various B cell subsets, particularly those expressing BAFF-R and CD24, associated with an increased risk, while Switched Memory B cells and specific myeloid cell phenotypes showed protective effects.

CONCLUSIONS

This study provides novel insights into the complex role of immune cells in the pathogenesis of EAC, revealing a dynamic interplay where certain immune phenotypes may be protective in early stages but become risk-enhancing in later stages of disease progression. These findings highlight the potential of immune cell phenotypes to serve as biomarkers for early detection and targeted therapeutic interventions across the GERD-BE-EAC continuum. Further research is warranted to validate these findings in diverse populations and to explore the underlying mechanisms driving these immune-mediated effects.

The Expression of F2RL1, P2RX2, P2RX3 and P2RY2 in the Esophagus of Patients with Gastroesophageal Reflux Disease and Their Relationship to Reflux Symptoms-A Pilot Study

Background: The current treatment of gastroesophageal reflux disease (GERD) is focused on decreasing gastric acid secretion. However, there is still a group of patients that do not respond to conventional therapy. Proteinase-activated receptors and purinergic receptors have been implicated in inflammation, visceral hyperalgesia and esophageal hypersensitivity. The aim of this study was to evaluate the esophageal expression of PAR2 (F2RL1) and P2RX2, P2RX3 and P2RY2 in GERD patients. Methods: A total of 53 patients with GERD and 9 healthy controls were enrolled in this study. The expression of the studied receptors was quantified using real-time PCR on esophageal biopsies from the patients with GERD and healthy controls. The correlation between the dilated intracellular spaces (DIS) score and patients' quality of life was investigated. Results: PAR2 receptor expression was higher in ERD compared to NERD and controls (326.10 ± 112.30 vs. 266.90 ± 84.76 vs. 77.60 ± 28.50; NS). P2X2 exhibited the highest expression in NERD compared to ERD and controls (302.20 ± 82.94 vs. 40.18 ± 17.78 vs. 26.81 ± 10.27), similarly to P2Y2, which expression was higher in NERD than in ERD and controls (7321.00 ± 1651.00 vs. 5306.0 ± 1738.00 vs. 3476.00 ± 508.0). Conclusions: We found that the expression of F2RL1, P2RX2 and P2RY2 is positively correlated to the DIS score in GERD patients. Higher PAR2, P2X2 and P2Y2 expression could mediate the sensitization of the esophagus and may be associated with the higher intensity of symptoms perceived by NERD patients.

Topical Protection of Esophageal Mucosa as a New Treatment of GERD

Among the various factors implicated in the pathogenesis of gastroesophageal reflux disease (GERD), visceral hypersensitivity and mucosal resistance have been recently re-evaluated in relation to the increasing phenomenon of proton pump inhibitor failure, particularly in patients with nonerosive reflux disease (NERD). Intensive research has allowed us to understand that noxious substances contained in the refluxate are able to interact with esophageal epithelium and to induce the elicitation of symptoms. The frequent evidence of microscopic esophagitis able to increase the permeability of the mucosa, the proximity of sensory afferent nerve fibers to the esophageal lumen favoring the higher sensitivity to noxious substances and the possible activation of inflammatory pathways interacting with sensory nerve endings are pathophysiological alterations confirming that mucosal resistance is impaired in GERD patients. Accordingly, the reinforcement of protective mechanisms of esophageal mucosa by topical therapies has become a novel treatment target. Alginate, the combination of hyaluronic acid+chondroitin sulphate and Poliprotect have been shown to adhere to esophageal mucosa and to have good protective properties. Several placebo-controlled clinical trials have shown that these compounds, given alone or as add-on therapy for short periods, enable to relieve symptoms and to improve the quality of life in NERD patients. Further studies are needed to confirm the above results and to find new mucosal protectants in order to improve the management of NERD patients.

A Non-Pharmacological Paradigm Captures the Complexity in the Mechanism of Action of Poliprotect Against Gastroesophageal Reflux Disease and Dyspepsia

When the protective mechanisms of the gastroesophageal mucosa are overwhelmed by injurious factors, the structural and functional mucosal integrity is compromised, resulting in a wide spectrum of disorders. Poliprotect has recently been shown to be non-inferior to standard-dose omeprazole for the treatment of endoscopy-negative patients with heartburn and/or epigastric pain or burning. Here, we provide preclinical data describing the mechanism of action of the Poliprotect formulation, a 100% natural, biodegradable, and environmental friendly medical device according to EU 2017/745 and containing UVCB (unknown or variable composition, complex-reaction products, or biological materials) substances of botanical and mineral origin, according to the REACH and European Chemical Agency definitions. Different in vitro assays demonstrated the capability of Poliprotect to adhere to mucus-secreting gastric cells and concomitantly deliver a local barrier with buffering and antioxidant activity. In studies conducted in accordance with systems biology principles, we evaluated the effects of this barrier on human gastric cells exposed to acidic stress. Biological functions identified via Ingenuity Pathway Analysis highlighted the product's ability to create a microenvironment that supports the mucosal structural and functional integrity, promotes healing, and restores a balanced mucosal inflammatory status. Additionally, transepithelial electrical resistance and an Ussing chamber showed the product's capability of preserving the integrity of the gastric and esophageal epithelial barriers when exposed to an acid solution. Two in vivo models of erosive gastropathy further highlighted its topical protection against ethanol- and drug-induced mucosal injury. Overall, our findings sustain the feasibility of a paradigm shift in therapeutics R&D by depicting a very innovative and desirable mode of interaction with the human body based on the emerging biophysical, rather than the pharmacological properties of these therapeutic agents.

HIF-2α level in adolescents with chronic inflammatory pathology of the upper gastrointestinal tract

Сhronic inflammatory diseases of the gastrointestinal tract are among the most common pathological conditions in adolescents. A significant role in the pathogenesis of gastrointestinal tract diseases is given to the functioning of the oxygen sensor system, the main mediator of which is hypoxia-inducible factor 2 (HIF-2α). Therefore, the purpose of the study was to determine the level of HIF-2α in the plasma of patients with chronic inflammatory pathology of the gastrointestinal tract, taking into account the endoscopic picture of the lesion, localization of the pathological process, age and gender of the patient. The study involved 70 adolescents aged 8-18 years with chronic gastroduodenitis (CGD), gastroesophageal reflux disease (GERD), gastric or duodenal ulcer and 25 peers who had been classified as healthy. The plasma concentration of HIF-2α was measured by a sandwich-linked ELISA. Helicobacter pylori infection was determined by urease test or by ELISA. According to the data obtained, the HIF-2α plasma level was higher in patients with chronic inflammatory gastrointestinal disease compared to the control group. In boys with chronic gastroduodenal disease, the level of HIF-2α was higher than in girls. CGD and GERD were characterized by a higher HIF-2α level in plasma than gastric and duodenal ulcers. The HIF-2α level did not depend on the age of the patients or the presence of Helicobacter pylori infection. Keywords: adolescents, chronic gastroduodenitis, gastroesophageal reflux disease, gastrointestinal tract, HIF-2α

Advances in laryngopharyngeal reflux: Etiology, diagnosis, and management

Laryngopharyngeal reflux (LPR) manifests as a variety of nonspecific upper aerodigestive tract symptoms. Rather than a single disorder, LPR may be conceived of as a spectrum of subtypes with varying clinical presentations. LPR signs and symptoms arise from the direct and/or indirect effects of refluxate, physical and molecular injury of the mucosa, and neurologic responses to esophageal events. Specific constituents of refluxate exert distinct mucosal responses and immediate or delayed effects resulting in transient or persistent symptoms and/or laryngeal hypersensitivity. While the complex etiology of LPR presents challenges to its diagnosis and management, tools that aid the identification of LPR subtypes can provide insight into treatment decision-making. Hypopharyngeal-esophageal multichannel intraluminal impedance-pH monitoring provides detailed analysis of reflux events, enabling the development of individualized treatment plans, yet cost and availability limit its widespread use. Alginates offer temporary symptom relief and antireflux surgery may provide benefit when symptoms are recalcitrant to other approaches. Pepsin inhibitors hold promise as a medical therapy when surgery is not an option. Laryngeal hypersensitivity should be considered as part of a comprehensive therapeutic approach. Promising medical and scientific research continues to yield new insights into the complex etiology of LPR and novel strategies for its diagnosis and management.

Transcriptomic Insights into Hub Genes, Immune Infiltration, and Candidate Drugs in Erosive Esophagitis

Purpose

This study aimed to investigate gene expression profiles, identify potential hub genes, and predict drugs for patients with erosive esophagitis (EE). Despite its clinical significance, molecular-level exploration of this condition has been limited.

Patients and Methods

RNA sequencing was performed on clinical biopsy samples from eight EE patients and eight healthy controls. Integrated bioinformatic tools were then utilized to analyze the data, including functional enrichment analysis, protein-protein interaction network analysis, weighted gene co-expression network analysis, immune infiltration analysis, and identification of small-molecule compounds. Additionally, the expressions of the identified hub genes were assessed in clinical samples.

Results

A total of 2801 genes with differential expression were identified, including four potential hub genes: SOX9, SPP1, TIMP1, and TLR4. Moreover, the overexpression of these hub genes was verified in clinical samples. Analysis of Immune infiltration indicated an imbalance in the distribution of immune cell types in patients with EE. Correlation analysis between immune cells and hub genes unveiled noteworthy relationships. Specifically, SOX9 exhibited a negative correlation with CD8 T cells but a positive correlation with resting memory CD4 T cells. SPP1 displayed a positive correlation with naïve B cells, while TIMP1 exhibited a negative correlation with resting dendritic cells. Furthermore, the study identified ten small-molecule drugs with potential therapeutic effects for EE, including loreclezole and mercaptopurine.

Conclusion

This study provides valuable insights into the molecular understanding of EE, offering new perspectives on disease mechanisms. The findings may inspire further research leading to the development of novel treatment strategies for EE.

The Clinical Spectrum of Gastroesophageal Reflux Disease: Facts and Fictions

Background

This review addresses the intricate spectrum of gastroesophageal reflux disease (GERD), a condition affecting 10-30% of the Western population. GERD is characterized by the backflow of gastric contents into the esophagus, causing typical and atypical symptoms. Its pathophysiology involves various factors such as hiatal hernia, esophageal motor disorders, and dietary triggers. The review explores the complexities of GERD spectrum, including nonerosive reflux disease (NERD), reflux hypersensitivity (RH), and functional heartburn (FH).

Summary

The diagnostic process for GERD, based on the Lyon Consensus 2.0 criteria, encompasses clinical evaluation, endoscopy, and functional tests, including pH-impedance and wireless-pH monitoring. NERD, a significant subset of GERD, is defined by reflux symptoms and abnormal reflux burden without mucosal damage. RH, classified under functional esophageal disorders by Rome IV criteria, presents with typical esophageal symptoms associated with reflux but lacks of structural, inflammatory, or motor causes. FH is identified by heartburn with normal endoscopy, reflux testing, and esophageal manometry results. The management of RH and FH, focusing on reducing esophageal hypersensitivity, varies from standard GERD treatments.

Key Messages

The review emphasizes the necessity of personalized treatment strategies due to the complexity and overlap of GERD subtypes. It highlights the importance of a multidisciplinary approach, involving gastroenterologists, psychologists, and other specialists, to improve patient outcomes and quality of life. The article underscores that understanding the distinctions and overlaps among NERD, RH, and FH is crucial for effective management, and the need for innovative approaches in diagnosis and treatment to address the unique challenges of each subtype.

Synthesis of Amphiphilic Amino Poly-Amido-Saccharide and Poly(lactic) Acid Block Copolymers and Fabrication of Paclitaxel-Loaded Mucoadhesive Nanoparticles

Drug delivery to the esophagus through systemic administration remains challenging, as minimal drug reaches the desired target. Local delivery offers the potential for improved efficacy while minimizing off-target toxicities but necessitates bioadhesive properties for mucosal delivery. Herein, we describe the synthesis of two new mucoadhesive amphiphilic copolymers prepared by sequential ring-opening copolymerization or postpolymerization click conjugation. Both strategies yield block copolymers containing a hydrophilic amine-functionalized poly-amido-saccharide and either a hydrophobic alkyl derivatized poly-amido-saccharide or poly(lactic acid), respectively. The latter resulting copolymers readily self-assemble into spherical, ≈200 nm diameter, positively charged mucoadhesive nanoparticles. The NPs entrap ultrahigh levels of paclitaxel via encapsulation of free paclitaxel and paclitaxel conjugated to a biodegradable, biocompatible poly(1,2-glycerol carbonate). Paclitaxel-loaded NPs rapidly enter cells, release paclitaxel, are cytotoxic to esophageal OE33 and OE19 tumor cells in vitro, and, importantly, demonstrate improved mucoadhesion compared to conventional poly(ethylene glycol)-poly(lactic acid) nanoparticles to ex vivo esophageal tissue.

Long-term efficacy of total versus posterior partial fundoplication in patients with gastro-oesophageal reflux disease: a systematic review and meta-analysis

INTRODUCTION

Laparoscopic fundoplication remains the standard treatment for patients with severe gastro-oesophageal reflux disease (GORD). Multiple randomised controlled trials (RCTs) have compared the two most commonly performed surgical techniques, total and posterior partial fundoplication (Nissen [NF] and Toupet [TF]), in terms of symptom control and treatment failure in patients without subsequent dysmotility disorders. We aimed to conduct a systematic review and meta-analysis of these two techniques with regard to the long-term effect on reflux control and associated dysphagia.

METHODS

The MEDLINE®, Embase®, PubMed® and Cochrane Library databases were searched, and all the relevant published RCTs were shortlisted according to the inclusion criteria. The summated outcomes of long-term results relating to the recurrence of GORD and dysphagia were evaluated in a meta-analysis using RevMan software.

RESULTS

Eight studies (all RCTs) on 1,545 patients undergoing NF or TF were eligible for inclusion in this meta-analysis. There were 799 patients in the NF group and 746 in the TF group. In the random effects model analysis, the incidence of long-term recurrence of GORD was not statistically different between the NF and TF cohorts (odds ratio [OR]: 0.69, 95% confidence interval [CI]: 0.34-1.41, z=1.01, p=0.31). However, the incidence of long-term dysphagia was statistically lower in the TF group (OR: 2.92, 95% CI: 1.49-5.72, z=3.13, p=0.002) with low between-study heterogeneity (I2=0%).

CONCLUSIONS

The findings of this systematic review and meta-analysis on symptomatic GORD appear to be in favour of partial posterior fundoplication (TF) as the optimal treatment. It provides equivalent outcomes in reflux symptom control with a lower risk of postoperative dysphagia compared with total fundoplication (NF).

Comparison between Conventional and Simple Measuring Methods of Mean Nocturnal Baseline Impedance in Pediatric Gastroesophageal Reflux Disease

(1) Background: Multichannel intraluminal impedance-pH (MII-pH) monitoring is commonly used to diagnose gastroesophageal reflux disease (GERD). The mean nocturnal baseline impedance (MNBI) is an important parameter, reflecting the esophageal mucosal integrity and improvement in GERD. This study aims to evaluate the correlation between conventionally measured MNBI and a recently described simple MNBI measurement method in diagnosing pediatric GERD. (2) Methods: This prospective observational study enrolled 64 children aged one month to 18 years who underwent 24 h MII-pH monitoring. Conventional MNBI was measured during stable 10 min intervals at night, while the simple MNBI method averaged impedance throughout the nocturnal supine period. (3) Results: Strong correlations were found between conventional and simple MNBI values across all impedance channels in both infants (r > 0.85) and older children (r > 0.9). Conventional and simple MNBIs in the most distal channel (Z6) effectively differentiated non-erosive reflux disease (NERD) from other phenotypes, with AUCs of 0.864 and 0.860, respectively. The simple MNBI demonstrated good diagnostic performance with similar sensitivity and specificity to the conventional MNBI. (4) Conclusions: Including MNBI measurements into routine MII-pH monitoring may enhance GERD diagnosis and reduce the need for more invasive procedures.

Roles of Cytokines in Pathological and Physiological Gastroesophageal Reflux Exposure

Background/Aims

Gastroesophageal reflux disease is frequently observed and has no definitive treatment. There are 2 main views on the pathogenesis of gastroesophageal reflux disease. The first is that epithelial damage starts from the mucosa by acidic-peptic damage and the inflammatory response of granulocytes. The other view is that T-lymphocytes attract chemoattractants from the basal layer to the mucosa, and granulocytes do not migrate until damage occurs. We aim to investigate the inflammatory processes occurring in the esophageal epithelium of the phenotypes at the molecular level. We also examined the effects of these changes on tissue integrity.

Methods

Patients with mild and severe erosive reflux, nonerosive reflux, reflux hypersensitivity, and functional heartburn were included. Inflammatory gene expressions (JAK/STAT Signaling and NFKappaB Primer Libraries), chemokine protein levels, and tissue integrity were examined in the esophageal biopsies.

Results

There was chronic inflammation in the severe erosion group, the acute response was also triggered. In the mild erosion group, these 2 processes worked together, but homeostatic cytokines were also secreted. In nonerosive groups, T-lymphocytes were more dominant. In addition, the inflammatory response was highly triggered in the reflux hypersensitivity and functional heartburn groups, and it was associated with physiological reflux exposure and sensitivity.

Conclusions

"Microinflammation" in physiological acid exposure groups indicates that even a mild trigger is sufficient for the initiation and progression of inflammatory activity. Additionally, the anti-inflammatory cytokines were highly increased. The results may have a potential role in the treatment of heartburn symptoms and healing of the mucosa.

Daily habits, diseases, drugs and knee osteoarthritis: a two-sample Mendelian randomization analysis

Background

The causal relationship between daily habits, diseases, drugs, and knee osteoarthritis (KOA) remains unclear. This study utilized a two-sample Mendelian randomization (MR) method to investigate the causal links between these factors and KOA, providing new insights for KOA prevention.

Methods

SNPs strongly associated with exposure factors (daily habits, diseases, drugs) were extracted from publicly available genome-wide association study (GWAS) as instrumental variables (IVs). We then selected GWAS of KOA as the outcome, conducting a two-sample MR analysis.

Results

Our findings revealed significant causal relationships between several factors and KOA. There was a notable association with time spent watching TV (OR = 4.038; 95% CI: 1.859-8.770; P = 4.192E-04), frequency of friend/family visits (OR = 0.415; 95% CI: 0.219-0.788; P = 7.174E-03), smoking history (OR = 0.781; 95% CI: 0.663-0.921; P = 3.235E-03), gastroesophageal reflux disease (GERD) (OR = 1.519; 95% CI: 1.244-1.856; P = 4.183E-05), hypercholesterolemia (OR = 0.498; 95% CI: 0.290-0.855; P = 0.011), hypothyroidism (OR = 1.048; 95% CI: 1.013-1.084; P = 6.645E-03), use of antithrombotic agents (OR = 0.892; 95% CI: 0.816-0.976; P = 0.013), statin medication (OR = 0.956; 95% CI: 0.916-0.998; P = 0.041), and thyroid preparations (OR = 1.042; 95% CI: 1.014-1.071; P = 2.974E-03) with KOA. Specifically, KOA was positively associated with longer time spent watching TV, GERD, hypothyroidism and thyroid preparations, however showed a negative correlation with more frequent visits from friends or family, smoking history, hypercholesterolemia, antithrombotic agents and statin medication. Sensitivity analysis indicated no significant pleiotropy in these studies (P > 0.05).

Conclusion

This comprehensive study underscores the significance of modifying certain habits to mitigate the risk of KOA. Additionally, the elevated risk of KOA among individuals with GERD, hypothyroidism, and those using thyroid preparations warrants attention. These results would be beneficial for clinical research and nursing education.

Gastroesophageal Reflux and Chronic Rhinosinusitis: A Mendelian Randomization Study

OBJECTIVE

Chronic rhinosinusitis (CRS) is associated with gastroesophageal reflux (GERD). However, the causal relationship is controversial. We conducted a two-sample Mendelian Randomization (MR) analysis to explore this potential association.

METHODS

Based on genome-wide association studies (GWAS), a univariable MR was performed to explore the causal relationship of GERD with CRS. Instrumental variables (IVs) pertinent to anti-GERD treatment were employed as a means of validation. The primary MR outcome was established using an inverse variance weighted (IVW) method, supplemented by multiple sensitivity analyses. Subsequently, a multivariable MR was conducted to account for potential confounding variables, thereby ascertaining a direct effect of GERD on CRS. Finally, a network MR analysis was carried out to elucidate the mediating role of asthma in the relationship between GERD and CRS.

RESULTS

The univariable MR demonstrated an association between GERD and an elevated risk of CRS (IVW OR = 1.30, 95% CI = 1.18-1.45, p = 4.19 × 10-7). Omeprazole usage was associated with a reduction in CRS risk (IVW OR = 0.64, 95% CI = 0.42-0.98, p = 0.039). The causal relationship between GERD and CRS remained after adjusting for potential confounders, such as smoking characteristics, body mass index, asthma, allergic rhinitis, in the multivariable MR analysis. Besides, the proportion of the causal effect of GERD on CRS mediated by asthma was 19.65% (95% CI = 2.69%-36.62%).

CONCLUSION

GERD was independently associated with an increased risk of CRS. The mediating role of asthma between GERD and CRS also reveals that GERD is one of the mechanisms underlying unified airway disease.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3086-3092, 2024.

Gastroesophageal reflux disease and non-alcoholic fatty liver disease: a two-sample Mendelian randomization combined with meta-analysis

Accumulating evidence from observational studies have suggested an association between gastroesophageal reflux disease (GERD) and non-alcoholic fatty liver disease (NAFLD). However, due to that such studies are prone to biases, we imported Mendelian randomization (MR) to explore whether the causal association between two diseases exsit. Hence, we aimed to analysis the potential association with MR. The single nucleotide polymorphisms (SNPs) of GERD were retrieved from the genome-wide association study dataset as the exposure. The SNPs of NAFLD were taken from the FinnGen dataset as the outcome. The relationship was analyzed with the assistance of inverse variance weighted, MR-Egger, and weighted median. We also uitilized the MR-Egger intercept, Cochran's Q test, leave-one-out analysis, MR-PRESSO, and Steiger directionality test to evaluate the robustness of the causal association. The meta-analysis were also implemented to give an overall evaluation. Finally, our analysis showed a causal relationship between GERD and NAFLD with aid of MR and meta-analysis (OR 1.71 95% CI 1.40-2.09; P < 0.0001).

Pepsin-mediated inflammation in laryngopharyngeal reflux via the ROS/NLRP3/IL-1β signaling pathway

BACKGROUND

Laryngopharyngeal reflux (LPR) is one of the most common disorders in otorhinolaryngology, affecting up to 10% of outpatients visiting otolaryngology departments. In addition, 50% of hoarseness cases are related to LPR. Pepsin reflux-induced aseptic inflammation is a major trigger of LPR; however, the underlying mechanisms are unclear. The nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) inflammasome has become an important bridge between stimulation and sterile inflammation and is activated by intracellular reactive oxygen species (ROS) in response to danger signals, leading to an inflammatory cascade. In this study, we aimed to determine whether pepsin causes LPR-associated inflammatory injury via mediating inflammasome activation and explore the potential mechanism.

METHODS

We evaluated NLRP3 inflammasome expression and ROS in the laryngeal mucosa using immunofluorescence and immunohistochemistry. Laryngeal epithelial cells were exposed to pepsin and analyzed using flow cytometry, western blotting, and real-time quantitative PCR to determine ROS, NLRP3, and pro-inflammatorycytokine levels.

RESULTS

Pepsin expression was positively correlated with ROS as well as caspase-1 and IL-1β levels in laryngeal tissues. Intracellular ROS levels were elevated by increased pepsin concentrations, which were attenuated by apocynin (APO)-a ROS inhibitor-in vitro. Furthermore, pepsin significantly induced the mRNA and protein expression of thioredoxin-interacting protein, NLRP3, caspase-1, and IL-1β in a dose-dependent manner. APO and the NLRP3 inhibitor, MCC950, inhibited NLRP3 inflammasome formation and suppressed laryngeal epithelial cell damage.

CONCLUSION

Our findings verified that pepsin could regulate the NLRP3/IL-1β signaling pathway through ROS activation and further induce inflammatory injury in LPR. Targeting the ROS/NLRP3 inflammasome signaling pathway may help treat patients with LPR disease.

Pilot study on anti-reflux mucoplasty: Advancing endoscopic anti-reflux therapy for gastroesophageal reflux disease

OBJECTIVES

Anti-reflux mucosectomy (ARMS) and anti-reflux mucosal ablation (ARMA) were developed as interventions for proton pump inhibitor (PPI)-refractory/-dependent gastroesophageal reflux disease (GERD). Although ARMS and ARMA are established treatments for PPI-refractory GERD, reliance on natural healing for ulcer scar formation introduces uncertainty and bleeding risk. To address these issues, we introduced a novel approach called anti-reflux mucoplasty (ARM-P), which involves immediate closure of mucosal defects following mucosectomy. This pilot study aims to evaluate the safety, feasibility, and efficacy of ARM-P.

METHODS

A retrospective single-center study was conducted using prospectively collected data from October 2022 to July 2023. Patients with PPI-refractory/-dependent GERD who underwent ARM-P were included. The study evaluated technical success of ARM-P, before and after ARM-P GERD-Health Related Quality of Life Questionnaire, GerdQ, and Frequency Scale for the Symptoms of GERD scores, along with PPI discontinuation and endoscopic esophagogastric junction morphology.

RESULTS

A total of 20 patients with a median age of 61.5 years underwent the ARM-P procedure. The procedure achieved 100% technical success without adverse events. After ARM-P, 55.0% discontinued PPI usage and 15.0% reduced PPI dose by half. Median GERD-Health Related Quality of Life Questionnaire score improved from 21 to 6 (P = 0.0026), median GerdQ score improved from 9 to 7 (P = 0.0022), and median Frequency Scale for the Symptoms of GERD score decreased from 16 to 7 (P = 0.0003). Median Hill's Classification significantly improved from grade III to grade I (P = 0.0001).

CONCLUSIONS

This study presents the first pilot report of ARM-P, demonstrating its procedural safety, technical feasibility, and short-term efficacy.

Overlapping approach Proton Pump Inhibitors/Nux vomica-Heel as new intervention for gastro-esophageal reflux management: Delphi consensus study

BACKGROUND

Gastro-esophageal reflux disease (GERD) may affect the upper digestive tract; up to 20% of population in Western nations are affected by GERD. Antacids, histamine H2-receptor antagonists, and Proton Pump Inhibitors (PPIs) are considered the referring medications for GERD. Nevertheless, PPIs must be managed carefully because their use, especially chronic, could be linked with some adverse effects. An effective and safe alternative pharmacological tool for GERD is needed. After the identification of potentially new medications to flank PPIs, it is mandatory to revise and improve good clinical practices even through a consensus process.

AIM

To optimize diagnosis and treatment guidelines for GERD through a consensus based on Delphi method.

METHODS

The availability of clinical studies describing the action of the multicomponent/multitarget medication Nux vomica-Heel, subject of the consensus, is the basic prerequisite for the consensus itself. A modified Delphi process was used to reach a consensus among a panel of Italian GERD specialists on the overlapping approach PPIs/Nux vomica-Heel as a new intervention model for the management of GERD. The Voting Consensus group was composed of 49 Italian Medical Doctors with different specializations: Gastroenterology, otolaryngology, geriatrics, and general medicine. A scientific committee analyzed the literature, determined areas that required investigation (in agreement with the multiple-choice questionnaire results), and identified two topics of interest: (1) GERD disease; and (2) GERD treatment. Statements for each of these topics were then formulated and validated. The Delphi process involved two rounds of questioning submitted to the panel experts using an online platform.

RESULTS

According to their routinary GERD practice and current clinical evidence, the panel members provided feedback to each questionnaire statement. The experts evaluated 15 statements and reached consensus on all 15. The statements regarding the GERD disease showed high levels of agreement, with consensus ranging from 70% to 92%. The statements regarding the GERD treatment also showed very high levels of agreement, with consensus ranging from 90% to 100%. This Delphi process was able to reach consensus among physicians in relevant aspects of GERD management, such as the adoption of a new approach to treat patients with GERD based on the overlapping between PPIs and Nux vomica-Heel. The consensus was unanimous among the physicians with different specializations, underlying the uniqueness of the agreement reached to identify in the overlapping approach between PPIs and Nux vomica-Heel a new intervention model for GERD management. The results support that an effective approach to deprescribe PPIs through a progressive decalage timetable (reducing PPIs administration to as-needed use), should be considered.

CONCLUSION

Nux vomica-Heel appears to be a valid opportunity for GERD treatment to favor the deprescription of PPIs and to maintain low disease activity together with the symptomatology remission.

Relationship between endoscopic gastroesophageal valve grading and mean nocturnal baseline impedance and postreflux swallow-induced peristaltic wave index in patients with gastroesophageal reflux disease

This study aimed to investigate the relationship between endoscopic gastroesophageal valve grading and mean nocturnal baseline impedance (MNBI) and postreflux swallow-induced peristaltic wave index (PSPWI) in patients with gastroesophageal reflux disease (GERD). A total of 120 patients diagnosed with GERD disease were included in the study. According to the classification of endoscopic gastroesophageal valves, the patients were divided into 5 groups, group 1 as baseline group, and Group 2-4 as Hill grade I-IV. Basic information about the patients was collected, including age and gender. The mean nocturnal baseline impedance and creep wave index induced by swallowing after rumination were measured by high resolution creep measurement technique. Through statistical analysis, the relationship between valve classification and observation index was discussed. In terms of MNBI, impedance values gradually decreased with increasing valve classification. The average impedance of the Grade 1 group was 23.5 mm Hg/cm2, while the average impedance of the Grade 5 group was 15.2 mm Hg/cm2. This reduction showed a significant decreasing trend (P < .001). In addition, in terms of the peristaltic wave index caused by swallowing after regurgitation, the peristaltic wave index gradually increased with the increase of valve classification. The mean index in the Grade 1 group was 1.8 beats/min, while the mean index in the Grade 5 group was 3.6 beats/min. This increase showed a significant positive relationship (P < .001). Endoscopic gastroesophageal valve grading was significantly correlated with MNBI and PSPWI in patients with GERD. These observations can serve as useful tools for assessing the severity of GERD and monitoring disease progression.

Pathophysiology of gastro-oesophageal reflux disease: implications for diagnosis and management

Gastro-oesophageal reflux disease (GERD) is a common gastrointestinal disorder in which retrograde flow of gastric content into the oesophagus causes uncomfortable symptoms and/or complications. It has a multifactorial and partially understood pathophysiology. GERD starts in the stomach, where the refluxate material is produced. Following the trajectory of reflux, the failure of the antireflux barrier, primarily the lower oesophageal sphincter and the crural diaphragm, enables the refluxate to reach the oesophageal lumen, triggering oesophageal or extra-oesophageal symptoms. Reflux clearance mechanisms such as primary and secondary peristalsis and the arrival of bicarbonate-rich saliva are critical to prevent mucosal damage. Alterations of the oesophageal mucosal integrity, such as macroscopic oesophagitis or microscopic changes, determine the perception of symptoms. The intensity of the symptoms is affected by peripheral and central neural and psychological mechanisms. In this Review, we describe an updated understanding of the complex and multifactorial pathophysiology of GERD. It is now recognized that different GERD phenotypes have different degrees of reflux, severity of mucosal integrity damage and type, and severity of symptoms. These variations are probably due to the occurrence of a predominant pathophysiological mechanism in each patient. We also describe the main pathophysiological mechanisms of GERD and their implications for personalized diagnosis and management.

The Role of Inflammatory Biomarkers in Mediating the Effect of Inflammatory Bowel Disease on nonmalignant Digestive System Diseases: A Multivariable Mendelian Randomized Study

Background

While observation studies have shown a positive correlation between inflammatory bowel disease (IBD) and the risk of nonmalignant digestive system diseases, a definitive causal relationship has not yet been clearly established.

Methods

Mendelian randomization (MR) was employed to investigate the potential causal association between genetic susceptibility to IBD and nonmalignant gastrointestinal diseases. Genetic variants were extracted as instrumental variables (IVs) from a genome-wide association study (GWAS) meta-analysis, which included 12,194 cases of Crohn's disease (CD) and 28,072 control cases of European ancestry. The GWAS for ulcerative colitis (UC) included 12,366 UC and 33,609 control cases of European ancestry. All IVs reached genome-wide significance (GWAS p value <5 × 10-8). Summary-level data for acute pancreatitis (AP), irritable bowel syndrome (IBS), gastroesophageal reflux disease, cholelithiasis, and CeD (celiac disease) were obtained from the GWAS meta-analysis and the FinnGen dataset. Summary-level data on relevant inflammatory factors were provided by the International Genetic Consortium. Univariate MR analysis was conducted using inverse variance weighting as the primary method for estimating causal effects. Multivariate MR analyses were also performed to detect possible mediators.

Results

Genetic susceptibility to UC was associated with an increased risk of AP (OR = 1.08; 95% CI = 1.03-1.13; p=0.002) and IBS odds ratio (OR] = 1.07; 95% confidence interval (CI] = 1.03-1.11; (p < 0.001). In terms of potential mediators, interleukin 6 (IL-6) had a driving effect on the association between UC and AP. There was no apparent evidence of increased risk with CD. Meanwhile, genetic susceptibility to CD increases the risk of CeD (OR = 1.14; 95% CI = 1.03-1.25; p=0.01).

Conclusions

The evidence suggests that UC is associated with an elevated risk of AP and IBS, and IL-6 may be responsible in AP. CD is associated with an increased risk of developing CeD. Implementing a proactive monitoring program for assessing the risk of gastrointestinal diseases in UC patients, particularly those with elevated IL-6 levels, may be of interest. In addition, the presence of AP and IBS may indicate the presence of UC. Preventing CeD is an essential consideration in the therapeutic management of patients with CD.

Comprehensive insights into the multifaceted roles of the transient receptor potential vanilloid 1 channel in the digestive system

The transient receptor potential vanilloid (TRPV) channel, a family of calcium transporters comprising six distinct members (TRPV1-6), takes on a paramount role in maintaining intracellular Ca2+ homeostasis in mammalian cells. Notably, TRPV1, among its counterparts, has emerged as the subject of extensive scrutiny, owing to its pervasive presence in diverse cellular, tissue, and organ settings. This ubiquitous distribution underscores its fundamental involvement in the genesis of pain, making it a central focus in pain-related research. However, recent investigations have unveiled that TRPV1's functional significance transcends the realm of pain modulation, extending its influence to encompass a wide spectrum of physiological and pathological processes. The ambit of TRPV1's influence encompasses not only pain responses but also embraces the intricate domains of nervous system disorders, cancer metastasis, as well as afflictions pertaining to the skin and heart. Moreover, compelling evidence now demonstrates that TRPV1 also wields substantial sway in the domain of digestive diseases, further highlighting its versatility and far-reaching impact on human health. Therefore, this comprehensive review endeavors to delve into the multifaceted roles played by TRPV1 in the various organs constituting the digestive system.

Identification of novel immune cell signature in gastroesophageal reflux disease: altered mucosal mast cells and dendritic cell profile

Introduction

Heartburn pathogenesis in GERD remains incompletely understood. We aimed to identify differences in the immune cell signature and sensory mucosal markers between reflux phenotypes and healthy asymptomatic subjects.

Methods

Thirty-seven patients with heartburn symptoms were phenotyped endoscopically and with objective reflux studies into erosive reflux disease (ERD) (N=10), nonerosive reflux disease (NERD) (N=9), functional heartburn (FH) (N=9), and Barrett's esophagus (BO) (N=9). Bulk mRNA-sequencing(RNA-seq) was conducted on RNA extracted from endoscopic biopsies, and immune cell deconvolution analysis was performed using CIBERSORT. RNA-seq findings were validated by immunofluorescent staining for CD1a, nerve growth factor (NGF), and mast cell tryptase in corresponding patient biopsies.

Results

Transcriptomic analysis detected higher mast cell abundance in BO, ERD, and NERD compared to healthy controls (p<0.05), with decreased dendritic cell infiltration in BO, ERD, and NERD patients compared to healthy controls and FH patients. CD1a-positive dendritic cell infiltration was significantly higher in the healthy esophageal mucosa at protein level compared to BO (p=0.0005), ERD (p=0.0004), and FH patients (p=0.0096). Moreover, NGF co-expression on mast cells in GERD patients was significantly higher than in healthy controls (p=0.0094).

Discussion

The mucosa in patients with GERD had a significant increase in NGF expression on mast cells, suggesting an upregulation of signalling for neuronal sprouting in GERD. Moreover, decreased dendritic cell abundance in GERD esophageal mucosa may play a role in reduced oral tolerance and development of subsequent immune responses which may participate in esophageal sensitivity.

Revisiting the Role of Esophageal Mucosal Dilated Intercellular Spaces in the Diagnosis and Pathophysiology of Heartburn

Background/Aims

Dilated intercellular spaces (DISs) facilitate the diffusion of noxious agents into the deep layers of the esophageal epithelium. The role of DIS in heartburn pathogenesis is still controversial. Therefore, we aim to reinvestigate DIS in an extensively evaluated group of patients and healthy controls (HCs).

Methods

We classified 149 subjects into the following groups: 15 HC, 58 mild erosive reflux disease (ERD), 17 severe ERD, 25 nonerosive reflux disease (NERD), 15 reflux hypersensitivity (RH), and 19 functional heartburn (FH). A total of 100 length measurements were performed for each patient's biopsy.

Results

The overall intercellular spaces (ISs) value of gastroesophageal reflux disease (GERD) patients was higher than that of HC (P = 0.020). In phenotypes, mild ERD (vs HC [P = 0.036], NERD [P = 0.004], RH [P = 0.014]) and severe ERD (vs HC [P = 0.002], NERD [P < 0.001], RH [P = 0.001], FH [P = 0.004]) showed significantly higher IS. There was no significant difference between the HC, NERD, RH, and FH groups. The 1.12 μm DIS cutoff value had 63.5% sensitivity and 66.7% specificity in the diagnosis of GERD. There was a weak correlation (r = 0.302) between the IS value and acid exposure time, and a weak correlation (r = -0.359) between the IS value and baseline impedance. A strong correlation was shown between acid exposure time and baseline impedance (r = -0.783).

Conclusions

Since the IS length measurement had better discrimination power only in erosive groups, it is not feasible to use in daily routine to discriminate other nonerosive phenotypes and FH. The role of DIS in heartburn in nonerosive patients should be reconsidered.

Chitosan Nanoparticles for Gastroesophageal Reflux Disease Treatment

Gastroesophageal Reflux Disease (GERD) is a chronic ailment that results from the backward flow of stomach acid into the esophagus, causing heartburn and acid regurgitation. This review explores nanotechnology as a novel treatment approach for GERD. Chitosan nanoparticles (CSNPs) offer several advantages, including biocompatibility, biodegradability, and targeted drug delivery capabilities. CSNPs have been extensively studied due to their ability to encapsulate and release medications in a controlled manner. Different nanoparticle (NP) delivery systems, including gels, microspheres, and coatings, have been developed to enhance drug retention, drug targeting, and controlled release in the esophagus. These nanoparticles can target specific molecular pathways associated with acid regulation, esophageal tissue protection, and inflammation modulation. However, the optimization of nanoparticle formulations faces challenges, including ensuring stability, scalability, and regulatory compliance. The future may see CSNPs combined with other treatments like proton pump inhibitors (PPIs) or mucosal protectants for a synergistic therapeutic approach. Thus, CSNPs provide exciting opportunities for novel GERD treatment strategies.

Functional Food in Relation to Gastroesophageal Reflux Disease (GERD)

Gastroesophageal reflux disease (GERD) is a common esophageal disorder characterized by troublesome symptoms associated with increased esophageal acid exposure. The cornerstones of therapy in this regard include treatment with acid-suppressive agents, lifestyle modifications, and dietary therapy, although the latter has not been well defined. As concerns regarding long-term proton pump inhibitor (PPI) use continue to be explored, patients and healthcare providers are becoming increasingly interested in the role of diet in disease management. However, dietary interventions lack evidence of the synthesis effect of functional foods. The following is a review of dietary therapy for GERD, emphasizing food components' impact on GERD pathophysiology and management. Although the sequential dietary elimination of food groups is a common practice, the literature supports broader intervention, including reduced overall sugar intake, increased dietary fiber, and changes in overall eating practices. While the primary concern of food companies is to provide safe products, the caloric, nutritional, and functional composition of foods is also generating interest in the food industry due to consumers' concerns.

Magnetic sphincter augmentation: considerations for use in Barrett's esophagus

Barrett's esophagus (BE) occurs in 5-15% of patients with gastroesophageal reflux disease (GERD). While acid suppressive therapy is a critical component of BE management to minimize the risk of progression to esophageal adenocarcinoma, surgical control of mechanical reflux is sometimes necessary. Magnetic sphincter augmentation (MSA) is an increasingly utilized anti-reflux surgical therapy for GERD. While the use of MSA is listed as a precaution by the United States Food and Drug Administration, there are limited data showing effective BE regression with MSA. MSA offers several advantages in BE including effective reflux control, anti-reflux barrier restoration and reduced hiatal hernia recurrence. However, careful patient selection for MSA is necessary.

JP-1366: A novel and potent potassium-competitive acid blocker that is effective in the treatment of acid-related diseases

The global prevalence of GERD is substantially increasing each year, and GERD is a chronic disease that reduces the quality of life of patients. The efficacy of conventional drugs is diverse, and most require long-term or lifetime administration; thus, the development of more effective therapeutic agents is needed. Herein, a more effective treatment for GERD was tested. We investigated whether JP-1366 affected gastric H+/K+-ATPase activity and used the Na+/K+-ATPase assay to confirm the selectivity of H+/K+-ATPase inhibition. To clarify the mechanism of enzyme inhibition, JP-1366 and TAK-438 were analyzed by Lineweaver-Burk. Also, we investigated the effects of JP-1366 in various models involving reflux esophagitis. We found that JP-1366 mediates strong, selective, and dose-dependent inhibition of H+/K+-ATPase. We found that JP-1366 significantly suppressed gastric acid secretion in histamine-treated pylorus-ligated rats in a dose-dependent manner. Additionally, we confirmed that JP-1366 inhibited histamine-stimulated gastric acid secretion in the HPD model. JP-1366 exhibited a more than 2-fold higher inhibitory effect on esophageal injury than TAK-438 in GERD lesions and had a more potent inhibitory effect in indomethacin- or aspirin-induced gastric ulcer rat models than TAK-438. Additionally, JP-1366 inhibited gastric ulcers. These results support the possibility that JP-1366 is a good candidate drug for treating acid-related diseases.

Acidosis-related pain and its receptors as targets for chronic pain

Sensing acidosis is an important somatosensory function in responses to ischemia, inflammation, and metabolic alteration. Accumulating evidence has shown that acidosis is an effective factor for pain induction and that many intractable chronic pain diseases are associated with acidosis signaling. Various receptors have been known to detect extracellular acidosis and all express in the somatosensory neurons, such as acid sensing ion channels (ASIC), transient receptor potential (TRP) channels and proton-sensing G-protein coupled receptors. In addition to sense noxious acidic stimulation, these proton-sensing receptors also play a vital role in pain processing. For example, ASICs and TRPs are involved in not only nociceptive activation but also anti-nociceptive effects as well as some other non-nociceptive pathways. Herein, we review recent progress in probing the roles of proton-sensing receptors in preclinical pain research and their clinical relevance. We also propose a new concept of sngception to address the specific somatosensory function of acid sensation. This review aims to connect these acid-sensing receptors with basic pain research and clinical pain diseases, thus helping with better understanding the acid-related pain pathogenesis and their potential therapeutic roles via the mechanism of acid-mediated antinociception.

Topical Alginate Protection against Pepsin-Mediated Esophageal Damage: E-Cadherin Proteolysis and Matrix Metalloproteinase Induction

Epithelial barrier dysfunction is a hallmark of gastroesophageal reflux disease (GERD) related to symptom origination, inflammatory remodeling and carcinogenesis. Alginate-based antireflux medications were previously shown to topically protect against peptic barrier disruption, yet the molecular mechanisms of injury and protection were unclear. Herein, Barrett's esophageal (BAR-T) cells were pretreated with buffered saline (HBSS; control), dilute alginate medications (Gaviscon Advance or Gaviscon Double Action, Reckitt Benckiser), a viscosity-matched placebo, or ADAM10 and matrix metalloproteinase (MMP) inhibitors before exposure to HBSS pH7.4 or pH4 ± 1 mg/mL pepsin for 10-60 min. Cell viability was assessed by ATP assay; mediators of epithelial integrity, E-cadherin, ADAM10, and MMPs were examined by Western blot and qPCR. Alginate rescued peptic reduction of cell viability (p < 0.0001). Pepsin-pH4 yielded E-cadherin fragments indicative of regulated intramembrane proteolysis (RIP) which was not rescued by inhibitors of known E-cadherin sheddases. Transcriptional targets of E-cadherin RIP fragments were elevated at 24 h (MMP-1,2,9,14; p < 0.01). Alginate rescued E-cadherin cleavage, ADAM10 maturation, and MMP induction (p < 0.01). Results support RIP as a novel mechanism of peptic injury during GERD. Alginate residue after wash-out to mimic physiologic esophageal clearance conferred lasting protection against pepsin-induced molecular mechanisms that may exacerbate GERD severity and promote carcinogenesis in the context of weakly acidic reflux.

Esophageal Mucosal Admittance: A New Technique to Diagnose Gastroesophageal Reflux Disease - Is It Feasible?

Purpose

Esophageal mucosal admittance (MA) is a promising diagnostic method for gastroesophageal reflux disease (GERD). We conducted a study to describe the esophageal MA in patients with reflux symptoms and determine its diagnostic accuracy.

Patients and Methods

We recruited 92 patients with ambulatory pH-impedance monitoring, upper gastrointestinal endoscopy, and MA measured by the tissue conductance meter. MA was measured during endoscopy at 5cm (distal esophagus) and 15cm above the Z line (middle esophagus), repeated at least five times at each position, and median MA was obtained. Afterwards, two biopsies were taken 5cm above the Z line for histopathological evaluation using the Esohisto criteria. Patients were classified as GERD or non-GERD according to the 2018 Lyon consensus.

Results

The mean age was 43.2 years, and 42 patients were males. The most common symptoms were regurgitation (75.0%), belching (65.2%), and heartburn (46.7%). Twenty-three (32.3%) were diagnosed with GERD using the Lyon consensus, and 24 (26.1%) had esophagitis on histopathology. The median MA at the distal and middle esophagus was moderately correlated. The median MA at both positions was higher in the GERD group but only statistically significant in the middle esophagus. MA was not associated with pH-impedance parameters and esophagitis on histopathology. The diagnostic model developed using the logistic regression did not have good accuracy.

Conclusion

MA was not different between GERD and non-GERD patients.

Alginates for Protection Against Pepsin-Acid Induced Aerodigestive Epithelial Barrier Disruption

OBJECTIVE

Gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) are chronic conditions caused by backflow of gastric and duodenal contents into the esophagus and proximal aerodigestive tract, respectively. Mucosal barrier dysfunction resultant from the synergistic actions of chemical injury and the mucosal inflammatory response during reflux contributes to symptom perception. Alginates effectively treat symptoms of mild to moderate GERD and have recently shown benefit for LPR. In addition to forming a "raft" over gastric contents to reduce acidic reflux episodes, alginates have been found to bind the esophageal mucosa thereby preserving functional barrier integrity measured by transepithelial electrical resistance. The aim of this study was to further examine the topical protective capacity of alginate-based Gaviscon Advance (GA) and Double Action (GDA) against pepsin-acid mediated aerodigestive epithelial barrier dysfunction in vitro.

STUDY DESIGN

Translational.

METHODS

Immortalized human esophageal and vocal cord epithelial cells cultured in transwells were pretreated with liquid formula GA, GDA, matched viscous placebo solution, or saline (control), then treated for 1 h with saline, acid (pH 3-6) or pepsin (0.1-1 mg/ml) at pH 3-6. Endpoint measure was taken of horseradish peroxidase (HRP) allowed to diffuse across monolayers for 2 h.

RESULTS

Pepsin (0.1-1 mg/ml) at pH 3-6 increased HRP flux through cultures pretreated with saline or placebo (p < 0.05); acid alone did not. GA and GDA prevented barrier dysfunction.

CONCLUSIONS

GA and GDA preserved epithelial barrier function during pepsin-acid insult better than placebo suggesting that protection was due to alginate. These data support topical protection as a therapeutic approach to GERD and LPR. Laryngoscope, 132:2327-2334, 2022.

Herbal Medicine Hewei Jiangni Decoction Is Noninferior to Oral Omeprazole for the Treatment of Nonerosive Gastroesophageal Reflux Disease: A Randomized, Double-Blind, and Double-Dummy Controlled Trail

Objectives. Conventional approaches for patients with nonerosive gastroesophageal reflux disease (NERD) were not satisfactory. This study aimed to evaluate the effectiveness and mechanisms of Chinese herbal medicine Hewei Jiangni Decoction (HWJND) as a novel and promising regimen for NERD. Methods. A total of 128 patients with NERD were randomly assigned to the Treatment group and Control group. The patients from the Treatment group were administered HWJND (81 g) plus dummy omeprazole (20 mg) daily for 8 weeks, and the others were given dummy HWJND granules (81 g) plus omeprazole (20 mg). The clinical efficacy was assessed using the gastroesophageal reflux disease questionnaire (GERD-Q) scale, patient reported outcomes (PRO) scale, and short form health survey 36 (SF-36) scale at week 4. Moreover, its pharmacological and molecular mechanisms were elucidated based on network pharmacology and molecular docking. Results. Due to case shedding and other reasons, 109 patients, including 56 in the Treatment group and 53 in the Control group completed this study. Our results showed that HWJND significantly improved heartburn, regurgitation, epigastric pain, nausea, and sleep disturbance, which led to a significant reduction of GERD-Q scores in NERD patients. In addition, PRO scores of NERD patients with HWJND administration were improved, and sufficient relief of physical role, body pain, general health, social function, and mental health on the SF-36 scale was also observed in patients after HWJND treatment. We further showed that the curative effect of HWJND was close to that of omeprazole, except for the better improvement of general health and social function. What’s more, the main active ingredients of HWJND included quercetin, beta-sitosterol, naringenin, baicalein, and kaempferol were retrieved, and the protective effects of HWJND against NERD may be closely related to targets such as TNF, IL6, IL1B, MMP9, CXCL8, and EGFR, which were mainly enriched in IL-17 signaling pathway and TNF signaling pathway. Conclusion. Our findings demonstrate that HWJND is noninferior to oral omeprazole for the treatment of patients with NERD, plays a therapeutic role through multiple targets and diverse pathways, and holds promise for complementary and alternative therapy for the treatment of NERD. This trial is registered with http://www.chictr.org.cn, Chinese Clinical Trials Registry [ChiCTR2200055960].

Atrophic gastritis is inversely associated with gastroesophageal reflux disease in a twin register based study

Background

The association between atrophic gastritis (AG) and symptomatic gastroesophageal reflux disease (GERD) needs to be better assessed.

Objective

We aimed to study this association in a twin setting, controlling for genetic and familial factors, in addition to a range of known covariates.

Methods

We performed a co‐twin control study based on the Swedish Twin Registry, including confirmed monozygotic (MZ) and dizygotic (DZ) twins. AG was determined by the measurement of serum pepsinogen I (PGI) and pepsinogen II (PGII), with different cut‐off values. GERD was defined using a structured questionnaire, by questions on symptoms of heartburn, acid regurgitation, pain behind the breastbone, and drug history. Patients were grouped into total GERD, less frequent (<1/week), and frequent GERD (≥1/week).

Results

A total of 12,533 twins were included in the study, among whom 37.7% showed less frequent GERD, and 18.7% had frequent GERD. There was an inverse association between AG and GERD, especially for frequent GERD. When PGI<30 was used as cut‐off value for AG, the odds ratio (OR) and corresponding 95% confidence interval (CI) was 0.52 (0.44, 0.62). When PGI<70 and PGI/PGII<3 was used as cut‐off value for AG, the OR (95% CI) was 0.53 (0.46, 0.63). A risk reduction for GERD was also observed in AG patients when the analysis was restricted in MZ or DZ twins.

Conclusion

In this co‐twin control study from the Swedish Twin Register, AG is persistently associated with a reduced risk for GERD, after controlling for genetic and shared familial factors.

Successful Management of Esophageal Perforation by Intraoperative Microscopy and Esophagoscopic Assistance: A Case Report

Surgical repair of esophageal perforation is a challenging procedure with a high risk of secondary complications, such as early esophageal leakage and late esophageal stricture, which can significantly reduce the patient's quality of life. A 34-year-old man underwent anterior cervical corpectomy decompression and fusion. On the ninth day post-operation, the patient developed fever and neck swelling. A computed tomography scan of the neck showed multiple subcutaneous pneumatosis. An esophageal perforation of approximately 1.5 cm in diameter was identified by esophagoscopy. During the operation, the fistula was first located using an esophagoscope. The distal end of the esophagoscope was then placed into the stomach to support the damaged segment of the esophagus. The esophageal mucosa was sutured under the microscope, and the perforation was successfully repaired. Postoperatively, the patient's body temperature decreased, and the infection indexes gradually returned to normal. Three months after the operation, the esophagoscopic review showed complete healing of the perforation. Esophagoscopy plays an important role in diagnosing and repairing esophageal perforations. The esophagoscope provides direct visualization of the perforation during diagnosis and detects smaller and not yet fully penetrated esophageal injuries. During the repair process, the esophagoscope immobilizes the esophagus, prevents its movement and facilitates suturing, maintains proper dilatation of the esophagus, provides space for suturing, and prevents esophageal stricture.

Peripheral and central pathophysiological changes in a new rat model of acid reflux combined with mental stress

BACKGROUND

Mental stress is an important risk factor for gastroesophageal reflux disease (GERD), which interacts with acid reflux and affects the efficacy of single acid suppression treatment. However, the specific mechanism remains elusive, and there is a lack of available models for further support.

METHODS

This study established a new compound model combining acid reflux and chronic unpredictable mild stress (CUMS) to observe potential peripheral and central pathophysiological changes.

KEY RESULTS

Rats in the compound model suffered from significant weight loss and manifested depression-like behaviours. In addition, the acid reflux was not aggravated despite the presence of mental stress, along with dilated intercellular space (DIS), increased expression of desmoglein-1 (DSG1) mRNA, and injury of the lower oesophageal mucosa. The balance between pro-inflammatory and anti-inflammatory factors was disrupted. In the hypothalamus of rats in the compound model, the expression of corticosterone-releasing factor (CRF) and its receptors, protein kinase A (PKA), and γ-aminobutyric acid (GABA) receptors were decreased. This might be related to the "escape" of stress, which weakened the suppressive effect on excitatory transmission to cope with the damage of pressure to the body.

CONCLUSIONS & INFERENCES

Mental stress and acid reflux affect GERD through peripheral and central aspects, which can result in the poor efficacy of acid inhibitors. This may provide a new direction for the treatment of GERD.

Network Pharmacology Analysis of Hewei Jiangni Granule for Gastroesophageal Reflux Disease and Experimental Verification of Its Anti-Neurogenic Inflammation Mechanism

Purpose

Proton pump inhibitors, as the first-line drugs for treating gastroesophageal reflux disease (GERD), are unable to completely relieve patients’ symptoms and patients are prone to recurrence after prolonged drug withdrawal. Thus, it is crucial to find herbal medicines as a complementary and alternative treatment. Hewei Jiangni granule (HWJNG) is a classical Chinese medicinal formula with clinical therapeutic effects on GERD, but its pharmacological mechanism of action remains unclear. This study aimed to explore and then verify the pharmacological mechanisms of HWJNG in GERD therapy.

Methods

A network pharmacology approach was applied to explore and then verify the pharmacological mechanisms of HWJNG in GERD therapy. The active ingredients of HWJNG, as well as therapeutic targets of GERD were acquired from specialized databases. The “herb-ingredient-gene-target” network for HWJNG in GERD treatment was built. The protein–protein interaction (PPI) network was constructed to screen the core coincident targets. Then, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. The core targets and signaling pathways associated with the anti-neurogenic inflammatory effect were partially verified via experiments in vivo at molecular level.

Results

In total, 179 chemical ingredients in HWJNG and 298 intersection targets between GERD and HWJNG were selected from databases. A large proportion of core targets and top signaling pathways were involved in neurogenic inflammation. HWJNG significantly alleviated pathological injuries of esophagus and reversed dilated intracellular spaces. Additionally, HWJNG markedly inhibited the excessive release of inflammatory cytokines such as interleukin (IL)-1β, IL-6, tumor necrosis factor receptor (TNF-a), as well as regulated stimulation sensors including transient receptor potential vanilloid type 1 (TRPV1) and its related neuroinflammatory mediators in GERD mice.

Conclusion

HWJNG is a promising therapeutic strategy for GERD treatment via regulation of multiple targets and pathways, its effects in alleviating neurogenic inflammation are especially acknowledged.

Higher Dementia Risk in People With Gastroesophageal Reflux Disease: A Real-World Evidence

Background

Whether or not patients with gastroesophageal reflux disease (GERD) have a higher risk of developing subsequent dementia remains unknown, and no observational evidence from population-based data is available. This study was to determine whether patients with GERD have a higher future risk of developing dementia.

Methods

For the period 2000–2012, datasets from the Longitudinal Health Insurance Database (LHID, subset of National Health Insurance Research Database in Taiwan) were analyzed. Definition of GERD was based on ICD-9-CM codes 530.11 and 530.81 and prescriptions for PPIs. After matching gender, age, index year, and comorbidities, each GERD patient was matched with four control patients without GERD. Future risk of dementia was evaluated, and sensitivity analysis of subgroups was conducted to clarify the potential association.

Results

In the present study, 13,570 patients were included in the GERD cohort and 54,280 patients were included in the control cohort. Patients with GERD showed higher risk developing dementia than control group, with an aHR of 1.34 (95% C.I., 1.07, 1.67). In GERD patients between above 70 years old, the risk of developing dementia was higher than that of the control groups (aHR = 1.34; 95% C.I., 1.01, 1.77).

Conclusion

Patients with GERD showed higher incidence of dementia, and elder patients had the highest risk of developing dementia. Clinicians should be concern of the association between GERD and dementia and should develop strategies to prevent dementia while managing patients with GERD.

Proanthocyanidins mitigate bile acid-induced changes in GSTT2 levels in a panel of racially diverse patient-derived primary esophageal cell cultures

Persistent and symptomatic reflux of gastric and duodenal contents, known as gastroesophageal reflux disease (GERD), is the strongest risk factor for esophageal adenocarcinoma (EAC). Despite similar rates of GERD and other risk factors across racial groups, EAC progression disproportionately impacts Caucasians. We recently reported that elevated tissue levels of the detoxification enzyme GSTT2 in the esophagi of Blacks compared to Caucasians may contribute protection. Herein, we extend our research to investigate whether cranberry proanthocyanidins (C-PAC) mitigate bile acid-induced damage and GSTT2 levels utilizing a racially diverse panel of patient-derived primary esophageal cultures. We have shown that C-PACs mitigate reflux-induced DNA damage through GSTT2 upregulation in a rat esophageal reflux model, but whether effects are recapitulated in humans or differentially based on race remains unknown. We isolated normal primary esophageal cells from Black and Caucasian patients and assessed GSTT2 protein levels and cellular viability following exposure to a bile acid cocktail with and without C-PAC treatment. Constitutive GSTT2 levels were significantly elevated in Black (2.9-fold) compared to Caucasian patients, as were GSTT2 levels in Black patients with GERD. C-PAC treatment induced GSTT2 levels 1.6-fold in primary normal esophageal cells. GSTT2 induction by C-PAC was greatest in cells with constitutively low GSTT2 expression. Overall, C-PAC mitigated bile-induced reductions of GSTT2 and subsequent loss of cell viability regardless of basal GSTT2 expression or race. These data support that C-PAC may be a safe efficacious agent to promote epithelial fitness through GSTT2 induction and in turn protect against bile acid-induced esophageal injury.

Cranberry Polyphenols in Esophageal Cancer Inhibition: New Insights

Esophageal adenocarcinoma (EAC) is a cancer characterized by rapidly rising incidence and poor survival, resulting in the need for new prevention and treatment options. We utilized two cranberry polyphenol extracts, one proanthocyanidin enriched (C-PAC) and a combination of anthocyanins, flavonoids, and glycosides (AFG) to assess inhibitory mechanisms utilizing premalignant Barrett’s esophagus (BE) and EAC derived cell lines. We employed reverse phase protein arrays (RPPA) and Western blots to examine cancer-associated pathways and specific signaling cascades modulated by C-PAC or AFG. Viability results show that C-PAC is more potent than AFG at inducing cell death in BE and EAC cell lines. Based on the RPPA results, C-PAC significantly modulated 37 and 69 proteins in JH-EsoAd1 (JHAD1) and OE19 EAC cells, respectively. AFG treatment significantly altered 49 proteins in both JHAD1 and OE19 cells. Bioinformatic analysis of RPPA results revealed many previously unidentified pathways as modulated by cranberry polyphenols including NOTCH signaling, immune response, and epithelial to mesenchymal transition. Collectively, these results provide new insight regarding mechanisms by which cranberry polyphenols exert cancer inhibitory effects targeting EAC, with implications for potential use of cranberry constituents as cancer preventive agents.

Pathophysiology of Pediatric Gastroesophageal Reflux Disease: Similarities and Differences With Adults

Gastroesophageal reflux (GOR) is defined as "the passage of gastric contents into the esophagus with or without regurgitation and vomiting" and gastroesophageal reflux disease (GORD) is defined "when GOR leads to troublesome symptoms affecting the daily functioning and/or complications." This definition was first developed in 2006 by the Montreal consensus group (1) and later on adopted by pediatric gastroenterology societies such as ESPGHAN and NASPGHAN in 2009 (2). The definition of gastroesophageal reflux reveals little about its pathophysiology and is focused on symptomatology. In this way, it acts as an umbrella term for the multifactorial causes of the disease and the various phenotypes encountered; from functional heartburn to hypersensitive esophagus and nonerosive reflux disease, to erosive esophagitis and Barrett's esophagus. This article is devoted to the pathophysiology of pediatric GORD in comparison to adult GORD and is divided in 2 parts. In the first part, we will systematically describe the different mechanisms for the generation and clearance of reflux events, while on the second part we will discuss the mechanisms involved in symptoms generation. Finally, we will discuss the similarities and differences between pediatric and adult GORD.

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.

Gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) is a common disorder in adults and children. The global prevalence of GERD is high and increasing. Non-erosive reflux disease is the most common phenotype of GERD. Heartburn and regurgitation are considered classic symptoms but GERD may present with various atypical and extra-oesophageal manifestations. The pathophysiology of GERD is multifactorial and different mechanisms may result in GERD symptoms, including gastric composition and motility, anti-reflux barrier, refluxate characteristics, clearance mechanisms, mucosal integrity and symptom perception. In clinical practice, the diagnosis of GERD is commonly established on the basis of response to anti-reflux treatment; however, a more accurate diagnosis requires testing that includes upper gastrointestinal tract endoscopy and reflux monitoring. New techniques and new reflux testing parameters help to better phenotype the condition. In children, the diagnosis of GERD is primarily based on history and physical examination and treatment vary with age. Treatment in adults includes a combination of lifestyle modifications with pharmacological, endoscopic or surgical intervention. In refractory GERD, optimization of proton-pump inhibitor treatment should be attempted before a series of diagnostic tests to assess the patient's phenotype.

Esophageal afferent innervation and its role in gastro-esophageal reflux disease symptoms

PURPOSE OF REVIEW

Despite the wide prevalence of gastro-esophageal reflux disease (GERD), the neurophysiological mechanisms underlying heartburn perception in the esophagus of patients with GERD remains incompletely understood. Recent studies have highlighted the potential influence sensory afferent nerves innervating the oesophageal epithelium may have on heartburn pathogenesis. The purpose of this review is to consider the current understanding of esophageal afferent neuronal innervation, including the nociceptive role of acid-sensing receptors expressed on these sensory nerves, in relation to pain perception in the esophagus of GERD patients.

RECENT FINDINGS

Central and peripheral pathways of sensitization following noxious stimulation of nociceptive receptors expressed on afferent nerves can regulate the strength of sensory nerve activation in the esophagus, which can result in the amplification or suppression of afferent signal transmission. The localization and characterization of mucosal sensory afferent nerves vary between GERD phenotypes and may explain the heterogeneity of symptom perception in patients with apparently similar levels of reflux.

SUMMARY

In this review, we discuss the relevance of afferent esophageal innervation in heartburn perception, with a particular focus on the pathways of reflux-induced activation of nociceptive nerves.

Role of microbial dysbiosis in the pathogenesis of esophageal mucosal disease: A paradigm shift from acid to bacteria?

Genomic sequencing, bioinformatics, and initial speciation (e.g., relative abundance) of the commensal microbiome have revolutionized the way we think about the “human” body in health and disease. The interactions between the gut bacteria and the immune system of the host play a key role in the pathogenesis of gastrointestinal diseases, including those impacting the esophagus. Although relatively stable, there are a number of factors that may disrupt the delicate balance between the luminal esophageal microbiome (EM) and the host. These changes are thought to be a product of age, diet, antibiotic and other medication use, oral hygiene, smoking, and/or expression of antibiotic products (bacteriocins) by other flora. These effects may lead to persistent dysbiosis which in turn increases the risk of local inflammation, systemic inflammation, and ultimately disease progression. Research has suggested that the etiology of gastroesophageal reflux disease-related esophagitis includes a cytokine-mediated inflammatory component and is, therefore, not merely the result of esophageal mucosal exposure to corrosives (i.e., acid). Emerging evidence also suggests that the EM plays a major role in the pathogenesis of disease by inciting an immunogenic response which ultimately propagates the inflammatory cascade. Here, we discuss the potential role for manipulating the EM as a therapeutic option for treating the root cause of various esophageal disease rather than just providing symptomatic relief (i.e., acid suppression).