The pathogenesis of heartburn in nonerosive reflux disease: a unifying hypothesis

Effective Restoration of Gastric and Esophageal Tissues in an In Vitro Model of GERD: Mucoadhesive and Protective Properties of Xyloglucan, Pea Proteins, and Polyacrylic Acid

Esophageal barrier dysfunction is a crucial pathophysiological mechanism of gastroesophageal reflux disease (GERD). However, treatments mainly aim to reduce gastric acidity rather than improve tissue integrity. This study evaluated the protective and mucoadhesive properties of a formulation containing xyloglucan, pea proteins, and polyacrylic acid (XPPA) in gastric and esophageal cells. Cells were exposed to hydrochloric acid (HCl) and subsequently treated with the test compound. Trans-epithelial electrical resistance (TEER), tight junction (TJ) expression, and mucoadhesion of XPPA on gastric and esophageal cells were evaluated. To further confirm the protective ability of XPPA, a Lucifer Yellow assay was performed on a human reconstructed esophageal epithelium to assess the ability of XPPA to prevent HCl-induced hyperpermeability. XPPA possesses noteworthy mucoadhesive properties, ensuring an extended contact time between the product and the damaged mucosa to allow sustained mucosal protection. Furthermore, XPPA effectively restored gastroesophageal barrier integrity after HCl-induced damage, as assessed with TEER, after 1 h (p < 0.05). Finally, XPPA helped to restore TJ expression (p < 0.05) and protected the tissues from hyperpermeability for at least 2 h (p < 0.05). These results pave the way for using XPPA as a promising treatment to ameliorate gastroesophageal barrier properties in GERD patients.

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.

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.

Poliprotect®, a Medical Device Made of Substances, Potently Protects the Human Esophageal Mucosa Challenged by Multiple Agents: Evidence from In Vitro and Ex Vivo Electrophysiological Models

The integrity of esophageal epithelial cells in patients with gastroesophageal reflux disease (GERD) or GERD-like symptoms is the first mechanism of protection to decrease the sensitivity to gastric reflux and heartburn symptoms. We investigated the protective effects of Poliprotect® (PPRO), a CE-marked medical device, on esophageal epithelial integrity using in vitro and ex vivo models. In vitro, the protective effects of PPRO were tested on Caco-2 cells. PPRO demonstrated safety and protection against oxidative damage induced by hydrogen peroxide. It also preserved epithelial integrity by maintaining transepithelial electrical resistance (TEER) against damage from calcium removal or bile acid exposure (taurodeoxycholic acid, TDCA). Ex vivo, esophageal biopsies from patients subjected to endoscopy were mounted in Ussing chambers and exposed to damaging agents (HCl or HCl + TDCA). Untreated biopsies (control) showed significant loss of epithelial resistance (up to -33%). In contrast, low concentrations of PPRO (50-100 µg/mL) provided strong protection against these damages (p < 0.001), even after 60 min of washing. Histological analysis confirmed the barrier-enhancing effect of PPRO. Overall, PPRO effectively protected the esophageal epithelium from damage in both models, suggesting its potential role in alleviating GERD or GERD-like symptoms by strengthening mucosal barriers and reducing epithelial sensitivity to reflux.

Efficacy and safety of Jianpi Qinghua granules for non-erosive reflux disease with spleen deficiency and damp-heat syndrome: a multicenter, randomized, double-blind, placebo-controlled clinical trial

Background

Non-erosive reflux disease (NERD), the most frequent phenotype of gastroesophageal reflux disease, presents without visible esophageal mucosal damage but significantly impacts patients' quality of life. Current treatments like proton pump inhibitors show limited efficacy for many NERD patients, necessitating alternative approaches. Jianpi Qinghua (JQ) granules, a traditional Chinese medicine, have shown promise in treating NERD by targeting symptoms of spleen deficiency and damp-heat syndrome.

Purpose

This study aims to evaluate the efficacy and safety of JQ granules in treating patients with NERD characterized by spleen deficiency and damp-heat syndrome.

Study design

A multicenter, randomized, double-blind, placebo-controlled clinical trial was conducted with a total of 78 NERD patients randomly assigned to receive either JQ granules or placebo for 4 weeks, followed by a 4-week follow-up period.

Methods

Seventy-eight NERD patients with spleen deficiency and damp-heat syndrome were recruited and randomly assigned to receive either JQ granules (n = 39) or placebo (n = 39). The trial included a 1-week lead-in, followed by a 4-week double-blind treatment, and a 4-week follow-up. Primary endpoints were the improvement rates of reflux and heartburn symptoms and VAS score changes. Secondary endpoints included atypical symptom scores, total TCM syndrome scores, GERD Health-Related Quality-of-Life (HRQL), and self-rated depression and anxiety scales. Safety assessments involved routine blood, urine, and liver and kidney function tests.

Results

After 4 weeks, the improvement rate for reflux or heartburn symptoms was 79.49% in the JQ group vs. 58.97% in the placebo group (P < 0.05). VAS scores showed significant reductions in both groups but without notable inter-group differences. Total TCM syndrome scores significantly decreased in both groups, with the JQ group showing greater improvement trends. The JQ group had higher rates of effective TCM syndrome improvement and better GERD-HRQL scores. Both groups saw significant reductions in self-rated depression and anxiety scores, with trends favoring JQ granules. Safety assessments were comparable between groups.

Conclusion

JQ granules significantly outperform placebo in treating NERD symptoms and display long-term effectiveness. They effectively address spleen deficiency and damp-heat syndrome, improving patients' social functioning, and have a favorable safety profile.

Clinical trial registration

https://clinicaltrials.gov/study/NCT04324138?term=NCT04324138&rank=1, identifier: NCT04324138.

Effects of Benesco™ on Esophageal Sensitivity, Mucosal Barrier Function, and Reflux Symptoms: A Mechanistic Study

INTRODUCTION

Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal diseases in the western world. Proton pump inhibitors (PPIs) are the cornerstone of GERD management however a subset of patients seeks for (natural) alternative therapies. Benesco™ is an over-the-counter supplement, of which the active ingredient is quercetin and has a presumed positive effect on esophageal barrier function. The aim of this study was therefore to evaluate the effect of benesco™ on esophageal sensitivity, mucosal barrier function, and reflux symptoms.

METHODS

Patients with GERD were evaluated using acid perfusion tests, an upper endoscopy with electrical tissue impedance spectroscopy, and esophageal biopsies.

RESULTS

8 patients (3 men, median age 45 (34-64)) were included. The perfusion sensitivity score (PSS) did not change significantly after treatment with benesco™ (90.5 (21.4-129.7) to 62.5 (16.4-96.9) p = 0.123). Esophageal sensitivity based on the maximum reported VAS score during the esophageal acid perfusion test did not change significantly after treatment with benesco™ (7.4 (5.3-9.8) to 7.7 (5.3-8.7) p = 0.482). Furthermore, no effects were seen on measures of mucosal barrier function such as extracellular in vivo impedance (ETIS) (6807 (5153-8883) Ω·m vs 6702 (5106-7847) Ω·m, p = 0.575), in vitro transepithelial electrical resistance (TEER) (183 (153-204) Ω.cm2 vs 201 (128-250) Ω.cm2, p = 1.000), or fluorescein flux (896 (73-1922) nmol/cm2/h vs 811 (187-2693) nmol/cm2/h, p = 0.237).

CONCLUSION

We did not observe an improvement of acid perception, mucosal barrier function, or reflux symptoms by benesco™ in this study.

TRIAL REGISTRATION

Dutch Trial Register number: NL9324.

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.

Risk factors associated with functional esophageal disorders (FED) versus gastroesophageal reflux disease (GERD)

INTRODUCTION

Despite the high prevalence of typical symptoms of gastroesophageal reflux disease (GERD), approximately 30% of patients have functional esophageal disorders (FED) on ambulatory reflux monitoring, which may include reflux hypersensitivity (RH; defined as physiologic acid exposure but temporally correlated symptoms of reflux), or functional heartburn (FH; defined as physiologic acid exposure and negative symptom correlation). There are limited epidemiological data characterizing these conditions. We investigated demographic and socioeconomic factors as well as medical comorbidities which may predispose to FED versus pathologic GERD.

METHODS

Adult patients with reflux symptoms for at least 3 months were studied with 24-h pH-impedance testing from 11/2019 to 3/2021. Participants were categorized into pathologic GERD, FH, or RH using pH-impedance data and reported symptom correlation. Demographic data, including age, gender, race/ethnicity, zip code, insurance status, and medical comorbidity data were retrospectively retrieved from the electronic medical record on all participants.

RESULTS

229 patients were included. Non-Hispanic Asian ethnicity (OR 5.65; p = 0.01), underweight BMI (OR 7.33; p = 0.06), chronic pain (OR 2.33; p < 0.01), insomnia (OR 2.83; p = 0.06), and allergic rhinitis (OR 3.90; p < 0.01) were associated with a greater risk for FED. Overweight BMI (OR 0.48; p = 0.03) and alcohol use (OR 0.57; p = 0.06) were associated with a decreased risk for FED.

DISCUSSION

This is the first report of a greater risk of FED in patients with underweight BMI, insomnia, chronic pain, allergic rhinitis, or of Asian or Hispanic ethnicities. The weak associations between female gender and anxiety are corroborated in other studies. Our findings enable clinicians to better screen patients with reflux for this disorder.

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.

The association between symptoms of gastroesophageal reflux disease and perceived stress: A countrywide study of Sri Lanka

BACKGROUND/AIMS

Stress is a known associated factor for gastroesophageal reflux disease (GERD). However, the dynamics between stress and GERD are not fully studied, especially in Sri Lanka. Our objective was to assess it.

METHODS

For this cross-sectional descriptive study, 1200 individuals (age ranged 18-70 years, mean 42.7 years [SD 14.4 years], 46.1% males), were recruited using stratified random cluster sampling from all 25 districts of Sri Lanka. An interviewer-administered questionnaire, which included a country-validated GERD symptom screening tool, and the Perceived Stress Scale (PSS), was used to assess GERD symptoms and stress. Probable GERD was defined as those having heartburn and/ or regurgitation at least once per week which is on par with globally accepted criteria. Those who did not fulfill these criteria were considered as controls.

RESULTS

PSS score was higher in those with probable GERD (mean 13.75 [standard deviation (SD) 6.87]) than in controls (mean 10.93 [SD 6.80]), (p <0.001, Mann-Whitney U test). The adjusted odds ratio for GERD symptoms was 1.96 times higher (95% confidence interval 1.50-2.55) in the moderate to high-stress level compared to the low-stress level participants. PSS score correlated significantly with the GERD screening tool score (R 0.242, p <0.001). Heartburn, regurgitation, chest pain, cough, and burping were significantly frequent in those with moderate to high-stress levels (p <0.001). Those with higher stress scores were more likely to use acid-lowering drugs (p = 0.006).

CONCLUSIONS

Individuals exposed to higher levels of stress are more likely to have GERD symptoms. Therefore, stress reduction should be an important part of GERD symptom management.

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.

The clinical effect of benesco™ on reflux symptoms: A double-blind randomized placebo-controlled trial

BACKGROUND

Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal diseases in the western world. Lifestyle modifications and proton pump inhibitors (PPIs) form the basis of the management of GERD. A subset of patients seeks for (natural) alternative therapies besides PPIs. benesco™ is an over-the-counter nutrition based on quercetin which has a presumed positive effect on esophageal barrier function. Therefore we aim to assess the effect of benesco™ on reflux symptoms.

METHODS

We performed a double-blind randomized placebo-controlled trial in participants with reflux symptoms. Participants were assigned randomly (1:1) to receive 6 weeks of benesco™ (three times daily one lozenge containing 200 mg of quercetin) or placebo. The primary outcome was treatment success (≥50% reduction in Reflux Disease Questionnaire Score). Secondary outcomes included GERD-related quality of life, reflux-free days and nights, and participant-reported treatment success.

KEY RESULTS

One hundred participants were randomized. Treatment success was seen in 18 (39%) of 46 participants in the intervention group versus 21 (47%) of 45 in the placebo group (p = 0.468). In the intervention group 10 (1-21) reflux-free days were reported compared to 10 (2-25) in the placebo group (p = 0.673). In addition, 38 (34-41) versus 39 (35-42) reflux-free nights were reported (p = 0.409).

CONCLUSIONS & INFERENCES

In our trial benesco™ showed no significant benefit over placebo at group level.

Correlation between Psychosomatic Assessment, Heart Rate Variability, and Refractory GERD: A Prospective Study in Patients with Acid Reflux Esophagitis

BACKGROUND

Gastroesophageal reflux disease (GERD) affects a significant proportion of individuals, with life stress being a contributing factor. This study aimed to investigate the correlation between psychosomatic evaluations, heart rate variability (HRV), and GERD in a cohort of individuals. Additionally, the study aimed to analyze the sequencing changes following proton pump inhibitor (PPI) treatment and identify predictive factors associated with refractory GERD.

METHODS

A prospective cohort of 105 individuals with reflux esophagitis and a control group of 50 participants without acid reflux symptoms were enrolled. Psychosomatic evaluations, including GERDQ, GERDQLQ, RSI, BAI, BDI, and SSS-8, were assessed at baseline and during treatment. HRV parameters were also evaluated. Multivariate analysis was used to identify predictive factors for refractory GERD. PPIs were administered regularly for the initial 2 months and then used on-demand. Refractory GERD was defined as less than 50% improvement in symptom relief or GERDQLQ score ≥ 20 after 8 weeks of PPI treatment.

RESULTS

The GERD group had higher scores in all psychosomatic evaluations compared to the control group (all p-values < 0.001). There were no significant changes in any parameters of HRV before and after treatment in the GERD group. Strong and consistent correlations were observed between GERD symptoms and psychological scores (BAI, BDI, and SSS-8) across all time points (W0, W4, and W8). Sequential reductions in GERD symptom scores and psychosomatic evaluations were observed during the initial eight weeks of treatment. Higher GERDQ (≥10) and SSS-8 (≥12) scores were predictive of refractory GERD (p = 0.004 and p = 0.009, respectively).

CONCLUSIONS

This study emphasizes the importance of considering physiological and psychological factors in the management of GERD. Psychosomatic evaluations provide valuable insights for assessing and treating GERD patients. Integrating stress management and comprehensive assessments into personalized treatment strategies is crucial.

Esophageal secondary peristalsis following acid infusion and chemical clearance correlate with mucosal integrity and acid sensitivity in GERD patients

Background

Acid sensitivity can be altered in patients with gastroesophageal reflux disease (GERD). Secondary peristalsis helps clear gastro-esophageal refluxate and residual ingested food bolus.

Objectives

The aim of this study was to investigate the associations among acid sensitivity, esophageal mucosal integrity, chemical clearance, and secondary peristalsis before and after esophageal acid infusion.

Design

This was an investigator-initiated, prospective, cross-sectional study.

Methods

Adult reflux patients underwent high resolution manometry and 24 h impedance-pH monitoring off acid suppression to identify GERD phenotypes, including non-erosive reflux disease (NERD), reflux hypersensitivity (RH), and functional heartburn (FH). Secondary peristalsis was assessed using five rapid 20 mL air injections into the esophagus before and after infusion of hydrochloric acid (0.1 N) into the mid-esophagus. Conventional acid infusion parameters recorded included lag time, intensity rating, and sensitivity score. Chemical clearance was evaluated using the post-reflux swallow-induced peristaltic wave (PSPW), and mucosal integrity was assessed by the mean nocturnal baseline impedance (MNBI) derived from impedance-pH monitoring.

Results

A total of 88 patients (age 21-64 years, 62.5% women) completed the study including 12 patients with NERD, 45 with RH, and 31 with FH. There was no significant difference in acid infusion parameters between patients with NERD, RH, and FH. Upon acid infusion, patients who exhibited successful secondary peristalsis had longer lag time, higher MNBI, and shorter bolus contact time than those without secondary peristalsis. Meanwhile, patients with intact PSPW demonstrated significantly higher intensity ratings in response to acid perfusion and higher MNBI than those with impaired PSPW. The lag time correlated positively with MNBI (r = 0.285; p = 0.007).

Conclusion

In conclusion, the protective effect of esophageal secondary peristalsis and chemical clearance on esophageal mucosal integrity was demonstrated. Concerning acid sensitivity, longer lag time in patients with intact secondary peristalsis may be attributed to better esophageal mucosal integrity, while stronger intensity ratings may have a greater tendency to induce PSPW and protect esophageal mucosal integrity.

Application of Artificial Intelligence in Measuring Novel pH-Impedance Metrics for Optimal Diagnosis of GERD

Novel metrics extracted from pH-impedance monitoring can augment the diagnosis of gastroesophageal reflux disease (GERD). Artificial intelligence (AI) is being widely used to improve the diagnostic capabilities of various diseases. In this review, we update the current literature regarding applications of artificial intelligence in measuring novel pH-impedance metrics. AI demonstrates high performance in the measurement of impedance metrics, including numbers of reflux episodes and post-reflux swallow-induced peristaltic wave index and, furthermore, extracts baseline impedance from the entire pH-impedance study. AI is expected to play a reliable role in facilitating measuring novel impedance metrics in patients with GERD in the near future.

Sensory Phenotype of the Oesophageal Mucosa in Gastro-Oesophageal Reflux Disease

Gastroesophageal reflux disease (GORD) affects up to 20% of Western populations, yet sensory mechanisms underlying heartburn pathogenesis remain incompletely understood. While central mechanisms of heartburn perception have been established in earlier studies, recent studies have highlighted an important role of neurochemical, inflammatory, and cellular changes occurring in the oesophageal mucosa itself. The localization and neurochemical characterisation of sensory afferent nerve endings differ among GORD phenotypes, and could explain symptom heterogeneity among patients who are exposed to similar levels of reflux. Acid-induced stimulation of nociceptors on pain-sensing nerve endings can regulate afferent signal transmission. This review considers the role of peripheral mechanisms of sensitization in the amplification of oesophageal sensitivity in patients with GORD.

Eosinophilic esophagitis: Immune mechanisms and therapeutic targets

Eosinophilic esophagitis (EoE) is an emerging chronic inflammatory disease of the oesophagus and is clinically characterized by upper gastrointestinal (GI) symptoms including dysphagia and esophageal food impaction. Histopathologic manifestations, which include intraepithelial eosinophilic inflammation and alterations of the esophageal squamous epithelium, such as basal zone hyperplasia (BZH) and dilated intercellular spaces (DIS), are thought to contribute to esophageal dysfunction and disease symptoms. Corroborative clinical and discovery science-based studies have established that EoE is characterized by an underlying allergic inflammatory response, in part, related to the IL-13/CCL26/eosinophil axis driving dysregulation of several key epithelial barrier and proliferative regulatory genes including kallikrein (KLK) serine proteases, calpain 14 (CAPN14) and anoctamin 1 (ANO1). The contribution of these inflammatory and proliferative processes to the clinical and histological manifestations of disease are not fully elucidated. Herein, we discuss the immune molecules and cells that are thought to underlie the clinical and pathologic manifestations of EoE and the emerging therapeutics targeting these processes for the treatment of EoE.

Gastroesophageal reflux disease: risk factors, current possibilities of diagnosis and treatment optimisation

Gastroesophageal reflux disease (GERD) is one of the most common causes of health care seeking at the primary care level in many countries. At an epidemiological level, GERD has been shown to be associated with a number of risk factors: obesity, tobacco smoking, alcohol abuse, certain patterns of eating behaviour, and the use of several medications. GERD is now regarded as a heterogeneous disease and includes different phenotypes (erosive reflux disease, non-erosive reflux disease, hypersensitive oesophagus, functional heartburn), the proper diagnosis of which improves the effectiveness of therapy in patients with heartburn symptoms. Daily impedance–pH monitoring is known to be an integral part of the diagnostic algorithm for GERD and is a functional diagnostic method to record all types of refluxes entering the oesophagus regardless of pH, to assess their association with symptoms, and to determine whether patients with heartburn symptoms belong to a particular phenotype. Esophageal manometry plays a key role in the evaluation of patients with heartburn symptoms, as it helps to rule out other conditions that may mimic GERD: achalasia cardia and scleroderma esophagus. This technique is used to assess thoracic esophageal motility and sphincter function and in the assessment of patients prior to antireflux surgery or in the refractory course of GERD. The article describes in detail GERD risk factors (triggers of heartburn), as well as diagnostic aspects, taking into account a differentiated approach to patients with heartburn based on daily impedance–pH monitoring data in accordance with the current guidelines and recommendations.

Oesophageal hypervigilance and visceral anxiety relate to reflux symptom severity and psychological distress but not to acid reflux parameters

BACKGROUND

The pathogenesis of gastro-oesophageal reflux disease (GERD) is complex and multifactorial. The oesophageal hypervigilance and anxiety scale (EHAS) is a novel cognitive-affective evaluation of visceral sensitivity.

AIMS

To investigate the interrelationship between EHAS and reflux symptom severity, psychological stress, acid reflux burden, phenotypes, and oesophageal mucosal integrity in patients with GERD.

METHODS

Patients with chronic reflux symptoms and negative endoscopy underwent 24-hour impedance-pH monitoring for phenotyping, acid reflux burden, and mucosal integrity with mean nocturnal baseline impedance (MNBI) calculation. Validated scores for patient-reported outcomes, including EHAS, GERD questionnaire (GERDQ), State-Trait Anxiety Inventory score, and Taiwanese Depression Questionnaire score, were recorded.

RESULTS

We enrolled 105 patients, aged 21-64 years (mean, 48.8), of whom 58.1% were female; 27 had non-erosive reflux disease, 43 had reflux hypersensitivity and 35 had functional heartburn. There were no significant differences in sex, EHAS, GERDQ, questionnaires of depression or anxiety among GERD phenotypes. EHAS was significantly correlated with GERDQ, questionnaires of depression and anxiety (P < 0.05). However, there were no significant correlations between GERDQ and questionnaires of depression or anxiety. Regarding patient-reported outcomes, GERDQ positively correlated with acid exposure time and negatively correlated with MNBI (P < 0.05).

CONCLUSIONS

EHAS associates with reflux symptom severity and psychological stress but not with acid reflux burden or mucosal integrity. Thus, EHAS assessment shows promise in assessment of subjective patient outcome and satisfaction with treatment, a hitherto unmet clinical need.

Efficacy and safety of the Chinese herbal formula Hewei Jiangni recipe for NERD with cold-heat complex syndrome: study protocol for a double-blinded randomized controlled trial

Background

Proton pump inhibitor (PPI) is effective for the treatment of nonerosive gastroesophageal reflux (NERD), but long-term use of PPI is prone to have complications and recurrence after withdrawal. Traditional Chinese medicine (TCM) can relieve the symptoms of reflux and improve the quality of life. The purpose of this study is to evaluate the safety and efficacy of Hewei Jiangni recipe (HWJNR) in the treatment of NERD with cold-heat complex syndrome, and clarify the mechanism of HWJNR on NERD based on the correlation analysis of intestinal flora and metabolites.

Methods

This is a single-center, randomized controlled, double-blind, placebo-controlled clinical trial in which 72 eligible participants with NERD and TCM syndrome of intermingled heat and cold will be randomly allocated in the ratio of 1:1 to two groups: TCM group and western medicine group. The TCM group will receive HWJNR with omeprazole enteric-coated tablets placebo, while the western medicine group will receive omeprazole enteric-coated tablets with HWJNR placebo. Each group will be treated for 8 weeks. The primary outcome is the score of gastroesophageal reflux disease (GERD) health-related quality of life questionnaire (GERD-Q). Secondary outcomes include SF-36 quality of life scale (SF-36), patient-reported outcomes (PRO) self-rating scale score, syndrome score of TCM, and adverse events. Mechanistic outcome is the correlation analysis of intestinal flora and metabolites from healthy individuals and NERD participants before and after the treatment respectively.

Discussion

The goal of this trial is to investigate the efficacy and safety of HWJNR in the treatment of NERD with cold-heat complex syndrome, and to study the composition structure and metabolite expression profile of intestinal flora in patients with NERD through 16SrRNA sequencing and metabolomic correlation analysis of fecal flora, which makes us identify the dominant links of treatment and reveal the potential mechanism of HWJNR.

ChiCTR2000041225. Registered on 22 December 2020

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.

ESNM/ANMS consensus paper: Diagnosis and management of refractory gastro-esophageal reflux disease

Up to 40% of patients with symptoms suspicious of gastroesophageal reflux disease (GERD) do not respond completely to proton pump inhibitor (PPI) therapy. The term "refractory GERD" has been used loosely in the literature. A distinction should be made between refractory symptoms (ie, symptoms may or may not be GERD-related), refractory GERD symptoms (ie, persisting symptoms in patients with proven GERD, regardless of relationship to ongoing reflux), and refractory GERD (ie, objective evidence of GERD despite adequate medical management). The present ESNM/ANMS consensus paper proposes use the term "refractory GERD symptoms" only in patients with persisting symptoms and previously proven GERD by either endoscopy or esophageal pH monitoring. Even in this context, symptoms may or may not be reflux related. Objective evaluation, including endoscopy and esophageal physiologic testing, is requisite to provide insights into mechanisms of symptom generation and evidence of true refractory GERD. Some patients may have true ongoing refractory acid or weakly acidic reflux despite PPIs, while others have no evidence of ongoing reflux, and yet others have functional esophageal disorders (overlapping with proven GERD confirmed off therapy). In this context, attention should also be paid to supragastric belching and rumination syndrome, which may be important contributors to refractory symptoms.

Mucosal pathogenesis in gastro-esophageal reflux disease

BACKGROUND

Despite gastro-esophageal reflux disease affecting up to 20% of Western populations, relatively little is known about the molecular mechanisms underlying its most troublesome symptom: heartburn. Recent findings have unveiled the role of components of the esophageal mucosa in the pathogenesis of GERD including sensory nociceptive nerves and inflammatory mediators. Erosive esophagitis was long believed to develop as a result of acid injury at the esophageal lumen, but novel concepts suggest the generation of reflux-induced esophageal injury as a result of cytokine-mediated inflammation. Moreover, the localization and characterization of mucosal afferent nerves vary between GERD phenotypes and could explain the heterogeneity of symptom perception between patients who experience similar levels of acid reflux.

PURPOSE

The purpose of this review is to consider the crosstalk of different factors of the esophageal mucosa in the pathogenesis of GERD, with a particular focus on mucosal innervation and molecular basis of acid-induced cytokine response. We discuss the current understanding of the mucosal response to acid injury, the nociceptive role of acid-sensitive receptors expressed in the esophageal mucosa, and the role of esophageal epithelial cells in initiating the onset of erosive esophagitis.

Impact of Feeding Strategies With Acid Suppression on Esophageal Reflexes in Human Neonates With Gastroesophageal Reflux Disease: A Single-Blinded Randomized Clinical Trial

INTRODUCTION

Aims were to test hypothesis that esophageal provocation-induced reflexes are superior with acid suppression plus feeding modifications vs acid suppression alone among infants treated for gastroesophageal reflux disease (GERD).

METHODS

Infants (N = 49, 41.3 ± 2.6 of postmenstrual age) with acid reflux index >3% underwent longitudinal motility testing (weeks 0 and 5) with graded midesophageal provocation to test randomly allocated therapies (4 weeks' proton pump inhibitor [PPI] ± feeding modifications) on sensory-motor aerodigestive reflexes. Feeding modification included restricted fluid volume <140 mL/kg per day, fed over 30 minutes in right lateral position and supine postprandial position. Primary motility outcome was frequency-occurrence of peristaltic reflex. Secondary outcomes included upper esophageal sphincter contractile reflex, lower esophageal sphincter (LES) relaxation reflex, respiratory change, and symptom characteristics.

RESULTS

Treatment groups did not differ for primary outcome (odds ratio = 0.8, 95% confidence interval 0.4-1.6, P = 0.99) or secondary outcomes (all P > 0.05). For both treatment groups at follow-up, distal esophageal contraction and LES tone decreased, and LES relaxation reflex occurrence is less frequent (all P < 0.05). In a subgroup analysis, comparing infants with PPI washout (N = 40) vs with continued (N = 9) PPI therapy, no differences were noted for aerodigestive reflex response frequency-occurrence (all P > 0.05).

DISCUSSION

In infants with GERD, feeding modification with acid suppression is not superior to acid suppression alone in modifying aerodigestive reflexes (frequency, sensation, or magnitude). Contiguous areas targeted by GER, i.e., LES and distal esophageal functions, worsened at follow-up for both groups despite PPI therapy. Maturation is likely the key factor for GERD resolution in infants, justifying the use of placebo in clinical trials for objectively determined GERD.

Mechanism and Pathophysiology of Gastroesophageal Reflux Disease

Gastroesophageal reflux (GER) describes a process in which gastric contents travel retrograde into the esophagus. GER can be either a physiologic phenomenon that occurs in asymptomatic individuals or can potentially cause symptoms. When the latter occurs, this represents GER disease (GERD). The process by which GER transforms into GERD begins at the esophagogastric junction. Impaired clearance of the refluxate also contributes to GERD. Reflux causes degradation of esophageal mucosal defense. The refluxate triggers sensory afferents leading to symptom generation.

Effects of intra-oesophageal acid infusion and a stress task on masseter muscle activity and autonomic nervous activity in wakefulness

BACKGROUND

Gastroesophageal reflux disease may be an important risk factor for awake bruxism. Additionally, it has been known that a psychological stress task affects masseter muscle activity, and autonomic nervous system (ANS) activity modulation induces masseter muscle activity.

OBJECTIVES

This study aimed to investigate whether task-induced stress and experimental oesophageal acid infusion increase masseter muscle activity and alter ANS activity, compared to rest task and oesophageal saline infusion, respectively.

METHODS

Polygraphic monitoring, consisting of electromyography of the masseter muscle and electrocardiography, was performed in 12 healthy adult men during 30-min interventions with intra-oesophageal saline or acid infusion, while reading a book quietly, as rest, and while performing calculation, as a stress task.

RESULTS

At rest, masseter muscle activity and parasympathetic nervous system (PNS) activity during acid infusion were significantly higher (P = .019) and lower (P = .021) than during saline infusion, respectively. During saline infusion, both masseter muscle activity and sympathetic nervous system (SNS) activity or PNS activity while performing the calculation task were higher (P = .022 and .012, respectively) or lower (P = .007) than those during the reading task, respectively. In two-way repeated-measures ANOVA, intra-oesophageal infusion (saline or acid) significantly affected masseter muscle activity (P = .008) and PNS activity (P = .021). However, performing tasks (reading or calculation) significantly affected only PNS activity (P = .028).

CONCLUSION

Intra-oesophageal acid infusion significantly increased masseter muscle activity and decreased PNS activity. In contrast, stress task not only significantly decreased PNS activity, but only modestly increased masseter muscle activity and SNS activity.

Reflux esophagitis, functional and non-functional

The pathogenesis of gastroesophageal reflux disease has been explained by acid-peptic model. However, related with the progress of the diagnostic modalities, another phenotypical group of patients were defined and called "functional disorders of the esophagus". These patients are important because diagnosis is particularly difficult, co-morbid disorders especially psychiatric diseases are common, proton pump inhibitor response is low, and surgical results are very poor. Simpler and translational science studies are required in functional groups in order to differentiate from acid-peptic disorders. New and more accurate diagnostic modalities as well as therapeutic approaches are strongly needed in this particularly new and exciting era, especially in the effect of neuromodulators. Current diagnostic modalities should also be evaluated and in fact, normal values should be established. New medications, especially acting at the level of esophageal epithelium and intercellular spaces, might shift the paradigm.

Gastroesophageal reflux in cystic fibrosis across the age spectrum

Background

Scientific advances have improved longevity in cystic fibrosis (CF) patients and many of these patients can expect to experience age-related gastrointestinal co-morbidities. We aimed to assess the extent to which age might impact gastroesophageal reflux (GER) in patients with CF.

Methods

Our esophageal pH-multichannel intraluminal impedance monitoring database was searched for tracings belonging to CF patients ≥2 years old without prior fundoplication and not taking anti-reflux medications immediately prior (within 7 days) and during the study. Tracings were retrospectively analyzed; Impedance and pH variables were evaluated with respect to age and pulmonary function.

Results

Twenty-eight patients were enrolled; 16 children (3.1-17.7 years) and 12 adults (18.2-48.9 years). Among pH probe parameters, correlation analysis showed DeMeester score (P=0.011) and number of acid reflux events lasting >5 minutes (P=0.047) to be significantly correlated with age. Age was not significantly correlated with any of the impedance parameters. Age was negatively correlated with baseline impedance (BI) in the distal esophagus (r=-0.424, P=0.023) and BI was negatively correlated with several pH parameters, including reflux index (r=-0.553, P=0.002), number of total acid reflux events (r=-0.576, P=0.001), number of acid reflux events lasting >5 minutes (r=-0.534, P=0.003), and DeMeester score (r=-0.510, P=0.006). Pulmonary function (percent predicted forced expiratory volume in one minute; ppFEV₁) was negatively correlated with age (r=-0.494, P=0.0007). The interaction of age and ppFEV₁ and any of the reflux parameters, however, was not significant (P>0.05); the strongest evidence for an interaction was found for the number of acid reflux events reaching the proximal esophagus, but this interaction still did not reach statistical significance (P=0.070).

Conclusions

In a small cohort, we found evidence that age may be associated with increased acid exposure and that both age and increased acid exposure are associated with reduced BI in the distal esophagus. The negative relationship between pulmonary function and age in our cohort is not related to GER. This pilot study supports the need for esophageal assessment and treatment of GER as standard components of clinical care for an aging CF population.

Evaluation of Baseline Impedance During Water-perfused High Resolution Impedance Manometry in Patients With Symptomatic GERD

GOALS

We aimed to investigate the hypothesis whether baseline impedance measured during water-perfused high resolution impedance manometry (HRIM) can help discriminate patients with reflux symptoms from the controls and predict the response to the proton pump inhibitors (PPIs).

BACKGROUND/AIM

Baseline impedance measured during solid-state HRIM can reliably discriminate patients with gastroesophageal reflux disease (GERD) from controls.

STUDY

We enrolled consecutive patients with typical reflux symptoms and healthy controls for the measurement of baseline impedance during the landmark period of HRIM. All patients were given PPIs and PPI response was assessed after 8 weeks of the treatment.

RESULTS

Baseline mucosa impedance measured during HRIM was lower in GERD patients than the controls (1861±183 vs. 3371±250 Ω; P<0.001). Baseline impedance during water-perfused HRIM had moderate diagnostic accuracy for differentiating symptomatic GERD with an area under the curve of 0.853 on receiver operating characteristics analysis. A threshold of 2530 Ω for baseline impedance had a sensitivity of 88.3% and specificity of 82.4% for GERD with a positive predictive value of 83.4% and negative predictive value of 87.6%. Among symptomatic GERD patients, poor PPI responders had higher baseline impedance than those without it (2340±260 vs. 1479±189 Ω; P=0.02). BMI negatively correlated to base impedance in either controls (r=-0.59; P=0.012) or GERD patients (r=-0.47; P=0.047).

CONCLUSIONS

Baseline impedance measurement during water-perfused HRIM helps differentiate patients with typical reflux symptoms from controls and also serves as a potential utility in predicting PPI response.

Differentiation of esophageal pH-impedance characteristics classified by the mucosal integrity marker in human neonates

BACKGROUND

In adults, distal baseline impedance (BI) is a determinant of esophageal mucosal integrity with values <900 Ω indicating inflammation. Relationships between acid gastroesophageal reflux (GER) and BI in neonates are unclear.

METHODS

NICU infants (N = 198, 30.4 ± 0.3 weeks gestation) were evaluated at 43 ± 0.4 weeks postmenstrual age using 24-h pH-impedance. Ten randomly selected 1-min windows during rest from the distal impedance channel (Z6) were averaged. Chi-square, t-tests, and ANOVA were used to compare pH-impedance and symptom characteristics by BI severity (BI < 900 Ω, BI 900-2000 Ω, BI > 2000 Ω). Regression analysis was used to identify potential contributing factors of BI.

RESULTS

In BI < 900 Ω: (1) pH-impedance characteristics were increased (acid reflux event frequency, duration, and severity, all P < 0.05 vs. BI > 2000 Ω), and (2) positive symptom correlations were noted with bolus (73%) and acid events (55%). Significant predictors of BI included chronological age, acid reflux index, and BPD diagnosis (all P < 0.05).

CONCLUSIONS

Low BI is associated with prolonged acid exposure, delayed clearance, and greater aerodigestive symptom prevalence, likely associated with inflammation and or increased mucosal permeability. BI > 2000 Ω likely involves little or no inflammation because acid exposure is minimal. Combination of SAP, pH-impedance metrics, and BI along with the clarification of dysmotility mechanisms provides the rationale for personalized anti-reflux therapies as needed.

Short-Term Symptomatic Relief in Gastroesophageal Reflux Disease: A Comparative Study of Esomeprazole and Vonoprazan

BACKGROUND AND AIM

Proton pump inhibitors and vonoprazan (a potassium-competitive acid blocker) are recommended as first-line treatments for gastroesophageal reflux disease (GERD). However, few reports have investigated the onset of action of these agents for GERD symptom relief. The present study compared the symptom relief of esomeprazole with that of vonoprazan via monitoring self-reported GERD symptoms after treatment initiation.

METHODS

This was a prospective, multicenter, randomized, open-label, parallel group, comparative clinical study between esomeprazole (20 mg/day) and vonoprazan (20 mg/day) administered for 4 weeks to patients with GERD symptoms. Patients who had scores ≥ 8 on the Gastroesophageal Reflux Disease Questionnaire (GerdQ) were defined as having GERD and enrolled in this study. Sixty patients were randomly assigned to either the esomeprazole group (n = 30) or the vonoprazan group (n = 30). Treatment response rates in each drug group were evaluated according to the GerdQ. The Frequency Scale for the Symptoms of GERD (FSSG) scores from the 1st day after treatment initiation and the Global Overall Symptom (GOS) scale scores during treatment were also evaluated.

RESULTS

At 4 weeks, the treatment response rates for symptom relief according to the GerdQ were 88.0% in the esomeprazole group and 81.8% in the vonoprazan group. The GOS scales, which reflect the impact of GERD symptoms, were similar for both groups. The FSSG scores decreased from the 1st to the 14th day in both groups.

CONCLUSIONS

There were no substantial differences in the symptom relief between the two groups at any time point in this short-term study.

Alcohol Consumption and the Risk of Gastroesophageal Reflux Disease: A Systematic Review and Meta-analysis

AIMS

Epidemiologic evidence on alcohol consumption increasing the risk of gastroesophageal reflux disease (GERD) is contradictory. This study aimed to investigate the correlation between alcohol consumption and GERD by a meta-analysis of observational studies.

SHORT SUMMARY

Gastroesophageal reflux disease (GERD) is a prevalent disease, and the incidence is rising. We conducted a meta-analysis of observational studies, indicating that there was a significant association between alcohol consumption and the risk of GERD. This finding provides important implications for the prevention and control of GERD.

METHODS

Two investigators retrieved relevant studies on PubMed, Cochrane and EMBASE, respectively. The summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by random effects model to assess the association. Heterogeneity was quantified using the Q statistic and I2. Subgroup analysis, publication bias and sensitivity analysis were also conducted.

RESULTS

Twenty-six cross-sectional studies and three case-control studies were included in the meta-analysis. The pooled random effects OR was 1.48 (95%CI, 1.31-1.67; I2 = 88.8%), in comparison between drinkers and non-/occasional drinkers. For reflux esophagitis and non-erosive reflux disease, two subtypes of GERD, the ORs were 1.78 (95%CI, 1.56-2.03; I2 = 87.5%) and 1.15 (95%CI, 1.04-1.28; I2 = 0.3%), respectively. In addition, the pooled OR for drinkers who drank <3-5 times or days per week was 1.29 (95%CI, 1.14-1.46; I2 = 35.5%), while for those who drank more frequently, the OR was 2.12 (95%CI, 1.63-2.75; I2 = 55.1%). Dose-response analysis showed a linear association between alcohol consumption and GERD (Pfornonlinearity=0.235). The pooled OR for a 12.5 g/day increment of alcohol was 1.16 (95%CI, 1.07-1.27; P = 0.001).

CONCLUSIONS

This meta-analysis provides evidence for a potential association between alcohol drinking and the risk of GERD. The increase in alcohol consumption and frequency showed a stronger association with GERD.

Adding Acotiamide to Gastric Acid Inhibitors Is Effective for Treating Refractory Symptoms in Patients with Non-erosive Reflux Disease

BACKGROUND

Approximately 30% of patients who are treated with proton pump inhibitors (PPIs) for gastroesophageal reflux disease (GERD) experience persistent symptoms. No prokinetic agent regiments are useful for symptom relief.

AIMS

This study was conducted to examine the effect of adding acotiamide to PPI or vonoprazan refractory GERD.

METHODS

This was a randomized, prospective, double-blind, placebo-controlled trial. Seventy-one patients were enrolled. Patients underwent upper endoscopy before initial therapy [15 reflux esophagitis and 55 non-erosive reflux disease (NERD)]. Patients with persistent reflux symptoms were administered 300 mg/day acotiamide or placebo for 2 weeks. The primary endpoint was overall treatment effect (OTE), and gastrointestinal symptoms were evaluated. High-resolution manometry (HRM) and 24-h multiple intraluminal impedance-pH (MII-pH) monitoring were conducted before and after treatment when possible.

RESULTS

Seventy patients were randomized (35 acotiamide and 35 placebo). Sixteen and 10 patients in the acotiamide and placebo groups, respectively, completed MII-pH and HRM. The OTE improvement rates were 28.6% and 14.3% in patients administered acotiamide and placebo, respectively (p = 0.145). In patients with NERD, however, the OTE improvement rate and responder rate for regurgitation in the acotiamide group was significantly higher than those in the placebo group (29.6 vs. 7.1%; p = 0.030, 37.0 vs. 10.7%; p = 0.021, respectively). Acotiamide significantly reduced the total reflux episodes (p = 0.001), acid (p = 0.020), proximal reflux (p = 0.007), and liquid reflux (p = 0.013) episodes.

CONCLUSION

Adding acotiamide to gastric acid inhibitors can improve symptoms in patients with refractory NERD.

Solute carrier family 9, subfamily A, member 3 (SLC9A3)/sodium-hydrogen exchanger member 3 (NHE3) dysregulation and dilated intercellular spaces in patients with eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is characterized by histopathologic modifications of esophageal tissue, including eosinophil-rich inflammation, basal zone hyperplasia, and dilated intercellular spaces (DIS). The underlying molecular processes that drive the histopathologic features of EoE remain largely unexplored.

OBJECTIVE

We sought to investigate the involvement of solute carrier family 9, subfamily A, member 3 (SLC9A3) in esophageal epithelial intracellular pH (pHi) and DIS formation and the histopathologic features of EoE.

METHODS

We examined expression of esophageal epithelial gene networks associated with regulation of pHi in the EoE transcriptome of primary esophageal epithelial cells and an in vitro esophageal epithelial 3-dimensional model system (EPC2-ALI). Molecular and cellular analyses and ion transport assays were used to evaluate the expression and function of SLC9A3.

RESULTS

We identified altered expression of gene networks associated with regulation of pHi and acid-protective mechanisms in esophageal biopsy specimens from pediatric patients with EoE (healthy subjects, n = 6; patients with EoE, n = 10). The most dysregulated gene central to regulating pHi was SLC9A3. SLC9A3 expression was increased within the basal layer of esophageal biopsy specimens from patients with EoE, and expression positively correlated with disease severity (eosinophils/high-power field) and DIS (healthy subjects, n = 10; patients with EoE, n = 10). Analyses of esophageal epithelial cells revealed IL-13-induced, signal transducer and activator of transcription 6-dependent SLC9A3 expression and Na+-dependent proton secretion and that SLC9A3 activity correlated positively with DIS formation. Finally, we showed that IL-13-mediated, Na+-dependent proton secretion was the primary intracellular acid-protective mechanism within the esophageal epithelium and that blockade of SLC9A3 transport abrogated IL-13-induced DIS formation.

CONCLUSIONS

SLC9A3 plays a functional role in DIS formation, and pharmacologic interventions targeting SLC9A3 function may suppress the histopathologic manifestations in patients with EoE.

Assessment of the Acute Effects of Carbonated Beverage Consumption on Symptoms and Objective Markers of Gastric Reflux

Previous studies have suggested that carbonated beverages may cause gastro-oesophageal reflux. Pepsin (the major enzyme secreted by the stomach) has been suggested to be an objective, acute marker of a reflux event. This pilot study aimed to investigate whether intake of carbonated beverages could affect pepsin concentration in saliva or reflux symptoms. This was assessed by a randomised, crossover trial where participants consumed 330 mL of beverage (carbonated cola, degassed cola or water) at separate visits. Saliva samples and symptom questionnaires were collected at baseline and over the 30 min postprandial period. Pepsin was detected in all saliva samples. No difference was found in the salivary pepsin concentrations between treatments at all time points. There were significantly higher scores (p > 0.05) for feelings of fullness, heartburn, urge to belch and frequency of belches after ingestion of carbonated cola than degassed cola and water. The ingestion of carbonated beverages did not appear to increase postprandial pepsin concentration in saliva compared to other beverages but did evoke higher levels of reflux-related symptoms such as fullness, heartburn and belching. This suggests carbonated beverages may cause symptoms associated with reflux but do not drive detectable levels of gastric juice to reach the oral cavity.

Detection of gastro-oesophageal reflux in the neonatal unit

AIM

To determine whether a pH probe or multichannel intraluminal impedance (MII) more frequently detected gastro-oesophageal reflux and test the hypothesis that acid reflux was associated with lower baseline impedance.

METHODS

A prospective study of infants in whom reflux was suspected and evaluated using combined pH and multichannel impedance. Studies were considered abnormal if the acid index was >10% or there were >79MII reflux events in 24 hours. The acid index was the percentage of total study time with a pH

RESULTS

Forty-two infants [median gestational age 31 (range 23-42) weeks] were assessed. Only nine infants (21%) had abnormal studies, seven detected by pH monitoring, one by MII monitoring and one by both techniques (p = 0.04). After correcting for gestational age and post-natal age, baseline impedance remained negatively correlated with the acid index (r = -0.34, p = 0.038) and the maximum ACT (r = -0.44, p = 0.006).

CONCLUSION

Clinical suspicion of reflux was frequently incorrect, and reflux was more frequently detected by a pH probe. The inverse relationship of acid reflux to baseline impedance suggests that mucosal disruption may result from acid reflux in this population.

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Key Words

• Baseline oesophageal impedance
• Multichannel intraluminal impedance
• pH study

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Grants

• National Institute for Health Research (NIHR) Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London

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Affiliation(s)

Thomas Rossor MRC Centre in Allergic Mechanisms of Asthma, King's College London, London, UK Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
Ingran Lingam Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
Abdel Douiri Department of Primary Care and Public Health Sciences, King's College London, London, UK NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust, King's College London, London, UK
Ravindra Bhat Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
Anne Greenough MRC Centre in Allergic Mechanisms of Asthma, King's College London, London, UK Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust, King's College London, London, UK

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Collaborators Collapse

Fragments of e-Cadherin as Biomarkers of Non-erosive Reflux Disease

BACKGROUND

Approximately, 20% of patients with heartburn and normal endoscopic findings do not symptomatically improve on proton pump inhibitor (PPI) therapy making diagnosis and treatment uncertain. A biomarker distinguishing PPI-responsive from PPI-refractory heartburn is desirable.

AIMS

We performed a pilot study assessing whether carboxy(C)-terminal fragments (CTFs) of e-cadherin in esophageal biopsies or amino(N)-terminal fragments (NTFs) of e-cadherin in serum could serve this purpose.

METHODS

Twenty-nine patients with endoscopy-negative heartburn had esophageal biopsies for CTFs on Western blot and blood for serum NTFs on ELISA. All patients received dexlansoprazole 30 mg daily for 4 weeks, and heartburn was assessed by daily diary entry. Post-treatment blood samples were obtained for serum NTFs. A control group without GERD symptoms (n = 6) had biopsies for CTFs and a second control group (n = 20) blood serum for serum NTFs.

RESULTS

Twenty-seven of 29 patients (93.1%) with endoscopy-negative heartburn, but 0 of 6 controls, were positive for CTFs. All patients and controls had measureable serum NTFs, but mean NTFs were significantly higher in those with PPI-responsive heartburn compared to those with PPI-refractory heartburn and controls. Following treatment, 24 of 29 (82.8) patients had relief of heartburn, which associated with a decline in mean NTFs compared to controls. NTFs in PPI-refractory patients (n = 5) were similar to controls before and after PPI therapy.

CONCLUSIONS

When heartburn responds to PPI, elevated serum NTFs decline to normal. These data suggest that cleaved products of e-cadherin may serve as biomarkers of NERD. Further data are needed to assess and confirm this concept.

Pathophysiology of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease pathophysiology is multifactorial and linked to a misbalance between the aggressiveness of the refluxate into the esophagus or adjacent organs and the failure of protective mechanisms associate or not to a defective valvular mechanism at the level of the esophagogastric junction incapable of dealing with a transdiaphragmatic pressure gradient. Antireflux mechanisms include the lower esophageal sphincter and abdominal esophagus, the diaphragm, the angle of His, the Gubaroff valve, and the phrenoesophageal membrane. Protective mechanisms include esophageal motility, saliva production, and epithelial protection. Disruption of this balance occurs most commonly due to the presence of a hiatal hernia, esophageal dysmotility, a rise in abdominal pressure (obesity), and decrease in thoracic pressure (chronic lung diseases).

Esophageal baseline impedance levels allow the identification of esophageal involvement in patients with systemic sclerosis

INTRODUCTION

Distal esophageal baseline impedance (BI) levels reflect the esophageal mucosal integrity in reflux disease. Systemic sclerosis (SSc) could potentially affect the integrity of esophageal mucosa and consequently impair distal and proximal BI levels, but data in this regard are lacking.

AIM AND METHODS

We aimed to prospectively investigate and compare BI levels among non-erosive reflux disease (NERD), SSc patients, and healthy controls (HCs). Consecutive patients with reflux symptoms and well-defined diagnosis of SSc underwent upper endoscopy and, in case of no lesions encountered, manometry and impedance-pH testing off-therapy. In addition to traditional impedance-pH parameters, BI values at 3, 5, 7, and 17cm above the lower esophageal sphincter were calculated.

RESULTS

Fifty-two patients with NERD, 50 with SSc, and 50 HCs were enrolled. Nineteen (38%) SSc patients and 22 (42%) NERD patients had abnormal acid exposure. In patients with SSc, median BI values were significantly lower than in NERD patients and HCs (p < 0.0001) at 3, 5, and 7cm; there was no difference between HCs and NERD patients at 17cm in the proximal esophagus, whereas a significant difference was observed at 17cm between SSc and NERD as well as HCs (p < 0.01).

CONCLUSION

Distal and proximal BI values in SSc patients were lower than in NERD and HCs, thus we speculated that these findings may be related to the deposition of collagen in the connective tissue. Measurement of BI may be used as an indirect, but simple and accurate marker of esophageal involvement in patients with SSc.

Pathophysiology of Gastroesophageal Reflux Disease

The pathogenesis of gastroesophageal reflux disease (GERD) is complex and involves changes in reflux exposure, epithelial resistance, and visceral sensitivity. The gastric refluxate is a noxious material that injures the esophagus and elicits symptoms. Esophageal exposure to gastric refluxate is the primary determinant of disease severity. This exposure arises via compromise of the anti-reflux barrier and reduced ability of the esophagus to clear and buffer the refluxate, leading to reflux disease. However, complications and symptoms also occur in the context of normal reflux burden, when there is either poor epithelial resistance or increased visceral sensitivity. Reflux therefore develops via alterations in the balance of aggressive and defensive forces.

Superficial Esophageal Mucosal Afferent Nerves May Contribute to Reflux Hypersensitivity in Nonerosive Reflux Disease

BACKGROUND & AIMS

Little is known about the causes of heartburn in patients with gastro-esophageal reflux disease. Visible epithelial damage is seldom associated with symptom severity, evidenced by the significant symptom burden in patients with nonerosive reflux disease (NERD) compared with patients with erosive reflux disease (ERD) or Barrett's esophagus (BE). We studied the distribution of mucosal nerve fibers in patients with NERD, ERD, and BE, and compared the results with those of healthy subjects.

METHODS

We performed a prospective study of 13 patients with NERD, 11 patients with ERD, and 16 patients with BE undergoing endoscopic evaluation in the United Kingdom or Greece. Biopsies were obtained from the proximal and distal esophageal mucosa of patients with NERD, from the distal esophageal mucosa of patients with ERD, and the distal-most squamous epithelium of patients with BE. These were examined for the presence and location of nerve fibers that reacted with a labeled antibody against calcitonin gene-related peptide (CGRP), a marker of nociceptive sensory nerves. The results were compared with those from 10 healthy volunteers (controls).

RESULTS

The distribution of CGRP-positive nerves did not differ significantly between the distal esophageal mucosa of controls (median, 25.5 cell layers to surface; interquartile range [IQR], 21.4-28.8) vs patients with ERD (median, 23 cell layers to surface; IQR, 16-27.5), or patients with BE (median, 21.5 cell layers to surface; IQR, 16.1-27.5). However, CGRP-positive nerves were significantly more superficial in mucosa from patients with NERD-both distal (median, 9.5 cell layers to surface; IQR, 1.5-13.3; P < .0001 vs ERD, BE, and controls) and proximal (median, 5.0 cell layers to surface; IQR, 2.5-9.3 vs median 10.4 cell layers to surface; IQR, 8.0-16.9; P = .0098 vs controls).

CONCLUSIONS

Proximal and distal esophageal mucosa of patients with NERD have more superficial afferent nerves compared with controls or patients with ERD or BE. Acid hypersensitivity in patients with NERD might be partially explained by the increased proximity of their afferent nerves to the esophageal lumen, and therefore greater exposure to noxious substances in refluxate.

Exploration of the Esophageal Mucosal Barrier in Non-Erosive Reflux Disease

In the absence of visible mucosal damage, it is hypothesized that the esophageal mucosal barrier is functionally impaired in patients with non-erosive reflux disease (NERD). The aim of the present study was to perform an exploratory analysis of the mucosal barrier in NERD compared to erosive esophagitis (EE) and controls. A second aim was to explore TRPV1 gene transcription in relation to the mucosal barrier function and heartburn symptoms. In this prospective study, 10 NERD patients, 11 patients with active erosive esophagitis and 10 healthy volunteers were included. Biopsies from non-eroded mucosa were obtained for (1) ex vivo analyses (Ussing chamber) of transepithelial electrical resistance (TEER) and permeability (2) gene transcription of tight-junction proteins and transient receptor potential vanilloid subfamily member 1 (TRPV1). No differences in TEER or permeability were found between NERD and healthy volunteers, whereas TEER was lower in patients with erosive esophagitis. TRPV1 gene transcription was not significantly different between EE, NERD and controls. Conclusions: esophageal mucosal barrier function and TRPV1 transcription is not significantly altered in NERD patients. Future research is needed to explore other potential mechanisms that may account for the high symptom burden in these patients.