Non-erosive Reflux Disease Patients Research Articles

Alteration in the gastric microbiota of Erosive Reflux Disease and Non-erosive Reflux Disease patients: An indicator for disease progression

Introduction and Aim: Erosive reflux disease (ERD) and Non-erosive reflux disease (NERD) are common gastrointestinal (GI) diseases in primary healthcare facilities that might result in alterations in gastric microflora. The aim was to characterize the altered composition of the gastric microflora in both groups and their effects on normal metabolic pathways. Materials and Methods: A total of 27 individuals, consisting of 18 patients of ERD, 4 patients of NERD, and 5 controls based on the questionnaire data and clinical diagnosis. The gastric microbiome was sequenced using 16S rRNA next-generation sequencing. Gastric microbial diversity and compositions were analyzed using MicrobiomeAnalyst. Functional analysis was performed using PICRUST. Results: Dysbiosis was observed in both ERD and NERD groups when compared to the control. Alpha diversity was found to be significant at the ACE index, at the order (p = 0.0239) and class (p = 0.019) taxonomic levels. The gastric microbiome composition at the genus level of the study groups represented a significant decrease of Gram-positive bacterial genera such as Streptococcus, Corynebacterium, and Granulicatella along with an increase of Gram-negative genera such as Helicobacter and Veillonella. Significant alterations in the metabolic pathways due to this dysbiosis were also predicted for both groups. Conclusion: The alterations in the gastric microflora are caused by both ERD and NERD, these alterations are further associated with a shift in microbial consortia towards the abundance of gram-negative bacterial genera that might lead to the progression of GI diseases to a chronic state.

Association between Mean Nocturnal Baseline Impedance (MNBI) and Post-Reflux Swallow-Induced Peristaltic Wave Index (PSPW) in GERD Patients.

Gastroesophageal reflux disease (GERD) is one of the most common gastrointestinal disorders in the world. Two parameters, mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave index (PSPW), have been recently proposed to help differentiate GERD phenotypes. Our study aimed to assess whether there is any correlation between the two parameters, while also taking a look at their ability to distinguish between GERD phenotypes. We recruited 81 patients who were divided into 4 groups based on their GERD phenotype: erosive reflux disease (ERD), non-erosive reflux disease (NERD), reflux hypersensitivity (RH), and functional heartburn (FH). Both MNBI (AUROC 0.855) and PSPW (AUROC 0.835) had very good performances in separating ERD patients from non-ERD patients. PSPW (AUROC 0.784) was superior to MNBI (AUROC 0.703) in distinguishing NERD patients from patients with RH or FH. The PSPW index (AUROC 0.762) was more effective than MNBI (AUROC 0.668) in separating RH from FH. We found that PSPW and MNBI have a strong statistical correlation (Pearson correlation coefficient, r = 0.722, p < 0.001). Furthermore, PSPW predicted pathological MNBI (<2292 Ω) with good performance (AUROC 0.807). MNBI and PSPW are useful in distinguishing GERD phenotypes, with a strong correlation between the two parameters.

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

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. 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. 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). 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.

Modern aspects of managing patients with non-erosive reflux disease

A review of current data on the management of patients with non-erosive reflux disease (NERD) was made. Diagnosis of gastroesophageal reflux disease (GERD) is based on symptom analysis, endoscopic evaluation of the esophageal mucosa, objective evidence of gastric contents reflux into the esophagus during pH-impedancemetry, and response to therapeutic intervention. Treatment for GERD should include weight loss if overweight, lifestyle modification, and dietary modification. Current consensus recommends starting NERD treatment with once-daily proton pump inhibitors (PPIs), but only 50% of patients with this pathology respond to such therapy. Incomplete response to PPIs is a reason to increase the dose of PPI and add Gaviscon to treatment to neutralize the post-prandial “acid pocket”. Gaviscon is especially effective in patients with postprandial or nocturnal symptoms and in those with hiatal hernia. The mechanism of action of Gaviscon is based on the formation of an alginate “raft” on the surface of the gastric contents, which neutralizes the acid and blocks its pathological effect to esophageal mucosa. A modern meta-analysis on the NERD treatment, which included 23 studies and 10,735 patients, showed the efficacy of Gaviscon monotherapy comparable to PPIs in treatment for 4 weeks. The combination of a PPI with Gaviscon offers the opportunity to optimize response to treatment in NERD patients with an incomplete response to PPIs monotherapy. The Russian Gastroenterological Association thinks that alginates can be used both as monotherapy for mild clinical variants of NERD and in complex treatment regimens for various GERD variants.

Among females older than 50years, saliva secretion is significantly lower in non-erosive reflux disease patients than in healthy controls.

Saliva secretion is significantly lower in patients with non-erosive reflux disease (NERD) than in healthy controls (HC). A previous study on HC showed that saliva secretion was lower in females than in males. Saliva secretion may be lower in female patients with NERD than in male patients. Therefore, the present study investigated sex differences in saliva secretion in patients with NERD. Subjects older than 50years were included in the present study and consisted of 20 male patients with NERD, 19 male HC, 25 female patients with NERD, and 23 female HC. Saliva secretion was assessed as follows: each patient chewed sugar-free gum for 3min prior to endoscopy, and the amount and pH of saliva before and after acid loading as an index of the acid-buffering capacity were measured. In males, no significant differences were observed in the amount of stimulated saliva secretion or salivary pH between NERD patients and HC. However, the acid-buffering capacity (NERD: 6.1 [5.9-6.5], HC: 6.4 [6.2-6.6]) was significantly lower in NERD patients than in HC. In females, the amount of stimulated saliva secretion (NERD: 2.6 [2.0-4.1], HC: 5.8 [3.7-7.5]), salivary pH (NERD: 7.0 [6.8-7.2], HC: 7.2 [7.0-7.2]), and the acid-buffering capacity (NERD: 5.8 [5.4-6.2], HC: 6.2 [6.0-6.5]) were significantly lower in NERD patients than in HC. Among females older than 50years, saliva secretion was significantly lower in NERD patients than in HC. This reduction in saliva secretion may contribute to the pathophysiology of NERD in females.

Improved Computer-Aided Diagnosis System for Nonerosive Reflux Disease Using Contrastive Self-Supervised Learning with Transfer Learning

Article Improved Computer-Aided Diagnosis System for Nonerosive Reflux Disease Using Contrastive Self-Supervised Learning with Transfer Learning Junkai Liao 1, Hak-Keung Lam 1,*, Shraddha Gulati 2, and Bu Hayee 2 1 Department of Engineering, King’s College London, London, United Kingdom 2 King’s Institute of Therapeutic Endoscopy, King’s College Hospital NHS Foundation Trust, London, United Kingdom * Correspondence: hak-keung.lam@kcl.ac.uk Received: 5 February 2023 Accepted: 21 July 2023 Published: 26 September 2023 Abstract: The nonerosive reflux disease (NERD) is a common condition, the symptoms of which mainly include heartburn, regurgitation, dysphagia and odynophagia. The conventional diagnosis of NERD needs the endoscopic examination, biopsy of the lining of the esophagus (mucosa), and ambulatory pH testing over 24 to 96 hours, which is complex and time-consuming. To address this problem, a computer-aided diagnosis system for NERD (named NERD-CADS) has been proposed in our previous paper. The NERD-CADS offers a more convenient and efficient approach to diagnosing NERD, which only requires the input of endoscopic images into the computer to produce a nearly instant diagnostic result. The NERD-CADS uses a convolutional neural network (CNN) as a classifier and can classify the endoscopic images captured in the esophagus of both healthy people and NERD patients. This is, in fact, a classification problem of two classes: non-NERD and NERD. We conduct ten-fold cross-validation to verify the classification accuracy of the NERD-CADS. The experiment shows that the mean of ten-fold classification accuracy of the NERD-CADS test reaches 77.8%. In this paper, we aim to improve the classification accuracy of the NERD-CADS. We add the contrastive self-supervised learning as an additional component to the NERD-CADS (named NERD-CADS-CSSL), and investigate whether it can learn the capability of extracting representations to improve the classification accuracy. This paper combines the contrastive self-supervised learning with transfer learning, which first employs massive public image data to train the CNN by the contrastive self-supervised learning, and then uses the endoscopic images to fine-tune the CNN. In this way, the capability of extracting representations (learned by the contrastive self-supervised learning) can be transferred into the downstream task (NERD diagnosis). The experiment shows that the NERD-CADS-CSSL can obtain a higher mean (80.6%) in tests than the NERD-CADS (77.8%).

The role of histology in the diagnosis of non-erosive reflux disease: A systematic review and meta-analysis.

Non-erosive reflux disease (NERD) accounts for over half of all gastroesophageal reflux cases and is characterized by reflux symptoms with pathologic acid exposure on pH monitoring but no evidence of erosions on upper endoscopy. Ambulatory pH monitoring is limited by availability and patient tolerance. The utility of performing esophageal mucosal biopsies in diagnosing NERD is unclear. We conducted a systematic review and meta-analysis to determine the sensitivity of esophageal mucosal biopsies in diagnosing NERD. Data were obtained from Embase and Ovid MEDLINE from inception to April 2021. Studies were included if esophageal mucosal biopsies were taken and analyzed using conventional histopathologic analysis in symptomatic NERD patients. Relevant data was including histologic abnormalities and location of the biopsy. Sensitivity and specificity were calculated against healthy controls or those with functional heartburn. The search yielded 2871 studies, of which 10 studies met our inclusion criteria and contained raw data. Histological abnormalities included histologic sum scores, papillary elongation, basal cell hyperplasia, and dilated intraepithelial spaces. When assessing for the presence of any abnormality, biopsies taken <3 cm from the lower esophageal sphincter (LES) had a pooled sensitivity of 0.71 (95% CI 0.64-0.77) and specificity of 0.64 (95% 0.54-0.73); however, analysis of individual histologic features such as the presence of eosinophils improved the sensitivity. Although esophageal mucosal biopsies had poor sensitivity at diagnosing NERD, biopsies taken within 3 cm of the LES had higher sensitivity when pathologists reported upon eosinophils and dilated intraepithelial spaces.

Value of 96-hour ambulatory esophageal pH monitoring in the assessment of patients with refractory acid reflux symptoms and their response to anti-reflux diet.

Ambulatory esophageal pH monitoring is a diagnostic tool in patients with heartburn and regurgitation. The aim of this study is to evaluate 96-hour esophageal pH monitoring in patients with gastroesophageal reflux disease (GERD), at baseline and under diet that impedes GER. We hypothesized that diet would potentially reduce pathologic acid exposure time (AET). Retrospective series of 88 patients with GERD undergoing wireless 96-hour pH monitoring. Two-day (48hours) tandem periods, one on liberal, followed by another on restricted diet assessed esophageal AET. Primary end point was >30% reduction in AET while on anti-GER diet. Of the 88 patients, 16 were excluded because of probe migration. Endoscopy and biopsies assessed erosive esophagitis (EE) and Barrett's esophagus (BE), or normal esophagus. Abnormal AET (% pH < 4.0 ≥ 6) further defined nonerosive reflux disease (NERD), whereas normal AET (% pH < 4.0 < 6) with normal endoscopy defined patients as functional heartburn (FH). There were 6 patients with EE (n = 5) and BE (n = 1), 23 with NERD and 43 with FH. Anti-GER diet led to >30% reduction in AET in EE and NERD patients, but not in those with FH. Most patients (n = 43/72; 60%) had FH and could have avoided acid suppression. Furthermore, (14/23; 61%) of patients with NERD completely normalized AET with diet, potentially negating acid suppression. Ninety-six-hour esophageal pH distinguishes GERD patients from those with FH. Fifty percent of EE/BE patients and 61% of those with NERD completely normalize AET with diet. If pathologic AET occurs despite diet, acid suppression is indicated.

Differences in salivary secretion and epidermal growth factor concentrations in mild reflux esophagitis and non-erosive reflux disease.

Sex differences in salivary secretion have been reported among healthy subjects. In the present study, salivary secretion and salivary epidermal growth factor (EGF) concentrations were investigated in mild reflux esophagitis patients, non-erosive reflux disease (NERD) patients, and healthy controls by matching the sex ratio. Thirty-three (male:female = 11:22) patients with NERD, 33 (11:22) with mild reflux esophagitis, and 33 (11:22) healthy controls were recruited for this case-control study. Salivary secretion was assessed as follows: each patient chewed sugar-free gum for 3min prior to endoscopy, and the amount of saliva secretion, salivary pH, and salivary pH after acid loading as an index of the acid-buffering capacity were measured. Salivary EGF concentrations were measured by ELISA. No significant differences were observed in the amount of saliva secretion, salivary pH, or the acid-buffering capacity between the mild reflux esophagitis and NERD groups. However, the amount of saliva secretion and the acid-buffering capacity in the mild reflux esophagitis group and the amount of saliva secretion, salivary pH, and the acid-buffering capacity in the NERD group were significantly lower than those in the healthy control group. No significant differences were noted in salivary EGF concentrations between the mild reflux esophagitis and NERD groups. After matching the sex ratio, the saliva secretion was significantly lower in patients with mild reflux esophagitis and NERD than in healthy controls. However, no significant differences were observed in the amount of saliva secretion or salivary EGF concentrations between both groups.

S390 Efficacy and Safety of On-Demand Vonoprazan versus Placebo in the Treatment of Heartburn in Symptomatic Nonerosive Reflux Disease (NERD) Patients: A Phase 2 Randomized Controlled Trial

S390 Efficacy and Safety of On-Demand Vonoprazan versus Placebo in the Treatment of Heartburn in Symptomatic Nonerosive Reflux Disease (NERD) Patients: A Phase 2 Randomized Controlled Trial

Esophageal manometry findings in patients with refractory symptoms of gastroesophageal reflux disease.

Gastroesophageal reflux disease (GERD) is a common gastrointestinal disorder. High-resolution esophageal manometry (HREM) and 24-h pH study help to properly evaluate GERD patients. The aim of the present study was to classify patients with refractory GERD symptoms into various groups based on endoscopic and physiological testing.The present study is a retrospective analysis of patients referred for HREM and 24-h pH recording between 2019 and 2021. We included all adult patients (age > 18 years) who were referred for evaluation of refractory GERD symptoms. Upper gastrointestinal endoscopy findings, HREM, and 24-h pH findings were noted. Patients were divided into erosive reflux disease (ERD), non-erosive reflux disease (NERD), reflux hypersensitivity (RH), and functional heartburn (FH) based on test results. Demographic details and HREM parameters were compared in the four groups. Statistics used are one-way analysis of variance (ANOVA) and Chi-squared tests. A p-value of <0.05 was considered statistically significant.A total of 144 patients were included-NERD (56, 38.9%), ERD (42, 29.2%), RH (28, 19.5%), and FH (18, 12.5%). Age (p 0.74), andsex distribution (p 0.47), and symptom profile (p 0.12) were similar. The presence of type 2/3 esophagogastric junction (EGJ) morphology was commoner in ERD and NERD (p <0.001). Moreover, the esophagogastric junction contractile integral (EGJ-CI) and basal inspiratory pressures were significantly lower in these two groups (p<0.05). EGJ-CI was low in 32 cases of ERD (76.2%), 41 cases with NERD (73.2%), 7 cases with RH (25%), and 3 cases with FH (16.7%), respectively (p-value < 0.00001).FH and RH account for 32% of cases with refractory GERD symptoms. Impaired EGJ function was more common in ERD and NERD patients compared to FH and RH patients.

Macrophage phenotype after human refluxate exposure, esophageal dysmotility and their correlation with gastroesophageal reflux disease

Aim of the study. To investigate the esophageal dysmotility, changes in the esophageal mucosa and the immune response depending on the type of refluxate in gastroesophageal reflux disease (GERD) patients.Material and methods. 68 patients with GERD were recruited: 28 (14 men; mean age, 45.74 ± 2.23 years) nonerosive reflux disease (NERD), 22 (15 men; mean age, 45.0 ± 3.24 years) erosive reflux disease (EE), 18 (13 men; mean age, 47.22 ± 2.95) Barrett’s Esophagus (BE). GERD patients underwent esophageal high-resolution manometry (HRM) with a 22-channel water-perfused catheter and Solar GI system (Medical Measurements Systems, Enschede, the Netherlands), 24-hour impedance and pH monitoring using the Ohmega Ambulatory Impedance pH Recorder (Medical Measurements Systems). We analyzed receptor characteristics of monocyte-derived macrophages in all groups of patients.Results. On HRM examination, we showed that DCI (distal contractile integral) in NERD patients was higher than in EE (p = 0.088) and BE (p = 0.076), also LES RP (lower esophageal sphincter resting pressure) in NERD patients was higher than in EE (p = 0.039) and BE (p = 0.012). The analysis of reflux characteristics showed that the total reflux time with pH &lt; 4 for BE patients was longer than that for NERD and EE patients. An analysis of receptor characteristics of monocyte-derived macrophages showed the prevalence of CD25 and CD80 expression in all groups of patients.Conclusion. An analysis of the phenotype of macrophages derived from blood monocytes of GERD patients revealed a prevalence of М1 macrophages that was typical for the Th1 type of immune response. The degree of esophageal dysmotility was correlated with GERD severity and type.

Effect of hiatus hernia on reflux patterns and mucosal integrity in patients with non-erosive reflux disease.

Hiatus hernia (HH) contributes to development of gastroesophageal reflux disease, Barrett's esophagus and esophageal adenocarcinoma. This study was aimed to investigate the influence of HH on reflux patterns and distal esophageal mucosal integrity in non-erosive reflux disease (NERD). We retrospectively analyzed PPI-refractory NERD patients referred to three tertiary referral centers who underwent high-resolution manometry and off-PPI 24-h impedance-pH monitoring (with or without bile spectrophotometry). Patients with HH ≥2cm (HH group, n=42) or no HH (non-HH group, n=40) with similar esophageal acid exposure time (AET 6%-12%) were included. Age, gender, BMI, esophageal motility, AET, and esophageal clearance were similar between the two groups. The HH group had higher numbers of total reflux episodes (p=0.015) with similar proportion of acid/non-acid reflux compared with the non-HH group. Mean nocturnal baseline impedance (MNBI) in the distal esophagus was significantly lower in the HH group than the non-HH group at both 5cm (p=0.002) and 3cm (p=0.015) above the lower esophageal sphincter. Multivariable regression analysis showed that HH, less non-acid reflux and lower post-reflux swallow-induced peristaltic wave index (PSPWI) were independently associated with lower MNBI. Among 31 patients tested with bile spectrophotometry, the HH group had significantly longer bile exposure time than the non-HH group (p=0.011), and bile reflux inversely and significantly correlated with MNBI (rho=-0.75, p &lt; 0.001). Hiatus hernia, less non-acid reflux and lower PSPWI were associated with lower MNBI. HH impairs distal esophageal mucosal integrity, the mechanism of which we speculate to be through excessive bile reflux.

Expression of VEGF, EGF, and Their Receptors in Squamous Esophageal Mucosa, with Correlations to Histological Findings and Endoscopic Minimal Changes, in Patients with Different GERD Phenotypes.

Background: Gastroesophageal reflux disease (GERD) may present as nonerosive reflux disease (NERD), erosive esophagitis (EE), or be complicated by Barrett’s esophagus (BE). The explanation as to what determines the phenotype of GERD is awaited. Therefore, we assessed the correlation between the growth factors expression and endoscopic as histologic findings in GERD patients. Methods: The squamous esophageal epithelium of 50 patients (20-NERD, 7-EE, 15-BE, 8 controls) was examined by: (1) magnification endoscopy with evaluation of minimal GERD changes such as: microerosions, white spots, palisade blood vessels visibility, and intrapapillary capillary loops (IPCLs) appearance, (2) histology, (3) immunohistochemistry with evaluation of the expression of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and their receptors (VEGFR and EGFR). Results: The expression of VEGF, but not VEGFR, EGF, and EGFR, was significantly increased in EE patients compared to NERD patients and controls. VEGF levels correlated significantly with the presence of white spots, but not with other minimal endoscopic and histologic features. The EGFR expression correlated positively with basal cell hyperplasia and enlarged IPCLs. Conclusions: Our findings suggest a correlation between growth factors expression and findings in conventional endoscopy, formation of endoscopic minimal changes, and histologic lesions.

Narrow-band imaging for the diagnosis of nonerosive reflux disease: an international, multicenter, randomized controlled trial

We examined the accuracy of narrow-band imaging (NBI) findings in nonerosive reflux disease (NERD) patients compared with control subjects and the impact of proton pump inhibitor (PPI) therapy on these mucosal changes in a multicenter, double-blind, randomized controlled trial. NERD patients (typical symptoms using a validated GERD questionnaire, absence of erosive esophagitis, and abnormal 48-hour pH study) and control subjects underwent high-definition white-light endoscopy followed by NBI and biopsy sampling of the distal esophagus. Then, NERD patients were randomized to esomeprazole 40 mg/day or placebo for 8 weeks, followed by repeat endoscopy. The presence of distal esophageal mucosal changes on NBI were recorded at baseline and after treatment: intrapapillary capillary loops (IPCLs; number, dilation, and tortuosity), microerosions, increased vascularity, columnar islands, and ridge/villous pattern (RVP) above the squamocolumnar junction. Of 122 screened, 21 NERD and 21 control subjects were identified (mean age, 49.5 ± 14.6 years; 62% men; and 85% white). The combination of IPCL tortuosity, RVP, and microerosions (62% vs 19%, P< .05) had a high specificity (86%) and moderate sensitivity (60%) for NERD with an area under the curve of .74. In 10 NERD patients treated with PPIs, resolution of microerosions was most significant (P= .047) compared with placebo (n= 11). RVP resolved in all NERD patients after therapy (P= .02) and correlated with acid exposure time (P= .004). Papillary length (P= .02) and basal cell thickness (P= .02) significantly correlated with a combination of IPCL tortuosity, RVP, and microerosions. In this randomized controlled trial, RVP on NBI demonstrated a high specificity, correlated with acid exposure time, and improved with PPI therapy, suggesting that it could be used as a surrogate marker for diagnosis of NERD. (Clinical trial registration number: NCT02081404.).

Analysis of Psychological and Gut Microbiome Characteristics in Patients With Non-erosive Reflux Disease

Objective: To assess the correlation between the incidence of non-erosive reflux disease (NERD) and psychological factors, especially somatoform disorders. To investigate the characteristics of gut microbiome in NERD patients.Methods: We enrolled 24 NERD patients and 24 healthy controls. All patients were evaluated via GerdQ, SOMS-7, SAS, HAMA, and HAMD. Fecal samples were collected and 16S rRNA sequencing was performed to evaluate the gut microbiome composition.Results: The main symptoms of the NERD patients were regurgitation (87.5%), belching (66.7%), pharyngeal discomfort (50%), and heartburn (37.5%). The average score of GerdQ was 13.42 ± 3.41. In 15 patients (62.5%), the total score of the last two items was <3 points, while the average score of 24 patients was 3.63 ± 2.32. NERD patients with somatoform disorders accounted for 50%. There were 17 patients without anxiety, 6 patients with mild anxiety (25%), 1 patient with moderate anxiety (4.2%), and no patient with severe anxiety. There were 22 patients (91.7%) without depression, 2 patients (8.3%) with mild depression, and no patient with moderate or severe depression. The alpha diversity of NERD group was higher than HC, which showed significant difference (P < 0.05). The beta-diversity was significantly different between HC and NERD patients (P = 0.026), male and female patients (P = 0.009). The beta-diversity was also significantly different between male and female patients (P = 0.009). There were several bacteria with significant differences between HC and NERD group, and NERD patients with or without somatoform disorders, such as Firmicutes, TM7 were enriched in the NERD group compared with the healthy control group, while Bacteroidetes were enriched in the healthy controls.Conclusions: NERD symptoms overlap with somatoform disorders. NERD symptoms have an impact on the daily life quality of patients. Some of them are accompanied by anxiety and depression of different degrees, and the two are significantly correlated. The diversity of gut microbiome in patients with NERD is significantly higher than healthy controls, which has its characteristics. The predominant bacteria in gut microbiome of patients with NERD are similar to the healthy population, with Firmicutes and Bacteroidetes as the main ones. The composition of gut microbiome in NERD patients with or without somatoform disorder is significantly different, which may be related to the interaction of microbiome-brain-gut axis.

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

PurposeTranscriptomic 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 MethodsWe 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.ResultsIn 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.ConclusionThe 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.

Esophageal Nocturnal Baseline Impedance and Post-reflux Swallow-induced Peristaltic Wave Index in Identifying Proton Pump Inhibitor-refractory Non-erosive Reflux Disease.

Background/AimsEsophageal mean nocturnal baseline impedance (MNBI) levels and post-reflux swallow-induced peristaltic wave (PSPW) index could increase the diagnostic value of 24-hour multichannel intraluminal impedance and pH monitoring in patients with gastroesophageal reflux disease. This study aims to compare the MNBI and PSPW index in patients with no evidence of erosive reflux disease.MethodsImpedance-pH monitoring tracings from 70 patients, 50 with non-erosive reflux disease (NERD) and 20 with functional heartburn (FH), were reviewed. According to proton pump inhibitors (PPI) treatment response, NERD patients were divided into NERD/PPI responders and NERD/PPI nonresponders. MNBI, PSPW index, and intercellular spaces were measured and compared among each group.ResultsMNBI values and PSPW index were lower in NERD patients than in FH (P < 0.01 and P < 0.05, respectively). MNBI positively correlated with PSPW index (r = 0.525, P < 0.001). NERD/PPI responders had lower MNBI values and PSPW index compared to NERD/PPI nonresponders (both P < 0.01). MNBI and PSPW index distinguished NERD from FH patients with an area under the curve of 0.914 and 0.677, respectively. Wider intercellular space could be identified in patients with NERD (P < 0.01).ConclusionMNBI and PSPW index may differentiate NERD from FH patients and relate to PPI treatment efficacy in patients with NERD.

Efficacy of S-pantoprazole 10 mg in the Symptom Control of Non-erosive Reflux Disease: A Phase III Placebo-controlled Trial.

Background/AimsS-isomer (S) pantoprazole is more bioavailable and less dependent on cytochrome 2C19 than is racemic pantoprazole. We aim to evaluate the efficacy and safety of 10 mg S-pantoprazole for treatment of non-erosive reflux disease (NERD).MethodsIn this phase 3, double-blind, randomized placebo controlled, multicenter study, 174 NERD patients were randomized to one of both treatment groups 10 mg S-pantoprazole, or placebo once daily for 4 weeks. Symptoms and safety were assessed. The efficacy endpoints were complete relief of symptoms, > 50% improvement of all reflux symptoms and recurrence.ResultsEighty-eight patients were assigned to the S-pantoprazole group (25 males, mean 43.7 years old) and 86 to the placebo group (32 males, mean 43.0 years old), and 163 patients were subjected to full Analysis Set. A higher proportion of patients in the S-pantoprazole group had complete symptom relief (42.0 % [34/81] vs 17.1% [14/82], P < 0.001) and > 50% symptom responses (66.0% vs 50.0%, P = 0.010 for heartburn; 64.2% vs 28.0%, P = 0.010 for acid regurgitation; and 51.9% vs 30.5%, P = 0.03 for epigastric discomfort) compared to the placebo group. The factors associated with poor responsiveness to PPI were older age, female, greater body mass index, and severe baseline symptoms.ConclusionsLow dose of S-pantoprazole (10 mg) for 4 weeks was more efficacious than placebo in providing reflux symptom relief in patients with NERD, especially acid regurgitation. More doses or longer periods of treatment with S-pantoprazole would be needed to completely eliminate symptoms.

Esophageal Mucosa Innervation in Children With Nonerosive Reflux Disease.

Esophageal mucosa innervation in adults with nonerosive reflux disease (NERD) is more superficial compared with healthy volunteers. We delineated the esophageal mucosal innervation in pediatric NERD and controls. Distal and proximal pediatric esophageal biopsies were immunohistochemically stained with calcitonin gene-related peptide and transient receptor potential cation channel subfamily V member 1. Mucosal innervation was assessed in 18 controls (9M:9F, median age: 9 years) and 11 NERD patients (6M:5F, median age: 5 years). Calcitonin gene-related peptide positive nerve fibers were lying deep in the mucosa in both groups, P > 0.05 and did not coexpress transient receptor potential cation channel subfamily V member 1. The pediatric esophageal mucosa in NERD displays deep lying nerve fibers, in contrast to adults.