Role of duodenogastroesophageal reflux in the pathogenesis of esophageal mucosal injury and gastroesophageal reflux symptoms

Analysis of clinical characteristics in proximal and distal reflux monitoring among patients with gastroesophageal reflux disease

The purpose of this study was to examine the characteristics of proximal and distal gastroesophageal reflux in patients with gastroesophageal reflux disorder and analyze their clinical symptoms. A total of 67 patients with typical esophageal symptoms were selected for this study. All participants completed the reflux disease questionnaire and a questionnaire survey of extraesophageal symptoms. Diagnosis was made using a 24-h impedance-pH detection and proton pump inhibitor. The results showed that the proximal reflux group had a higher number of acid reflux episodes compared to the distal reflux group (P < 0.05). Similarly, the proximal reflux group also had a higher number of gas reflux episodes compared to the distal reflux group (P < 0.05). On the other hand, the distal reflux group had a higher number of mixed reflux episodes compared to the proximal reflux group (P < 0.05). These differences were statistically significant. This study revealed that acid reflux and gas reflux were more predominant in the proximal reflux group, while mixed reflux was more predominant in the distal reflux group.

Potential therapeutic benefit of ursodeoxycholic acid in the management of non hepato-biliary upper gastrointestinal disorders

OBJECTIVES

To examine the potential therapeutic effects of ursodeoxycholic acid (UDCA) on diseases of the esophagus, stomach, and duodenum.

METHODS

A search was conducted using EBSCO, Medline, PubMed, Google Scholar and Web of Science as well as international guidelines using MESH terms for treatment of UDCA for diseases of the upper gastrointestinal disorders in adult humans without regard to publication language or date restrictions.

RESULTS

A total of 256 articles and 22 guidelines were initially identified, and 221 were excluded. Final revision of 13 articles and 22 guidelines confirmed that UDCA is found to have a cytoprotective role in Barret's esophagus within esophageal disorders, improves abdominal pain in functional dyspepsia, and does not alter Helicobacter pylori colonization or inflammation. Conflicting results are noted regarding the role of UDCA in the duodenum as chemopreventive treatment for familial adenomatous polyposis, with polyps regressing and their growth characteristics improving with low doses (10-25 mg/kg/day). On the contrary, no positive effect was noted upon the combination with Celecoxib and with doses of 1000-2000 mg or 20-30 mg/kg/d. Gastrointestinal side effects were predominantly reported. No side effects necessitated hospitalization or ICU admission.

CONCLUSION

Ursodeoxycholic acid has a limited therapeutic role in functional dyspepsia. There is promising evidence that it may serve as a chemopreventive for Familial adenomatous polyposis and Barret's esophagus, although further research is needed to confirm these findings.PROSPERO No.: CRD 42021267689.

Systematic review: duodenogastroesophageal (biliary) reflux prevalence, symptoms, oesophageal lesions and treatment

BACKGROUND

The prevalence of duodenogastroesophageal reflux (DGER) and its effect on symptoms and oesophageal lesions in gastroesophageal reflux disease (GERD) is unclear.

AIMS

To conduct a systematic review to determine the prevalence of DGER among patients with GERD, the effect of DGER on symptoms and oesophageal lesions, and the treatment of DGER.

METHODS

We searched Pubmed and MEDLINE for full text, English language articles until October 2020 that evaluated DGER prevalence among patients with GERD, the effect of DGER on symptoms and oesophageal lesions, and the treatment of DGER.

RESULTS

We identified 3891 reports and included 35 which analysed DGER prevalence in GERD, 15 which evaluated its effect in non-erosive reflux disease (NERD), 17 on erosive oesophagitis, 23 in Barrett's, and 13 which evaluated the treatment of DGER. The prevalence of DGER, when evaluated by Bilitec, among all GERD patients ranged from 10% to 97%, in NERD 10%-63%, in erosive oesophagitis 22%-80% and in Barrett's 50%-100%. There were no differences in the presence or degree of DGER among patients who were asymptomatic or symptomatic on proton pump inhibitors (PPI). The most commonly evaluated treatments for DGER were PPIs and DGER reduced post-PPI therapy in all studies.

CONCLUSIONS

The prevalence of DGER increased with more advanced oesophageal lesions and did not explain persisting symptoms among patients taking PPI therapy. PPIs appear to be effective in the treatment of DGER. DGER remains an important consideration in patients with GERD and future therapies deserve more study.

Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung

The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated state. Bile acids are particularly associated with the dominance of Proteobacterial pathogens. The ability of bile acids to impact directly on both the lung microbiota and the host response offers a unifying principle underpinning the pathogenesis of CF. The modulating role of bile acids in lung microbiota dysbiosis and inflammation could offer new potential targets for designing innovative therapeutic approaches for respiratory disease.

Relationship between primary bile reflux gastritis and gastroesophageal reflux disease

AIM: To investigate the relationship between primary bile reflux gastritis (PBRG) and gastroesophageal reflux disease (GERD).

METHODS: A total of 1 060 patients diagnosed with PBRG comprised the observation group, and 1 060 people without PBRG were used as controls. The incidence rate of GERD in the two groups was compared. The patients with PBRG and GERD were divided into mild group, moderate group, severe group based on the severity of PBRG. The degree of esophageal mucosal injury and the distribution of GERD symptoms were then compared.

RESULTS: The incidence rate of GERD in the PBRG group was higher than that in the control group (24.5% vs 9.8%, P < 0.05). The incidence rate of esophageal mucosal injury increased with the aggravation of PBRG. The degree of PBRG showed no significant association with the distribution of GERD symptoms.

CONCLUSION: PBRG has a positive correlation with the formation of reflux esophagitis (RE), and PBRG does not play a major role in producing typical GERD symptoms.

Reflux and sex: what drives testing, what drives treatment?

Gastroesophageal reflux (GER) affects ∼10-20% of American adults. Although symptoms are equally common in men and women, we hypothesized that sex influences diagnostic and therapeutic approaches in patients with GER. PubMed database between 1997 and October 2011 was searched for English language studies describing symptoms, consultative visits, endoscopic findings, use and results of ambulatory pH study, and surgical therapy for GER. Using data from Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality, we determined the sex distribution for admissions and reflux surgery between 1997 and 2008. Studies on symptoms or consultative visits did not show sex-specific differences. Even though women are less likely to have esophagitis or Barrett's esophagus, endoscopic studies enrolled as many women as men, and women were more likely to undergo ambulatory pH studies with a female predominance in studies from the US. Surgical GER treatment is more commonly performed in men. However, studies from the US showed an equal sex distribution, with Nationwide Inpatient Sample data demonstrating an increase in women who accounted for 63% of the annual fundoplications in 2008. Despite less common or severe mucosal disease, women are more likely to undergo invasive diagnostic testing. In the US, women are also more likely to undergo antireflux surgery. These results suggest that healthcare-seeking behavior and socioeconomic factors rather than the biology of disease influence the clinical approaches to reflux disease.

Mechanisms of reflux perception in gastroesophageal reflux disease: a review

Patients with reflux symptoms often do not have excessive esophageal acid exposure, and patients with severe gastroesophageal reflux often do not have reflux symptoms. Understanding why different types of reflux induce symptoms in different patients is vital for addressing therapeutic gaps in the treatment of gastroesophageal reflux disease (GERD). Here we review studies providing insight into how gastroesophageal reflux is perceived, with a focus on comparing reflux characteristics and esophageal sensitivity among subgroups of patients with GERD. The available studies indicate that patients with nonerosive reflux disease have fewer acid reflux episodes and thus less esophageal acid exposure than patients with reflux esophagitis but perceive less intense stimuli because of greater esophageal sensitivity. Reflux characteristics other than acidity, such as the presence of bile, pepsin, liquid, or gas in reflux, and the proximal extent or volume of reflux, may also contribute to symptom perception. Factors contributing to greater esophageal sensitivity may include impaired mucosal barrier function, peripherally mediated esophageal sensitivity (enhanced esophageal receptor signaling), and centrally mediated esophageal sensitivity (physiological stressors, sensitization of spinal sensory neurons). Further insight into mechanisms of reflux perception may require a shift toward studies aimed at understanding predisposing cellular, molecular, and genetic factors.

Effects of ursodeoxycholic acid in esophageal motility and the role of the mucosa. An experimental study

Esophageal motor abnormalities are frequently found in patients with gastroesophageal reflux disease. The role of bile in reflux-induced dysmotility is still elusive. Furthermore, it is questionable weather mucosal or muscular stimulation leads to motor dysfunction. The aims of this study were to analyze (i) the effect of bile in the amplitude of esophageal contractions; and (ii) the effect of mucosal versus muscular stimulation. Eighteen guinea pig esophagi were isolated, and its contractility assessed with force transducers. Three groups were studied. In group A (n= 6), the entire esophagus was incubated in 100 µmL ursodeoxycholic acid for 1 hour; in group B (n= 6) the mucosal layer was removed and the muscular layer incubated in 100 µmL ursodeoxycholic acid for 1 hour; and in group C (n= 6) (control group) the entire esophagus was incubated in saline solution. In all groups, five sequential contractions induced by 40 mm KCl spaced by 5 minutes were measured before and after incubation. Contractions amplitudes before incubation were 1.319 g, 0.306 g, and 1.795 g, for groups A, B, and C, respectively. There were no differences between groups A and C (P= 0.633), but there were differences between groups A and B (P= 0.039), and B and C (P= 0.048). After incubation amplitude of contraction were 0.709 g, 0.278 g, and 1.353 g for groups A, B, and C, respectively. Only group A showed difference when pre and post-stimulation amplitudes were compared (P= 0.030). Our results show that (i) bile exposure decreases esophageal contraction amplitude; and (ii) the esophageal mucosa seems to play an important role in esophageal motility.

Gastroesophageal reflux in cirrhotic patients without esophageal varices

AIM: To evaluate the esophageal motility and abnormal acid and bile reflux incidence in cirrhotic patients without esophageal varices (EV).

METHODS: Seventy-eight patients with liver cirrhosis without EV confirmed by upper gastroesophageal endoscopy and 30 healthy control volunteers were prospectively enrolled in this study. All the patients were evaluated using a modified protocol including Child-Pugh score, upper gastrointestinal endoscopy, esophageal manometry, simultaneous ambulatory 24-h esophageal pH and bilirubin monitoring. All the patients and volunteers accepted the manometric study.

RESULTS: In the liver cirrhosis group, lower esophageal sphincter pressure (LESP, 15.32 ± 2.91 mmHg), peristaltic amplitude (PA, 61.41 ± 10.52 mmHg), peristaltic duration (PD, 5.32 ± 1.22 s), and peristaltic velocity (PV, 5.22 ± 1.11 cm/s) were all significantly abnormal in comparison with those in the control group (P < 0.05), and LESP was negatively correlated with Child-Pugh score. The incidence of reflux esophagitis (RE) and pathologic reflux was 37.18% and 55.13%, respectively (vs control, P < 0.05). And the incidence of isolated abnormal acid reflux, bile reflux and mixed reflux was 12.82%, 14.10% and 28.21% in patients with liver cirrhosis without EV.

CONCLUSION: Cirrhotic patients without EV presented esophageal motor disorders and mixed acid and bile reflux was the main pattern; the cirrhosis itself was an important causative factor.

New developments in gastroesophageal reflux disease diagnosis and therapy

PURPOSE OF REVIEW

Gastroesophageal reflux disease is a highly prevalent chronic condition in Western populations. It has a profound effect on our society in terms of economic cost and quality of life. There have been major advances in understanding of disease pathogenesis over the last few years which are summarized in this article.

RECENT FINDINGS

With improved understanding of gastroesophageal reflux disease, newer developments in diagnostic techniques have evolved. The proton pump inhibitor test has been formally described as one of the initial diagnostic tests. Other new tests include multiple channel impedance monitoring, bilirubin reflux monitoring, Barostat measurements and intraluminal ultrasounds which, along with other newer technologies, are described in this review.

SUMMARY

The mechanisms involved in the pathogenesis of gastroesophageal reflux disease are complex and multifactorial. The lower esophageal sphincter pressure, the motility of the esophageal body and the stomach, the composition of the reflux material and the sensitivity or resistance of the esophageal mucosa to the reflux material are important factors involved in the pathogenesis of disease-related symptoms and lesions. Based on our improving understanding, novel diagnostic tools are available to improve investigation of the disease.

Effect of Roux-en-Y surgery and medical intervention on Barrett's-type changes: an in vivo model

In animal models, mixed acid and bile reflux into lower esophagus induces histological changes comparable to Barrett's metaplasia (BM) and neoplasia. The aim of this study was to compare the effects of Roux-en-Y (REY) surgery and medical therapy on BM in animals before the development of neoplasia. Vagus preserving esophagojejunostomy operation was performed on Sprague-Dawley rats to achieve gastroduodenal reflux (GDR) into the esophagus in 30 animals. After 3 months, changes were reversed in 10 animals (Group REY) by REY operation, 10 animals (Group proton pump inhibitor [PPI]) were given PPI during the postoperative period, and 10 animals (Group GDR) did not have further intervention. At 4 months, histological examination of the lower esophagus was performed by an experienced pathologist. Physiological parameters were also analyzed in all animals preoperatively and at 4 months postoperatively. The length of columnar mucosa, degree of acute inflammation, degree of metaplasia, and composite BM score were significantly reduced by REY surgery compared with medical therapy and with control (columnar mucosa in cm [mean +/- standard error of the mean] Group REY 0.44 +/- 0.06, Group PPI 0.92 +/- 0.08, P < 0.001/Group GDR 1.17 +/- 0.31, P < 0.03). There was no neoplasia seen in any specimen. At 4 months, postoperatively controls Group REY surgery showed significantly more normalization of physiological parameters to preoperative levels than Group PPI (P < 0.05). REY surgery is potentially more beneficial than medical therapy in reversing the histological and biochemical changes of Barrett's esophagus due to GDR.

Review article: the pathophysiology of gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease (GERD) is a common condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications.

AIM

To review the current knowledge on the underlying factors contributing to GERD, with particular emphasis on the most recent research.

METHODS

Literature searches were conducted in Medline and EMBASE. The abstracts from recent large congresses were also reviewed to ensure coverage of the latest findings.

RESULTS

The pathophysiological factors causing GERD can be split into those inducing greater exposure of the oesophagus to stomach contents, and those that provide increased perception of reflux or increased mucosal damage. Transient lower oesophageal sphincter relaxations, which are likely to be triggered by gastric distension, appear to be a key physiological cause of GERD. Excessive reflux may also be provoked by impaired oesophageal or gastric clearance mechanisms. Pre-epithelial, epithelial and post-epithelial defences all normally protect the oesophagus from injury, and may be compromised in individuals with GERD. Heartburn could also be caused by oesophageal hypersensitivity as a result of visceral neural pathway dysfunction.

CONCLUSION

The pathophysiology of GERD is multifactorial, and abnormalities in the gastro-oesophageal junction, the stomach, the oesophagus and the nervous system may all contribute to this disease state.

Developments in pathogenesis and diagnosis of gastroesophageal reflux disease

PURPOSE OF REVIEW

Although gastroesophageal reflux is a common disorder, diagnosis is still imprecise. Moreover, its pathogenesis is incompletely understood. This review summarizes recent progress in diagnosis and our understanding of the pathogenesis of gastroesophageal reflux disease.

RECENT FINDINGS

Recent studies have focused on the pattern of reflux in the distal esophagus, just above the esophago-gastric junction, challenging its importance on the genesis of reflux symptoms. New techniques, such as impedance, could improve the diagnostic yield, especially in patients with nonacid reflux. Esophageal sensitivity and motility, transient lower esophageal sphincter relaxations, and hiatus hernia are important pathogenic mechanisms of reflux disease. Studies showed that obesity plays a role in the pathogenesis of reflux symptoms; a disruption of the esophago-gastric junction (leading to hiatus hernia) could allow reflux to occur. The association between reflux (particularly nonacid) and extraesophageal manifestations of gastroesophageal reflux disease has been further evaluated.

SUMMARY

Improvement of diagnostic techniques and better understanding of the pathogenesis of reflux may lead to new or better therapeutic modalities. Our understanding of some of the risk factors for reflux has been increased. Extra-esophageal manifestations and their association with gastroesophageal reflux are still a very controversial and promising area of research.