Pyloric reflux and G-cell hyperfunction

Bile reflux alters the profile of the gastric mucosa microbiota

Background

Bile reflux can cause inflammation, gastric mucosa atrophy, and diseases such as stomach cancer. Alkaline bile flowing back into the stomach affects the intragastric environment and can alter the gastric bacterial community. We sought to identify the characteristics of the stomach mucosal microbiota in patients with bile reflux.

Methods

Gastric mucosal samples were collected from 52 and 40 chronic gastritis patients with and without bile reflux, respectively. The bacterial profile was determined using 16S rRNA gene analysis.

Results

In the absence of H. pylori infection, the richness (based on the Sobs and Chao1 indices; P <0.05) and diversity (based on Shannon indices; P <0.05) of gastric mucosa microbiota were higher in patients with bile reflux patients than in those without. There was a marked difference in the microbiota structure between patients with and without bile reflux (ANOSIM, R=0.058, P=0.011). While the genera, Comamonas, Halomonas, Bradymonas, Pseudomonas, Marinobacter, Arthrobacter, and Shewanella were enriched in patients with bile reflux, the genera, Haemophilus, Porphyromonas, and Subdoligranulum, were enriched in those without bile reflux.

Conclusion

Our results demonstrate that bile reflux significantly alters the composition of the gastric microbiota.

Analysis of Risk Factors and Establishment of a Prediction Model for Endoscopic Primary Bile Reflux: A Single-Center Retrospective Study

Background: Endoscopic primary bile reflux is one of the main diagnostic criteria for bile reflux gastritis (BRG). Presently, the risk factors and prediction models of endoscopic primary bile reflux (EPBR) in gastropathy patients who cannot or will not undergo endoscopy due to contraindications are not clear. Thus, this study aimed to evaluate the risk factors of EPBR and to establish and verify a prediction model.

Methods: A series of 844 patients (564 subjects with EPBR and 280 control subjects) were retrospectively selected for this study and divided into a training set (n = 591) and a validation set (n = 253) according to the usual ratio of 70:30% for the subsequent internal validation of the logistic regression model for EPBR. Fifteen parameters that might affect the occurrence of EPBR were collected. Subsequently, univariate and stepwise logistic regression analyses were introduced to reveal the risk factors and the multivariate prediction model. An R package was dedicated to the corresponding internal validation of the EPBR model.

Results: The univariate analysis showed that gender, age, smoking, Helicobacter pylori (H. pylori) infection status, metabolic syndrome (MS), non-steroidal anti-inflammatory drugs (NSAIDs) use history, and previous medical histories of chronic liver diseases, cholelithiasis, and erosive gastritis were statistically significant between the two groups (P < 0.05). Multivariate regression described that being a male [OR (95%confidence interval (CI)) = 2.29 (1.50–3.50), P < 0.001], age≥45 years old [OR (95% CI) = 4.24 (2.59–6.96), P < 0.001], H. pylori infection status [OR (95% CI) = 2.34 (1.37–4.01), P = 0.002], MS [OR (95% CI) = 3.14 (1.77–5.54), P < 0.001], NSAIDs use history [OR (95% CI) = 1.87 (1.03–3.40), P = 0.04], cholelithiasis history [OR (95% CI) = 3.95 (2.18–7.18), P < 0.001] and erosive gastritis history [OR (95% CI) = 6.77 (3.73–12.29), P < 0.001] were the risk factors for the occurrence of EPBR. Based on the results of these risk factors, an EPBR prediction model with an adequate calibration and excellent discrimination was established [area under the curve (AUC): 0.839, 95% CI = 0.806–0.872].

Conclusions: Being a male, age ≥ 45 years old, H. pylori infection, histories of MS, NSAIDs use, cholelithiasis, and erosive gastritis appear to be the risk factors for EPBR, and our favorable prediction model might be an option for the prediction of EPBR.

The Relationship between Primary Duodenogastric Reflux and Helicobacter pylori Gastritis in Children

BACKGROUND

Most studies of the relationship between duodenogastric reflux (DGR) and Helicobacter pylori have reported that the presence of DGR decreases H. pylori colonization, while H. pylori infection increases the frequency of DGR by impairing antroduodenal motility. The present study aimed to investigate the relationship between primary DGR and the prevalence of H. pylori in children, as well as the degree of colonization and the presence and severity of gastritis.

METHODS

Included in the study were 410 patients between the ages of 2 and 18 years, referred to the pediatric gastroenterology clinic with complaints of dyspepsia, abdominal pain, and nausea/vomiting, who underwent upper gastrointestinal system endoscopic examination and stomach biopsy. The study group included 60 patients with DGR, while 350 non-DGR patients formed the control group.

RESULTS

The mean age of patients with DGR was 15.7 ± 2.1 years, while the mean age of the control group was 14.2 ± 3.8 years (p = 0.02). Of those with DGR, 50 (83.3%) were girls, while in the control group, 215 (61.4%) were girls (p = 0.001). Of patients with DGR, 16 were H. pylori (+) (26.7%), while in the control group, 168 were H. pylori (+) (48%) (p = 0.002). There was no significant difference between the 2 groups with respect to H. pylori degree of colonization (p = 0.08). Gastritis was present in 56 (93.3%) patients in the DGR group and 322 (92%) patients in the control group (p = 0.72). A significant difference was found between the 2 groups in terms of gastritis severity (p = 0.01).

CONCLUSIONS

The mean age of patients with DGR was significantly higher than that of patients without DGR, and DGR was found to be more common in girls. In patients with DGR, H. pylori prevalence was significantly lower than in those without DGR; however, no significant difference was found between the 2 groups with respect to the colonization degree.

Helicobacter pylori may induce bile reflux: link between H pylori and bile induced injury to gastric epithelium

Helicobacter pylori and duodenogastric reflux are both recognised as playing aetiological roles in chronic gastritis. This study investigated whether H pylori colonisation of the antral mucosa and duodenogastric reflux are independent phenomena or have a causal relationship. Thirty eight patients (15 men, 23 women) aged (mean (SD)) 48 (17) years participated. Each patient underwent gastroscopy. Antral biopsy specimens were taken to investigate H pylori colonisation. In addition BrIDA-99mTc/111In-DTPA scintigraphy was used to quantify duodenogastric reflux. H pylori positive patients who were found to have duodenogastric reflux were treated with amoxycillin (1 g/d) and metronidazole (1.5 g/d) for seven days and four tablets of bismuth subcitrate daily for four weeks. Follow up antral biopsies and scintigraphy were repeated at six months. Duodenogastric reflux could not be found in 18 patients, including eight (44%) who were H pylori positive. Ten of the 11 patients who had duodenogastric reflux (reflux % 11.6 (9.2)), however, were H pylori positive (chi 2 = 6.26, p = 0.01). These 10 patients were given eradication treatment. At six months, in six patients who became H pylori negative, duodenogastric reflux was significantly reduced from a pretreatment value of 14.3% to 3.3% (two tail, paired t = 2.57, p = 0.016). These data suggest that H pylori may induced duodenogastric reflux which may be important in the pathogenesis of H pylori gastritis or carcinogenesis, or both.