Helicobacter pylori and gastric acid: an intimate and reciprocal relationship

Inflammation and Digestive Cancer

Chronic inflammation is linked to carcinogenesis, particularly in the digestive organs, i.e., the stomach, colon, and liver. The mechanism of this effect has, however, only partly been focused on. In this review, we focus on different forms of chronic hepatitis, chronic inflammatory bowel disease, and chronic gastritis, conditions predisposing individuals to the development of malignancy. Chronic inflammation may cause malignancy because (1) the cause of the chronic inflammation is itself genotoxic, (2) substances released from the inflammatory cells may be genotoxic, (3) the cell death induced by the inflammation induces a compensatory increase in proliferation with an inherent risk of mutation, (4) changes in cell composition due to inflammation may modify function, resulting in hormonal disturbances affecting cellular proliferation. The present review focuses on chronic gastritis (Helicobacter pylori or autoimmune type) since all four mechanisms may be relevant to this condition. Genotoxicity due to the hepatitis B virus is an important factor in hepatocellular cancer and viral infection can similarly be central in the etiology and malignancy of inflammatory bowel diseases. Helicobacter pylori (H. pylori) is the dominating cause of chronic gastritis and has not been shown to be genotoxic, so its carcinogenic effect is most probably due to the induction of atrophic oxyntic gastritis leading to hypergastrinemia.

Garlic Extracts: Effect of pH on Inhibition of Helicobacter pylori

The present work studies the influence of pH on the stability of thiosulfinates, compounds responsible for the bacteriostatic properties shown by ethanolic and acetonic garlic extracts (EGE and AGE) against the in vitro growth of Helicobacter pylori (Hp), a bacterium which is implicated in the etiology of diverse gastrointestinal diseases. The influence of pH and time on the stability of thiosulfinates and the microbiological activities of EGE and AGE has been evaluated at human body temperature (37 °C) and in a pH range of 0.9-4.7. A marked decrease in thiosulfinate concentration was observed in a relatively short time at pH values below 2.0. However, at pH values over 2.0, the samples maintained 70% of thiosulfinate concentration for 12 h. The inhibition halo diameters showed a maximum value at pH 2.50, with an inhibition halo of 28.94 ± 0.61 mm. The reduction in the activity at pH values below 2.0 was particularly remarkable. These results suggest that, for medical application, the pH of the selected extracts must only be maintained above 2 to maintain a high level of antibacterial activity. This fact would overcome the need for proton pump inhibitors and/or antibiotics during the treatment of Hp infections in human patients.

Relationship Between Recreational Cannabis Use and Helicobacter pylori Infection

Background: Cannabis plant extracts suppress gastric acid secretion and inflammation, and promote gastroduodenal ulcer healing, all of which are triggered by Helicobacter Pylori infection (HPI). Here, we evaluate the association between cannabis use and HPI among a representative community sample. Materials and Methods: We identified respondents who completed cannabis use questions and were tested for HPI (H. pylori IgG antibody seropositivity) from the National Health and Nutrition Examination Survey III dataset (n=4556). Cannabis usage was categorized as ever-use (ever, never), cumulative lifetime use (>10-times, 1-10-times, never), or recent use (>31-days-ago, within-31-days, never). We calculated the crude and adjusted risk (prevalence rate ratio, cPRR and aPRR) of having HPI with cannabis use using generalized Poisson models (SAS 9.4). The models were adjusted for demographics and risk factors for HPI. Results: The prevalence of HPI was lower among ever versus never cannabis users (18.6% vs. 33%, p<0.0001). Cannabis use was associated with a decreased risk of HPI (cPRR: 0.56 confidence interval [95% CI: 0.47-0.67]; p<0.0001), which persisted after adjusting for demographics (aPRR: 0.75 [95% CI: 0.63-0.90]; p=0.0016) and comorbidities (aPRR: 0.79 [95% CI: 0.66-0.95]; p=0.0145). Further, individuals with >10-times lifetime cannabis use had a decreased risk of HPI compared with those with 1-10-times lifetime use (aPRR: 0.70 [95% CI: 0.55-0.89]; p=0.0011) and never-users (aPRR: 0.65 [95% CI: 0.50-0.84]; p=0.0002). Conclusion: Recreational cannabis use is associated with diminished risk of HPI. These observations suggest the need for additional research assessing the effects of medical cannabis formulations on HPI.

Changes in Acidity Levels in the Gastric Tube After Esophagectomy for Esophageal Cancer

Reflux esophagitis and gastric tube ulcer sometimes cause severe clinical problems in patients undergoing esophagectomy with gastric tube reconstruction. We previously reported that acidity in the gastric tube was decreased for 1 year after esophagectomy, and that lower acidity levels were associated with Helicobacter pylori (H. pylori) infection. However, the long-term changes in gastric acidity remain unknown. We aimed to investigate the long-term changes in gastric acidity after surgery. Eighty-nine patients who underwent esophagectomy with gastric tube reconstruction for esophageal cancer were analyzed. They underwent 24-hour pH monitoring, serum gastrin measurement, and H. pylori infection examination before surgery, at 1 month, 1 year, and 2 years after surgery. The gastric acidity at 1 month and 1 year after surgery was significantly lower than that before surgery (p=0.003, p=0.003). However, there was no difference in gastric acidity before and 2 years after surgery. The gas tric acidity in H. pylori-infected patients was significantly lower in comparison to non-infected patients at each time point (p=0.0003, p<0.0001, p<0.0001, p<0.0001, respectively). In H. pylori-infected patients, gastric acid ity was decreased for 1 year after surgery, and recovered within 2 years after surgery. However, no significant differences were observed in the acidity levels of non-infected patients during the 2-year follow-up period. The serum gastrin level increased after esophagectomy. The acidity levels in the gastric tube recovered within 2 years after surgery. Periodic endoscopy examination is recommended for early detection of acid-related disease, such as reflux esophagitis or gastric tube ulcer, after esophagectomy with gastric tube reconstruction.

Impact of gastric and bowel surgery on gastrointestinal drug delivery

General surgical procedures on the gastrointestinal tract are commonly performed worldwide. Surgical resections of the stomach, small intestine, or large intestine can have a significant impact on the anatomy and physiological environment of the gastrointestinal tract. These physiological changes can affect the effectiveness of orally administered formulations and drug absorption and, therefore, should be considered in rational drug formulation design for specific pathological conditions that are commonly associated with surgical intervention. For optimal drug delivery, it is important to understand how different surgical procedures affect the short-term and long-term functionality of the gastrointestinal tract. The significance of the surgical intervention is dependent on factors such as the specific region of resection, the degree of the resection, the adaptive and absorptive capacity of the remaining tissue, and the nature of the underlying disease. This review will focus on the common pathological conditions affecting the gastric and bowel regions that may require surgical intervention and the physiological impact of the surgery on gastrointestinal drug delivery. The pharmaceutical considerations for conventional and novel oral drug delivery approaches that may be impacted by general surgical procedures of the gastrointestinal tract will also be addressed.

IL-1β, an important cytokine affecting Helicobacter pylori-mediated gastric carcinogenesis

Infection with Helicobacter pylori (H. pylori) is prevalent around the world and responsible for gastric cancer (GC). The development of GC from gastritis is closely associated with the bacterial virulence and the body's immune response ability. In this process, interleukin-1β (IL-1β) plays an important role. Under H. pylori infection, IL-1β is highly expressed that result in gastric acid inhibition, GC-related gene methylations and disfunctions, angiogenesis. Nod-like receptor pyrin domain containing 3 (NLRP3) inflammasome mediates IL-1β maturation in cells such as macrophages, neutrophils and dendritic cells. But how does IL-1β get released across the cell membrane still unclear. In this review, we focus on the secretion mechanism of IL-1β across the membrane, and to explore the role of IL-1β in the progression of GC.

Success of 14-day triple and quadruple therapy for the control of Helicobacter pylori infections in Kohat district

Introduction:

Helicobacter pylori is an important medical pathogen present in more than half of the world’s population. Various treatment regimen are in use for the eradication of H. pylori, but due to the emergence of antibiotic resistance, its management is a big issue for clinicians.

Methods:

In this study all suspected cases that had visited District Headquarters Hospital Kohat were considered for screening of H. pylori infections. Preliminary information about their age, gender, general health conditions, occupation, etc. was taken for consideration. After recording initial signs and symptoms, samples were considered for H. pylori detection using stool antigen test and endoscopy. Fourteen-day proton pump inhibitor base triple and quadruple therapy were administered to each patient.

Results:

In total (n = 178), there were high numbers of positivity in patients aged below 30 years (82; 46.06%), most of whom belonged to rural areas.

Conclusion:

This study concludes that there were high numbers of positive patients aged below 30 years, and according to this study MEL (Metronidazole + Esomeprazole + Levofloxacin) is the most effective treatment regimen for the eradication of H. pylori.

Efficacy and safety of polaprezinc in the treatment of gastric ulcer: A multicenter, randomized, double-blind, double-dummy, positive-controlled clinical trial

OBJECTIVE

To investigate the clinical efficacy and safety of polaprezinc compared with rebamipide in the treatment of gastric ulcers (GU).

METHODS

GU patients (n = 224) from 10 clinical centers were prospectively enrolled and randomly divided into a control (n = 113) or test (n = 111) group. The control group was treated with rebamipide tablets, while the test group was treated with polaprezinc. The primary endpoint was the effective treatment rate, which was confirmed by gastroscopy after 8 weeks of treatment. The secondary efficacy endpoint was the improvement rate of gastrointestinal symptoms after 4 and 8 weeks of treatment.

RESULTS

The basic characteristics of the two groups were well balanced. For the primary efficacy endpoint, the effective rates confirmed by gastroscopy, after treatment for the test and control groups were 81.48% and 74.31% (P = 0.1557), respectively. After 4 and 8 weeks of treatments, both treatment groups had comparable improvements rates in gastrointestinal symptoms (test vs. control: 44.44% vs. 39.45% [P = 0.4559] and 81.48% vs. 77.06% [P = 0.4223]). Further, the two groups had similar adverse events and reactions to the study drugs.

CONCLUSION

These findings suggest that the efficacy and safety of polaprezinc were similar to those of rebamipide in the treatment of GU.

Clinical characteristics and predictors of esophagogastric variceal bleeding among patients with HCV-induced liver cirrhosis: An observational comparative study

OBJECTIVES

To investigate the clinical characteristics, risk factors, and predictors of esophagogastric variceal bleeding in patients with hepatitis C virus (HCV)-induced liver cirrhosis.

METHODS

This comparative observational study was carried out on 100 patients suffering from post hepatitis cirrhosis and portal hypertension who were admitted to the Internal Medicine Department, Al-Azhar University Hospital, Damietta Egypt. Patients were classified into two groups: 50 of them presented with esophagogastric varices with acute variceal bleeding, and 50 patients presented without bleeding. Data were collected, coded, revised, and entered into the Stata software version 16.

RESULTS

The mean age of patients with bleeding was slightly higher than those without bleeding (55.58 ± 5.89 vs. 52.54 ± 9.01 years), p = 0.049. Mild ascites, positive H.Pylori, and Child-Pugh score B and C were an independent predictors of esophagogastric variceal bleeding (OR = 0.036, 95% CI: 0.0004-0.36; p = 0.005), (OR = 7.36, 95% CI: 1.44-37.59; p = 0.016), (OR = 19.0, 95% CI: 2.02-186.3; p = 0.010), and (OR = 40.51, 95% CI: 2.18-751.31; p = 0.013). The sensitivity of this model was 93.88%, specificity was 53.85%, PPV was 88.46%, NPV was 70.0%, correctly classified patients were 85.48%, and AUC was 90.27%. In the second model, pepsinogen level higher than 43.5 μg/l, AST (>54.5), Bilirubin (>1.45), and Hemoglobin (>11.5) were a significant independent predictors of esophagogastric variceal bleeding (OR = 1.18, 95% CI: 1.09-1.27; p<0.001), (OR = 1.14, 95% CI: 1.03-1.27; p = 0.007), (OR = 5.55, 95% CI: 1.21-25.43; p = 0.027), and (OR = 0.05, 95% CI: 0.008-0.32; p = 0.002), respectively. The sensitivity of this model was 92%, specificity was 98%, PPV was 97.87%, NPV was 92.45%, correctly classified patients were 95%, and AUC was 98.68%.

CONCLUSION

The independent predictors of esophagogastric variceal bleeding were ascites, positive H. pylori, Child-Pugh score B and C, pepsinogen level higher than 43.5 μg/l, AST (>54.5), bilirubin (>1.45), and hemoglobin (>11.5). Laboratory investigations are more reliable in predicting variceal bleeding and excluding non-variceal bleeding; however, clinical symptoms should not be neglected, especially H. pylori infection, ascites, and Child-Pugh score.

Inverse relations between Helicobacter pylori infection and risk of esophageal precancerous lesions in drinkers and peanut consumption

BACKGROUND

Helicobacter pylori (H. pylori) is a Gram-negative bacterium found in the upper digestive tract. Although H. pylori infection is an identified risk factor for gastric cancer, its role in esophageal squamous cell carcinoma (ESCC) remains a topic of much debate.

AIM

To evaluate the association between H. pylori infection and the risk of precancerous lesions of ESCC, and further explore the association between dietary factors and the risk of H. pylori infection.

METHODS

Two hundred patients with esophageal precancerous lesions (EPL) aged 63.01 ± 6.08 years and 200 healthy controls aged 62.85 ± 6.03 years were included in this case-control study. Epidemiological data and qualitative food frequency data were investigated. Enzyme-linked immunosorbent assay measuring serum immunoglobulin G antibodies was used to determine H. pylori seropositivity. An unconditional logistic regression model was used to assess the association between H. pylori infection and EPL risk dichotomized by gender, age, and the use of tobacco and alcohol, as well as the association between dietary factors and the risk of H. pylori infection.

RESULTS

A total of 47 (23.5%) EPL cases and 58 (29.0%) healthy controls had positive H. pylori infection. An inverse relation between H. pylori infection and the risk of EPL was found in the group of drinkers after adjustment for covariates [odds ratio (OR) = 0.32, 95% confidence interval (95%CI): 0.11-0.95]. Additionally, peanut intake was significantly associated with a decreased risk of H. pylori infection (OR = 0.39, 95%CI: 0.20-0.74).

CONCLUSION

Our study suggested that H. pylori infection may decrease the risk of EPL for drinkers in a rural adult Chinese population, and the consumption of peanut may reduce the risk of H. pylori infection. These findings should be framed as preliminary evidence, and further studies are required to address whether the mechanisms are related to the localization of lesions and alcohol consumption.

Explore and Analyze the Composition and Characteristics of Intestinal Microbiota between Gastric Cancer Patients and Healthy People

Gastric cancer is one of the most common malignant tumors in the world. As the intestine is downstream of the digestive tract, the occurrence of gastric cancer may have a certain significant impact on it. Therefore, it is particularly important to find out the intestinal bacteria closely related to gastric cancer, to identify the specific flora related to gastric cancer, and to maintain the stability of the core structure of intestinal microecology in patients with gastric cancer. Based on this, the fecal samples of gastric cancer patients and healthy people were collected, and the diversity and composition of intestinal flora in patients with gastric cancer were analyzed by 16S rRNA sequencing technology. We found that there was no significant difference in the diversity and abundance of intestinal flora between gastric cancer patients and healthy people. The relative abundance of Faecalibacterium, Bifidobacterium, and Subdoligranulum in the intestinal tract of patients with gastric cancer was significantly lower than that in healthy people, while the relative abundance of Enterococcus, Streptococcus, and Bacteroides was increased. This study found that there were six kinds of intestinal microflora closely related to the occurrence of gastric cancer, which provided a theoretical basis for further exploring the pathogenesis of gastric cancer.

Chronic restraint stress promotes gastric epithelial malignant transformation by activating the Akt/p53 signaling pathway via ADRB2

The etiology of gastric cancer is associated with infectious, environmental and dietary factors, as well as genetic background. Additionally, emerging evidence has supported the vital role of chronic emotional stress on gastric carcinogenesis; however, the underlying mechanism remains unclear. The present study aimed to investigate the effects of chronic stress and a detrimental diet on gastric malignant epithelial transformation in rats. Therefore, 26 Wistar rats were randomly divided into the following four groups: i) Control; ii) detrimental diet (DD); iii) detrimental diet with chronic restraint (DR) and iv) detrimental diet with chronic restraint and propranolol treatment (DRP). ELISA was performed to detect the serum levels of epinephrine and norepinephrine. Epithelial cell apoptosis was analyzed using the TUNEL assay. The mRNA and protein expression levels of Akt and p53 were detected using reverse transcription quantitative PCR and western blotting, respectively. Pathological changes were analyzed using hematoxylin and eosin staining (H&E). The H&E staining results showed that dysplasia in the gastric mucosa occurred in two of eight rats in the DD group and in four of five rats in the DR group, whereas no dysplasia was detected in the DRP group. The apoptotic ratios of gastric epithelial cells were significantly decreased in all treatment groups compared with the control group. Adrenoceptor β2 (ADRB2) protein expression levels were increased significantly only in the DR group and this effect was significantly reduced in the DRP group. The mRNA expression levels of Akt and p53 were significantly upregulated in the DD group, and Akt mRNA expression was further elevated in the DR group. With regard to protein expression, the levels of Akt and p-Akt were significantly increased in the DR group, whereas these effects were reversed in the DRP group. Furthermore, the ratio of p-p53/p53 protein was significantly reduced in the DD or DR groups, but was reversed in the DRP group. Collectively, the findings of the present study suggested that chronic restraint stress potentially aggravates the gastric epithelial malignant transformation induced by a detrimental diet, at least partially via the Akt/p53 signaling pathway mediated via ADRB2.

The degree of mucosal atrophy is associated with post-endoscopic submucosal dissection bleeding in early gastric cancer

BACKGROUND AND AIM

Despite the widespread use of endoscopic submucosal dissection (ESD) for early gastric cancer, post-ESD bleeding remains a significant problem. Intragastric pH plays an important role in intragastric bleeding. Because gastric acid secretion contributes to intragastric pH, both the presence or absence of Helicobacter pylori infection and the degree of gastric mucosal atrophy may affect bleeding. The present study aimed to clarify the relationship between post-ESD bleeding and the degree of gastric mucosal atrophy based on H. pylori infection status.

METHODS

We included 8170 patients who underwent ESD for early gastric cancer at 33 hospitals in Japan from November 2013 to October 2016. We analyzed the risk factors contributing to post-ESD bleeding.

RESULTS

There were 3935 H. pylori-positive patients and 4235 H. pylori-negative patients. A nonsevere degree of gastric mucosal atrophy was an independent risk factor for post-ESD bleeding in H. pylori-negative patients (odds ratio: 1.51, P = 0.007), but not in H. pylori-positive patients (odds ratio: 0.91, P = 0.600). Further, in H. pylori-negative, but not H. pylori-positive, patients, the rate of post-ESD bleeding increased in a stepwise manner for patients continuing antithrombotic drug use, patients who withdrew antithrombotic drug use, and antithrombotic drug nonusers.

CONCLUSIONS

Nonsevere gastric mucosal atrophy was a risk factor for post-ESD bleeding in early gastric cancer in H. pylori-negative patients but not in H. pylori-positive patients.

Lactobacillus spp. for Gastrointestinal Health: Current and Future Perspectives

In recent decades, probiotic bacteria have become increasingly popular as a result of mounting scientific evidence to indicate their beneficial role in modulating human health. Although there is strong evidence associating various Lactobacillus probiotics to various health benefits, further research is needed, in particular to determine the various mechanisms by which probiotics may exert these effects and indeed to gauge inter-individual value one can expect from consuming these products. One must take into consideration the differences in individual and combination strains, and conditions which create difficulty in making direct comparisons. The aim of this paper is to review the current understanding of the means by which Lactobacillus species stand to benefit our gastrointestinal health.

In situ Diagnosis of Helicobacter pylori Infection Using the Endoscopic Kyoto Scoring System

Background/Aims: This study aimed to investigate the possibility of in situ diagnosis of Helicobacter pylori (H. pylori) infection during endoscopic examination. The predictive infection value was estimated using the endoscopic Kyoto scoring system (EKSS), and specific endoscopic findings were evaluated for diagnosing H. pylori infection in H. pylori naïve patients and those with a eradication history.Materials and Methods: A total of 836 patients with H. pylori infection were analyzed. The state of the infection was predicted using the EKSS and specific endoscopic findings.Results: Patients were classified into two groups: the H. pylori naïve group and the group with a the bacterial eradication history. The area under the curve (AUC) on receiver operating characteristics analysis was 0.90 for EKSS in H. pylori naïve patients and 0.83 for the other group patients. For patients with open type atrophy and/or intestinal metaplasia, EKSS (24.4%; 95% CI, 12.4~0.3%) and regular arrangement of collecting venules (RAC) (46.3%; 95% CI, 30.7~62.9%) showed low specificities. Mucosal swelling (66.2%; 95% CI, 62.5~69.7%) and sticky mucus (80.5%; 95% CI, 74.8~85.2%) presented relatively high positive predictive values for H. pylori infection in naïve patients, whereas reflux esophagitis, hematin, red streak, and duodenitis exhibited high negative predictive values in patients with a H. pylori eradication history (98.0%; 95% CI, 96.4~99.1%).Conclusions: EKSS and RAC are excellent tools for predicting H. pylori infection. However, they have a limited role in patients with open type atrophy and/or intestinal metaplasia. Specific endoscopic findings could help predict the infection state.

Gastric Mucosal Abnormality and Risk of Pancreatic Cancer: A Population-Based Gastric Biopsy Cohort Study in Sweden

BACKGROUND

It remains open whether gastric precancerous lesions are associated with an elevated risk of pancreatic cancer. Our aim was to investigate the association between gastric mucosal status and pancreatic cancer risk.

METHODS

Patients with gastric biopsies [normal, minor changes, superficial gastritis, and atrophic gastritis/intestinal metaplasia/dysplasia (AG/IM/Dys)] from the Swedish histopathology registers during 1979 to 2011 were included. Cross-linkages with several nationwide registries allowed complete follow-up and identification of pancreatic cancer cases until 2014. Standardized incidence ratios (SIR) and HRs were estimated.

RESULTS

During 3,438,248 person-years of follow-up with 318,653 participants, 3,540 cases of pancreatic cancer were identified. The same pattern of excess risk of pancreatic cancer compared with the general population was observed across all groups: a peak of 12- to 21-fold excess risk in the first year after biopsy [e.g., normal: SIR = 17.4; 95% confidence interval (CI), 15.7-19.3; AG/IM/Dys: SIR = 11.5; 95% CI, 9.9-13.4], which dropped dramatically during the second and third years, followed by 20% to 30% increased risk after the third year (e.g., normal: SIR = 1.2; 95% CI, 1.1-1.4; AG/IM/Dys: SIR = 1.3; 95% CI, 1.1-1.5). However, no significant excess risk was observed with the normal gastric mucosa as reference.

CONCLUSIONS

This unique, large pathologic cohort study did not find evidence that abnormal gastric mucosal status is causally associated with a long-term pancreatic cancer risk. However, a highly increased short-term risk was observed for people undergoing gastroscopy with biopsy sampling compared with the general population.

IMPACT

Further studies for a long-term risk of pancreatic cancer in patients with gastric biopsies are needed, with further adjustments.

Impact of Helicobacter pylori infection on gut microbiota

A number of studies have revealed the association between Helicobacter pylori (H. pylori) infection and the gut microbiota. More than half of the investigations on the impact of H. pylori on the gut microbiota have been the sub-analyses of the influence of eradication therapy. It was observed that H. pylori eradication altered gut microbiota within a short period after eradication, and majority of the alterations took a long period of time to reverse back to the original. Changes in the gut microbiota within a short period after eradication may be attributed to antibiotics and proton pump inhibitors. Modification of gastric acidity in the stomach caused by a long-term H. pylori infection alters the gut microbiota. Analysis of the gut microbiota should be conducted in a large population, adjusting for considerable biases associated with the composition of the gut microbiota, such as age, sex, body mass index, diet and the virulence of H. pylori.

Systematic review with meta-analysis: association of Helicobacter pylori infection with gastro-oesophageal reflux and its complications

BACKGROUND

Conflicting results exist on the association between Helicobacter pylori infection and gastro-oesophageal reflux (GOR), and its complications, such as erosive oesophagitis (EO) and Barrett's oesophagus (BO).

AIMS

To explore the association of H. pylori infection with GOR symptoms and their complications METHODS: We searched Embase, PubMed, Web of Science and Scopus databases through December 2020 for relevant articles. Regarding the association between H. pylori and GOR symptoms (heartburn, regurgitation or reflux), we included observational studies comparing the prevalence of GOR symptoms between H. pylori-positive and -negative individuals. Concerning the association between H. pylori and complications of GOR, we included studies comparing the prevalence of EO or BO between H. pylori-positive and -negative individuals.

RESULTS

In total, 36 papers were eligible. Based on seven cross-sectional surveys, H. pylori infection was associated with a lower odds of GOR symptoms (odds ratio [OR] 0.74, 95% confidence interval [CI] 0.61-0.90). However, in four case-control studies, H. pylori infection was not associated with odds of GOR symptoms (OR 1.10, 95% CI 0.85-0.1.43). In 26 cross-sectional studies in patients with GOR symptoms, the OR for EO was 0.70 (95% CI 0.58-0.84) in H. pylori-positive vs -negative cases. Based on nine cross-sectional studies in subjects with GOR complications, no significant association was found between H. pylori infection and either endoscopically-diagnosed (OR 1.84, 95% CI 0.67-5.02) or histologically confirmed (OR 0.85, 95% CI 0.60-1.20) BO.

CONCLUSIONS

Helicobacter pylori infection appears to be associated with a decreased odds of GOR symptoms and EO. In contrast, H. pylori infection did not seem to affect the odds of BO in patients with GER complications.

Human gut-microbiome interplay: Analysis of clinical studies for the emerging roles of diagnostic microbiology in inflammation, oncogenesis and cancer management

Microorganisms have been known to coexist in various parts of human body including the gut. The interactions between microbes and the surrounding tissues of the host are critical for fine fettle of the gut. The incidence of such microorganisms tends to vary among specific type of cancer affected individuals. Such microbial communities of specific tumor sites in cancer affected individuals could plausibly be used as prognostic and/or diagnostic markers for tumors associated with that specific site. Microorganisms of intestinal and non-intestinal origins including Helicobacter pylori can target several organs, act as carcinogens and promote cancer. It is interesting to note that diets causing inflammation can also increase the cancer risk. Yet, dietary supplementation with prebiotics and probiotics can reduce the incidence of cancer. Therefore, both diet and microbial community of the gut have dual roles of prevention and oncogenesis. Hence, this review intends to summarize certain important details related to gut microbiome and cancer.

Short-chain fatty acid butyrate: A novel shield against chronic gastric ulcer

Butyrate is one of the most abundant short-chain fatty acids produced by intestinal bacteria. In the present study, the action of butyrate on chronic gastric mucosa lesions was investigated, as well as its underlying mechanism in mice. Male mice from the Institute of Cancer Research were randomly divided into three groups: Sham, model and butyrate groups. Butyrate was administered intragastrically for 7 days to butyrate group mice following the establishment of a gastric ulcer model. Hematoxylin and eosin staining, immunohistochemical analysis, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction were used to determine the therapeutic effects and molecular mechanism of butyrate treatment. The findings demonstrated that butyrate induced a marked shift in superoxide dismutase and catalase activities, along with a decrease in malondialdehyde levels, thereby attenuating oxidative stress. Furthermore, butyrate decreased the levels of pro-inflammatory cytokines interleukin-1β, tumour necrosis factor-α and leukotriene B4, which helped combat inflammatory responses. Moreover, butyrate treatment exerted remarkable positive influences that mediate an increase in 6-keto-PGF-1α (a degradation product of prostacyclin), trefoil factor 2, MUC5AC and fibroblast growth factor-7 levels to promote gastric mucosal repair. The expression of specific receptor GPR109A for butyrate was upregulated, with no significant difference noted in the expression of GPR43 or GPR41. Overall, the present findings revealed that butyrate exerted therapeutic effects by upregulating mucosal repair factors and stimulating protective responses against oxidation and inflammation. GPR109A may be the key receptor for butyrate therapy.

The Dark Side of the Force: When the Immune System Is the Fuel of Tumor Onset

Nowadays, it is well accepted that inflammation is a critical player in cancer, being, in most cases, the main character of the process. Different types of tumor arise from sites of infection or chronic inflammation. This non-resolving inflammation is responsible for tumor development at different levels: it promotes tumor initiation, as well as tumor progression, stimulating both tumor growth and metastasis. Environmental factors, lifestyle and infections are the three main triggers of chronic immune activation that promote or increase the risk of many different cancers. In this review, we focus our attention on tumor onset; in particular, we summarize the knowledge about the cause and the mechanisms behind the inflammation-driven cancer development.

Anemia and its association with Helicobacter pylori infection among adult dyspeptic patients attending Wachemo University Nigist Eleni Mohammad Memorial Referral Hospital, Southwest Ethiopia: A cross-sectional study

BACKGROUND

Anemia is a worldwide public health problem and also associated with Helicobacter pylori (H. pylori) infection. Determining the association of anemia with H. pylori infection is important to develop evidence-based decision and intervention strategies, which is not well known in Ethiopia. Thus, this study aimed to determine the association between anemia and H. pylori infection among adult dyspeptic patients attending Wachemo University Nigist Eleni Mohammad Memorial Referral Hospital in Southwest Ethiopia.

METHODS

A cross-sectional study was conducted from January to April 2019 involving 362 consecutive adult dyspeptic patients who came to the hospital during the study period. Socio-demographic, clinical and other related data were collected by structured questionnaires. Four milliliters of the venous blood sample was collected for hematological parameters analysis and blood film preparation. A stool sample was collected to detect H. pylori antigen and intestinal parasites. Data were analyzed by SPSS version 21. Logistic regression analyses were performed and p-value <0.05 was considered as statistically significant.

RESULTS

The overall prevalence of anemia among dyspeptic patients was 24.3% (95%CI: 19.9-28.7). Among H.pylori infected participants 29.2% were anemic, of which 69.2% had mild anemia and 63.5% had normocytic normochromic anemia. Rural residence (AOR: 1.9, 95%CI: 1.1-3.3), H. pylori infection (AOR: 1.77, 95%CI: 1.05-2.98) and intestinal parasitic infection (AOR: 2.14, 95%CI: 1.14-4.03) were significantly associated with anemia.

CONCLUSION

The prevalence of anemia in this study indicated that it is a moderate public health problem. Rural residence, H. pylori and intestinal parasitic infection were significantly associated with anemia. The findings of this study should be taken into account for the prevention and control of anemia among dyspeptic adults.

Novel in vitro and in vivo anti-Helicobacter pylori effects of pomegranate peel ethanol extract

BACKGROUND AND AIM

Interest in plants with antimicrobial properties has been revived due to emerging problems associated with using antibiotics to eradicate Helicobacter pylori. Accordingly, this study aims to assess the antibacterial effects of Punica granatum and the possible synergistic effect of its extract along with metronidazole against H. pylori.

MATERIALS AND METHODS

Pomegranate peel ethanol extracts (PPEE) was tested against a control strain of H. pylori (NCTC 11916) in vitro and in vivo in female Wistar rats. Moreover, the synergistic effect of PPEE in combination with metronidazole was tested in vitro.

RESULTS

The PPEE exhibited a remarkable activity against H. pylori with a minimum inhibitory concentration (MIC) of 0.156 mg/mL. Furthermore, the extract exhibited a pronounced urease inhibitory activity (IC50 ~6 mg/mL) against the tested strain. A synergistic effect between PPEE and metronidazole was also observed (fractional inhibitory concentrations <0.5). Oral treatment of rats with PPEE for 8 days produced a significant reduction in H. pylori gastritis and a significant decrease in both lymphocytic and positive chronicity.

CONCLUSION

Pomegranate extract is probably safe and represents a potential alternative and complementary therapy for reducing H. pylori associated with gastric ulcers.

The role of dietary nitrate and the oral microbiome on blood pressure and vascular tone

There is increasing evidence for the health benefits of dietary nitrates including lowering blood pressure and enhancing cardiovascular health. Although commensal oral bacteria play an important role in converting dietary nitrate to nitrite, very little is known about the potential role of these bacteria in blood pressure regulation and maintenance of vascular tone. The main purpose of this review is to present the current evidence on the involvement of the oral microbiome in mediating the beneficial effects of dietary nitrate on vascular function and to identify sources of inter-individual differences in bacterial composition. A systematic approach was used to identify the relevant articles published on PubMed and Web of Science in English from January 1950 until September 2019 examining the effects of dietary nitrate on oral microbiome composition and association with blood pressure and vascular tone. To date, only a limited number of studies have been conducted, with nine in human subjects and three in animals focusing mainly on blood pressure. In general, elimination of oral bacteria with use of a chlorhexidine-based antiseptic mouthwash reduced the conversion of nitrate to nitrite and was accompanied in some studies by an increase in blood pressure in normotensive subjects. In conclusion, our findings suggest that oral bacteria may play an important role in mediating the beneficial effects of nitrate-rich foods on blood pressure. Further human intervention studies assessing the potential effects of dietary nitrate on oral bacteria composition and relationship to real-time measures of vascular function are needed, particularly in individuals with hypertension and those at risk of developing CVD.

Helicobacter pylori Related Diseases and Osteoporotic Fractures (Narrative Review)

Osteoporosis (OP) and osteoporotic fractures (OFs) are common multifactorial and heterogenic disorders of increasing incidence. Helicobacter pylori (H.p.) colonizes the stomach approximately in half of the world's population, causes gastroduodenal diseases and is prevalent in numerous extra-digestive diseases known to be associated with OP/OF. The studies regarding relationship between H.p. infection (HPI) and OP/OFs are inconsistent. The current review summarizes the relevant literature on the potential role of HPI in OP, falls and OFs and highlights the reasons for controversies in the publications. In the first section, after a brief overview of HPI biological features, we analyze the studies evaluating the association of HPI and bone status. The second part includes data on the prevalence of OP/OFs in HPI-induced gastroduodenal diseases (peptic ulcer, chronic/atrophic gastritis and cancer) and the effects of acid-suppressive drugs. In the next section, we discuss the possible contribution of HPI-associated extra-digestive diseases and medications to OP/OF, focusing on conditions affecting both bone homeostasis and predisposing to falls. In the last section, we describe clinical implications of accumulated data on HPI as a co-factor of OP/OF and present a feasible five-step algorithm for OP/OF risk assessment and management in regard to HPI, emphasizing the importance of an integrative (but differentiated) holistic approach. Increased awareness about the consequences of HPI linked to OP/OF can aid early detection and management. Further research on the HPI-OP/OF relationship is needed to close current knowledge gaps and improve clinical management of both OP/OF and HPI-related disorders.

Pathways of Gastric Carcinogenesis, Helicobacter pylori Virulence and Interactions with Antioxidant Systems, Vitamin C and Phytochemicals

Helicobacter pylori is a class one carcinogen which causes chronic atrophic gastritis, gastric intestinal metaplasia, dysplasia and adenocarcinoma. The mechanisms by which H. pylori interacts with other risk and protective factors, particularly vitamin C in gastric carcinogenesis are complex. Gastric carcinogenesis includes metabolic, environmental, epigenetic, genomic, infective, inflammatory and oncogenic pathways. The molecular classification of gastric cancer subtypes has revolutionized the understanding of gastric carcinogenesis. This includes the tumour microenvironment, germline mutations, and the role of Helicobacter pylori bacteria, Epstein Barr virus and epigenetics in somatic mutations. There is evidence that ascorbic acid, phytochemicals and endogenous antioxidant systems can modify the risk of gastric cancer. Gastric juice ascorbate levels depend on dietary intake of ascorbic acid but can also be decreased by H. pylori infection, H. pylori CagA secretion, tobacco smoking, achlorhydria and chronic atrophic gastritis. Ascorbic acid may be protective against gastric cancer by its antioxidant effect in gastric cytoprotection, regenerating active vitamin E and glutathione, inhibiting endogenous N-nitrosation, reducing toxic effects of ingested nitrosodimethylamines and heterocyclic amines, and preventing H. pylori infection. The effectiveness of such cytoprotection is related to H. pylori strain virulence, particularly CagA expression. The role of vitamin C in epigenetic reprogramming in gastric cancer is still evolving. Other factors in conjunction with vitamin C also play a role in gastric carcinogenesis. Eradication of H. pylori may lead to recovery of vitamin C secretion by gastric epithelium and enable regression of premalignant gastric lesions, thereby interrupting the Correa cascade of gastric carcinogenesis.

Effect of Helicobacter pylori on gastrointestinal microbiota: a population-based study in Linqu, a high-risk area of gastric cancer

OBJECTIVE

Gastrointestinal microbiota may be involved in Helicobacter pylori-associated gastric cancer development. The aim of this study was to explore the possible microbial mechanisms in gastric carcinogenesis and potential dysbiosis arising from H. pylori infection.

DESIGN

Deep sequencing of the microbial 16S ribosomal RNA gene was used to investigate alterations in paired gastric biopsies and stool samples in 58 subjects with successful and 57 subjects with failed anti-H. pylori treatment, relative to 49 H. pylori negative subjects.

RESULTS

In H. pylori positive subjects, richness and Shannon indexes increased significantly (both p<0.001) after successful eradication and showed no difference to those of negative subjects (p=0.493 for richness and p=0.420 for Shannon index). Differential taxa analysis identified 18 significantly altered gastric genera after eradication. The combination of these genera into a Microbial Dysbiosis Index revealed that the dysbiotic microbiota in H. pylori positive mucosa was associated with advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia/dysplasia) and could be reversed by eradication. Strong coexcluding interactions between Helicobacter and Fusobacterium, Neisseria, Prevotella, Veillonella, Rothia were found only in advanced gastric lesion patients, and were absent in normal/superficial gastritis group. Changes in faecal microbiota included increased Bifidobacterium after successful H. pylori eradication and more upregulated drug-resistant functional orthologs after failed treatment.

CONCLUSION

H. pylori infection contributes significantly to gastric microbial dysbiosis that may be involved in carcinogenesis. Successful H. pylori eradication potentially restores gastric microbiota to a similar status as found in uninfected individuals, and shows beneficial effects on gut microbiota.

Immune Response in H. pylori-Associated Gastritis and Gastric Cancer

Helicobacter pylori (H. pylori) is the dominant member of the gastric microbiota and has infected more than half of the human population, of whom 5–15% develop gastric diseases ranging from gastritis and metaplasia to gastric cancer. These diseases always follow inflammation induced by cell surface and intracellular receptors and subsequent signaling, such as the NF-κB pathway and inflammasomes. Some types of immune cells are recruited to enforce an antibacterial response, which could be impeded by H. pylori virulence factors with or without a specific immune cell. Following decreased inflammation, neoplasm may appear with a little immune surveillance and may inhibit antitumor immunity. Therefore, the balance between H. pylori-associated inflammation and anti-inflammation is crucial for human health and remains to be determined. Here, we discuss multiple inflammation and immunoregulatory cells in gastritis and summarize the main immune evasion strategies employed by gastric cancer.

Gold nanoclusters for ratiometric sensing of pH in extremely acidic media

AuNCs capped with β-nicotinamide adenine dinucleotide phosphate exhibit an outstanding performance as ratiometric, fluorescent pH sensors in extremely acid media (0.6–2.7) and in the 7.0–9.2 pH range; the nanocluster itself is the fluorophore.

Helicobacter pylori infection associates with fecal microbiota composition and diversity

Helicobacter (H.) pylori is the most important cause for peptic ulcer disease and a risk factor for gastric carcinoma. How colonization with H. pylori affects the intestinal microbiota composition in humans is unknown. We investigated the association of H. pylori infection with intestinal microbiota composition in the population-based cohort Study-of-Health-in-Pomerania (SHIP)-TREND. Anti-H. pylori serology and H. pylori stool antigen tests were used to determine the H. pylori infection status. The fecal microbiota composition of 212 H. pylori positive subjects and 212 matched negative control individuals was assessed using 16S rRNA gene sequencing. H. pylori infection was found to be significantly associated with fecal microbiota alterations and a general increase in fecal microbial diversity. In infected individuals, the H. pylori stool antigen load determined a larger portion of the microbial variation than age or sex. The highest H. pylori stool antigen loads were associated with a putatively harmful microbiota composition. This study demonstrates profound alterations in human fecal microbiota of H. pylori infected individuals. While the increased microbiota diversity associated with H. pylori infection as well as changes in abundance of specific genera could be considered to be beneficial, others may be associated with adverse health effects, reflecting the complex relationship between H. pylori and its human host.

Gastric IL-1β, IL-8, and IL-17A expression in Moroccan patients infected with Helicobacter pylori may be a predictive signature of severe pathological stages

INTRODUCTION

Helicobacter pylori induces acute gastritis that can progress to serious diseases such as gastric cancer. H. pylori interacts with host cells within the gastric mucosa, resulting in activation of multiple innate immune signalling pathways, leading to pro-inflammatory cytokines production and immune cells recruitment. Various studies have shown that there are ethnic- and population-related differences in the expression of these cytokines. Although the H. pylori infection is a major public health problem in Morocco, to our knowledge, no study has been carried out in gastric cytokine expression from H. pylori-infected Moroccan patients. Thus we aimed to (i) determine the IL-1β, IL-8 and IL-17A gene expression in gastric biopsies from Moroccan patients infected with H. pylori, and (ii) to determine the cytokine signature of each pathological stages associated with this infection.

MATERIAL AND METHODS

71 patients with epigastralgic pain were included in this study. The H. pylori detection on gastric biopsies was performed by histopathological and PCR analysis. The IL-1β, IL-8 and IL-17A mRNA expression in the antrun and fundus biopsies was performed by RT-qPCR.

RESULTS

The histopathological and PCR analyses revealed that 87.32% of the patients were infected with H. pylori. IL-1β mRNA expression was significantly lower in the antral mucosa of H. pylori-infected patients (p = 0.0038) than in the uninfected while there was no significant difference in the expression of IL-8 and IL-17A mRNA. The expression of the three cytokines was higher in the fundic mucosa of H. pylori-infected patients than in the uninfected patients, but only IL-8 and IL-17A expression reached statistical significance (p = 0.042 and p = 0.0179 respectively). Furthermore, the multivariate predictive analysis highlighted a cytokine signature that may predict metaplasia during the infection progression that involves a specific down-regulation of IL17A and an up-regulation of IL1β in antral and fundic metaplasia respectively.

Increased risk of osteoporosis in patients with peptic ulcer: a follow-up study using a national sample cohort

We performed a nationwide, population-based cohort study to investigate the risk of osteoporosis in patients with peptic ulcer disease in South Korea and concluded that peptic ulcer disease is associated with an increased risk of osteoporosis.

PURPOSE

This study aimed to evaluate the association between peptic ulcer disease (PUD) and the occurrence of osteoporosis using a national sample cohort from South Korea.

METHODS

Using the national cohort study from the Korean National Health Insurance Service, we extracted data for patients with PUD (n = 50,002) and for 1:1 matched control participants (n = 50,002); we then analyzed the occurrence of osteoporosis from 2002 to 2013. The patients were matched according to age, sex, income, region of residence, and past medical history. A stratified Cox proportional hazards model was used to analyze the hazard ratios (HRs) and the 95% confidence intervals (CIs). Subgroup analyses were performed based on age and sex.

RESULTS

The adjusted HR for osteoporosis was 1.36 (95% CI = 1.33-1.40, P < 0.001) in the PUD group. In the subgroup analysis based on age and sex, the respective adjusted HRs of PUD for osteoporosis were 1.33 (95% CI = 1.21-1.47) in the < 65-year-old group of men and 1.42 (95% CI = 1.30-1.56) in the ≥ 65-year-old group of men (each P < 0.001). The respective adjusted HRs of PUD for osteoporosis were 1.34 (95% CI = 1.29-1.39) in the < 65-year-old group of women and 1.38 (95% CI = 1.33-1.47) in the ≥ 65-year-old group of women (each P < 0.001).

CONCLUSION

In the current nationwide cohort study, we found that PUD is associated with an increased risk of osteoporosis regardless of sex.

The relationship between Helicobacter pylori infection and depressive symptoms in the general population in China: The TCLSIH cohort study

BACKGROUND

Depressive symptoms are a common, debilitating, and costly public health issue. Helicobacter pylori (H pylori) infection cause changes in the normal physiological state of the gastrointestinal (GI) flora. Although the physiological state of the GI tract is closely related to mental disorders, few population studies have examined the relationship between H pylori infection and depressive symptoms in the general population. The aim of this study was to examine whether H pylori infection is related to depressive symptoms among the general adult population.

MATERIALS AND METHODS

This cross-sectional study included 5558 inhabitants of Tianjin, China. H pylori infection was diagnosed with the carbon 13 breath test. Depressive symptoms were assessed using the Chinese version of 20-item Self-rating Depression Scale (SDS) with three cutoffs (45, 48, and 50) to indicate elevated depressive symptoms. Multiple logistic regression analysis were conducted to assess the association between H pylori infection and depressive symptoms.

RESULTS

The prevalence of depressive symptoms (SDS ≥ 45) was 12.7% in men and 17.4% in women. In multivariable models, the odds ratios and 95% confidence interval of having depressive symptoms by H pylori infection were 1.25 (1.01-1.56), 1.46 (1.11-1.91), and 1.46 (1.05-2.06) for three cutoffs: 45, 48, and 50 in women. However, no significant difference was found between H pylori infection and depressive symptoms in men.

CONCLUSIONS

This study firstly suggested that H pylori infection was related to depressive symptoms in women in the general adult population. Further prospective studies or randomized trials are required to clarify the causality.

Optimizing proton pump inhibitors in Helicobacter pylori treatment: Old and new tricks to improve effectiveness

The survival and replication cycle of Helicobacter pylori (H. pylori) is strictly dependant on intragastric pH, since H. pylori enters replicative phase at an almost neutral pH (6-7), while at acid pH (3-6) it turns into its coccoid form, which is resistant to antibiotics. On these bases, it is crucial to increase intragastric pH by proton pump inhibitors (PPIs) when an antibiotic-based eradicating therapy needs to be administered. Therefore, several tricks need to be used to optimize eradication rate of different regimens. The administration of the highest dose as possible of PPI, by doubling or increasing the number of pills/day, has shown to be able to improve therapeutic outcome and has often proposed in rescue therapies, even if specific trials have not been performed. A pre-treatment with PPI before starting antibiotics does not seem to be effective, therefore it is discouraged. However, the choice of PPI molecule could have a certain weight, since second-generation substances (esomeprazole, rabeprazole) are likely more effective than those of first generation (omeprazole, lansoprazole). A possible explanation is due to their metabolism, which has been proven to be less dependent on cytochrome P450 (CYP) 2C19 genetic variables. Finally, vonoprazan, a competitive inhibitor of H+/K+-ATPase present on luminal membrane of gastric parietal cells has shown the highest efficacy, due to both its highest acid inhibition power and rapid pharmacologic effect. However current data come only from Eastern Asia, therefore its strong power needs to be confirmed outside this geographic area in Western countries as well as related to the local different antibiotic resistance rates.

Helicobacter pylori Eradication Therapy for Functional Dyspepsia: A Meta-Analysis by Region and H. pylori Prevalence

BACKGROUND

Previous studies on the effect of Helicobacter pylori eradication on functional dyspepsia (FD) are conflicting. We performed a comprehensive meta-analysis on this issue according to region and prevalence of H. pylori.

METHODS

Randomized controlled trials (RCTs) evaluating the effect of eradication of H. pylori on functional dyspepsia up to December 2018 were searched through PubMed, EMBASE, and the Cochrane Library. Subgroup analyses by the outcome measure, region, and prevalence of H. pylori were performed. All data were analyzed with Review Manager 5.3.

RESULTS

Eighteen RCTs were included in our meta-analysis. Overall, the H. pylori eradication group showed significant improvement of symptoms compared with the control group (risk ratio (RR) = 1.18; 95% confidence interval (CI): 1.07-1.30, p < 0.01). There was moderate heterogeneity among studies (I2 = 34%) and the number needed to treat (NNT) was 15.0. Helicobacter pylori eradication improved dyspeptic symptoms both in low (<50%) and high (≥50%) H. pylori prevalence regions (RR = 1.21 and 1.17; 95% CI: 1.02-1.44 and 1.06-1.29, I2 = 49% and 5%, respectively.) In the analysis of studies from Asia, however, the effect of eradication on improvement of dyspepsia was not significant (RR = 1.14; 95% CI: 0.99-1.33, p = 0.08, I2 = 37%).

CONCLUSION

Overall, H. pylori eradication provides significant improvement of symptoms in functional dyspepsia patients regardless of H. pylori prevalence. However, in the analysis of studies from Asia, the eradication did not significantly improve dyspeptic symptoms. In this region, eradication for dyspepsia can be individualized.

Gut microbiota shifts in patients with gastric cancer in perioperative period

Gastric cancer (GC) is one of the common malignant tumors in China, with a high morbidity and mortality. With the development and application of high-throughput sequencing technologies and metagenomics, a great quantity of studies have shown that gastrointestinal microbiota is closely related to digestive system diseases. Although some studies have reported the effect of long-term follow-up after subtotal gastrectomy on intestinal flora changes in patients with GC. However, the features of gut microbiota and their shifts in patients with GC in perioperative period remain unclear.This study was designed to characterize fecal microbiota shifts of the patients with GC before and after the radical distal gastrectomy (RDG) during their hospital staying periods. Furthermore, fecal microbiota was also compared between the GC patients and healthy individuals.Patients who were diagnosed with advanced gastric adenocarcinoma at distal stomach were enrolled in the study. The bacterial burden within fecal samples was determined using quantitative polymerase chain reaction. To analyze the diversity and composition of gut microbiota from fecal DNA of 20 GC patients and 22 healthy controls, amplicons of the 16S rRNA gene from all subjects were pyrosequenced. To study gut microbiota shifts, the fecal microbiota from 6 GC patients before and after RDG was detected and subsequently analyzed. Short-chain fatty acids were also detected by chromatography spectrometer in these 6 GC patients.RDG had a moderate effect on bacterial richness and evenness, but had pronounced effects on the composition of postoperative gut microbiota compared with preoperative group. The relative abundances of genera Akkermansia, Esherichia/Shigella, Lactobacillus, and Dialister were significant changed in perioperative period. Remarkably, higher abundances of Escherichia/Shigella, Veillonella, and Clostridium XVIII and lower abundances of Bacteroides were observed in gut microbiota of overall GC patients compared to healthy controls.This study is the first study to characterize the altered gut microbiota within fecal samples from GC patients during perioperative period, and provide a new insights on such microbial perturbations as a potential effector of perioperative period phenotype. Further research must validate these discoveries and may evaluate targeted microbiota shifts to improve outcomes in GC patients.

The Enterochromaffin-like [ECL] Cell-Central in Gastric Physiology and Pathology

Background: Studies on the regulation of gastric and pancreatic secretion began more than 100 years ago. Secretin was the first hormone postulated to exist, initiating the field of endocrinology. Gastrin produced in the antral mucosa was the second postulated hormone, and together with histamine and acetylcholine, represent the three major gastric acid secretagogues known since 1920. For a long time, the mast cell was the only recognized histamine-producing cell in the oxyntic mucosa and, in the mid-1980s, the ECL cell was recognized as the cell producing histamine, taking part in the regulation of gastric acid secretion. Methods: This review is based upon literature research and personal knowledge. Results: The ECL cell carries the gastrin receptor, and gastrin regulates its function (histamine release) as well as proliferation. Long-term hypergastrinemia results in gastric neoplasia of variable malignancies, implying that gastric hypoacidity resulting in increased gastrin release will induce gastric neoplasia, including gastric cancer. Conclusions: The trophic effect of gastrin on the ECL cell has implications to the treatment with inhibitors of acid secretion.

Impact of Helicobacter pylori Infection on Gastric Variceal Bleeding among Patients with Liver Cirrhosis

BACKGROUND AND AIMS

Currently, it is well known that Helicobacter pylori- (H. pylori-) related peptic ulcer is one of the main causes of nonvariceal bleeding in cirrhotic patients. However, there is a lack of data to identify the exact effect of H. pylori infection on variceal bleeding. This study was conducted to identify the impact of H. pylori infection on gastric variceal bleeding in cirrhotic patients.

PATIENTS AND METHODS

76 cirrhotic patients with gastric varices were included in this prospective study and divided into 2 groups: nonbleeding gastric varices (32 patients) and bleeding gastric varices (44 patients). The fasting serum gastrin level was measured. Mucosal biopsies from the gastric body and antrum were examined to determine the patterns of gastritis and the presence of H. pylori.

RESULTS

The frequency of H. pylori infection in the studied patients was 59.2%. There were significant differences between both groups regarding liver decompensation (P = 0.001), red color sign over gastric varices (P = 0.0011), prevalence of H. pylori infection (P = 0.0049), histological patterns of gastritis (P = 0.0069), and serum gastrin level (P = 0.0200). By multivariate analysis, Child C cirrhosis, red color sign over gastric varices, and H. pylori-induced follicular gastritis were independent risk factors for bleeding from gastric varices.

CONCLUSION

H. pylori-induced follicular gastritis is considered as an additional risk factor for bleeding from gastric varices.

Characterization of clarithromycin heteroresistance among Helicobacter pylori strains isolated from the antrum and corpus of the stomach

Mixed infections and heteroresistance of Helicobacter pylori contribute to decreased efficacy of treatments. This study aimed to investigate frequency of clarithromycin heteroresistance and its link with mixed infections, medication history, and disease severity. A total of 40 pairs of H. pylori strains were isolated from the antrum and corpus of 97 patients. Susceptibility of the strains to clarithromycin was measured by agar dilution method. Site-specific mutations of 23S rRNA at A2143G, A2142G, and A2142C positions were analyzed by PCR and genomic relatedness of pairs of the strains was determined by random amplified polymorphic DNA (RAPD)-PCR. The results showed a prevalence of 35% (14/40) clarithromycin resistance. Diversity of the antrum and corpus isolates in resistance to clarithromycin was detected among 17.5% (7/40) of the patients. Similarly, diversity in MIC value was also detected in two patients infected with the sensitive strains. Significant difference in frequency of resistance was detected among patients with peptic ulcer disease (PUD) (MIC90 32 μg/mL) and severe gastritis (MIC90 16 μg/mL), compared with those who suffered from non-ulcer dyspepsia (NUD) (MIC90 8 μg/mL) and chronic gastritis (MIC90 0.25 μg/mL). MIC values showed 8-32 folds increased levels in the corpus. A2142G, A2143G, and A2142C mutations were detected in three, two, and two patients, respectively, but not observed in 46% of the resistant strains. RAPD-PCR fingerprints showed identical molecular patterns for the isolates of the corpus and antrum in each patient. In conclusion, microevolution of H. pylori strains during chronic infection, rather than mixed infection, and inappropriate medication appear to be main reasons of treatment failure in adults.

Not only stem cells, but also mature cells, particularly neuroendocrine cells, may develop into tumours: time for a paradigm shift

Stem cells are considered the origin of neoplasms in general, and malignant tumours in particular, and the stage at which the stem cells stop their differentiation determines the degree of malignancy. However, there is increasing evidence supporting an alternative paradigm. Tumours may develop by dedifferentiation from mature cells able to proliferate. Studies of gastric carcinogenesis demonstrate that mature neuroendocrine (NE) cells upon long-term overstimulation may develop through stages of hyperplasia, dysplasia, and rather benign tumours, into highly malignant carcinomas. Dedifferentiation of cells may change the histological appearance and impede the identification of the cellular origin, as seen with gastric carcinomas, which in many cases are dedifferentiated neuroendocrine tumours. Finding the cell of origin is important to identify risk factors for cancer, prevent tumour development, and tailor treatment. In the present review, we focus not only on gastric tumours, but also evaluate the role of neuroendocrine cells in tumourigenesis in two other foregut-derived organs, the lungs and the pancreas, as well as in the midgut-derived small intestine.

Characteristics of non-cardia gastric cancer with a high serum anti-Helicobacter pylori IgG titer and its association with diffuse-type histology

Background

Data on implications of a high positive titer of serum anti-Helicobacter pylori antibody on gastric cancer (GC) is limited. This study aimed to investigate the characteristics of GC with a high serum anti-H. pylori IgG (Hp-IgG) titer, and its association with diffuse-type GC.

Methods

We analyzed clinical and histological characteristics of 917 non-cardia GC patients who underwent gastrectomy. H. pylori infection was determined serologically by measuring Hp-IgG titer with immunoassay. Seropositive patients were divided into three groups (low-positive, mid-positive, and high-positive) according to the Hp-IgG titer value. Tumors were classified according to the Lauren criteria as diffuse or intestinal types.

Results

The median age of the patients was 59.0 years, and 33.8% were female. The patents were grouped as follows: seronegative, 188 (20.5%); low-positive, 288 (31.4%); mid-positive, 290 (31.6%); and high-positive 151 (16.5%). The high-positive group was significantly younger (median age, 55.0 years), with a higher proportion of female (45.0%) and non-smokers (58.9%). The proportion of diffuse-type GC increased in the order low-, mid-, and high-positive groups (p<0.001). In univariate analysis, the factors associated with diffuse-type GC were younger age, female sex, non-smokers, and a high-positive Hp-IgG titer. Younger age, female sex, and non-smokers remained significant on multivariate analysis whereas the high-positive Hp-IgG titer showed only a tendency toward the association (p = 0.078).

Conclusions

Non-cardia GC patients with a high Hp-IgG titer have distinct clinicopathologic characteristics. A high-positive Hp-IgG titer should be interpreted together with patients’ age, sex, and smoking status.

Ethnic/racial differences in gastrointestinal symptoms and diagnosis associated with the risk of Helicobacter pylori infection in the US

Background

In the US, neither the prevalence nor the gastrointestinal (GI) diagnosis/symptoms associated with Helicobacter pylori (HP) have been examined in different racial/ethnic groups.

Aim

To determine the racial/ethnic differences in HP infection associated with GI diagnoses/symptoms using the Cerner Health Facts^® database.

Methods

This cross-sectional study collected data during the period of 2000–2015 from the following ethnic/racial groups: 8,236,317 white, 2,085,389 black, 426,622 Hispanic, 293,156 Asian Pacific/Islander (APIs), and 89,179 Native American/Alaskan Native (NA/AN) patients aged 21–65 years old; the data were then analyzed. The primary dependent variable was a diagnosis of HP (ICD-9-Clinical Modification/ICD-10 classification). SAS version 9.4 was used for the statistical analysis. The statistical analysis was performed on 11,130,663 patients with GI symptoms, and of these, 152,086 patients were positive for the infection.

Results

Hispanics and NA/ANs had the highest prevalence of HP associated with upper GI symptoms/diagnosis. Nevertheless, blacks and APIs presented the highest relative risk (RR) of HP associated with dyspepsia (RR [95% CI] =11.2 [10.7–11.9] and 14.2 [12.8–15.6]), peptic ulcer (RR =13.8 [13.3–14.5] and 10.7 [9.3–12.3]), and atrophic gastritis (RR =9 [8.5–9.6] and 7.4 [6.4–8.5]), respectively. In all racial/ethnic groups, HP was also associated with inflammatory bowel diseases, liver diseases, and celiac diseases.

Conclusion

Black and API populations had the highest risk of HP associated with upper GI symptoms/diagnosis. Black patients also had the highest risk for HP associated with GI cancer.

Physiologic, pathophysiologic, and pharmacologic regulation of gastric acid secretion

PURPOSE OF REVIEW

The present review summarizes the past year's literature, both clinical and basic science, regarding physiologic and pharmacologic regulation of gastric acid secretion in health and disease.

RECENT FINDINGS

Gastric acid kills microorganisms, assists digestion, and facilitates absorption of iron, calcium, and vitamin B12. The main stimulants of acid secretion are the hormone gastrin, released from antral G cells; paracrine agent histamine, released from oxyntic enterochromaffin-like cells; and neuropeptide acetylcholine, released from antral and oxyntic intramural neurons. Gastrin is also a trophic hormone that participates in carcinogenesis. Helicobacter pylori may increase or decrease acid secretion depending upon the acuity and predominant anatomic focus of infection; most patients manifest hypochlorhydria. Despite the fact that proton pump inhibitors (PPIs) are amongst the most widely prescribed drugs, they are underutilized in patients at high risk for UGI bleeding. Although generally considered well tolerated, concerns have been raised regarding associations between PPI use and dementia, kidney disease, myocardial infarction, pneumonia, osteoporosis, dysbiosis, small bowel injury, micronutrient deficiency, and fundic gland polyps.

SUMMARY

Our understanding of the physiologic, pathophysiologic, and pharmacologic regulation of gastric secretion continues to advance. Such knowledge is crucial for improved and safe management of acid-peptic disorders.

Relationship between Helicobacter pylori infection and vomiting induced by gastrointestinal cancer chemotherapy

BACKGROUND

Nausea and vomiting are the most common adverse reactions to chemotherapy.

AIM

To discuss the relationship between Helicobacter pylori and chemotherapy-induced nausea and vomiting (CINV).

METHODS

A total of 112 patients with malignant tumours of the gastrointestinal tract was selected. Based on the 14C-urea breath test results, the patients were divided into H. pylori-positive (n = 59) and H. pylori-negative (n = 53) groups. Both groups received prophylactic antiemetic treatment during chemotherapy. The incidence of nausea and vomiting and their effects on the patients' life functions was recorded using the Multinational Association of Supportive Care in Cancer (MASCC) Antiemetic Tool (MAT) and the Functional Living Index Emesis (FLIE) from 0-120 h after chemotherapy. Records of the H. pylori-positive and H. pylori-negative groups were compared.

RESULTS

The rates of nausea and vomiting remission were higher in the H. pylori -negative group than in the H. pylori -positive group. The proportions of no effect in daily life (NIDL) patients in the nausea and vomiting section were 73.4 and 75.5% in the H. pylori -negative group respectively. There was a higher proportion of NIDL patients in the H. pylori -negative group than in the H. pylori -positive group (P < 0.001, P = 0.046). A multivariate unconditional logistic regression analysis was performed, and the results showed that H. pylori infection was a factor affecting the nausea scores on the FLIE (odds ratio = 0.757, 95% confidence interval 0.597-0.960, P = 0.021).

CONCLUSION

H. pylori infection in patients with cancer may be a factor that increases CINV.