Helicobacter pylori vacA genotype is a predominant determinant of immune response to Helicobacter pylori CagA

Helicobacter pylori and Its Treatment Impact on Immune-Mediated Ocular Diseases

PURPOSE

Helicobacter pylori (HP), which colonizes exclusively in the gastrointestinal tract, has been reported to dysregulate the immune response and gives rise to several extra-gastrointestinal autoimmune disorders. However, the relationship between HP and immune-mediated ocular diseases remains ambiguous. This study aims to clarify the association between immune-mediated ocular diseases and HP infection, as well as the impact of HP treatment on the incidence of immune-mediated ocular diseases.

METHODS

This is a retrospective population-based study using National Health Insurance Research Database in Taiwan. Patients with newly diagnosed peptic ulcer disease or HP infection between 2009 and 2015 were identified as HP group and compared to the non-HP group with one-to-one exact matching. Moreover, the incident risk of immune-mediated ocular diseases and its two subgroups (ocular surface and orbital inflammation group, intraocular inflammation group) were compared in HP patients with or without treatment.

RESULTS

A total of 1,030,119 subjects in the non-HP group and 1,030,119 patients in the HP group were enrolled. The incidence rate of immune-mediated ocular diseases was significantly higher in the HP group (95% confidence interval (CI): 2.534-2.547). The incident rate ratio was significantly higher in HP with treatment than without treatment (HR: 1.654, 95% CI: 1.641-1.668). The Cox proportional hazards regression model demonstrated a significantly increased HR of immune-mediated ocular diseases in HP treated group (HR: 2.265, 95% CI: 2.024-2.534) and less increased HR in HP non-treated group (HR: 1.427, 95% CI: 1.273-1.598) when comparing to non-HP group. Subgroup analysis demonstrated a significantly higher incidence rate of ocular surface and orbital inflammation as well as intraocular inflammation in the HP group.

CONCLUSION

This study illustrated a higher incidence of immune-mediated ocular diseases in HP infection, and a heightened risk following HP eradication.

Inflammation promotes stomach epithelial defense by stimulating the secretion of antimicrobial peptides in the mucus

The mucus serves as a protective barrier in the gastrointestinal tract against microbial attacks. While its role extends beyond merely being a physical barrier, the extent of its active bactericidal properties remains unclear, and the mechanisms regulating these properties are not yet understood. We propose that inflammation induces epithelial cells to secrete antimicrobial peptides, transforming mucus into an active bactericidal agent. To investigate the properties of mucus, we previously developed mucosoid culture models that mimic the healthy human stomach epithelium. Similar to organoids, mucosoids are stem cell-driven cultures; however, the cells are cultivated on transwells at air-liquid interface. The epithelial cells of mucosoids form a polarized monolayer, allowing differentiation into all stomach lineages, including mucus-secreting cells. This setup facilitates the secretion and accumulation of mucus on the apical side of the mucosoids, enabling analysis of its bactericidal effects and protein composition, including antimicrobial peptides. Our findings show that TNFα, IL1β, and IFNγ induce the secretion of antimicrobials such as lactotransferrin, lipocalin2, complement component 3, and CXCL9 into the mucus. This antimicrobial-enriched mucus can partially eliminate Helicobacter pylori, a key stomach pathogen. The bactericidal activity depends on the concentration of each antimicrobial and their gene expression is higher in patients with inflammation and H.pylori-associated chronic gastritis. However, we also find that H. pylori infection can reduce the expression of antimicrobial encoding genes promoted by inflammation. These findings suggest that controlling antimicrobial secretion in the mucus is a critical component of epithelial immunity. However, pathogens like H. pylori can overcome these defenses and survive in the mucosa.

Relationship between antibiotic resistance and the cagA and vacA genotypes among Helicobacter pylori strain isolates from patients in Xi'an

The issue of drug resistance of Helicobacter pylori is becoming increasingly serious. To analyze the correlation between the cagA and vacA genotypes of H. pylori strains and their resistance to metronidazole, levofloxacin, and clarithromycin in patients in Xi'an, we studied 117 H. pylori strains isolated from patients in Xi'an. Antibiotic susceptibility testing of H. pylori was performed. The cagA and vacA genotypes were investigated using PCR. Among 117 strains of H. pylori, the rate of detection of cagA was 91.45% (107/117), among which the detection rate of East Asian-type cagA was 85.05% (91/107) and that of Western-type cagA was 14.95% (16/107). There were only two genotypes of vacA: s1m1 and s1m2. The detection rate of vacAs1m1 was 47.01% (55/117) and that of vacAs1m2 was 52.99% (62/117). The dominant strains in Xi'an were cagA + vacAs1m2 strains. The metronidazole resistance rate of vacAs1m2 H. pylori strains was significantly higher than that of vacAs1m1 H. pylori strains (91.94% vs. 69.09%, P = 0.002). The levofloxacin resistance rate of Western-type cagA strains was significantly higher than that of East Asian-type cagA strains (56.25% vs. 20.88%, P = 0.004). The metronidazole resistance rate of cagA + vacAs1m2 H. pylori strains was significantly higher than that of cagA + vacAs1m1 H. pylori strains (91.23% vs. 66.00%, P = 0.001). Our results showed that Western-type cagA strains were more likely to develop levofloxacin resistance than East Asian-type cagA strains. VacAs1m2 strains were more prone to metronidazole resistance than vacAs1m1 strains.

Association between the presence and genotype of Helicobacter pylori and periodontitis

Whether Helicobacter pylori (H. pylori) infection is associated with periodontitis has been contested for decades. The relationship between H. pylori genotypes and periodontitis has not been clarified either. The present study provides a novel perspective to better understand the role of H. pylori in the pathogenesis of periodontitis. A total of 53 volunteers were recruited and divided into 3 groups in this cross-sectional study, namely the periodontally healthy group (15 participants), the stage I/II periodontitis group (20 participants) and the stage III/IV periodontitis group (18 participants). DNA from the subgingival plaque of all participants was extracted and PCR was performed using specific primers for the urease C gene and cytotoxin-associated gene A (cagA)/vacuolating cytotoxin gene A (vacA) to detect the presence and genotype of H. pylori. A χ2 test and one-way ANOVA were performed on the data. There was no significant difference in sex, age or body mass index between the groups. The detection rate of H. pylori was 39.62% in the total population and increased with the deepening of probing depth and clinical attachment loss. There were significant differences in the detection rate of H. pylori among the three groups, with 13.33, 40.00 and 61.11% in the periodontally healthy, stage I/II periodontitis and stage III/IV periodontitis groups, respectively (χ2=8.760, P<0.001). The cagA-/vacAs2m2 genotype was most commonly detected in the periodontally healthy group (100%). In the periodontitis group, cagA+/vacAs1m2 was the most commonly detected genotype in the stage I/II periodontitis group (37.5%) and cagA+/vacAs1m1 in the stage III/IV periodontitis group (36.3%). The results of the present study suggest that the detection rates and genotypes of H. pylori in the subgingival plaque are associated with the status of periodontitis. cagA+/vacAs1m1 and cagA+/vacAs1m2 may be considered virulence markers of periodontitis. However, given the small sample size and lack of correlation analysis of the study, further larger scale and high-quality clinical trials are required to confirm these findings.

The Translational Impact of Plant-Derived Xeno-miRNA miR-168 in Gastrointestinal Cancers and Preneoplastic Conditions

INTRODUCTION

Diet is one of the most important factors contributing to the multistep process of carcinogenesis. The clinical relevance of exogenous food-derived xeno-microRNAs (miRNAs) in human diseases is poorly understood. In this study, we aimed to evaluate the potential clinical relevance of the xeno-miRNA miR-168 in the gastric mucosa along the preneoplastic conditions and gastric carcinogenesis.

METHODS

For a systematic analysis, we included stomach tissues from patients with different pathologies, including normal mucosa (N), chronic non-atrophic (CNAG) and atrophic gastritis (CAG) and intestinal metaplasia (IM) (n = 72), matched non-tumorous (NT) and tumorous (T) gastric cancer (GC) tissues (n = 81), matched colorectal cancer (CRC) tissues (n = 40), and colon mucosa and faeces from controls and IBD patients.

RESULTS

miR-168 was reproducibly detectable in all samples studied, with the highest levels in the proximal upper GI and in non-tumorous compared to tumorous tissues in both GC and CRC. There was no difference related to H. pylori positivity or inflammation grade, while higher miR-168 levels were observed in patients with moderate or severe AG/IM or OLGIM3/4. Survival analysis showed only a small, non-significant trend towards worse overall survival for patients with the highest to lowest miR-168 levels, while no differences were related to Lauren's classification.

CONCLUSIONS

Food-derived xeno miRNAs are reproducibly detectable in the gastric and colonic mucosa. Although the clinically relevant function remains to be elucidated, higher levels of miR-168 in patients with moderate and severe IM merit further investigation.

Can neutrophil to lymphocyte ratio be a non-invasive indicator of the presence of duodenal ulcer related Helicobacter pylori in dyspeptic patients?

Background and aims

Neutrophil to lymphocyte ratio (NLR), a novel inflammatory marker, has been shown to increase in various systemic inflammatory conditions. In this way, we want to evaluate the relationship between the presence of H. pylori, duodenal ulcer related H. pylori and NLR in dyspeptic patients.

Material and methods

The patients were divided into three groups after evaluating of the EGD and histopathology results. The groups were determined as follow; Group A: H. pylori positive and DU negative, Group B: H. pylori positive and DU positive, Group C: H. pylori negative and DU negative. Then, groups were compared with each other for demographic features, laboratory tests and NLR.

Results

There were significant differences between groups for NLR when groups compared with each other. Significantly high NLR was seen in group A (H. pylori positive, DU negative) and group B (H. pylori positive, DU positive) when compared with group C (H. pylori negative, DU negative) (respectively p < 0.042, p < 0.001). Significantly higher NLR was determined in the group B when compared with group A and group C (respectively p < 0.021, p < 0.001). The cut-off value for NLR was 2,17 with a specificity of 61% and sensitivity of 66% for group B comparing with Group C (AUC:0,66).

Conclusions

Significantly higher NLR was determined in patients with H. pylori and DU. As a result, NLR may be used as a non-invasive test for documenting the presence of H. pylori and H. pylori related DU.

A Genetic and Immunohistochemical Analysis of Helicobacter pylori Phenotypes and p27 Expression in Adenocarcinoma Patients in Jordan

Stomach (gastric) cancer is one of the most prevalent and deadly cancers worldwide and most gastric cancers are adenocarcinomas. Based on prior research, there is an association between Helicobacter pylori (H. pylori) infection together with the frequency of duodenal ulcer, distal gastric adenocarcinoma, mucosa-associated lymphoid tissue (MALT) lymphoma, and antral gastritis. Helicobacter pylori virulence and toxicity factors have been identified before that significantly influence the clinical outcomes of H. pylori infection and gastric adenocarcinoma. However, it remains unclear exactly how different strains of H. pylori affect gastric adenocarcinoma. Current research suggests this involves tumor suppressor genes, like p27 but also H. pylori toxic virulence proteins. Therefore, we quantified known H. pylori genotypes within adenocarcinoma patients to establish the prevalence of known toxins that include cytotoxin-associated gene A (cagA) as well as vacuolating cytotoxin A (vacA) within patients of variable adenocarcinoma diagnosis. This analysis used gastrectomy samples validated for DNA viability. The incidence of H. pylori in adenocarcinoma patients in Jordan was established to be 54.5% positive (ureA gene positive) with cagA genotype occurrence at 57.1%, but also in this population study vacA gene ratios found to be 24.7%:22.1%:14.3%:14.3%. (vacAs1:vacAs2:vacAm1:vacAm2). Using immunohistochemistry (IHC), we confirmed with statistical significance that p27 was dysregulated and suppressed, within nearly all H. pylori vacA genotypes. In addition, within 24.6% of H. pylori samples analyzed was a different bacterial genotype, and curiously that p27 protein expression was retained in 12% of tested adenocarcinoma H. pylori samples. This is suggestive that p27 could be used as a prognostic indicator but also that an unknown genotype could be contributing to the regulatory effects of p27 protein within this bacterial and cellular environment that may include other virulence factors and unknown immune system regulatory changes.

Causal associations of circulating Helicobacter pylori antibodies with stroke and the mediating role of inflammation

BACKGROUND

Observational studies have shown that Helicobacter pylori (H. pylori) infection and H. pylori antibodies are associated with an increased risk of stroke. However, which and how H. pylori antibodies serve as the causal determinant of the development of stroke remains largely unknown.

METHODS

Genome-wide association studies (GWAS) on seven different antibodies of H. pylori-specific proteins, stroke, and stroke subtypes were included in this study. Mendelian randomization (MR) and multivariable MR (MVMR) analysis were performed to assess the causal associations between H. pylori antibodies and the development of stroke and to determine the potential mechanisms underlying the associations.

RESULTS

Genetically predicted serum H. pylori vacuolating cytotoxin-A (VacA) antibody level was associated with an increased risk of all-cause stroke (odds ratio [OR] = 1.04, 95% CI 1.01-1.07, P = 0.017) and cardioembolic stroke (CES, OR = 1.11, 95% CI 1.04-1.18, P = 0.001). The results of multivariable MR (MVMR) showed that C-reactive protein (CRP), but not monocyte chemoattractant protein-1 and peptic ulcer, mediated the causal effects of VacA-positive H. pylori infection on all-cause stroke and CES. No strong causal associations were found between other H. pylori antibodies and stroke and its subtypes.

CONCLUSIONS

Our results demonstrate that H. pylori VacA antibody is the only causal determinant associated with the risk of stroke in the spectrum of H. pylori-related antibodies, in which CRP may mediate the association. This study suggests that inhibition of the CRP signaling pathway may reduce the risk of stroke in patients with VacA-positive H. pylori infection.

New Advances in Nano-Drug Delivery Systems: Helicobacter pylori and Gastric Cancer

With the development of materials science and biomedicine, the application of nanomaterials in the medical field is further promoted. In the process of the diagnosis and treatment of diseases, a variety of drugs need to be used. It is an ideal state to make these drugs arrive at a specific location at a specific time and release at a specific speed, which can improve the bioavailability of drugs and reduce the adverse effects of drugs on normal tissues. Traditional drug delivery methods such as tablets, capsules, syrups, and ointments have certain limitations. The emergence of a new nano-drug delivery system further improves the accuracy of drug delivery and the efficacy of drugs. It is well known that the development of the cancer of the stomach is the most serious consequence for the infection of Helicobacter pylori. For the patients who are suffering from gastric cancer, the treatments are mainly surgery, chemotherapy, targeted and immune therapy, and other comprehensive treatments. Although great progress has been made, the diagnosis and prognosis of gastric cancer are still poor with patients usually diagnosed with cancer at an advanced stage. Current treatments are of limited benefits for patients, resulting in a poor 5-year survival rate. Nanomaterials may play a critical role in early diagnosis. A nano-drug delivery system can significantly improve the chemotherapy, targeted therapy, and immunotherapy of advanced gastric cancer, reduce the side effects of the original treatment plan and provide patients with better benefits. It is a promising treatment for gastric cancer. This article introduces the application of nanomaterials in the diagnosis and treatment of H. pylori and gastric cancer.

Differential Expression of Long Noncoding RNA HOTAIR in Intestinal Metaplasia and Gastric Cancer

INTRODUCTION

High expression of HOTAIR promotes tumor growth and carries a dismal prognosis for the patient. We investigated the prognostic value of HOTAIR expression in gastric cancer (GC) and systematically delineate the expression in relation to Helicobacter pylori infection and preneoplastic changes.

METHODS

HOTAIR expression was analyzed in surgical paired tissue samples of patients with GC and biopsy samples from patients with atrophic gastritis and/or intestinal metaplasia (AG ± -IM), chronic nonatrophic gastritis, and controls. The cancer genome atlas (TCGA) data were used for validation. HOTAIR expression was evaluated in sera and ascites of patients with GC. Quantitative HOTAIR expression analysis was performed using quantitative polymerase chain reaction, and LINE-1 methylation was assessed by bisulfite pyrosequencing.

RESULTS

HOTAIR was more frequently detected in tumor tissues compared with adjacent gastric mucosa (65.4% vs 8.6%). HOTAIR expression was associated with depth of tumor invasion and tumor location and with shorter overall survival in patients with diffuse-type GC as confirmed in the TCGA cohort. HOTAIR was not detectable in controls but was found in 2.2% of patients with chronic nonatrophic gastritis and 18.3% of patients with AG ± IM, which was further associated with IM, grade of IM, and H. pylori positivity.

DISCUSSION

HOTAIR expression was associated with GC and preneoplastic changes of stomach mucosa. Although HOTAIR expression was strongly linked to IM, HOTAIR expression was only associated with worse prognosis in Lauren diffuse and not intestinal type of GC. Further studies are needed to evaluate the value of HOTAIR as diagnostic and predictive biomarker in IM and translational therapeutic relevance of HOTAIR in diffuse-type GC.

EGF and BMPs Govern Differentiation and Patterning in Human Gastric Glands

BACKGROUND & AIMS

The homeostasis of the gastrointestinal epithelium relies on cell regeneration and differentiation into distinct lineages organized inside glands and crypts. Regeneration depends on Wnt/β-catenin pathway activation, but to understand homeostasis and its dysregulation in disease, we need to identify the signaling microenvironment governing cell differentiation. By using gastric glands as a model, we have identified the signals inducing differentiation of surface mucus-, zymogen-, and gastric acid-producing cells.

METHODS

We generated mucosoid cultures from the human stomach and exposed them to different growth factors to obtain cells with features of differentiated foveolar, chief, and parietal cells. We localized the source of the growth factors in the tissue of origin.

RESULTS

We show that epidermal growth factor is the major fate determinant distinguishing the surface and inner part of human gastric glands. In combination with bone morphogenetic factor/Noggin signals, epidermal growth factor controls the differentiation of foveolar cells vs parietal or chief cells. We also show that epidermal growth factor is likely to underlie alteration of the gastric mucosa in the precancerous condition atrophic gastritis.

CONCLUSIONS

Use of our recently established mucosoid cultures in combination with analysis of the tissue of origin provided a robust strategy to understand differentiation and patterning of human tissue and allowed us to draw a new, detailed map of the signaling microenvironment in the human gastric glands.

Diagnosis of Helicobacter pylori Infection in a Routine Testing Workflow: Effect of Bacterial Load and Virulence Factors

Reliable diagnostic methods are mandatory for effective management of Helicobacter pylori infection. Histology and culture are the most common invasive methods in current practice, even if molecular methods are gaining in importance. The performance of these conventional methods varies significantly. We conducted a retrospective study of 1540 adults and 504 children with gastric biopsies taken during endoscopy to assess the impact of bacterial load and the cagA virulence factor on the performance of H. pylori infection testing. The association between virulence and histology findings was also investigated. With 23S rRNA qPCR confirmed by glmM amplification as the gold standard, culture and histology had lower sensitivity, 74.4% and 73.3%, respectively. However, their sensitivity was enhanced (>90%) in biopsies with high bacterial load (qPCR Ct < 30). Positive cagA status of the strain was associated with high bacterial load (94.9%), thus resulting in more frequent positive culture (94.3%) and H. pylori histology detection (91.7%) and more severe lesions on histology (p < 0.001). Conversely, the cagA status of the strains was negative in 110/119 (92.4%) of biopsies with low bacterial load (qPCR Ct < 30), 82/90 (91.1%) with negative H. pylori histology detection and 119/131 (90%) with negative culture findings (p < 0.001). This study highlights the low sensitivity of conventional culture and histology that may lead to false negative diagnosis if used alone. H. pylori quantification associated with cagA genotyping in routine workflow are essential for a sensitive and reliable diagnosis, to identify patients at high risk and to manage eradication therapies.

Inflammatory microRNAs in gastric mucosa are modulated by Helicobacter pylori infection and proton-pump inhibitors but not by aspirin or NSAIDs

Gastric carcinogenesis is associated with alterations of microRNAs (miRNAs) and reversal of these alterations may be a crucial element in cancer prevention. Here we evaluate the influence of H. pylori eradication, low-dose aspirin (LDA), non-steroidal anti-inflammatory drugs (NSAIDs) and proton-pump inhibitors (PPI) on modification of inflammatory mucosal miRNAs miR-155 and miR-223 in Helicobacter pylori-infected and non-infected subjects. The study was performed in two parts: 1) interventional study in 20 healthy subjects with and without H. pylori infection or following eradication (each n = 10) where LDA (100 mg) was given daily for 7 days; 2) prospective case-control observational study (n = 188). MiR-155 and miR-223 expression was strongly linked to H. pylori-infection and in short-term view showed a trend for reversal after eradication. Daily LDA as well as regular NSAIDs showed no influence on miRNAs expression both in healthy subjects and patients, while regular PPI intake was associated with lower miR-155 expression in antrum of patients with chronic gastritis independent of density of neutrophils and mononuclear infiltrate. In summary, PPI but not LDA or NSAIDs were associated with modification of inflammatory miRNAs miR-155 and miR-223 in an H. pylori dependent manner. The functional role of inflammatory miR-155 and miR-223 in understanding of H. pylori-related diseases needs further evaluation.

Helicobacter pylori induced gastric carcinogenesis - The best molecular model we have?

Gastric carcinogenesis can be described as a consequence of multilevel molecular alterations that is triggered by a cascade of events. Historically, diet and environmental factors have been identified to substantially contribute to carcinogenesis before the discovery of Helicobacter pylori (H. pylori). But H. pylori infection has revolutionized the understanding of gastric carcinogenesis. Although the model of H. pylori-driven carcinogenesis remains valid, there is a continuous effort to precisely delineate the molecular pathways involved and to understand the interplay with additional risk factors including recent relevant knowledge on the stomach microbiota. In this review, we provide an updated view on the models of gastric carcinogenesis. This includes historically appreciated H. pylori-induced models and expands these taking recent molecular data into consideration. Based on the data provided, we conclude that indeed H. pylori-carcinogenesis remains one of the best-established models at least for a subset of gastric cancers. Implementation of the recently identified molecular subtypes in novel genetic animal models is required to expand our knowledge on H. pylori-independent carcinogenesis.

Quantitative proteomics approach to investigate the antibacterial response of Helicobacter pylori to daphnetin, a traditional Chinese medicine monomer

Helicobacter pylori is a Gram-negative bacterium related to the development of peptic ulcers and stomach cancer. An increasing number of infected individuals are found to harbor antibiotic-resistant H. pylori, which results in treatment failure. Daphnetin, a traditional Chinese medicine, has a broad spectrum of antibacterial activity without the development of bacterial resistance. However, the antibacterial mechanisms of daphnetin have not been elucidated entirely. To better understand the mechanisms of daphnetin's effect on H. pylori, a label-free quantitative proteomics approach based on an EASY-nLC 1200 system coupled with an Orbitrap Fusion Lumos mass spectrometer was established to investigate the key protein differences between daphnetin- and non-daphnetin-treated H. pylori. Using the criteria of greater than 1.5-fold changes and adjusted p value <0.05, proteins related to metabolism, membrane structure, nucleic acid and protein synthesis, ion binding, H. pylori colonization and infection, stress reaction, flagellar assembly and so on were found to be changed under daphnetin pressure. And the changes of selected proteins in expression level were confirmed by targeted proteomics. These new data provide us a more comprehensive horizon of the proteome changes in H. pylori that occur in response to daphnetin.

Helicobacter pylori Virulence Factors-Mechanisms of Bacterial Pathogenicity in the Gastric Microenvironment

Gastric cancer constitutes one of the most prevalent malignancies in both sexes; it is currently the fourth major cause of cancer-related deaths worldwide. The pathogenesis of gastric cancer is associated with the interaction between genetic and environmental factors, among which infection by Helicobacter pylori (H. pylori) is of major importance. The invasion, survival, colonization, and stimulation of further inflammation within the gastric mucosa are possible due to several evasive mechanisms induced by the virulence factors that are expressed by the bacterium. The knowledge concerning the mechanisms of H. pylori pathogenicity is crucial to ameliorate eradication strategies preventing the possible induction of carcinogenesis. This review highlights the current state of knowledge and the most recent findings regarding H. pylori virulence factors and their relationship with gastric premalignant lesions and further carcinogenesis.

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.

VacA genotypes and cagA-EPIYA-C motifs of Helicobacter pylori and gastric histopathological lesions

Helicobacter pylori infection induces inflammation of the gastric mucosa, which may progress to precancerous lesions and gastric cancer. The gastric histo-pathological damages may be associated with some virulence genes of the bacterium, notably vacA and cagA genes. To establish correlations between these genes and the lesions, biopsies from 1303 adults consenting patients that were previously analyzed by PCR to characterize vacA-s vacA-m, vacA-i regions and cagA 3' region polymorphism, were used. The highest average age was obtained in patients with intestinal metaplasia (53.65 ± 15.26 years) and gastric cancer (53.60 ± 14.32 years). Thus, these lesions are more frequent in elderly and male subjects. Tobacco smoking was significantly associated with neutrophilic activity (P = .02). No significant association was obtained between patients with chronic inflammation and vacA and cagA H. pylori genotypes. However, a significant association has been obtained between this lesion and cagA+ in aged patients (P = .02), while intestinal metaplasia was significantly associated with vacAi1 and vacAm1 separately (P < .01 and .01). Also, a significant association was obtained between intestinal metaplasia and strains with one EPIYA-C motif in young patients (P = .001). Interestingly, a significant association was obtained between gastric cancer and cagA+, vacAi1, vacAm1 H. pylori genotypes and also with two EPIYA-C motifs independently of age groups (all P < .05). The results of our study show that H. pylori vacAi1 could be more potent than the other H. pylori virulent factors for predicting the precancerous gastric lesions, confirming that this gene may be helpful to identify patients at high risk for gastric cancer.

Epidemiology and role of Helicobacter pylori virulence factors in gastric cancer carcinogenesis

Infection with Helicobacter pylori is associated with the development of gastric cancer. Although the prevalence of gastric cancer has declined throughout years due to improvement in early screening strategy, mortality due to gastric cancer has not changed. Incidence and mortality due to gastric cancer are higher in developing countries as compared to developed countries. Diagnosis and prognosis of gastric cancer are still poor with patients usually diagnosed with cancer at an advanced stage. Eradication of H. pylori is pertinent for the prevention of gastric cancer. However, the rise in antimicrobial resistance among H. pylori isolates has complicated the prevention strategy. H. pylori express multiple virulence factors for survival in the hostile acid gastric environment. The expression of oncogenic protein cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA), and outer inflammatory protein is essential for H. pylori to exert pathogenesis towards the host. Interestingly, <3% of H. pylori-infected subjects develop gastric cancer, suggesting a unique way of interaction between the host's immune response and H. pylori virulence factors. This article is aimed to review the epidemiology and role of H. pylori in gastric carcinogenesis. A better understanding of the interaction between H. pylori virulence factors and host is required for better gastric cancer prevention.

Systematic review with meta-analysis: association between Helicobacter pylori CagA seropositivity and odds of inflammatory bowel disease

BACKGROUND

Accumulating data support a protective role of Helicobacter pylori against inflammatory bowel diseases (IBD), which might be mediated by strain-specific constituents, specifically cagA expression.

AIM

To perform a systematic review and meta-analysis to more clearly define the association between CagA seropositivity and IBD.

METHODS

We identified comparative studies that included sufficient detail to determine the odds or risk of IBD, Crohn's disease (CD) or ulcerative colitis (UC) amongst individuals with vs without evidence of cagA expression (eg CagA seropositivity). Estimates were pooled using a random effects model.

RESULTS

Three clinical studies met inclusion criteria. cagA expression was represented by CagA seropositivity in all studies. Compared to CagA seronegativity overall, CagA seropositivity was associated with lower odds of IBD (OR 0.31, 95% CI 0.21-0.44) and CD (OR 0.25, 95% CI 0.17-0.38), and statistically nonsignificant lower odds for UC (OR 0.68, 95% CI 0.35-1.32). Similarly, compared to H pylori non-exposed individuals, H pylori exposed, CagA seropositive individuals had lower odds of IBD (OR 0.26, 95% CI 0.16-0.41) and CD (OR 0.23, 95% CI 0.15-0.35), but not UC (OR 0.66, 0.34-1.27). However, there was no significant difference in the odds of IBD, CD or UC between H pylori exposed, CagA seronegative and H pylori non-exposed individuals.

CONCLUSION

We found evidence for a significant association between CagA seropositive H pylori exposure and reduced odds of IBD, particularly CD, but not for CagA seronegative H pylori exposure. Additional studies are needed to confirm these findings and define underlying mechanisms.

Food-Derived Xeno-microRNAs: Influence of Diet and Detectability in Gastrointestinal Tract-Proof-of-Principle Study

SCOPE

Diet is amongst the most crucial factors contributing to the multistep process of carcinogenesis. The role of exogenous microRNAs (miRNAs) is still debatable. In this proof-of-principle work, the presence of miRNAs in a variety of foods, its stability to processing, and detectability in GI mucosa and feces are studied and the effect of short-term diet on human- or plant-derived miRNAs in feces and blood is examined.

METHODS AND RESULTS

Animal and plant miRNAs are detected in all foods irrespective of processing. Animal-derived foods showed the highest miRNA level and the lowest is found in cheese and milk. The impact of the short-term vegetarian or meat-rich diet on blood and feces miRNA is evaluated in healthy subjects using qPCR and Affymetrix profiling. Diet is not associated with changes in ultraconserved miRNAs. However, a vegetarian diet is associated with an increase of miR-168 in feces but not in blood. Overall, plant miR-168 is detectable in normal GI mucosa and in colorectal cancer.

CONCLUSIONS

Food provides a great source of miRNAs and diet may be associated with changes in xenomiRs. Plant-derived miR-168 is ubiquitously present in feces, normal mucosa, and cancer. Further studies are needed to evaluate the functional interaction between diet-derived miRNAs and GI tract.

MicroRNAs as non-invasive diagnostic biomarkers for gastric cancer: Current insights and future perspectives

Non-invasive diagnostic biomarkers may contribute to an early identification of gastric cancer (GC) and improve the clinical management. Unfortunately, no sensitive and specific screening biomarkers are available yet and the currently available approaches are limited by the nature of the disease. GC is a heterogenic disease with various distinct genetic and epigenetic events that occur during the multifactorial cascade of carcinogenesis. MicroRNAs (miRNAs) are commonly deregulated in gastric mucosa during the Helicobacter pylori infection and in stepwise manner from chronic gastritis, through preneoplastic conditions such as atrophic gastritis and intestinal metaplasia, to early dysplasia and invasive cancer. Identification of miRNAs in blood in 2008 led to a great interest on miRNA-based diagnostic, prognostic biomarkers in GC. In this review, we provide the most recent systematic review on the existing studies related to miRNAs as diagnostic biomarkers for GC. Here, we systematically evaluate 75 studies related to differential expression of circulating miRNAs in GC patients and provide novel view on various heterogenic aspects of the existing data and summarize the methodological differences. Finally, we highlight several important aspects crucial to improve the future translational and clinical research in the field.

Helicobacter Pylori Serology in Relation to Hepatitis C Virus Infection and IL28B Single Nucleotide Polymorphism

The aim of the study was to evaluate the serological rate of Helicobacter pylori (H. pylori) infection in patients with chronic hepatitis C virus (HCV) infection and determine any correlations with liver damage and IL28B single-nucleotide polymorphism (SNP). One hundred eighty-nine patients with chronic HCV infection were included in the study, and H. pylori status was defined based on anti-H. pylori-IgG or anti-CagA-IgG antibodies using enzyme-linked immunosorbent assay (ELISA). Liver damage was assessed using histology or transient elastography. IL28B C/T polymorphism (rs12979860) was evaluated in circulating blood cells using a PCR-based restriction fragment length polymorphism assay. Overall H. pylori serology was positive in 38.1% of our HCV-infected subjects. Among those, the anti-CagA-IgG positivity rate was 43.1% and was within the range of previously described populations of the same region. Highest prevalence of H. pylori was found in patients between 31 and 40 years compared to other age subgroups. The seropositivity rate was higher in the non-cirrhotic group than the cirrhotic one (45.4% vs. 20.0%, p < 0.05). No difference was found in IL28B genotype between H. pylori-positive and -negative cohorts. However, we observed a trend for the lower anti-CagA-IgG expression level in relation to the IL28B T-allele. Our results do not support an association between HCV and H. pylori infection. Whether IL28B SNP has a functional role in modulation of serological response to H. pylori CagA needs further investigation.