Helicobacter pylori vs coronary heart disease - searching for connections

Helicobacter cinaedi bacterium association with atherosclerosis and other diseases

Helicobacter is a genus of spiral-shaped Gram-negative enterohepatic bacteria whose members are capable of causing bacteremia in humans. One of the poorly studied members of this genus is the bacterium Helicobacter cinaedi. This microorganism was first isolated from human fecal samples in 1984. Although it was long considered to be associated with only immunocompromised patients, more evidence in recent years has implicated H. cinaedi in causing serious pathologies in immunocompetent populations. In addition, H. cinaedi is also reported to be associated with a few chronic or severe illnesses, such as atherosclerosis, which in turn can lead to the development of other cardiovascular pathologies: one of the leading causes of mortality worldwide. Helicobacter cinaedi often goes unnoticed in standard diagnostic methods due to its slow growth under microaerobic conditions. This often leads to significant underdetection and hence undermines the role of this bacterium in the pathogenesis of various diseases and the extent of its spread in humans. In this review, we have compiled information on pathologies associated with H. cinaedi, the occurrence of the bacterium in humans and animals, and the latest developments in diagnosing the bacterium and treating associated diseases.

Helicobacter pylori components increase the severity of metabolic syndrome and its hepatic manifestations induced by a high fat diet

The metabolic syndrome, often accompanied by hepatic manifestations, is a high-risk factor for developing cardiovascular disease. Patients with metabolic dysfunction associated with steatohepatic disease (MASDL) are at significant risk of developing coronary artery disease. Atherosclerosis is a systemic inflammatory disorder in which several factors, including dietary or infectious factors, can cause an inflammatory response. Helicobacter pylori (HP) bacteria have been implicated in the progression of proatherogenic vascular endothelial lesions, moreover, our previous study in an experimental in vivo model of Cavia porcellus showed that HP components and high-fat substances acted synergistically in promoting vascular endothelial inflammation, leading to an early onset of a proatherogenic environment. In the present study, our goal was to determine the contribution of HP components to the development of hepatic manifestations of metabolic syndrome in an experimental model. Our results showed that HP infection in animals exposed to a high-fat diet increased oxidative stress and lipid peroxidation, followed by endothelial lipid deposition, impaired endothelial apoptosis, cell lysis, and increased vascular stiffness. Finally, histopathological analysis of liver tissue showed signs of MASLD development in HP-infected animals fed a high-fat diet.

Unveiling the Silent Intruder: H. pylori's Hidden Link to Ischemic Heart Disease

Cardiovascular disease is the leading cause of death. In addition to the well-known risk factors associated with cardiovascular disease, such as age, diabetes mellitus, smoking, hypertension, and obesity, there has been a growing concern regarding cardiac complications stemming from the Gram-negative bacteria Helicobacter pylori. While H. pylori is most commonly associated with chronic gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric lymphoma, it has also been implicated in extra gastric manifestations, encompassing cardiac, neurologic, ocular, and dermatologic issues. Key virulent factors for coronary artery disease include the vacuolating cytotoxin gene A and the cytotoxin-associated gene A. The most likely pathogenic mechanism of the relationship between H. pylori and coronary artery disease is initiating a chronic inflammatory process associated with infection and the modifications of classic risk factors. These alterations lead to the creation of prothrombotic and procoagulant environments. Here, we review the cardiac manifestations of H. pylori and the underlying pathophysiological mechanisms.

Helicobacter pylori Infection: Current Status and Future Prospects on Diagnostic, Therapeutic and Control Challenges

Helicobacter pylori (H. pylori) infection, which affects approximately half of the world's population, remains a serious public health problem. As H. pylori infection leads to a number of gastric pathologies, including inflammation, gastroduodenal ulcers, and malignancies, early detection and treatment are crucial to preventing the spread of the infection. Multiple extragastric complications, such as iron deficiency anaemia, immune thrombocytopenic purpura, vitamin B12 deficiency, diabetes mellitus, cardiovascular diseases, and certain neurological disorders, have also been linked to H. pylori infection. An awareness of H. pylori and associated health hazards is necessary to minimize or even eradicate the infection. Therefore, there is an urgent need to raise the standards for the currently employed diagnostic, eradication, alternative treatment strategies. In addition, a brief overview of traditional and cutting-edge approaches that have proven effective in identifying and managing H. pylori is needed. Based on the test and laboratory equipment available and patient clinical characteristics, the optimal diagnostic approach requires weighing several factors. The pathophysiology and pathogenic mechanisms of H. pylori should also be studied, focusing more on the infection-causing virulence factors of this bacterium. Accordingly, this review aims to demonstrate the various diagnostic, pathophysiological, therapeutic, and eradication tactics available for H. pylori, emphasizing both their advantages and disadvantages. Invasive methods (such as quick urease testing, biopsy, or culture) or noninvasive methods (such as breath tests, stool investigations, or serological tests) can be used. We also present the most recent worldwide recommendations along with scientific evidence for treating H. pylori. In addition to the current antibiotic regimens, alternative therapies may also be considered. It is imperative to eradicate the infections caused by H. pylori as soon as possible to prevent problems and the development of stomach cancer. In conclusion, significant advances have been made in identifying and treating H. pylori. To improve eradication rates, peptide mass fingerprinting can be used as a diagnostic tool, and vaccines can also eliminate the infection.

Searching for serum biomarkers linking coronary heart disease and Helicobacter pylori infection using infrared spectroscopy and artificial neural networks

Helicobacter pylori (Hp) Gram-negative bacteria cause gastritis or gastric ulcers. They may be involved in the development of systemic diseases i.e. coronary heart disease (CHD). Both Hp infection and CHD are related to inflammation accompanied by C-reactive protein (CRP), tumor necrosis factor alfa (TNF-α) and homocysteine. Low density lipoprotein (LDL) and triglicerides are a classic risk factors of CHD. Infrared spectroscopy has been introduced for monitoring chronic infections or endogenous disorders using specific absorption bands for biocomponents typed as diagnostic markers. In this study we selected specific motives of infrared radiation (IR) spectra for the sera from CHD patients infected with Hp. In total 141 sera were used: 90 from patients with CHD, all Hp positive, and 51 from healthy donors, 32 Hp negative and 21 Hp positive. Hp status was evaluated by anti-Hp IgG antibodies and/or ¹³C urea breath testing. IR spectra were measured using FT-IR/FT-NIR Spectrum 400 spectrometer (PerkinElmer) chemometrically analyzed using artificial neural networks and they showed differences in absorption bands corresponding to triglicerides, CRP, homocysteine, LDL and TNF-α, and selected component groups between CHD patients infected with Hp vs healthy uninfected donors (96.15% accuracy). Triglicerides and CRP were the best biomarkers linking Hp infection with CHD.

Helicobacter Pylori Infection Induces Intestinal Dysbiosis That Could Be Related to the Onset of Atherosclerosis

Cardiovascular diseases represent one of the first causes of death around the world, and atherosclerosis is one of the first steps in the development of them. Although these problems occur mainly in elderly, the incidence in younger people is being reported, and an undetermined portion of patients without the classic risk factors develop subclinical atherosclerosis at earlier stages of life. Recently, both the H. pylori infection and the intestinal microbiota have been linked to atherosclerosis. The mechanisms behind those associations are poorly understood, but some of the proposed explanations are (a) the effect of the chronic systemic inflammation induced by H. pylori, (b) a direct action over the endothelial cells by the cytotoxin associated gene A protein, and (c) alterations of the lipid metabolism and endothelial dysfunction induced by H. pylori infection. Regarding the microbiota, several studies show that induction of atherosclerosis is related to high levels of Trimethylamine N-oxide. In this review, we present the information published about the effects of H. pylori over the intestinal microbiota and their relationship with atherosclerosis and propose a hypothesis to explain the nature of these associations. If H. pylori contributes to atherosclerosis, then interventions for eradication and restoration of the gut microbiota at early stages could represent a way to prevent disease progression.

Accumulation of Deleterious Effects in Gastric Epithelial Cells and Vascular Endothelial Cells In Vitro in the Milieu of Helicobacter pylori Components, 7-Ketocholesterol and Acetylsalicylic Acid

The Gastric pathogen Helicobacter pylori (HP) may influence the development of coronary heart disease (CHD). H. pylori induce reactive oxygen species (ROS), which transform cholesterol to 7-ketocholesterol (7-kCh), a CHD risk factor. Acetylsalicylic acid (ASA)—an Anti-aggregation drug used in CHD patients—may increase gastric bleeding and inflammation. We examined whether H. pylori driven ROS effects in the cell cultures of gastric epithelial cells (AGS) and vascular endothelial cells (HUVEC) progress in the milieu of 7-kCh and ASA. Cell cultures, exposed to 7-kCh or ASA alone or pulsed with the H. pylori antigenic complex—Glycine acid extract (GE), urease (UreA), cytotoxin associated gene A (CagA) protein or lipopolysaccharide (LPS), alone or with 7-kCh and ASA—were examined for ROS, apoptosis, cell integrity, interleukin (IL)-8, the activation of signal transducer, the activator of transcription 3 (STAT3), and wound healing. ASA and 7-kCh alone, and particularly in conjunction with H. pylori components, increased the ROS level and the rate of apoptosis, which was followed by cell disintegration, the activation of STAT3, and IL-8 elevation. AGS cells were unable to undergo wound healing. The cell ROS response to H. pylori components may be elevated by 7-kCh and ASA.

Antibodies towards TVLLPVIFF Amino Acid Sequence of TNF Receptor Induced by Helicobacter pylori in Patients with Coronary Heart Disease

Background: Molecular mimicry between Helicobacter pylori (Hp) and the host components resulting in induction of cross-reacting antibodies has been suggested as accessory mechanism in the development of coronary heart disease (CHD). A potential target for antibodies induced during Hp infection by the components of these bacteria might be amino acid sequence TVLLPVIFF (P1) of tumor necrosis factor receptor (TNFR), which is exposed on vascular endothelium and immunocompetent cells, driving inflammation. Aim: To examine whether anti-P1 IgG are induced during Hp infection in CHD patients. Methods: Sera from CHD patients infected with Hp (54) vs. sera of uninfected healthy donors (22) were tested by the ELISA for anti-H. pylori antibodies, anti-P1 IgG, and for antibodies towards control sequence IAKEGFEKIS (P2). Sera of Caviae porcellus infected experimentally with Hp (30) or uninfected (10) were included into this study. The same serum samples, which were positive for anti-P1 IgG, were adsorbed with Hp and then subjected to the ELISA. The biological activity of anti-P1 IgG was assessed in complement (C1q) binding assay. Results: Sera of 43 CHD patients seropositive for anti-Hp IgG contained anti-P1 IgG binding C1q. Additionally, 10 serum samples of animals seropositive for anti-Hp IgG contained anti-P1 IgG. Anti-P1 IgG in tested sera were neutralized by their adsorption with Hp. Conclusion: In CHD patients infected with Hp, antibodies cross-reacting with TNFR common sequence are produced. Further studies are necessary to define immunogenic Hp determinants and to confirm possible cellular effects of cross-reacting antibodies.

An Updated Meta-Analysis of the Relationship Between Helicobacter pylori Infection and the Risk of Coronary Heart Disease

Background

Coronary heart disease (CHD) is one of the leading causes of mortality in the world. Although the traditional risk factors for CHD have been identified, it seems that there are still many CHD cases without these factors. Previous studies have hypothesized that Helicobacter pylori (H. pylori) infection was associated with the risk of CHD.

Objective

The association between H. pylori infection and the risk of CHD was studied using a systematic evaluation and meta-analysis method.

Methods

In order to find relevant studies, four electronic databases were systematically searched until August 2021. According to the inclusion and exclusion criteria, studies were screened and data were extracted. Under the random-effects or the fixed-effects model, the odds ratio (OR) and 95% confidence interval (95% CI) were combined. All analyses were conducted using Review Manager software (RevMan 5.4).

Results

Among the included studies, 2 studies were analyzed for H. pylori stool antigen test, 2 studies were analyzed for H. pylori histological staining test, 13 studies were analyzed for the anti-CagA test, and 38 studies were analyzed for the anti-H. pylori IgG test. The pooled results revealed that positive anti-H. pylori IgG was significantly associated with an increased risk of CHD (OR, 1.58; 95% CI: 1.34–1.87). Similarly, positive anti-CagA, positive H. pylori stool antigen, and positive H. pylori histological staining were significantly associated with the development of CHD with (OR: 1.33, 95% CI: 1.16–1.53), (OR: 3.50, 95% CI: 1.60–7.66), and (OR: 1.78, 95% CI: 1.12–2.83), respectively.

Conclusion

This meta-analysis showed that H. pylori infection increased the risk of CHD. However, more studies are needed to further investigate whether early eradication of H. pylori may reduce the morbidity of CHD.

Changes in the gut microbiome in relation to the degree of gastric mucosal atrophy before and after Helicobacter pylori eradication

OBJECTIVES

Helicobacter pylori infection causes atrophic gastritis, which affects the gut microbiome; the gastric acid concentration depends on the degree of atrophic gastritis. Helicobacter pylori eradication also affects gastric acidity. Here, we determined the differences in the post-eradication changes in the gut microbiome in relation to the progression of gastric atrophy.

MATERIALS AND METHODS

Ten patients were included in the closed group and five in the open group, consisting of patients with non-progressive and progressive atrophy, respectively, diagnosed by endoscopy. The faecal microbiome was analysed and compared among three time-points: before eradication, 8 weeks after eradication, and 6 months after eradication. The microbiome was analysed by targeting 16S rRNA using Illumina Miseq.

RESULTS

The relative abundance of 14 genera significantly differed between the closed and open groups before eradication, but only 12 and 6 genera presented a significant difference in the relative abundance at 8 weeks and 6 months after eradication, respectively. Of the 12 genera that differed between the closed and open groups before eradication, 8 genera, namely, Actinomyces, Aggregatibacter, Campylobacter, Granulicatella, Pyramidobacter, Streptococcus, Cardiobacterium, and Haemophilus, were oral-origin bacteria. Longitudinal changes showed that Haemophilus and Catenibacterium were consistently significantly more abundant in the open group than in the closed group during the follow-up period.

CONCLUSION

The gut microbiome substantially differed depending on the progression of gastric atrophy, but this difference was decreased by eradication, especially the differences in the number of oral bacteria in the gut. Eradication therapy may improve dysbiosis that result from gastric atrophy.

Evaluation of Lipid Profile and Inflammatory Marker in Patients with Gastric Helicobacter pylori Infection, Ethiopia

INTRODUCTION

H. pylori are gram-negative, microaerophilic helical-shaped bacteria with multiple flagella and commonly exist in the stomach. This infection may cause significant mucosal inflammation and damage, leading to ulcers in the stomach. It can also affect organ systems external to the gastrointestinal tract. To assess cardiovascular risk factors and to predict cardiovascular disorders, we are evaluating and comparing lipid profile and inflammatory marker between H. pylori-positive and negative patients.

OBJECTIVE

To evaluate and compare lipid profile (TC; TG; LDL; HDL) and inflammatory marker (hs-CRP) in dyspeptic patients with and without H. pylori infection.

METHODS

Comparative cross-sectional study was conducted from September 2020 to January 2021 at Debre Markos Referral Hospital, Debre Markos Health Center, and Hidassie Health Center, Ethiopia. Each of 50 H. pylori-positive and negative dyspeptic patients were studied. The data were checked for completeness and analyzed by SPSS version 25.0 Software. A p-value < 0.05 was considered statistically significant.

RESULTS

Serum mean high-density lipoprotein (HDL) values were 37.54 ± 7.98 mg/dL and 43.12 ± 7.86 mg/dL (p < 0.05) for H. pylori-positive and negative dyspeptic patients, respectively, and median serum high sensitive C reactive protein (hs-CRP) levels were 6.29 mg/L (1.66-41.34) and 3.35 mg/L (0.39-10.01) (p < 0.05) for H. pylori-positive and negative dyspeptic patients, respectively.

CONCLUSION

H. pylori infection significantly alters serum high-density lipoprotein (HDL) and high sensitive C reactive protein (hs-CRP) levels in dyspeptic patients, as a result, increase the potential risk of cardiovascular diseases.

Helicobacter pylori infection and susceptibility to cardiac syndrome X: A systematic review and meta-analysis

BACKGROUND

Cardiac syndrome X (CSX) is characterized by persistent angina with normal coronary arteries. Several pathophysiologic mechanisms have been introduced, particularly Helicobacter pylori (H. pylori) infection.

AIM

To investigate the association between H. pylori infection and CSX.

METHODS

All studies related to H. pylori infection and CSX were evaluated by comprehensive searches of global databases such as ISI Web of Knowledge, PubMed, Scopus, EMBASE, and Google scholar. Statistical analyses of selected articles were evaluated based on the summary odds ratio (OR). Finally, heterogeneity and publication bias were estimated using the I² statistic and Cochrane Q-test as well as Begg’s and Egger’s tests.

RESULTS

A total of 11 studies met our inclusion criteria and 1435 patients (63% female, and 37% male) were reviewed. A significant association was observed between female patients and this syndrome (P = 0.02). Our results showed a positive association between infection with this pathogen and presence of CSX (OR: 5.65; 95% confidence interval [CI]: 4.17-7.64; I²: 82.20). However, no significant association was observed with cagA-positive H. pylori strains and this syndrome (OR: 0.97; 0.56-1.70 with 95%CI). Given the heterogeneity and publication bias, the results need to confirmed by further prospective investigation.

CONCLUSION

Based on our results, H. pylori infection is associated with an increased risk of CSX. This bacterium appears to play a major role in the pathogenesis of CXS by inducing persistent inflammation.

Helicobacter pylori Infection Acts Synergistically with a High-Fat Diet in the Development of a Proinflammatory and Potentially Proatherogenic Endothelial Cell Environment in an Experimental Model

Classic atherosclerosis risk factors do not explain all cases of chronic heart disease. There is significant evidence that gut microbiota may influence the development of atherosclerosis. The widespread prevalence of chronic Helicobacter pylori (H. pylori, HP) infections suggests that HP can be the source of components that stimulate local and systemic inflammatory responses. Elevated production of reactive oxygen species during HP infection leads to cholesterol oxidation, which drives atherogenesis. The aim of this study is to explore the link between persistent HP infection and a high-fat diet in the development of proinflammatory conditions that are potentially proatherogenic. An in vivo model of Caviae porcellus infected with HP and exposed to an experimental diet was investigated for the occurrence of a proinflammatory and proatherogenic endothelial environment. Vascular endothelial primary cells exposed to HP components were tested in vitro for oxidative stress, cell activation and apoptosis. The infiltration of inflammatory cells into the vascular endothelium of animals infected with HP and exposed to a high-fat diet was observed in conjunction with an increased level of inflammatory markers systemically. The arteries of such animals were the least elastic, suggesting the role of HP in arterial stiffness. Soluble HP components induced transformation of macrophages to foam cells in vitro and influenced the endothelial life span, which was correlated with Collagen I upregulation. These preliminary results support the hypothesis that HP antigens act synergistically with a high-fat diet in the development of proatherogenic conditions.

Dyslipidemia and Associated Factors Among Patients Suspected to Have Helicobacter pylori Infection at Jimma University Medical Center, Jimma, Ethiopia

BACKGROUND

Dyslipidemia is a group of plasma lipid and lipoprotein abnormality that is metabolically associated, and it is categorized by low HDL-C and increased LDL-C, TGs, and total cholesterol (TC) levels. Colonization of the stomach by Helicobacter pylori (H. pylori) causes chronic inflammation of the stomach wall which can change some biochemical factors in the patient. On the association of H. pylori infection and its contributions to change in serum lipid profile, different studies reported varying outcomes.

OBJECTIVE

To assess the prevalence of dyslipidemia and associated factors among patients suspected for H. pylori infection in the outpatient department of Jimma University Medical Center, Jimma, Ethiopia.

MATERIALS AND METHODS

A hospital-based cross-sectional study was conducted from January 03 to April 05, 2019, at Jimma University Medical Center on 369 H. pylori suspected patients. The study subjects were selected by convenient sampling technique. About 5mL of blood was collected from an overnight fasting individual. Data were edited, coded, and entered into Epidata version 3.1 and exported to (SPSS) version 25 for analysis. Bivariate analysis was used to screen those variables which were candidates for multivariate analysis.

RESULTS

From the total study subjects 77.5% had at least one abnormality in lipid profile and 87.2% of H. pylori positive patients had at least one abnormality in lipid profile. Our study demonstrated that there was significant increase of mean ± SD of TC, TG, and LDL-C in H. pylori positive patients than H. pylori negative patients (P-value < 0.05). After adjusting for traditional dyslipidemia risk factors, H. pylori infection was an independent predictor of dyslipidemia (AOR 2.628, 95% CI 1.477-4.678, P=0.001).

CONCLUSION

An increase in prevalence of dyslipidemia among H. pylori positive patients indicates H. pylori infected patients have a possibility of altered lipid profile, therefore assessment of lipid profile in H. pylori infected patients is recommended.

Anti-Glycan Autoantibodies Induced by Helicobacter pylori as a Potential Risk Factor for Myocardial Infarction

A number of epidemiological studies have evaluated the potential association between H. pylori and cardiovascular disease, but with contrasting results. We have previously shown that Helicobacter pylori infection is able to induce in mice and humans autoantibodies cross-reacting with histo–blood group Lewis antigens, expressed in different organs and in plasma glycoproteins and glycolipids. The aim of this study was to assess whether immunization of animals with H. pylori might induce myocardial histopathological changes. We have retrospectively examined, in detail, the histology of archived organs from mice and rabbits immunized with H. pylori in our previous studies. Human sera and cross-reacting monoclonal antibodies were also tested against bacterial preparations and tissue sections. Areas of myocardial necrosis, associated with coronary thrombotic occlusion, were found in 5 of 20 mice and 2 of 5 rabbits previously immunized with suspensions of H. pylori. No similar lesions were found in control animals, suggesting a causal link with H. pylori immunization. The animals bearing myocardial lesions had not been infected but only immunized months earlier with parenteral injections of dead H. pylori cells. This strongly suggests that immunization, by itself, might play a causative role. We propose that the cross-reactive autoimmune response induced by H. pylori could promote thrombotic occlusion through direct endothelial damage or by perturbing the coagulation process.

Escherichia coli lipopolysaccharide may affect the endothelial barrier and IL-10 expression of apolipoprotein B100-pulsed dendritic cells

Atherogenesis is associated with chronic gut infections; however, the mechanisms are not clear. The aim of the study was to determine whether lipopolysaccharide of E. coli (E. coli LPS) may affect endothelial barrier and modify IL-10 expression in dendritic cells (DCs). Human umbilical vein endothelial cells (HUVECs) and monocyte-derived DCs were treated with E. coli LPS, apolipoprotein B100 (ApoB100) and 7-ketocholesterol (7-kCH) - harmful oxidized form of cholesterol. The effect of E. coli LPS, 7-kCH and ApoB100 on the barrier functions of HUVECs in real-time cell electric impedance sensing system (RTCA-DP) was assessed. Furthermore, the effect of 7-kCH and ApoB100 on barrier functions of HUVECs co-cultured with DCs previously treated with LPS was analyzed. Both E. coli LPS and 7-kCH decreased barrier functions of HUVECs and reduced tight junction protein mRNA expression, whereas ApoB100 increased endothelial barrier. In DCs, ApoB100 and E. coli LPS decreased IL-10 mRNA expression. In HUVECs co-cultured with DCs treated with LPS and subsequently pulsed with ApoB100 or 7-kCH, IL-10 mRNA expression was lower. E. coli LPS-exposed DCs diminished the protective effect of ApoB100 on endothelial integrity and led to the decrease in occludin mRNA expression. LPS potentially derived from gut microflora may destabilize endothelial barrier together with oxidized cholesterol and intensify the immunogenicity of ApoB100.

Inflammatory responses induced by Helicobacter pylori on the carcinogenesis of gastric epithelial GES‑1 cells

Helicobacter pylori (HP) is a pathogenic bacterium associated with chronic gastritis, gastric ulcer and gastric cancer. In the present study, the primary carcinogenesis process of normal gastric epithelial cells (GES‑1) infected with HP was investigated. It was determined that infected gastric mucosal epithelial GES‑1 cells secreted increased interleukin‑8 (IL‑8) and IL‑23, and exhibited enhanced expression of inducible nitric oxide synthase and cyclooxygenase‑2, inducing inflammatory reactions and resulting in apoptosis. The bacterial infection significantly increased the expression of carcinogenesis‑associated genes, including p16, c‑Myc, p53 and p21, as well as the expression of cell surface signaling molecules cluster of differentiation 44 (CD44) and CD54 in GES‑1 cells or tissues of patients with gastritis and gastric cancer in vitro or in vivo. Simultaneously, the migration and invasion abilities of normal gastric epithelial GES‑1 cells were increased following HP infection. These observations demonstrated that the inflammatory response of HP infection could cause normal gastric epithelial cells to undergo significant cancerous reactions, indicating that HP is a risk factor for gastric cancer.

Autoantibodies to a specific peptide epitope of human Hsp60 (ATVLA) with homology to Helicobacter pylori HspB in H. pylori-infected patients

Helicobacter pylori (Hp) may initiate autoimmunity as a result of molecular mimicry. The aim of this study was to compare the level of IgG antibodies to a specific epitope (P1 peptide) of human heat shock protein (Hsp)60 homologous to Hp Hsp60 (HspB) in the sera of healthy donors (HD), patients with Hp-related gastritis or coronary heart disease (CHD), uninfected or with Hp infection confirmed by rapid urease test, histological examination (dyspeptic patients) the ¹³ C urea breath test (¹³ C UBT), and anti-Hp antibodies (healthy donors, CHD patients). The Anti-P1 IgG induction by Hp was verified by adsorption of sera with these bacteria and by experimental immunization of Caviae porcellus with Hp. Cytokine secretion by THP-1Blue™ monocytes in response to P1 was also assessed. Anti-P1 antibodies were detected in patients with gastritis or CHD infected with Hp and they were not found in uninfected individuals or asymptomatic carriers. No antibodies were raised against P2 in any group. Reduced cross-reactivity to P1 was exhibited by sera adsorbed with Hp. Caviae porcellus infected with Hp produced anti-P1 autoantibodies. THP-1XBlue™ monocytes responded to P1 by production of proinflammatory cytokines. Autoantibodies against P1 in Hp-positive patients with gastritis or CHD and upregulation of proinflammatory cytokines by P1 may contribute to the pathogenesis of Hp infection.

Helicobacter pylori outer membrane vesicles involvement in the infection development and Helicobacter pylori-related diseases

Helicobacter pylori - (H. pylori) play a role in the pathogenesis of gastritis, gastric and duodenal ulcers as well as gastric cancer. A possible involvement of outer membrane vesicles (OMVs) produced by H. pylori in the distribution of bacterial antigens through the gastric epithelial barrier and their role in the development of local and systemic host inflammatory and immune responses has been suggested. OMVs contain various biologically active compounds, which internalize into host cells affecting signaling pathways and promoting apoptosis of gastric epithelial and immunocompetent cells. OMVs-associated H. pylori virulence factors may strengthen or downregulate the immune responses leading to disease development. This review describes the biological importance of H. pylori OMVs and their role in the course of H. pylori infections, as well as H. pylori related local and systemic effects.

H. pylori infection and extra-gastroduodenal diseases

Helicobacter pylori infection is the principal cause of peptic ulcer disease, gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue lymphoma. Recent studies have shown that it may interfere with many biological processes and determine or influence the occurrence of many diseases outside the stomach. Currently, the role of H. pylori in idiopathic thrombocytopenic purpura and iron deficiency anemia is well documented. Emerging evidence suggests that it may also contribute to vitamin B12 deficiency, insulin resistance, metabolic syndrome, diabetes mellitus and non-alcoholic liver disease. Additionally, it may increase the risk of acute coronary syndrome, cerebrovascular disease, neurodegenerative disease and other miscellaneous disorders. Different pathogenic mechanisms have been hypothesized, including the occurrence of molecular mimicry and the induction of a low-grade inflammation. This review summarizes the results of the most relevant studies on the extra-gastroduodenal manifestations of H. pylori infection.

Helicobacter pylori and extragastric diseases: A review

Helicobacter pylori (H. pylori) infection is very common and affects approximately half of the world population. It causes gastric diseases, but some authors have reported an association of H. pylori infection with other systemic manifestations beginning in 1994. The list of potential effects of H. pylori outside the stomach includes a number of extragastric manifestations and we focused on neurological, dermatological, hematologic, ocular, cardiovascular, metabolic, allergic, and hepatobiliary diseases. This review discusses these important reported manifestations that are not related to the gastrointestinal tract.

Current Helicobacter pylori infection is significantly associated with subclinical coronary atherosclerosis in healthy subjects: A cross-sectional study

Helicobacter pylori is a gastrointestinal pathogen known to be associated with cardiovascular disease (CVD). However, most analyses about the effect of H. pylori infection have been done in patients with a history of CVD but not in healthy subjects. We evaluated the association between H. pylori infection and subclinical atherosclerosis by using cardiac multidetector computed tomography (MDCT) in healthy subjects without previous CVD. From December 2007 to February 2014, 463 subjects who underwent the rapid urease test (CLO test), pulse-wave velocity (PWV) measurement, and MDCT for a self-referred health check-up were enrolled to this study. Helicobacter pylori infection was defined on the basis of CLO test positivity on endoscopic gastric biopsy. Significant coronary artery stenosis was defined as ≥50% stenosis in any of the major epicardial coronary vessel on MDCT. The CLO-positive subjects had a lower high-density lipoprotein-cholesterol (HDL-cholesterol) level compared to the CLO-negative subjects. The incidence of significant coronary stenosis was higher in the CLO-positive group (7.6% vs. 2.9%, P = 0.01). Furthermore, the number of subjects with coronary artery calcium score >0 and log{(number of segments with plaque)+1} were also significantly higher in the CLO-positive group. However, there was no statistical difference in the number of subjects with coronary artery calcium score >100, the prevalence of any plaque nor the plaque characteristics (calcified, mixed, or soft). Pulse-wave velocity (PWV) was neither associated with CLO test positivity. The CLO-positive group was 3-fold more likely to have significant coronary artery stenosis even after adjusting for confounding factors (adjusted odds ratio 2.813, 95% confidence interval 1.051–7.528, P = 0.04). In a healthy population, current H. pylori infection was associated with subclinical but significant coronary artery stenosis. The causal relationship between H. pylori infection and subclinical atherosclerosis in a “healthy” population remains to be investigated in the future.

The association of Helicobacter pylori with choroidal and retinal nerve fiber layer thickness

PURPOSE

To investigate the effect of Helicobacter pylori (H. pylori) infection on choroidal thickness (CT) and retinal nerve fiber layer thickness (RNFLT).

METHODS

The study included 25 patients with H. pylori infection and 25 healthy individuals as the control group. Helicobacter pylori patients were classified as the pre-treatment (Group 1; n: 25) and the post-treatment (Group 2; n: 25). RNFLT and CT were measured before and after treatment of H. pylori infection, using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (Spectralis, Heidelberg Engineering, Heidelberg, Germany). The axial length and intraocular pressure were also measured.

RESULTS

The mean subfoveal CT was 320.96 ± 29.15 μm in Group 1 and 287.48 ± 49.17 in the control group (p = 0.007), while the mean subfoveal CT did not show any difference between Group 2 and the control group (p > 0.05). No statistically significant difference was determined between the H. pylori patients and the control group in respect of RNFLT values (p > 0.05).

CONCLUSIONS

CT increases during H. pylori infection and returns to the normal range within 6 weeks of treatment. RNFLT does not show any change during H. pylori infection. The data related to the subfoveal CT may be useful in understanding the pathogenesis of central serous chorioretinopathy developing in H. pylori patients.

Molecular mimicry in Helicobacter pylori infections

Gram-negative bacteria Helicobacter pylori (H. pylori) colonize gastric mucosa in humans and increase the risk of serious diseases such as gastric and duodenal ulcers, stomach cancers and mucosa associated lymphoid tissue lymphoma. The role of H. pylori infection in the pathogenesis of several extragastric diseases has been suggested including immune thrombocytopenic purpura, iron deficiency anemia, vitamin D deficiency, cardiovascular diseases, diabetes mellitus and dermatological disorders. Also neurological diseases and even lung cancer have attracted researchers concern. The relation between H. pylori infection and a growth retardation in children has also been suggested. Many mechanisms of molecular mimicry between H. pylori and the host have been proposed as a pathogen strategy to manipulate the immune system of the host in order to remain unrecognized and avoid eradication. A lot of effort has been put into the demonstration of homologous sequences between H. pylori and host compounds. However, knowledge about how often autoantibodies or autoreactive T lymphocytes induced during H. pylori infections cause pathological disorders is insufficient. This review provides data on H. pylori antigenic mimicry and possible deleterious effects due to the induction of immune response to the components common to these bacteria and the host.

幽门螺杆菌感染与心血管疾病

随着社会经济的发展与生活方式的改变, 心血管疾病的发生率明显上升, 相关的危险因素包括年龄、吸烟、肥胖、糖尿病、高血压和血脂异常等, 但仍有一部分心血管疾病尚未发现确切病因. 近年来, 随着幽门螺杆菌(Helicobacter pylori, H. pylori)研究的不断深入, 发现其与多种胃肠外疾病的发生发展密切相关. 目前国内外多项研究探讨了H. pylori感染与心血管疾病的相关性, 多数研究认为心血管疾病患者H. pylori感染率明显增加, 联合H. pylori根除治疗有益于心血管疾病的防治, 但也有结果并不完全一致. 本文就心血管疾病中H. pylori感染的研究现状, 根除H. pylori对心血管疾病的影响以及H. pylori感染诱导心血管疾病的机制等方面的相关研究作一综述.

Host pathogen interactions in Helicobacter pylori related gastric cancer

Helicobacter pylori (H. pylori), discovered in 1982, is a microaerophilic, spiral-shaped gram-negative bacterium that is able to colonize the human stomach. Nearly half of the world's population is infected by this pathogen. Its ability to induce gastritis, peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma has been confirmed. The susceptibility of an individual to these clinical outcomes is multifactorial and depends on H. pylori virulence, environmental factors, the genetic susceptibility of the host and the reactivity of the host immune system. Despite the host immune response, H. pylori infection can be difficult to eradicate. H. pylori is categorized as a group I carcinogen since this bacterium is responsible for the highest rate of cancer-related deaths worldwide. Early detection of cancer can be lifesaving. The 5-year survival rate for gastric cancer patients diagnosed in the early stages is nearly 90%. Gastric cancer is asymptomatic in the early stages but always progresses over time and begins to cause symptoms when untreated. In 97% of stomach cancer cases, cancer cells metastasize to other organs. H. pylori infection is responsible for nearly 60% of the intestinal-type gastric cancer cases but also influences the development of diffuse gastric cancer. The host genetic susceptibility depends on polymorphisms of genes involved in H. pylori-related inflammation and the cytokine response of gastric epithelial and immune cells. H. pylori strains differ in their ability to induce a deleterious inflammatory response. H. pylori-driven cytokines accelerate the inflammatory response and promote malignancy. Chronic H. pylori infection induces genetic instability in gastric epithelial cells and affects the DNA damage repair systems. Therefore, H. pylori infection should always be considered a pro-cancerous factor.

Population attributable burden of Helicobacter pylori-related gastric cancer, coronary heart disease, and ischemic stroke in China

Helicobacter pylori, a risk factor of cancer and chronic diseases, remains highly prevalent in China. This review aims to systematically evaluate the H. pylori-attributable burden for gastric cancer (GC), coronary heart disease (CHD), and ischemic stroke (IS) in the Chinese population. Helicobacter pylori prevalence was updated by pooling the results reported in studies across China. The population attributable fraction (PAF) was calculated based on the H. pylori prevalence 10 years ago and relative risks of specific disease by reviewing the prospective studies published from 2000 through 2015. In China, the nationwide average prevalence of H. pylori was estimated to be 42.06 % in the general population during 2009-2013. The fixed effects pooled relative risk (RR) of 1.89 [95 % confidence interval (CI): 1.57-2.26] was obtained for gastric cancer and H. pylori infection. Helicobacter pylori infection was responsible for around 37.38 % of noncardia GC, corresponding to about 105,536 cases in 2012. As for extra-gastric disorders, H. pylori infections had higher risk of CHD (RR = 1.55, 95 % CI: 1.37-1.76) and IS (RR = 1.54, 95 % CI: 1.42-1.66). About 23.15 % of CHD and 22.29 % of IS were attributable to H. pylori infection. The estimates of H. pylori-attributable burden reveal a great potential of reducing H. pylori-related chronic disease burden by H. pylori eradication. Large prospective studies are warranted to identify which H. pylori strains, which subtypes of the disease, and which subgroups of the population have the greatest risk of relevant diseases and the effect of H. pylori eradication on the prevention of H. pylori-related diseases.

Impact of Helicobacter pylori on the healing process of the gastric barrier

AIM

To determine the impact of selected well defined Helicobacter pylori (H. pylori) antigens on gastric barrier cell turnover.

METHODS

In this study, using two cellular models of gastric epithelial cells and fibroblasts, we have focused on exploring the effects of well defined H. pylori soluble components such as glycine acid extract antigenic complex (GE), subunit A of urease (UreA), cytotoxin associated gene A protein (CagA) and lipopolysaccharide (LPS) on cell turnover by comparing the wound healing capacity of the cells in terms of their proliferative and metabolic activity as well as cell cycle distribution. Toxic effects of H. pylori components have been assessed in an association with damage to cell nuclei and inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation.

RESULTS

We showed that H. pylori GE, CagA and UreA promoted regeneration of epithelial cells and fibroblasts, which is necessary for effective tissue healing. However, in vivo increased proliferative activity of these cells may constitute an increased risk of gastric neoplasia. In contrast, H. pylori LPS showed a dose-dependent influence on the process of wound healing. At a low concentration (1 ng/mL) H. pylori LPS accelerated of healing epithelial cells, which was linked to significantly enhanced cell proliferation and MTT reduction as well as lack of alterations in cell cycle and downregulation of epidermal growth factor (EGF) production as well as cell nuclei destruction. By comparison, H. pylori LPS at a high concentration (25 ng/mL) inhibited the process of wound repair, which was related to diminished proliferative activity of the cells, cell cycle arrest, destruction of cell nuclei and downregulation of the EGF/STAT3 signalling pathway.

CONCLUSION

In vivo H. pylori LPS driven effects might lead to the maintenance of chronic inflammatory response and pathological disorders on the level of the gastric mucosal barrier.

Correlation between coronary atherosclerotic heart disease and Helicobacter pylori infection

AIM: To investigate the relationship between Helicobacter pylori (H. pylori) infection and coronary atherosclerotic heart disease (CAHD).

METHODS: A total of 1030 patients with CAHD and 1116 patients with non-coronary atherosclerotic heart disease underwent ¹⁴C-urea breath test. H. pylori positive rate were compared between the two groups. The CAHD group was further divided into two groups according to the test results for H. pylori: an H. pylori positive group and an H. pylori negative group. According to SYNTAX score, CAHD patients were divided into a low risk group, a moderate risk group, and a high risk group, and the difference in H. pylori positive rates was analyzed.

RESULTS: The positive rate of H. pylori in patients with CAHD was higher than that of the control group. Serum homocysteine level in H. pylori positive CAHD patients was significantly higher than that in the negative group (P < 0.01). The positive rate of H. pylori in the high risk group was the highest, followed by moderate and low risk groups, but the difference was not statistically significant (P > 0.05). Serum homocysteine level increased with the increasing of the CAHD risk degree in H. pylori positive CAHD patients (P < 0.01).

CONCLUSION: H. pylori infection is an important risk factor for CAHD. H. pylori infection may increase the degree of CAHD by elevating serum homocysteine levels, thereby promoting the development of coronary atherosclerosis.

LACK OF ASSOCIATION BETWEEN HELICOBACTER PYLORI'S VIRULENCE AND INCREASED SERUM C-REACTIVE PROTEIN LEVELS IN FUNCTIONAL DYSPEPTIC PATIENTS

ABSTRACT Background Recently, a great variety of studies aimed to investigate and even suggestHelicobacter pylori as an important key factor in gastrointestinal and non-gastrointestinal events development. The well-established relationship between bacterial virulence and increased risk for peptic ulcer or gastric carcinoma is not so clear when comparing inflammation markers alterations, such C-reactive protein, with the pathogen. Objective The objective of this study was to evaluate the presence of H. pylori, bacterial virulence and C-reactive protein serum levels in individuals diagnosed with functional dyspepsia. Methods Were prospectively included in this study 489 dyspeptic individuals. They fulfill Rome III clinical criteria for the diagnosis of functional dyspepsia with no organic disease at endoscopy. The bacterial infection was established by histology and urease rapid test. The levels of serum C-reactive protein were obtained by immunonefelometry and CagA status ofH. pylori positive individuals was determined through an imunoenzimatic assay. Results Prevalence rate of H. pylori was 66.3% and virulence factor CagA was detected in nearly 43% of positive samples. In addition, it has been noticed an association between Ilex paraguariensis(yerba maté) consumption and pathogen's prevalence. An important effect of bacterial infection on inflammation was only observed in gastric epithelium. Conclusion No systemic response to the pathogen, measured through C-reactive protein levels, was observed, regardless of CagA status. Otherwise, the intake of yerba maté should be considered as a cultural factor possibly related toH. pylori's transmission.

Meta-analysis of relationship between Helicobacter pylori infection and level of insulin resistance

AIM: To investigate the association between Helicobacter pylori (H. pylori) infection and level of insulin resistance (IR).

METHODS: The articles on the association of H. pylori with IR level were retrieved by searching databases from the inception of each database to July 2015. Data extraction and quality assessment were completed by two authors. Meta-analysis was performed using RevMan 5.3 software.

RESULTS: Seven papers with nine studies were included for meta-analysis. A total of 3097 patients, including 1718 H. pylori (+) subjects, were involved. The results of Meta-analysis showed that there was a significant difference in insulin resistance levels between patients with H. pylori infection and those without in the overall population (WMD = 0.38, 95%CI: 0.13-0.64, P < 0.05). Subgroup analysis indicated that the significant difference in insulin resistance levels between patients with H. pylori infection and those without existed in patients aged < 45 years (WMD = 0.63, 95%CI: 0.40-0.86, P < 0.05), those who underwent endoscopic biopsy (WMD = 0.70, 95%CI: 0.46-0.94, P < 0.05), those who had a body mass index (BMI) < 25 kg/m² (WMD = 0.72, 95%CI:0.49-0.96, P < 0.05), and Asian patients (WMD = 0.66, 95%CI: 0.44-0.87, P < 0.05), but not in patients aged ≥ 45 years, those who underwent serum H. pylori-IgG antibody testing, those who had a BMI ≥ 25 kg/m², or American patients. The results of publication bias and sensitivity analysis confirmed the reliability and stability of this Meta-analysis.

CONCLUSION: H. pylori infection is associated with elevated insulin resistance.