Burden of Helicobacter pylori and H. pylori-related diseases in developed countries: recent developments and future implications

Helicobacter pylori and oral-gut microbiome: clinical implications

More than half of the world's population are colonized with H. pylori; however, the prevalence varies geographically with the highest incidence in Africa. H. pylori is probably a commensal organism that has been associated with the development of gastritis, ulcers, and gastric cancer. H. pylori alone is most probably not enough for the development of gastric carcinoma, but evidence for its association with the disease is high and has, therefore, been classified by the International Agency for Research on Cancer as a Class 1 carcinogen. Bacteroidetes and Fusobacteria positively coexisted during H. pylori infection along the oral-gut axis. The eradication therapy required to treat H. pylori infection can also have detrimental consequences for the gut microbiota, leading to a decreased alpha diversity. Therefore, therapy regimens integrated with probiotics may abolish the negative effects of antibiotic therapy on the gut microbiota. These eradication therapies combined with probiotics have also higher rates of eradication, when compared to standard treatments, and are associated with reduced side effects, improving the patient's compliance. The eradication therapy not only affects gut microbiome but also affects the oral microbiome with robust predominance of harmful bacteria. However, there have been reports of a protective role of H. pylori in Barrett's esophagus, esophageal adenocarcinoma, eosinophilic esophagitis, IBD, asthma, and even multiple sclerosis. Therefore, eradication therapy should be carefully considered, and test to treat policy should be tailored to specific communities especially in highly endemic areas. Supplementation of probiotics, prebiotics, herbals, and microbial metabolites to reduce the negative effects of eradication therapy should be considered. After failure of many eradication attempts, the benefits of H. pylori eradication should be carefully balanced against the risk of adverse effects especially in the elderly, persons with frailty, and intolerance to antibiotics.

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.

Helicobacter pylori and Epstein-Barr Virus Co-Infection in Gastric Disease: What Is the Correlation with p53 Mutation, Genes Methylation and Microsatellite Instability in a Cohort of Sicilian Population?

Genetic predisposition, environmental factors, and infectious agents interact in the development of gastric diseases. Helicobacter pylori (Hp) and Epstein-Barr virus (EBV) infection has recently been shown to be correlated with these diseases. A cross-sectional study was performed on 100 hospitalized Italian patients with and without gastric diseases. The patients were stratified into four groups. Significant methylation status differences among CDH1, DAPK, COX2, hMLH1 and CDKN2A were observed for coinfected (Hp-EBV group) patients; particularly, a significant presence of COX2 (p = 0.0179) was observed. For microsatellite instability, minor stability was described in the Hp-HBV group (69.23%, p = 0.0456). Finally, for p53 mutation in the EBV group, exon 6 was, significantly, most frequent in comparison to others (p = 0.0124), and in the Hp-EBV group exon 8 was, significantly, most frequent in comparison to others (p < 0.0001). A significant positive relationship was found between patients with infection (Hp, EBV or both) and p53 mutation (rho = 0.383, p = 0.0001), methylation status (rho = 0.432, p < 0.0001) and microsatellite instability (rho = 0.285, p = 0.004). Finally, we observed among infection and methylation status, microsatellite instability, and p53 mutation a significant positive relationship only between infection and methylation status (OR = 3.78, p = 0.0075) and infection and p53 mutation (OR = 6.21, p = 0.0082). According to our analysis, gastric disease in the Sicilian population has different pathways depending on the presence of various factors, including infectious agents such as Hp and EBV and genetic factors of the subject.

Anti-Heliobacter pylori and Anti-Inflammatory Potential of Salvia officinalis Metabolites: In Vitro and In Silico Studies

Due to its rising antibiotic resistance and associated inflammations, Helicobacter pylori poses a challenge in modern medicine. Salvia officinalis, a member of the Lamiaceae family, is a promising medicinal herb. In this regard, a phytochemical screening followed by GC-MS and LC-MS was done to evaluate the chemical profile of the total ethanolic extract (TES) and the essential oil, respectively. The anti-H. pylori and the anti-inflammatory activities were evaluated by a micro-well dilution technique and COX-2 inhibition assay. Potential anti-H. pylori inhibitors were determined by an in silico study. The results revealed that the main metabolites were flavonoids, sterols, volatile oil, saponins, and carbohydrates. The LC-MS negative ionization mode demonstrated 12 compounds, while GC-MS showed 21 compounds. Carnosic acid (37.66%), epirosmanol (20.65%), carnosol1 (3.3%), and 12-O-methyl carnosol (6.15%) were predominated, while eucalyptol (50.04%) and camphor (17.75%) were dominant in LC-MS and GC-MS, respectively. TES exhibited the strongest anti-H. pylori activity (3.9 µg/mL) asymptotic to clarithromycin (0.43 µg/mL), followed by the oil (15.63 µg/mL). Carnosic acid has the best-fitting energy to inhibit H. pylori (-46.6769 Kcal/mol). TES showed the highest reduction in Cox-2 expression approaching celecoxib with IC₅₀ = 1.7 ± 0.27 µg/mL, followed by the oil with IC₅₀ = 5.3 ± 0.62 µg/mL. Our findings suggest that S. officinalis metabolites with anti-inflammatory capabilities could be useful in H. pylori management. Further in vivo studies are required to evaluate and assess its promising activity.

Management of H. pylori Induced Peptic ulcer – A Phytotherapeutic Approach

A peptic ulcer is a chronic infectious disease that creates erosion on the epithelial lining of the stomach. It is a commonly encountered problem in the gastrointestinal tract (GI tract). Patients failed multiple regimens due to resistant H. pylori infection. H. pylori show maximum resistance towards Clarithromycin. Due to the consistent increase in resistance there is urgent need for the development of new drugs. Paying much for the antibiotic treatment one should go for the natural treatments with no side effects. Modern treatment of peptic ulcers emphasizes diet with routinely recommend hospitalization of several weeks. Currently, a lot of medications are coming out of natural products. The phytotherapeutic approach for the resistant H.pylori treatment is assessed. The plant produces many secondary metabolic substances which have a lot of beneficial roles in maintaining human health. Administration of plant products would prevent disease and able to eradicate resistant H.pylori. This review includes many phytoproducts having a wide range of antimicrobial activity. Reviewed phytoproducts includes Phytoceutical, Caffeic acid, phenethyl ester, Flavonoid, Capsaicin, Carotenoid, etc are effective treatment against H.pylori. To see their effect on the resistant H.pylori and to manage this resistant bacteria with an application of plant products is the prime concern of this review. The linkage between phytochemical and peptic ulcers will provide a novel framework for the future.

Oral organic nanovaccines against bacterial and viral diseases

Vaccines have saved millions of humans and animals from deadly diseases. Many vaccines are still under development to fight against lethal diseases. Indeed, subunit vaccines are a versatile approach with several advantageous attributes, but they lack strong immunogenicity. Nanotechnology is an avenue to vaccine development because nanoparticles may serve as nanocarriers and adjuvants, which are critical aspects for oral vaccines. This review provides an update of oral organic nanovaccines, describing suitable nanomaterials for oral vaccine design and recent (last five-year view) oral nanovaccine developments to fight against those principal pathogens causing human and animal diseases.

Transgenically expressed Helicobacter pylori CagA in vascular endothelial cells accelerates arteriosclerosis in mice

Arteriosclerosis is intimately associated with cardiovascular diseases. Recently, evidence accumulated that infection with Helicobacter pylori cagA-positive strains, which causes gastritis, peptic ulceration, and gastric cancer, is also involved in the development of arteriosclerosis. The cagA-encoded CagA protein is injected into the attached gastric epithelial cells via the type IV secretion system. We previously showed that CagA-containing exosomes are secreted from CagA-injected gastric epithelial cells and enter the systemic blood circulation, delivering CagA into endothelial cells. In the present study, transgenic mice were established in which CagA was selectively expressed in endothelial cells by Cre-loxP system. Treatment of the mice with a high-fat diet revealed that atherogenic lesions were induced in mice expressing CagA in vascular endothelial cells but not in CagA-nonexpressing mice. To investigate the effects of CagA on endothelial cells, we also established conditional CagA-expressing human vascular endothelial cells using the Tet-on system. Upon induction of CagA, a dramatic change in cell morphology was observed that was concomitantly associated with the loss of the endothelial cells to form tube-like structures. Induction of CagA also activated the pro-inflammatory transcription factor STAT3. Thus, exosome-delivered CagA deregulates signals that activates STAT3 in endothelial cells, which accelerates inflammation that promotes arteriosclerosis/atherosclerosis.

Helicobacter pylori acquisition rates and the associated risk factors amongst newlywed couples; a prospective cohort study in Tehran, Iran

BACKGROUND

The rates and routes of Helicobacter pylori transmission, in a high prevalent country like Iran, with gastric cancer as the leading cause of male cancer mortality is of essence. Here, we have studied the H. pylori-associated risk factors and the likelihood of interspousal transmission.

METHODS

In a cohort of 686 young prewed couples, questionnaires were self-administered and serum samples were collected, for assessment of risk factors and sero-status of H. pylori, at baseline and follow-up. Of the 475 H. pylori single- or double-seronegative couples, 201 returned for follow-up. The average follow-up duration was 2.2 (SD 0.6) years, with a total of 560.1 person-years. Logistic regression and Cox regression models were used to estimate the odds ratios (ORs) and hazard ratios (HRs).

RESULTS

The risk of infection was higher in men than women (OR:1.3, 95%CI:1.0-1.8) and among metropolitan than rural residents (OR=1.4, 95%CI:1.1-1.9). The risk of infection was significantly higher among those with three siblings (OR=1.6, 95%CI:1.1-2.2), and four or more siblings (OR=1.4, 95%CI:1.0-1.9), in reference to those with one or no siblings. H. pylori acquisition occurred in 10.9% (27/247) of the H. pylori seronegative participants. The risk of acquisition was significantly higher in older aged (HR=1.2, 95%CI: 1.1-1.3) and higher educated (HR=0.2, 95%CI:0.1-0.9) participants, than younger and illiterate subjects, respectively. Our analysis did not find any evidence for interspousal transmission (HR=1.0, 95%CI: 0.4-2.2).

CONCLUSION

Although we detected H. pylori acquisition in the young adult Iranian population, our findings did not support interspousal transmission, as a mode of adult H. pylori aquisition.

Targeting Cytotoxin-Associated Antigen A, a Virulent Factor of Helicobacter pylori-Associated Gastric Cancer: Structure-Based In Silico Screening of Natural Compounds

Gastric cancer is the fifth most frequent cancer and the third major cause of mortality worldwide. Helicobacter pylori, a bacterial infection linked with GC, injects the cytotoxin-associated antigen A (CagA; an oncoprotein) into host cells. When the phosphorylated CagA protein enters the cell, it attaches to other cellular components, interfering with normal cellular signaling pathways. CagA plays an important role in the progression of GC by interacting with phosphatidylserine of the host cell membrane. Therefore, disrupting the CagA-phosphatidylserine connection using small molecules appears to be a promising therapeutic approach. In this report, we screened the natural compounds from ZINC database against the CagA protein using the bioinformatics tools. Hits were initially chosen based on their physicochemical, absorption, distribution, metabolism, excretion, and toxicity (ADMET) characteristics, as well as other drug-like characteristics. To locate safe and effective hits, the PAINS filter, binding affinities estimation, and interaction analysis were used. Three compounds with high binding affinity and specificity for the CagA binding pocket were discovered. The final hits, ZINC153731, ZINC69482055, and ZINC164387, were found to bind strongly with CagA protein, with binding energies of -11.53, -10.67, and -9.21 kcal/mol, respectively, which were higher than that of the control compound (-7.25 kcal/mol). Further, based on binding affinity and interaction pattern, two leads (ZINC153731, ZINC69482055) were chosen for molecular dynamics (MD) simulation analysis. MD results showed that they displayed stability in their vicinity at 100 ns. This study suggested that these compounds could be used as possible inhibitors of CagA protein in the fight against GC. However, additional benchwork tests are required to validate them as CagA protein inhibitors.

Helicobacter pylori induced Immune Thrombocytopenic Purpura and perspective role of Helicobacter pylori eradication therapy for treating Immune Thrombocytopenic Purpura

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterised by production of autoantibodies against platelet surface antigens. Recent studies have demonstrated a paramount association of ITP and Helicobacter pylori (H-pylori) infection with significant rise in platelet count following H-pylori eradication therapy. The H-pylori infection induced ITP is validated by many proposed mechanisms such as molecular mimicry due to production of autoantibodies against H-pylori surface virulent factors (CagA) and cross reactivity of these antibodies with platelet surface antigens (GP IIb/IIIa, GP Ib/IX, and GP Ia/IIa), phagocytic perturbation due to enhanced phagocytic activity of monocytes, enhanced dendritic cell numbers and response, platelets aggregation due to presence of anti- H-pylori IgG and von Willebrand factor (vWf) and finally host immune response against H-pylori virulent factors CagA and VacA leading to ITP. The effectiveness of H-pylori eradication therapy has also been demonstrated with platelet count being used as a predictive factor for assessment of treatment efficacy. Out of 201 patients 118 were responding to the triple therapy and remaining 83 patients were non-responders, showing the response rate of 58.7%. Out of 118 responders 69 patients were showing complete response (CR) and 49 were showing partial response (PR) to the H-pylori eradication therapy. However, more studies are required to elucidate this association and treatment efficacy.

Global Incidence and Mortality of Gastric Cancer, 1980-2018

IMPORTANCE

Gastric cancer is one of the most common cancers, with a high mortality-to-incidence ratio. It is uncertain whether developed nations may encounter an increasing burden of gastric cancer in young adults, as occurs for other cancers.

OBJECTIVES

To evaluate the incidence and mortality of gastric cancer and compare the global incidence trends between younger (<40 years) and older (≥40 years) populations.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study analyzed data from global and national cancer registries, including data from 1980 to 2018, with at least 15 calendar years of incidence and mortality data. Data on age-standardized incidence and mortality rates of gastric cancer among 48 countries were retrieved from the Surveillance, Epidemiology, and End Results Program, the National Cancer Institute, the Nordic Cancer Registries, and the World Health Organization Mortality Database. The 10-year incidence trend of gastric cancer was assessed by age and sex. The 2018 GLOBOCAN database was used for reporting the global incidence and mortality of gastric cancer, the most recent data available at the time of analysis. Analyses were performed between January 10, 2020, and March 20, 2020.

MAIN OUTCOMES AND MEASURES

The average annual percent change (AAPC) of the incidence and mortality trends as evaluated by joinpoint regression analysis.

RESULTS

A total of 1 033 701 new cases of gastric cancer and 782 685 related deaths were reported in 2018. Overall, the incidence of gastric cancer decreased in 29 countries, and mortality decreased in 41 countries. The age-standardized incidence of gastric cancer decreased from a range of 2.6 to 59.1 in 1980 to a range of 2.5 to 56.8 in 2018 per 100 000 persons. The overall age-standardized mortality rate changed from a range of 1.3 to 25.8 in 1980 to a range of 1.5 to 18.5 in 2018 per 100 000 persons, but increasing mortality was observed in Thailand (female: AAPC, 5.30; 95% CI, 4.38-6.23; P < .001; male: AAPC, 3.92; 95% CI, 2.14-5.74; P < .001). The incidence of gastric cancer decreased in most regions among individuals 40 years or older and increased in populations younger than 40 years in several countries, including Sweden (male: AAPC, 13.92; 95% CI, 7.16-21.11; P = .001), Ecuador (female: AAPC, 6.05; 95% CI, 1.40-10.92; P = .02), and the UK (male: AAPC, 4.27; 95% CI, 0.15-8.55; P = .04; female: AAPC, 3.60; 95% CI, 3.59-3.61; P < .001).

CONCLUSIONS AND RELEVANCE

In this population-based cohort study, an increasing incidence of gastric cancer was observed in younger individuals in some countries, highlighting the need for more preventive strategies in younger populations. Future research should explore the reasons for these epidemiologic trends.

Three-Decade Failure to the Eradication of Refractory Helicobacter pylori Infection and Recent Efforts to Eradicate the Infection

BACKGROUND

Helicobacter pylori causes dangerous and deadly diseases such as gastric cancer and duodenal ulcers. Eradication and treatment of this bacterium are very important due to the deadly diseases caused by H. pylori and the high cost of treatment for countries.

METHODS

Thus, we present a complete list of the most important causes of failure in the treatment and eradication of H. pylori, and address new therapeutic methods that may be effective in controlling this bacterium in the future.

RESULTS

Many efforts have been made to control and eradicate this bacterium over the years, but no success has been achieved since its eradication is a complex process affected by the bacterial properties and host factors. Previous studies have shown that various factors are involved in the failure to eradicate H. pylori, such as new genotypes of the bacterium with higher pathogenicity, inappropriate patient cooperation, mutations, biofilm formation and dormant forms that cause antibiotic resistance, acidic stomach pH, high bacterial load, smoking, immunosuppressive features and intracellular occurrence of H. pylori. On the other hand, recent studies reported that the use of probiotics, nanoparticles, antimicrobial peptides, natural product and vaccines can be helpful in the treatment and eradication of H. pylori infections.

CONCLUSION

Eradication of H. pylori is crucial for the treatment of important diseases such as gastric cancer. Therefore, it seems that identifying the failure causes of treating this bacterium can be helpful in controlling the infections. Besides, further studies on new therapeutic strategies may help eradicate H. pylori in the future.

Impact of a Fermented High-Fiber Rye Diet on Helicobacter pylori and Cardio-Metabolic Risk Factors: A Randomized Controlled Trial Among Helicobacter pylori-Positive Chinese Adults

Background: High dietary fiber intake has been associated with reduced risk of Helicobacter pylori infection and co-morbidities such as gastric cancer but also with reduced risk of cardiovascular disease. It has been suggested that fermented rye could affect Helicobacter pylori bacterial load and that high- fiber rye may be superior to wheat for improvement of several cardiometabolic risk factors, but few long-term interventions with high fiber rye foods have been conducted. Objective: To examine the effect of high-fiber wholegrain rye foods with added fermented rye bran vs. refined wheat on Helicobacter pylori infection and cardiometabolic risk markers in a Chinese population with a low habitual consumption of high fiber cereal foods. Design: A parallel dietary intervention was set up and 182 normal- or overweight men and women were randomized to consume wholegrain rye products containing fermented rye bran (FRB) or refined wheat (RW) for 12 weeks. Anthropometric measurements, fasting blood sample collection and ¹³C-urea breath test (¹³C-UBT) were performed at baseline and after 6 and 12 weeks of intervention as well as 12 weeks after the end of the intervention. Results: No difference between diets on Helicobacter pylori bacterial load measured by ¹³C-UBT breath test or in virulence factors of Helicobacter pylori in blood samples were found. Low density lipoprotein cholesterol (LDL-C) and high sensitivity C-reactive protein (hs-CRP) were significantly lower in the FRB group, compared to the RW group after 12 weeks of intervention. The intervention diets did not affect markers of glucose metabolism or insulin sensitivity. Conclusions: While the results of the present study did not support any effect of FRB on Helicobacter pylori bacterial load, beneficial effects on LDL-C and hs-CRP were clearly shown. This suggest that consumption of high fiber rye foods instead of refined wheat could be one strategy for primary prevention of cardiovascular disease. Clinical Trial Registration: The trial was registered at www.clinicaltrials.gov, Identifier: NCT03103386.

Predictive Effect of Helicobacter pylori in Gastric Carcinoma Development: Systematic Review and Quantitative Evidence Synthesis

Helicobacter pylori (H. pylori) is a bacterial pathogen implicated in gastritis, gastric ulceration, and gastric carcinoma. This study aimed to synthesize literature in providing evidence on the causative role of H. pylori in gastric carcinoma development. This study is based on assessing public literature using an applied meta-analysis, namely, quantitative evidence synthesis (QES). The analytic procedure uses DerSimonian-Laird, including assessing heterogeneity. The QES also utilizes meta-regression and the environmental effect associated with H. pylori in gastric cancer development. Eighteen studies are included in the QES. There is increased prevalence of H. pylori exposure among the cases. The heterogeneity between the CES and individual effect sizes is also significant. Despite controlling for the confoundings, there is increased exposure to H. pylori among the gastric cancer cases, regardless of the differences in the geographic location. H. pylori in this synthesized literature illustrates the contributory role of this microbe in gastric carcinoma. Additionally, regardless of geographic locale, namely, South Korea or Spain, H. pylori is implicated in gastric cancer development.

Molecular anatomy and pathogenic actions of Helicobacter pylori CagA that underpin gastric carcinogenesis

Chronic infection with Helicobacter pylori cagA-positive strains is the strongest risk factor for gastric cancer. The cagA gene product, CagA, is delivered into gastric epithelial cells via the bacterial type IV secretion system. Delivered CagA then undergoes tyrosine phosphorylation at the Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs in its C-terminal region and acts as an oncogenic scaffold protein that physically interacts with multiple host signaling proteins in both tyrosine phosphorylation-dependent and -independent manners. Analysis of CagA using in vitro cultured gastric epithelial cells has indicated that the nonphysiological scaffolding actions of CagA cell-autonomously promote the malignant transformation of the cells by endowing the cells with multiple phenotypic cancer hallmarks: sustained proliferation, evasion of growth suppressors, invasiveness, resistance to cell death, and genomic instability. Transgenic expression of CagA in mice leads to in vivo oncogenic action of CagA without any overt inflammation. The in vivo oncogenic activity of CagA is further potentiated in the presence of chronic inflammation. Since Helicobacter pylori infection triggers a proinflammatory response in host cells, a feedforward stimulation loop that augments the oncogenic actions of CagA and inflammation is created in CagA-injected gastric mucosa. Given that Helicobacter pylori is no longer colonized in established gastric cancer lesions, the multistep nature of gastric cancer development should include a “hit-and-run” process of CagA action. Thus, acquisition of genetic and epigenetic alterations that compensate for CagA-directed cancer hallmarks may be required for completion of the “hit-and-run” process of gastric carcinogenesis.

Correlation between Helicobacter pylori Infection and Gastric Atrophy Examined in the Sera of Mongolian People

Serum specimens obtained from 680 individuals were examined to measure the amounts of pepsinogens 1 and 2, anti-CagA antibodies, and anti-Helicobacter pylori antibodies. We examined sera obtained from 610 Mongolian individuals living in the capital city, Ulaanbaatar. Seventy serum specimens were collected from Japanese people who were health-screened: These were stored at the gastroenterology laboratory of Jichi Medical University. The sera of the Japanese people were used as a control specimen. Two enzyme-linked immunosorbent assay (ELISA) kits, an E-plate ELISA kit from Eiken Chemical Co., Ltd. (Tokyo, Japan), and a Biohit ELISA kit from Biohit Oyj (Helsinki, Finland), were used for the detection of anti-H. pylori IgG antibodies in the sera of the 610 Mongolian people. An ELISA kit EIA-4138 from DRG Instruments GmbH (Germany) was used for the detection of anti-CagA IgG antibodies in the serum specimens. Serum pepsinogens were detected by an ELISA kit from Biohit Oyj. Of the 610 serum specimens, 385 specimens tested positive for the detection of anti-H. pylori antibodies using the two ELISA kits, and 47 tested negative. For the detection of anti-H. pylori antibodies by the Biohit ELISA kit, 560 and 50 specimens were positive and negative, respectively. The ratio of serum pepsinogen 1/2 was statistically lower (p < 0.0001) in the H. pylori-positive (560 specimens) than in the H. pylori-negative (50 specimens) specimens. However, the levels of serum pepsinogen 1 had no statistical significance (p = 0.465) between the specimens of the H. pylori-positive and -negative specimens. The ratio of serum pepsinogen 1/2 was 6.74 ± 0.12 in the H. pylori-positive specimens, whereas the ratio of serum pepsinogen 1/2 was 12.69 ± 1.02 in the H. pylori-negative specimens. This study demonstrated the high prevalence of H. pylori infection in Mongolian people, including young generations, and the people infected with H. pylori possessed low pepsinogen 1/2 ratios, indicating atrophic gastritis. The serological examinations by the two ELISA kits did not consistently reflect the prevalence of H. pylori infection in Mongolian people.

Biochemical and Biophysical Characterization of the Enolase from Helicobacter pylori

Enolase, which catalyses the conversion of 2-phospho-D-glycerate to phosphoenolpyruvate, is an important enzyme in the classic glycolysis pathway in cells. Enolase is highly conserved in organisms from bacteria to humans, indicating its importance in cells. Thus, enolase is a good target for developing new drugs. In the last decade, new functions of this enzyme have been found. Helicobacter pylori is a common human pathogen that causes gastric diseases and even gastric cancer. In this study, the sequence of H. pylori enolase (HpEno) was analysed; the conservation (at least partial) of binding sites for cofactor, plasminogen, and host extracellular RNA, as well as catalytic site, indicates that HpEno should be capable of performing the functions. Recombinant HpEno was overexpressed and purified from E. coli. Compared to the enolases from other species, HpEno had similar characteristics for its secondary structure. The temperature-induced profiles indicate that HpEno is quite stable to temperature, compared to other homologs. Regarding the kinetics of the unfolding reaction, we found that the activation enthalpy associated with the thermal unfolding reaction is equivalent to the reported activation enthalpy for yeast enolase, indicating a similar scaffold and kinetic stability. Although a wide range of experimental conditions were assayed, it was not possible to detect any enzymatic activity of HpEno. To prove the lack of activity, still a much wider range of experiments should be carried out.

Advances and Opportunities in Nanoparticle- and Nanomaterial-Based Vaccines against Bacterial Infections

As the dawn of the postantibiotic era we approach, antibacterial vaccines are becoming increasingly important for managing bacterial infection and reducing the need for antibiotics. Despite the success of vaccination, vaccines remain unavailable for many pressing microbial diseases, including tuberculosis, chlamydia, and staphylococcus infections. Amid continuing research efforts in antibacterial vaccine development, the advancement of nanomaterial engineering has brought forth new opportunities in vaccine designs. With increasing knowledge in antibacterial immunity and immunologic adjuvants, innovative nanoparticles are designed to elicit the appropriate immune responses for effective antimicrobial defense. Rationally designed nanoparticles are demonstrated to overcome delivery barriers to shape the adaptive immunity. This article reviews the advances in nanoparticle- and nanomaterial-based antibacterial vaccines and summarizes the development of nanoparticulate adjuvants for immune potentiation against microbial pathogens. In addition, challenges and progress in ongoing antibacterial vaccine development are discussed to highlight the opportunities for future vaccine designs.

Gastric cancer & prospects of cancer in Saudi Arabia peninsula

Gastric cancer is classified to be an aggressive disease with poor treatment outcome, as most cases remain undetected until later stages, wherein surgery and few chemotherapeutics become the only recommended treatment course. The process of cancer development is multistep involving many stages and types of precancerous lesions, and hence, routine monitoring becomes a necessity in those detected with these or exposed to risk factors. Studying the pattern of gastric cancer for any geographical region is also important to control mortality and focus on implementation of efficient management and treatment guidelines. The cause for gastric cancer can be genetic, racial as well as environmental, and hence the pattern of this malignancy differs across geographical regions and between the developing and the developed nations. In case of the Kindgom of Saudi Arabia, very few hospital-based reports have been published highlighting the pattern of gastric cancer, and the associated incidence and mortality rates. However, classified to be one of the most crucial cancer forms in Saudi Arabia, research pertaining to epidemiology, presentation and pathological features are limited. Studying gastric cancer occurrence from public health viewpoint is important also because eradication of causative agents like those that H. pylori has also shown been not reduce the risk of cancer development among individuals with atrophic metaplastic gastritis. In case of Saudi Arabia, many inherent risks for this malignancy exists like waterpipe smoking and shift in diet pattern from the traditional Mediterranean diet. Our review focusses on pattern of gastric cancer on a global scale in comparison to scenario in Saudi Arabia. The aim is to encompass all of the less stressed upon facts about this malignancy in the Kingdom, paving way for future work in this regards.

Prevalence of Helicobacter pylori vacA Genotypes and cagA Gene in Dental Plaque of Asymptomatic Mexican Children

The variability in Helicobacter pylori vacA and cagA genes has been related to the progression of the gastrointestinal disease; also the presence of H. pylori in the oral cavity has been associated with periodontal disease in adults, but, in children without dyspeptic symptoms, little is known about this. We evaluated the prevalence of H. pylori and the presence of vacA/cagA genotypes in the oral cavity of Mexican children without dyspeptic symptoms. The gingival status was measured, and dental plaque samples (n = 100) were taken. 38% of children were positive for H. pylori 16S rRNA gene by qPCR. A significant association between H. pylori oral infection and gingival status was observed (P < 0.001). In 34.6% (9/26) of mild gingivitis cases, s1m2 genotype was found, while s1m1 was typed in 50% (3/6) of moderate gingivitis. The cagA prevalence among H. pylori-positive children was 80.8% (21/26), 83.3% (5/6), and 16.7% (1/6) of cases of mild gingivitis, moderate gingivitis, and nongingivitis, respectively (P < 0.001). The s1m1/cagA+ combinational genotype was the most detected in children with gingivitis. Our results suggest that the prevalence of H. pylori and detection of vacA/cagA genotypes-associated gastrointestinal disease in the oral cavity could be related to the progression of gingivitis in asymptomatic children.

Global patterns and trends in stomach cancer incidence: Age, period and birth cohort analysis

The cases of stomach cancer (SC) incidence are increasing per year and the SC burden has remained very high in some countries. We aimed to evaluate the global geographical variation in SC incidence and temporal trends from 1978 to 2007, with an emphasis on the effect of birth cohort. Joinpoint regression and age-period-cohort model were applied. From 2003 to 2007, male rate were 1.5- to 3-fold higher than female in all countries. Rates were highest in Eastern Asian and South American countries. Except for Uganda, all countries showed favorable trends. Pronounced cohort-specific increases in risk for recent birth cohorts were seen in Brazil, Colombia, Iceland, New Zealand, Norway, Uganda and US white people for males and in Australia, Brazil, Colombia, Costa Rica, Czech Republic, Ecuador, Iceland, India, Malta, New Zealand, Norway, Switzerland, United Kingdom, Uganda, US black and white people for females. The cohort-specific ratio for male significantly decreased in Japan, Malta and Spain for cohorts born since 1950 and in Austria, China, Croatia, Ecuador, Russia, Switzerland and Thailand for cohorts born since 1960 and for female in Japan for cohorts born since 1950 and in Canada, China, Croatia, Latvia, Russia and Thailand for cohorts born since 1960. Disparities in incidence and carcinogenic risk persist worldwide. The favorable trends may be due to changes in environmental exposure and lifestyle, including decreased Helicobacter pylori prevalence, increased intake of fresh fruits and vegetables, the availability of refrigeration and decreased intake of salted and preserved food and smoking prevalence.

Prevalence of helicobacter pylori infection among children living in a rural setting in Sub-Saharan Africa

BACKGROUND

Helicobacter pylori infection affects more than half of the world's population. It is generally acquired during childhood with no symptoms but has long- term clinical sequelae. This study estimated the prevalence of H. pylori infection amongst children in a rural environment in Africa.

METHODS

We conducted a cross-sectional study over a four (4)-month period within two rural communities. 240 asymptomatic children were tested using lateral flow immunochromatographic assay for the qualitative detection of H. pylori antigen in a fecal specimen. Statistical analysis and processing was done using Stata version 11.

RESULTS

The mean age of the participants was 10.5 ± 2.7 years with the predominant age range being 8-10 years (34.6%), and a mean household size of 7.1 ± 1.7. The study population showed a female preponderance of 57.1%. 88% of the H. pylori positive children lacked pipe and borehole drinking water. All of the positive H. pylori children practiced open-air defecation. The overall prevalence of H. pylori infection among children in this study was at least 14.2%.

CONCLUSION

Our study demonstrated a high prevalence of H. pylori infection among children in a rural setting. Educational status of parents did not affect H. pylori prevalence but increasing household numbers, female gender, source of drinking water other than pipe and borehole, open-air defecation and younger age were associated with a higher H. pylori prevalence.

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.

Direct detection of Helicobacter pylori in biopsy specimens using a high-throughput multiple genetic detection system

AIM

We evaluated the direct high-throughput multiple genetic detection system (dHMGS) for Helicobacter pylori in gastric biopsies.

MATERIALS & METHODS

One hundred and thirty-three specimens were concurrently analyzed by dHMGS, rapid urease test, culture and sequencing.

RESULTS

dHMGS was highly sensitive and specific for H. pylori identification compared with culture and rapid urease test. The correlation coefficient of the quantitative standard curve was R² = 0.983. A significant difference in the relative H. pylori DNA abundance was found in different gastroduodenal diseases. Concordance rates between dHMGS and sequencing for resistance mutations were 97.1, 100.0, 85.3 and 97.1%, respectively. Finally, dHMGS could efficiently distinguish mixed infection in biopsy specimens.

CONCLUSION

The dHMGS could efficiently diagnose and quantify H. pylori burden in biopsies, simultaneously screening for virulence, antibiotic resistance and presence of the multistrain infections.

Modification of drug delivery to improve antibiotic targeting to the stomach

The obstacles to the successful eradication of Helicobacter pylori infections include the presence of antibiotic-resistant bacteria and therapy requiring multiple drugs with complicated dosing schedules. Other obstacles include bacterial residence in an environment where high antibiotic concentrations are difficult to achieve. Biofilm production by the bacteria is an additional challenge to the effective treatment of this infection. Conventional oral formulations used in the treatment of this infection have a short gastric residence time, thus limiting the duration of exposure of drug to the bacteria. This review summarizes the current research in the development of gastroretentive formulations and the prospective future applications of this approach in the targeted delivery of drugs such as antibiotics to the stomach.

Histologic types of gastric cancer among migrants from the former Soviet Union and the general population in Germany: what kind of prevention do we need?

OBJECTIVE

The incidence of gastric cancer (GC) is high among migrants from Eastern Europe and Asia, but a detailed picture of disease characteristics is missing. Our study examined the incidence of histologic types among resettlers from the former Soviet Union and the general population in Germany to draw conclusions on risk factors and possible prevention strategies.

METHODS

Between 1990 and 2009, all GC diagnoses among a cohort of 18 619 resettlers residing in the Saarland were identified in the Saarland Cancer Registry database. Age-standardized incidence rates (ASRs) of the entire Saarland population and standardized incidence ratios (SIRs) of resettlers compared with the Saarland population were calculated for types according to Laurén. In addition, ASRs and SIRs were modeled using Poisson's regression to investigate time trends.

RESULTS

The ASR of intestinal GC in the Saarland population decreased over time, whereas the ASR of diffuse GC remained unchanged. Resettlers' incidence of intestinal GC was elevated among men [SIR: 3.04, 95% confidence interval (CI): 2.05-4.50] and women (SIR: 2.78, 95% CI: 1.61-4.79), whereas diffuse GC was elevated only among women (SIR: 1.98, 95% CI: 1.07-3.69). No time trends for SIRs could be observed in regression analysis.

CONCLUSION

Different trends of diffuse GC incidence in Germany and the USA underline the importance of environmental risk factors. The continuously elevated risk of GC among male resettlers is probably associated with risk factors affecting exclusively the intestinal type such as a low intake of fruit and vegetables and heavy alcohol consumption. Future prevention programs for resettlers should include dietary measures.

Helicobacter pylori infection: seroprevalence and predictors among healthy individuals in Al Madinah, Saudi Arabia

BACKGROUND

Helicobacter pylori infection is one of the most common chronic bacterial infections among humans worldwide. However, there is no information on the epidemiology of H. pylori infection in Al Madinah, Saudi Arabia.

OBJECTIVE

This study was conducted to determine the seroprevalence of H. pylori in asymptomatic healthy individuals and the possible relationship between H. pylori infection and sociodemographic, lifestyle, and environmental factors in this region.

METHODS

A hospital-based cross-sectional study was conducted on a consecutive sample of asymptomatic healthy individuals. A pilot-tested interview format was used as the research tool. Venous blood was collected from individuals and sera were separated. The enzyme-linked immunosorbent assay was used to determine H. pylori IgG antibody levels in all serum samples.

RESULTS

A total of 456 samples were collected. H. pylori antibodies were found in 129 (28.3%) individuals. Seroprevalence of 16.9% was found in individuals younger than 20 years of age, which gradually increased with age and reached 36.8% by the age of 50. After controlling for the confounding factors, significant independent predictors of seropositive state were: rural residence [odds ratio (OR)=2.5, 95% confidence interval (CI)=1.3, 4.7], crowded housing (OR=1.6, 95% CI=1.1, 2.6), low socioeconomic status (OR=3.3, 95% CI=1.6, 8.8), using tanks for drinking water supply (OR=2.2, 95% CI=1.2, 7.4), active smoking (OR=5.6, 95% CI=3.2, 9.8), alcohol drinking (OR=2.3, 95% CI=1.5, 6.2), eating raw vegetables (OR=3.2, 95% CI=1.4, 7.1), eating spicy food (OR=2.1, 95% CI=1.3, 3.5), and presence of asthmatic/atopic symptoms (OR=2.5, 95% CI=1.3, 5.9). No associations were found between infection and age, gender, source of sewage disposal, eating fruits, or family history of upper gastrointestinal symptoms.

CONCLUSION AND RECOMMENDATIONS

Infection with H. pylori is declining among healthy individuals of Al Madinah, Saudi Arabia. Infection is acquired at an early age and reaches up to 36.9% as age advances. The risk of H. pylori seropositivity was related to socioeconomic, lifestyle, and environmental factors. A nationwide epidemiological study is warranted to determine the seroprevalence of H. pylori in Saudi Arabia.

Crystal structure of truncated FlgD from the human pathogen Helicobacter pylori

Flagellin component D (FlgD) participates in the assembly of flagella, helical tubular structures that provide motility in non-filamentous bacteria. FlgD guides and controls the polymerization of FlgE that builds the hook, a short curved and hollow cylinder that connects the flagellar basal body spanning the cell envelope to the protruding filament. Crystal structures of truncated forms of Helicobacter pylori FlgD from two different strains in two space groups, I422 and P2, are reported here, at 2.2Å and 2.8Å resolution, respectively. Analogously to Pseudomonas aeruginosa and Xanthomonas campestris FlgD proteins, crystallization experiments set up for the full length protein resulted in crystals of a truncated form, lacking both N- and C-terminus ends. The crystal structures of the central domain show that the monomer is composed of a tudor and a fibronectin type III domain. The full length HpFlgD contains a long N-terminal signal region, probably partially flexible, a central globular region and a C-terminal segment with a peculiar repetitive pattern of amino acids. The spatial orientation of the two domains in HpFlgD differs from that of the homologous FlgD family members, P. aeruginosa and X. campestris. This difference together with the observation that HpFlgD assembles into tetramers, both in the solution and in the two crystal forms, strongly suggests that significant differences exist in the molecular organization of the flagella in different bacterial species.

Helicobacter pylori Eradication in Patients with Immune Thrombocytopenic Purpura: A Review and the Role of Biogeography

Idiopathic thrombocytopenic purpura (ITP) is typically a diagnosis of exclusion, assigned by clinicians after ruling out other identifiable etiologies. Since a report by Gasbarrini et al. in 1998, an accumulating body of evidence has proposed a pathophysiological link between ITP and chronic Helicobacter pylori (H. pylori) infection. Clinical reports have described a spontaneous resolution of ITP symptoms in about 50% of chronic ITP patients following empirical treatment of H. pylori infection, but response appears to be geography dependent. Studies have also documented that ITP patients in East Asian countries are more likely to express positive antibody titers against H. pylori-specific cytotoxic-associated gene A (CagA), a virulence factor that is associated with an increased risk for gastric diseases including carcinoma. While a definitive mechanism by which H. pylori may induce thrombocytopenia remains elusive, proposed pathways include molecular mimicry of CagA by host autoantibodies against platelet surface glycoproteins, as well as perturbations in the phagocytic activity of monocytes. Traditional treatments of ITP have been largely empirical, involving the use of immunosuppressive agents and immunoglobulin therapy. However, based on the findings of clinical reports emerging over the past 20 years, health organizations around the world increasingly suggest the detection and eradication of H. pylori as a treatment for ITP. Elucidating the exact molecular mechanisms of platelet activation in H. pylori-positive ITP patients, while considering biogeographical differences in response rates, could offer insight into how best to use clinical H. pylori eradication to treat ITP, but will require well-designed studies to confirm the suggested causative relationship between bacterial infection and an autoimmune disease state.

Investigation of association between oipA and iceA1/iceA2 genotypes of Helicobacter pylori and gastric cancer in Iran

BACKGROUND

H pylori is the main causative agent of Gastric cancer and chronic gastritis. Genetic diversity of H. pylori has major contribution in its pathogenesis. We investigated the prevalence of oipA and iceA1/iceA2 positive strains of H. pylori among patients with gastric cancer and gastritis.

MATERIALS AND METHODS

Sampling performed by means of endoscopy from 86 patients. DNA was extracted from tissue samples using DNA extraction kit. PCR assay was performed and products were monitored by Agarose Gel Electrophoresis.

RESULTS

Urease Test and 16S rRNA PCR did not show significant differences in detection of H. pylori. The frequency of iceA1 allele in patients with gastric cancer was significantly higher than those with gastritis (p<0.05). However, there was no significant difference in prevalence of oipA and iceA2 genes among the two groups of patients (p>0.05).

CONCLUSIONS

The iceA1 gene, but the oipA and iceA2 genes , is associated with H. pylori-induced gastric cancer. However, confirmatory studies must be performed in future.

Immunology and vaccines and nanovaccines for Helicobacter pylori infection

Helicobacter pylori infection is very common worldwide and is an important cause of gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric adenocarcinoma. Since the eradication requires treatment with multidrug regimens, prevention of primary infection by a suitable vaccine is attractive. Developing vaccines on the spot when and where an infection is breaking out might be possible, thanks to engineered nanoparticles. In this review, the nature of the host immune response to H. pylori infection is considered. We explain recent candidate vaccines and prophylactic or therapeutic immunization strategies for use against H. pylori. We also describe identification of different types of immune responses that may be related to protection against H. pylori infection. Thus, it seems that there is still a strong need to clarify the main protective immune response against H. pylori.

Formulation and evaluation of floating mucoadhesive alginate beads for targeting Helicobacter pylori

OBJECTIVES

There are various obstacles in the eradication of Helicobacter pylori infections, including low antibiotic levels and poor accessibility of the drug at the site of the infection. This study describes the preparation and characterisation of novel floating mucoadhesive alginate beads loaded with clarithromycin for delivery to the gastric mucosa to improve the eradication of this microorganism.

METHODS

Calcium alginate beads were prepared by ionotropic gelation. The formulation was modified through addition of oil and coating with chitosan to improve floating, mucoadhesion and modify drug release.

KEY FINDINGS

Scanning electron microscopy confirmed the sphericity of the beads with X-ray microtomography showing the three-dimensional structure of the beads with the layered internal structure of the bead and the even distribution of the drug within the bead. This formulation combined two gastro-retentive strategies, and produced excellent in-vitro floating, mucoadhesive and drug release characteristics. Enhanced stability of the beads in phosphate buffer raises a potential for the modified formulations to be targeted to regions of higher pH within the gastrointestinal tract. Drug release from these beads was sustained through an unstirred mucin layer simulating in-vivo conditions under which the H. pylori resides in the gastric mucosa.

CONCLUSIONS

This novel formulation will ensure retention for a longer period in the stomach than conventional formulations and control drug release, ensuring high local drug concentrations, leading to improved eradication of the bacteria.

The association of H. pylori and colorectal adenoma: does it exist in the US Hispanic population?

BACKGROUND

Although data on the association between colorectal adenomas and Helicobacter pylori (H. pylori) exists in White and Black patients, there is no data on this association in a US Hispanic population. Our aim was to study the association of adenoma detection and biopsy proven H. pylori infection in a cohort of US Hispanics.

METHODS

Data were collected from Nassau University Medical Center, a 530-bed tertiary care teaching hospital in East Meadow, New York. Patients who underwent both an esophagogastroduodenoscopy (EGD) and colonoscopy from July 2009 to March 2011 were pulled from an electronic database. A total of 1,737 patients completed colonoscopies during this time with 95 excluded: 17 inflammatory bowel disease, 12 malignancy, 22 prior history of colorectal adenoma, and 44 incomplete. Among the colonoscopies, 799 patients had EGD's performed prior to colonoscopies that were eligible for our study.

RESULTS

H. pylori prevalence was highest in Hispanics 40.9%, followed by Blacks 29.1% (OR 0.59, 95% CI: 0.42-0.84), then Whites 7.9% (OR 0.12, 95% CI: 0.06-0.24). The adenoma detection rate was significantly higher in Whites 23.2% and Blacks 21.8% compared to Hispanics 14.5%, P=0.0002 respectively. Smoking and alcohol were lower in the H. pylori group, 18.6% (n=44) vs. 26.1% (n=147) for smoking (P=0.02) and 14.4% (n=34) vs. 19% (n=107) for alcohol (P=0.12), respectively. There was no evidence in the Hispanics for an association between adenoma detection and H. pylori infection. Furthermore size, location, and multiple polyps did not differ between the two groups.

CONCLUSIONS

While data has shown an association between H. pylori and colorectal adenomas, we did not find this in our Hispanic population. With the growing population of Hispanics in the U.S, large scale studies are needed to conclusively characterize the role of H. pylori infection in colorectal adenoma and adenocarcinoma in this group of patients.

Use of probiotics in the fight against Helicobacter pylori

After the discovery of Helicobacter pylori (H. pylori), and the evidence of its relationship with gastric diseases, antibiotic-based therapies were developed, which efficacy was however limited by antibiotic resistance and lack of patient compliance. A vaccine would overcome these drawbacks, but currently there is not any H. pylori vaccine licensed. In the frame of the studies aimed at finding alternative therapies or at increasing the efficacy of the current ones and/or reducing their side effects, the investigation on the use of probiotics plays an interesting role. In vitro and preclinical studies have shown the feasibility of this approach. Several clinical trials indicated that administration of probiotics can reduce the side effects of H. pylori eradication treatment, increasing tolerability, and often increases the overall efficacy. The results of these trials vary, likely reflecting the variety of probiotics assessed and that of the eradication treatment, as well as the differences in the geographic area that imply different H. pylori strains distribution, host susceptibility, and therapy efficacy. In conclusion, the use of probiotics appears promising as an adjuvant for the current H. pylori eradication treatment, though it still requires optimization.

The effect of Helicobacter pylori eradication on insulin resistance and HbA1c level in people with normal glucose levels: a prospective study

BACKGROUND AND AIM

Helicobacter pylori (H. pylori) infection is reported to be associated with various extragastrointestinal conditions such as insulin resistance, diabetes mellitus and metabolic syndrome. These conditions are attributed to systemic inflammation, leptin or ghrelin changes due to H. pylori infection. Therefore, increasing trends in the management of H. pylori infection are ordered to maintain glycemic control. In this study, we evaluated the effect of H. pylori eradication on insulin resistance in patients with normal blood glucose concentrations.

METHOD

A total of 370 patients with successful eradication were included in the study. Patients with H. pylori were given triple eradication treatment. All patients with H. pylori infection were tested for fasting glucose, fasting insulin, glicated hemoglobin (HbA1c) at baseline and 6 months after eradication treatment. Also, insulin resistance was calculated using the homeostatic model assessment of insulin resistance (HOMA-IR). Body mass index was also determined as a metabolic syndrome criteria effecting insulin resistance.

RESULTS

There were significant differences in fasting glucose, fasting insulin, HbA1c, and HOMA-IR values between before treatment and after treatment(P <0.04, <0.01, <0.01, <0.01). The favorable effect of eradication was more significant in patients with BMI≥25 mg/m(2)(P<0.05).

CONCLUSION

Eradication treatment has beneficial effects on insulin resistance in patients with normal glucose concentrations.

Esophageal intraepithelial invasion of Helicobacter pylori correlates with atypical hyperplasia

Helicobacter pylori (H. pylori), a common pathogen residing in the gastrointestinal tract, has been well characterized in stomach cancer,while its correlation with esophageal cancer remains poorly understood. In this study, we aim to assess the relationship between esophageal intraepithelial H. pylori invasion and inflammation as well as atypical hyperplasia in esophageal squamous epithelial tissues. Esophageal squamous cell carcinoma (ESCC) tissue samples from 196 individuals from both southern and northern esophageal carcinoma high-risk areas in China were examined (125 from northern high-risk areas, 71 from southern high-risk area), while additional 30 samples were collected adjacent to the esophageal squamous cell carcinoma (A-ESCC). H. pylori infection was identified by Giemsa staining, immuno-histochemical staining, and H. pylori 16S rRNA-based PCR. A significant increase of H. pylori infection was found in tumor tissues (including ESCC and A-ESCC samples) compared to that of non-tumor tissues (p < 0.05). The positive rate of H. pylori 16S rRNA in ESCC, A-ESCC, and normal groups were 62.5, 74.1, and 26.7%, respectively. The PCR results showed that the positive incidence of the H. pylori virulence factor CagA gene in tumor (ESCC and A-ESCC) and normal groups was 54.9 and 20%, respectively (p < 0.05). To explore the possible causes of CagA+ H. pylori infection leading to carcinogenesis, we found that CagA+ H. pylori filtrate induced DNA strand breaks in esophageal epithelial NE3 cells, suggesting that H. pylori infection may be an original cause leading to atypical hyperplasia of esophageal squamous epithelial tissues and contributed to pathological carcinogenesis of ESCC.

Serum adiponectin level in diabetic patients with and without Helicobacter pylori infection: is there any difference?

Background. Increased insulin resistance is an extragastrointestinal manifestation of Helicobacter pylori (HP) infection. HP changes the level of inflammatory markers and cytokines and changes the adipocyte function by altering the adiponectin level. Given the high prevalence of HP and diabetes in our society, we evaluated the association between HP and serum adiponectin level. In this cross-sectional study, 211 diabetic patients under treatment other than insulin were studied. These patients were divided into two groups of HP+ and HP− based on their HP IgG antibody serology and their blood adiponectin levels were measured. Data was analyzed using independent t-test, Chi-square test, and Fisher's exact test. Results. Seventy-two patients with an average age of 51.56 ± 8.34 years were HP− and 139 patients with an average age of 50.35 ± 9.01 years were HP+. The mean serum adiponectin level in HP− and HP+ groups was 4.54 ± 5.43 and 5.64 ± 3.88 ng/mL, respectively. Insulin resistance degree was significantly higher in HP+ group (HP− = 3.160 ± 3.327 versus HP+ = 4.484 ± 3.781, P = 0.013) but no significant difference was found between the mean serum adiponectin level in HP− and HP+ groups (P = 0.140). Conclusions. Although the insulin resistance degree was significantly higher in HP+ diabetic patients, no significant relationship was found between HP infection and serum levels of adiponectin.

Oral immunization with recombinant Lactobacillus acidophilus expressing the adhesin Hp0410 of Helicobacter pylori induces mucosal and systemic immune responses

Helicobacter pylori infection is relatively common worldwide and is closely related to gastric mucosa-associated lymphoid tissue (MALT) lymphoma, chronic gastritis, and stomach ulcers. Therefore, a safe and effective method for preventing H. pylori infection is urgently needed. Given that developing an effective vaccine against H. pylori is one of the best alternatives, H. pylori adhesin Hp0410 was expressed in the food-grade bacterium Lactobacillus acidophilus. The recombinant live bacterial vaccine was then used to orally vaccinate mice, and the immunoprotective effects of Hp0410-producing strains were investigated. H. pylori colonization in the stomach of mice immunized with the recombinant L. acidophilus was significantly reduced, in comparison with that in control groups. Furthermore, mucosal secretory IgA antibodies were elicited in the mucosal tissue of mice immunized with the recombinant bacteria, and specific anti-Hp0410 IgG responses were also detected in mouse serum. There was a significant increase in the level of protection against gastric Helicobacter infection following a challenge with H. pylori Sydney strain 1 (SS1). Our results collectively indicate that adhesin Hp0410 is a promising candidate vaccine antigen, and recombinant L. acidophilus expressing Hp0410 is likely to constitute an effective, low-cost, live bacterial vaccine against H. pylori.

NMR study on small proteins from Helicobacter pylori for antibiotic target discovery: a review

Due to the widespread and increasing appearance of antibiotic resistance, a new strategy is needed for developing novel antibiotics. Especially, there are no specific antibiotics for Helicobacter pylori (H. pylori). H. pylori are bacteria that live in the stomach and are related to many serious gastric problems such as peptic ulcers, chronic gastritis, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Because of its importance as a human pathogen, it's worth studying the structure and function of the proteins from H. pylori. After the sequencing of the H. pylori strain 26695 in 1997, more than 1,600 genes were identified from H. pylori. Until now, the structures of 334 proteins from H. pylori have been determined. Among them, 309 structures were determined by X-ray crystallography and 25 structures by Nuclear Magnetic Resonance (NMR), respectively. Overall, the structures of large proteins were determined by X-ray crystallography and those of small proteins by NMR. In our lab, we have studied the structural and functional characteristics of small proteins from H. pylori. In this review, 25 NMR structures of H. pylori proteins will be introduced and their structure-function relationships will be discussed.

Helicobacter pylori CagA: From Pathogenic Mechanisms to Its Use as an Anti-Cancer Vaccine

Helicobacter pylori colonizes the gastric mucosa of more than 50% of the human population, causing chronic inflammation, which however is largely asymptomatic. Nevertheless, H. pylori-infected subjects can develop chronic gastritis, peptic ulcer, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Chronic exposure to the pathogen and its ability to induce epithelial to mesenchymal transition (EMT) through the injection of cytotoxin-associated gene A into gastric epithelial cells may be key triggers of carcinogenesis. By deregulating cell-cell and cell-matrix interactions as well as DNA methylation, histone modifications, expression of micro RNAs, and resistance to apoptosis, EMT can actively contribute to early stages of the cancer formation. Host response to the infection significantly contributes to disease development and the concomitance of particular genotypes of both pathogen and host may turn into the most severe outcomes. T regulatory cells (Treg) have been recently demonstrated to play an important role in H. pylori-related disease development and at the same time the Treg-induced tolerance has been proposed as a possible mechanism that leads to less severe disease. Efficacy of antibiotic therapies of H. pylori infection has significantly dropped. Unfortunately, no vaccine against H. pylori is currently licensed, and protective immunity mechanisms against H. pylori are only partially understood. In spite of promising results obtained in animal models of infection with a number of vaccine candidates, few clinical trials have been conducted so far and with no satisfactory outcomes. However, prophylactic vaccination may be the only means to efficiently prevent H. pylori-associated cancers.

Protein HP1028 from the human pathogen Helicobacter pylori belongs to the lipocalin family

Helicobacter pylori is a bacterial pathogen that causes severe diseases, including gastritis, ulcers and gastric cancer. Although this bacterium has been extensively studied, the physiological functions of a large number of the proteins encoded by its genome are unknown. HP1028 is a protein that is relevant to colonization and to the survival of the bacterium in the stomach, but its function is not clearly understood. Bioinformatics studies suggest that HP1028 is a monomeric protein that is secreted in the H. pylori periplasm. The crystal structure of HP1028 has been determined at 2.6 Å resolution using the SAD method. The three-dimensional structure of the protein reveals that it belongs to the lipocalin family, a group of proteins that bind and transport (often hydrophobic) small molecules. The structure of HP1028, together with the possible localization of the mature protein in the bacterial periplasm and the position of the hp1028 gene in the bacterial genome, point to a role in H. pylori chemotaxis.