Helicobacter pylori Oncogenicity: Mechanism, Prevention, and Risk Factors

Analyzing the expression and clinical significance of CENPE in gastric cancer

BACKGROUND

Gastric cancer (GC) is a prevalent type of malignant gastrointestinal tumor. Many studies have shown that CENPE acts as an oncogene in some cancers. However, its expression level and clinical value in GC are not clear.

METHODS

Obtaining clinical data information on gastric adenocarcinoma from TCGA and GEO databases. The gene expression profiling interaction analysis (GEPIA) was used to evaluate the relationship between prognosis and CENPE expression in gastric cancer patients. Utilizing the UALCAN platform, the correlation between CENPE expression and clinical parameters was examined. Functions and signaling pathways of CENPE were analyzed using the Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA). The association between immunological infiltrating cells and CENPE expression was examined using TIMER2.0. Validation was performed by real-time quantitative PCR (qPT-PCR) and immunohistochemical analysis.

RESULTS

According to the analysis of the GEPIA database, the expression of CENPE is increased in gastric cancer tissues compared to normal tissues. It was also found to have an important relationship with the prognosis of the patient (p<0.05). The prognosis was worse and overall survival was lower in individuals with increased expression of CENPE. In line with the findings of the GEPIA, real-time fluorescence quantitative PCR (qPT-PCR) confirmed that CENPE was overexpressed in gastric cancer cells. Furthermore, It was discovered that H. pylori infection status and tumor grade were related to CENPE expression. Enrichment analysis revealed that CENPE expression was linked to multiple biological functions and tumor-associated pathways. CENPE expression also correlated with immune-infiltrating cells in the gastric cancer microenvironment and was positively connected to NK cells and mast cells. According to immunohistochemical examination, paracancerous tissues had minimal expression of CENPE, but gastric cancer showed significant expression of the protein.

CONCLUSIONS

According to our findings, CENPE is substantially expressed in GC and may perhaps contribute to its growth. CENPE might be a target for gastric cancer therapy and a predictor of a bad prognosis.

The Role of Probiotics in the Eradication of Helicobacter pylori and Overall Impact on Management of Peptic Ulcer: A Study Involving Patients Undergoing Triple Therapy in Bangladesh

Background Helicobacter pylori infection has been identified to cause constantly recurring inflammation, leading to gastrointestinal tract disorders, including carcinoma. The standard triple therapy (STT), used to eradicate H. pylori, includes two antimicrobials and a proton pump inhibitor for two weeks. Other drug regimens have also been developed since H. pylori exhibits antimicrobial resistance. These regimens, including probiotics, have been shown to lower adverse drug reactions (ADR), improve drug adherence, exert bacteriostatic effect, and reduce inflammation. Objective This study intended to explore probiotic intervention for improving eradication rates and mitigating adverse effects while administrating STT.  Methods This prospective study was conducted from May to December, 2021, in the Department of Gastroenterology of Ship International Hospital, Dhaka, Bangladesh, to observe the effects of probiotics inclusion along with STT on H. pylori eradication. A total of 100 patients aged ≥18 years who tested positive for H. pylori were included. The experimental group (n=50) was given STT and probiotics, and the control group (n=50) was given only STT without probiotics for 14 days. Necessary follow-up was done six weeks after treatment. An independent sample t-test, chi-square test, and multiple regression analysis were used for statistical analysis. Result The odds of getting rapid urease test (RUT) negative results from positive were 2.06 times higher (95%CI= 0.95, 3.22, p=0.054) in the experimental group. ADRs were crucially towering in the control group (p=0.045) compared to the probiotics group. The probiotics group had a lower risk of having adverse effects by 0.54 times (95%CI=0.19, 0.84, p=0.032) than the control group. Conclusion Using probiotics and STT together to eradicate H. pylori may lower ADR and improve treatment adherence. It may also help terminate H. pylori infection more effectively. More research is required as H. pylori is very contagious and can ultimately cause life-threatening gastric cancer.

Phylogenetic analysis of pathogenic genes in Helicobacter species

BACKGROUND

Helicobacter bacteria are associated with gastrointestinal diseases, especially Helicobacter pylori (H. pylori). With the isolation of many non-Helicobacter pylori Helicobacters (NHPH) from the liver, intestines, and gallbladder of natural animal reservoirs, NHPH have been potential zoonotic pathogens, but their infection and pathogenic mechanisms are still unclear.

AIM

To explore the phylogenetic relationship of Helicobacter species based on their pathogenic genes.

METHODS

The present study collected the genomic sequences of 50 strains in genus Helicobacter, including 12 strains of H. pylori and 38 strains of NHPH. Based on 16S rRNA gene and several pathogenic genes (flagella, urease, and virulence factors), MAGA software (Version 11.0) was used to align their sequences and construct phylogenetic trees.

RESULTS

The phylogenetic tree of 16S rRNA gene showed that gastric Helicobacter (GH) and enterohepatic Helicobacter species (EHS) were clustered into two large branches, respectively. All of the GH's hosts were mammals, while the hosts of EHS were many wild poultry and mammals. Based on the flagella motility-related genes (flaA, flaB, fliP, fliQ, fliR, fliG, fliM, and fliN), the phylogenetic trees were divided into two major branches (GH and EHS). Similarly, the phylogenetic trees of lipopolysaccharide (LPS) biosynthesis-related genes (lptA, waaC, and waaF) presented two major branches (GH and EHS), too. The urease genes existed in all of the 12 strains of H. pylori, 13 strains of gastric NHPH, and 4 strains of EHS (H. hepaticus, H. muridarum, H. bilis, and H. anseris). However, no significant phylogenetic patterns of GH and EHS were observed in the seven urease genes (ureA, ureB, ureE, ureF, ureG, ureH, and ureI).

CONCLUSION

The phylogenetic relationship of Helicobacter species' pathogenic genes is dominated distinctly by the special colonization areas including gastric and enterohepatic niches.

In silico identification and analysis of potential inhibitors for acid phosphatase, HppA from Helicobacter pylori

Helicobacter pylori is the most common cause of gastric ulcers and is associated with gastric cancer. The enzyme HppA of class C nonspecific acid phosphohydrolases (NSAPs) of H. pylori plays a crucial role in the electron transport chain. Herein, we report an in silico homology model of HppA consisting of a monomeric α + β model. A high throughput structure-based virtual screening approach yielded potential inhibitors against HppA with higher binding energies. Further analyses of molecular interaction maps and protein-ligand fingerprints, followed by molecular mechanics-generalized Born surface area (MM-GBSA) end point binding energy calculations of docked complexes, resulted in the detection of top binders/ligands. Our investigations identified potential substrate-competitive small molecule inhibitors of HppA, with admissible pharmacokinetic properties. These molecules may provide a starting point for developing novel therapeutic agents against H. pylori.

Bacterial Therapy of Cancer: A Way to the Dustbin of History or to the Medicine of the Future?

Bacteria are the constant companions of the human body throughout its life and even after its death. The history of a human disease such as cancer and the history of microorganisms, particularly bacteria, are believed to closely intertwined. This review was conceived to highlight the attempts of scientists from ancient times to the present day to discover the relationship between bacteria and the emergence or development of tumors in the human body. Challenges and achievements of 21st century science in forcing bacteria to serve for cancer treatment are considered. The future possibilities of bacterial cancer therapy, including the creation of bacterial microrobots, or "bacteriobots", are also discussed.

Effect of Helicobacter pylori on non-homologous end joining-mediated repair of proximal DNA double-strand breaks in GCV6 cells

Infection with Helicobacter pylori is the strongest known risk factor for gastric cancer, which is one of the leading causes of cancer-related mortality worldwide. H. pylori can contribute to carcinogenesis by inducing the genomic instability of infected cells through increasing accumulation of DNA double-stranded breaks (DSBs) and deregulating DSB repair systems. However, the mechanism of this phenomenon is still being elucidated. This study aims to investigate the impact of H. pylori on the efficacy of non-homologous end joining (NHEJ)-mediated repair of DSB. In this study, we used a human fibroblast cell line bearing a single copy of an NHEJ-reporter substrate stably inserted into the genome, which provides a quantitative measurement of NHEJ. Our results indicated the potential abilities of H. pylori strains to alter the NHEJ-mediated repair of proximal DSB in infected cells. In addition, we found an association between the alteration in the NHEJ efficiency, and the inflammation responses of infected cells caused by H. pylori.

A "new" option in Helicobacter pylori eradication: High-dose amoxicillin dual therapy outperforms bismuth quadruple therapy in a high dual resistance setting

BACKGROUND

Currently, bismuth quadruple therapy (BQT) is indicated as a first-line treatment for Helicobacter pylori eradication in areas with high dual metronidazole and clarithromycin resistance, with its use being limited by its low tolerability and significant cost. A novel regimen with high-dose amoxicillin dual therapy (HDADT) has emerged as an alternative. The aim of this study was to compare the results of these two treatments on HP eradication.

MATERIALS AND METHODS

Prospective randomized study including 100 consecutive patients undergoing H. pylori eradication. Each patient was randomized (in a 1:1 ratio) to one group of treatment: BQT (bismuth 140 mg + metronidazole 125 mg + tetracycline 125 mg, four times a day, for 10 days) or HDADT (amoxicillin 1000 mg alternating with amoxicillin 500 mg, four times a day, for 14 days), both associated with esomeprazole 40 mg twice a day. The primary aim was to compare treatments' efficacies. Secondary aims were to assess symptoms persistence and tolerability.

RESULTS

A total of 100 patients were included, 54% women, with a mean age of 55 ± 14 years. From these, five were lost to follow-up. Effective eradication proven by negative stool antigen test was significantly higher in patients randomized to HDADT when compared to BQT for both intention-to-treat (ITT) (96.2% vs. 81.4%; p = .022) and per-protocol (PP) (95.9% vs. 81%; p = .025) analysis. These differences were even more pronounced when only considering second line treatment (100% vs. 62.5%; p = .028). Side effects did not differ significantly between BQT and HDADT groups for both ITT (7.0% vs. 2.0%; p = .254) and PP (4.8% vs. 0%; p = .210) analysis.

CONCLUSIONS

When compared to BQT, treatment with HDADT presented higher and near 100% efficacy in eradicating H. pylori, without differences in reported side effects or compliance. This treatment represents an important alternative for populations with increasing incidences of resistance to the currently recommended antibiotic regimens.

Is Helicobacter pylori Anyway Pathogen in Children?

Helicobacter pylori (H. pylori) infection is a continuous challenge for both gastroenterologists and pediatricians. The international guidelines regarding diagnostic and treatment pathways differ between adults and children. The pediatric guidelines are more restrictive because children are rarely affected by serious consequences, particularly in Western countries. Therefore, infected children should be treated only after a careful case-by-case evaluation by a pediatric gastroenterologist. In any case, recent studies are confirming an increasingly all-around pathological role of H. pylori even in asymptomatic children. For these reasons, following the current evidence, we feel that H. pylori-infected children could be treated starting in pre-adolescence, particularly in Eastern countries, because their stomachs have already begun to develop the biomarkers of gastric damage. Therefore, we believe that H. pylori is anyway pathogen in children. Nevertheless, the possible beneficial role of H. pylori in humans has not yet been conclusively disproved.

Establishment and Validation of a Pathologic Upgrade Prediction Nomogram Model for Gastric Low-Grade Intraepithelial Neoplasia Patients After the Eradication of Helicobacter pylori

BACKGROUND

As yet, there is no unified method of treatment for the evaluation and management of gastric low-grade intraepithelial neoplasia (LGIN) worldwide.

METHODS

Patients with gastric LGIN who had been treated with Helicobacter pylori eradication were gathered retrospectively. Based on several relevant characteristics described and analyzed by LASSO regression analysis and multivariable logistic regression, a prediction nomogram model was established. C-index, the area under the receiver operating characteristic curve (AUC), calibration plot, and decision curve analysis (DCA) were adopted to evaluate the accuracy and reliability of the model.

RESULTS

A total of 309 patients with LGIN were randomly divided into the training groups and the validation groups. LASSO regression analysis and multivariable logistic regression identified that 6 variables including gender, size, location, borderline, number, and erosion were independent risk factors. The nomogram model displayed good discrimination with a C-index of .765 (95% confidence interval: .702-.828). The accuracy and reliability of the model were also verified by an AUC of .764 in the training group and .757 in the validation group. Meanwhile, the calibration curve and the DCA suggested that the predictive nomogram had promising accuracy and clinical utility.

CONCLUSIONS

A predictive nomogram model was constructed and proved to be clinically applicable to identify high-risk groups with possible pathologic upgrade in patients with gastric LGIN. Since it is regarded that strengthening follow-up or endoscopic treatment of high-risk patients may contribute to improving the detection rate or reducing the incidence of gastric cancer, the predictive nomogram model provides a reliable basis for the treatment of LGIN.

Evaluation of Tumor Necrosis Factor-Alpha Gene (−308 G/A, −238 G/A and −857 C/T) Polymorphisms and the Risk of Gastric Cancer in Eastern Indian Population

Introduction: Gastric cancer (GC) is one of the leading causes of cancer-related decimations worldwide. The gastric infection at both the stomach and duodenum with Helicobacter pylori causes inflammation by the tumor necrosis factor-alpha (TNF-α). The aim of the study was to associate and evaluate the three TNF-α gene polymorphisms at positions −308 G/A, −238 G/A, and −857 C/T with the risk of GC. Methods: A total of 156 individuals (consecutively diagnosed 95 GC patients and 61 controls) above the age of 18 years were enrolled in the study. Healthy individuals with normal upper gastrointestinal endoscopy (UGIE) irrespective of their family history of GC or peptic ulcer were included as controls. The cited three TNF-α gene polymorphisms were evaluated using polymerase chain reaction-restriction fragment length polymorphism (RFLP). Results: There was no significant difference in the distribution of gene polymorphisms as genetic factors, TNF-α−308 GA/AA (22.1% vs. 14.8%, p = 0.2), TNF-α−238 GA/AA (21% vs. 19.6%, p = 0.8), and TNF-α−857 CT/TT (8.4% vs. 11.5%, p = 0.5), between GC cases and healthy controls. A subgroup analysis of H. pylori-positive patients showed that there was no significant difference in the distribution of GA/AA polymorphisms in TNF-α−308 (15(45.5%) vs. 3(23%); p = 0.17) and −238 (12(36.3%) vs. 2(15.4%); p = 0.17), and the distribution of TT/CT −857 CT/TT (13(39.4%) vs. 2(15.4%); p = 0.13), among the GC cases and controls. Conclusion: The statistical comparisons of GA/AA vs. GG genotypes at −308 (with OR = 1.6, 95% CI: 0.6–3.8), −238 (OR = 1.09, 95% CI: 0.4–2.4) and TT/CT vs. CC genotypes at −857 (OR = 0.7, 95% CI: 0.2–2.1) did not suggest any association of TNF-α with GC in the population herein. Hence, the TNF-α (−308 G/A, −238 G/A and −857 C/T) may not be the associating factor for GC incidence determined by the PCR–RFLP method.

Gastric Cancer Pre-Stage Detection and Early Diagnosis of Gastritis Using Serum Protein Signatures

Background: A gastric cancer (GC) diagnosis relies on histopathology. Endoscopy rates are increasing. Helicobacter pylori infection is a major GC risk factor. In an effort to elucidate abundant blood biomarkers, and potentially reduce the number of diagnostic surgical interventions, we investigated sera and biopsies from a cohort of 219 H. pylori positive and negative patients diagnosed with GC, gastritis, and ulcers. This allowed the comparative investigation of the different gastroduodenal diseases, and the exclusion of protein changes resulting from bacterial infection or inflammation of the gastric mucosa when searching for GC-dependent proteins. Methods: High-definition mass spectrometry-based expression analysis of tryptically digested proteins was performed, followed by multivariate statistical and network analyses for the different disease groups, with respect to H. pylori infection status. Significantly regulated proteins differing more than two-fold between groups were shortlisted, and their role in gastritis and GC discussed. Results: We present data of comparative protein analyses of biopsies and sera from patients suffering from mild to advanced gastritis, ulcers, and early to advanced GC, in conjunction with a wealth of metadata, clinical information, histopathological evaluation, and H. pylori infection status. We used samples from pre-malignant stages to extract prospective serum markers for early-stage GC, and present a 29-protein marker panel containing, amongst others, integrin β-6 and glutathione peroxidase. Furthermore, ten serum markers specific for advanced GC, independent of H. pylori infection, are provided. They include CRP, protein S100A9, and kallistatin. The majority of these proteins were previously discussed in the context of cancer or GC. In addition, we detected hypoalbuminemia and increased fibrinogen serum levels in gastritis. Conclusion: Two protein panels were suggested for the development of multiplex tests for GC serum diagnostics. For most of the elements contained in these panels, individual commercial tests are available. Thus, we envision the design of multi-protein assays, incorporating several to all of the panel members, in order to gain a level of specificity that cannot be achieved by testing a single protein alone. As their development and validation will take time, gastritis diagnosis based on the fibrinogen to albumin serum ratio may be a quick way forward. Its determination at the primary/secondary care level for early diagnosis could significantly reduce the number of referrals to endoscopy. Preventive measures are in high demand. The protein marker panels presented in this work will contribute to improved GC diagnostics, once they have been transferred from a research result to a practical tool.

Environmental factors associated with gastric carcinogenesis

PURPOSE OF REVIEW

Gastric cancer is one of the leading causes of cancer-related deaths globally. Several modifiable environmental factors have been linked to gastric carcinogenesis but in many cases, evidence is either weak or fragmented. In this review, we interrogate the latest evidence implicating environmental factors in the development of gastric cancer.

RECENT FINDINGS

We are writing this review at a time when technological advancements are enabling scientists to effectively conduct large epidemiological studies with better tools for exposure estimations. We have highlighted risk factors that do not yet have enough evidence to be included as definite carcinogens in the International Agency for Research on Cancer monographs but have the potential for inclusion in the near future. Considered in our review are the links between gastric cancer and exposure to biomass smoke, particulate matter, occupational hazards and water contamination.

SUMMARY

This review illustrates the need for vigilance as evidence linking gastric cancer to various environmental factors is mounting. Many of these factors are modifiable, allowing for preventive strategies that could further decrease the global burden of gastric cancer.

The tumor immune-microenvironment in gastric cancer

AIMS AND BACKGROUND

The tumor microenvironment significantly influences malignant behavior and progression. Many components are involved in the tumor microenvironment, including extracellular matrix, stromal cells, immune and inflammatory cells, as well as cytokines that promote tumor development with complex interactions through the exchange of molecular information. It is now known that tumor immune escape may be influenced by the tumor microenvironment. The aim of this work is to conduct a review of the tumor immune-microenvironment in gastric cancer.

METHODS

We review the current knowledge of several immune cells involved in the gastric tumor microenvironment. In addition, a brief description of immunotherapy strategies for gastric cancer is also reviewed.

CONCLUSIONS

Among immune cell populations, lymphocytes, macrophages, dendritic cells and myeloid-derived suppressor cells are revealed to make the difference in promoting or suppressing gastric tumorigenesis, either directly or indirectly, via regulating the immune responses. Understanding these interactions in detail within the tumor immune-microenvironment will contribute to unraveling new therapeutic targets.

New Strategy for the Detection and Treatment of Helicobacter pylori Infections in Primary Care Guided by a Non-Invasive PCR in Stool: Protocol of the French HepyPrim Study

Helicobacter pylori (Hp) infects half of the world population and is responsible for gastric, duodenal ulcers and gastric cancer. The eradication of Hp cures ulcers and prevents ulcer recurrences and gastric cancer. Antibiotic resistance of Hp, and particularly clarithromycin resistance, is the primary cause of treatment failure and is a major concern identified by the WHO as a high priority requiring research into new strategies. Treatments guided by the detection of antibiotic resistance have proven their medical and economical superiority. However, this strategy is severely hampered by the invasive nature of the fibroscopy, since antibiotic resistance detection requires gastric biopsies. The eradication of Hp involves primary care physicians. The objective of this study will be to evaluate the feasibility of a strategy for the management of Hp infection in primary care by a recently developed non-invasive procedure and its non-inferiority in eradication rates compared with the strategy recommended by the French National Authority of Health. The non-invasive procedure is a PCR on stool to detect Hp infection and mutations conferring resistance to clarithromycin allowing a treatment guided by the results of the PCR. We present the protocol of a prospective, multicenter, randomized, controlled interventional study in two arms.

Helicobacter pylori: an up-to-date overview on the virulence and pathogenesis mechanisms

Helicobacter pylori is an organism associated with ulcer disease and gastric cancer. The latter is one of the most prevalent malignancies and currently the fourth major cause of cancer-related deaths globally. The pathogen infects about 50% of the world population, and currently, no treatment ensures its total elimination. There has been an increase in our understanding of the pathophysiology and pathogenesis mechanisms of H. pylori over the years. H. pylori can induce several genetic alterations, express numerous virulence factors, and trigger diverse adaptive mechanisms during its adherence and colonization. For successful colonization and infection establishment, several effector proteins/toxins are released by the organism. Evidence is also available reporting spiral to coccoid transition as a unique tactic H. pylori uses to survive in the host’s gastrointestinal tract (GIT). Thus, the virulence and pathogenicity of H. pylori are under the control of complex interplay between the virulence factors, host, and environmental factors. Expounding the role of the various virulence factors in H. pylori pathogenesis and clinical outcomes is crucial for vaccine development and in providing and developing a more effective therapeutic intervention. Here we critically reflect on H. pylori infection and delineate what is currently known about the virulence and pathogenesis mechanisms of H. pylori.

Molecular Docking of Anti Helicobacter pylori Antibiotics and Proton Pump Inhibitor: A Single Center Survey

Helicobacter pylorus (H. pylori) is a deadly bacterium responsible for significant worldwide Gastric Cancer (GC) related mortality. The present study aimed to screen all the anti-microbial drugs used to eradicate H .pylori infection and to identify the most efficient drug by using computational methods through molecular docking analysis. The 3-D structure of protein chorismate synthase of H. pylori was downloaded from the Protein data bank (PDB) online browser. The x-ray crystallography structures of 13 common drugs used against H.pylori infection were also downloaded from the drug bank. We screened all 13 common drugs through molecular docking to know the most efficient binding interaction between the diverse ligand-protein complexes. The results were further compared with clinical survey data from the patients with diverse gastrointestinal H. pylori infected cases. Among the screened compounds, by in-silico approach we found that fluoroquinolone (FLRQ) and tetracycline (TET) manifested more significant interactions with chorismate synthase (CS) protein along with binding energies of -9.2 and -8.1 kcal/mole respectively. Further, the drugs were also corroborated with the survey data from patients with varied gastrointestinal disorders in our study. With this computational study, we could find FLRQ and TET may be the most efficient drug for H. pylori treatment, which can be tried in case of anti H. Pylori treatment failure due to resistance. Hence, effective inter-analysis between the experimental and computational approaches is crucial to build up a strong inhibitor.

Revisiting Therapeutic Strategies for H. pylori Treatment in the Context of Antibiotic Resistance: Focus on Alternative and Complementary Therapies

The prevalence of Helicobacter pylori infection remains significant worldwide and it depends on many factors: gender, age, socio-economic status, geographic area, diet, and lifestyle. All successful infectious diseases treatments use antibiotic-susceptibility testing, but this strategy is not currently practical for H. pylori and the usual cure rates of H. pylori are lower than other bacterial infections. Actually, there is no treatment that ensures complete eradication of this pathogen. In the context of an alarming increase in resistance to antibiotics (especially to clarithromycin and metronidazole), alternative and complementary options and strategies are taken into consideration. As the success of antibacterial therapy depends not only on the susceptibility to given drugs, but also on the specific doses, formulations, use of adjuvants, treatment duration, and reinfection rates, this review discusses the current therapies for H. pylori treatment along with their advantages and limitations. As an alternative option, this work offers an extensively referenced approach on natural medicines against H. pylori, including the significance of nanotechnology in developing new strategies for treatment of H. pylori infection.

Role of Bacteria in the Incidence of Common GIT Cancers: The Dialectical Role of Integrated Bacterial DNA in Human Carcinogenesis

Despite the wide medical knowledge about the direct role of many viruses in the pathogenesis of certain cancers, there is still ambiguity and hazy vision about the direct role of bacteria in cancer incidence. Understanding the role of bacteria in carcinogenesis is no longer a scientific luxury, but it has become an urgent and extremely important necessity to realize the pathogenesis of cancer caused by oncogenic bacteria as an attempt to overcome the oncogenic mechanisms exhibited by these oncogenic bacteria. This review shed the light on the indirect role of the host's inflammatory and immunological responses in the pathogenesis of bacteria-induced cancer. Also, this review discussed the indirect role of the bacterial toxins and virulence factors in the induction of common gastrointestinal cancers, such as gallbladder cancer (GBC), colorectal cancer (CRC), and gastric cancer (GC). Finally, this review dealt with the debate about the possibility of bacterial DNA integration into the human genome and cancer incidence.

A retrospective study assessing the acceleration effect of type I Helicobacter pylori infection on the progress of atrophic gastritis

Based on the antibody typing classification, Helicobacter pylori infection can be divided into type I H. pylori infection and type II H. pylori infection. To observe the effects of different H. pylori infection types on the distribution of histopathological characteristics and the levels of three items of serum gastric function (PG I, PG II, G-17). 1175 cases from October 2018 to February 2020 were collected with ratio 1:2. All patients were performed with ¹⁴C-Urea breath test (¹⁴C-UBT), H. pylori antibody typing classification, three items of serum gastric function detection, painless gastroscopy, pathological examination, etc. According to H. pylori antibody typing classification, patients were divided into three groups: type I H. pylori infection group, type II H. pylori infection group and control group. Significant difference existed among type I H. pylori infection group, type II H. pylori infection group and control group in inflammation and activity (χ² = 165.43, 354.88, P all < 0.01). The proportion of three groups in OLGA staging had statistic difference (χ² = 67.99, P all < 0.01); Compared with type II H. pylori infection group and control group, the level of pepsinogen I, pepsinogen II, gastrin17 in type I H. pylori infection group increased, and PG I/PG II ratio (PG I/PG II ratio, PGR) decreased, which was statistically significant (χ² = 35.08, 166.24, 134.21, 141.19; P all < 0.01). Type I H. pylori infection worsened the severity of gastric mucosal inflammation and activity. H. pylori infection was prone to induce atrophy of gastric mucosa, while type I H. pylori infection played a key role in promoting the progress of atrophic gastritis and affected the level of serum gastric function. The study indicated that the eradication of H. pylori should be treated individually.