The Role of Helicobacter pylori Neutrophil-Activating Protein in the Pathogenesis of H. pylori and Beyond: From a Virulence Factor to Therapeutic Targets and Therapeutic Agents

The urease E subunit vaccine stimulate the immune response versus Helicobacter pylori in animal model

There is a strong association between Helicobacter pylori (H. pylori) and the occurrence of gastritis and gastric mucosal lymphoma in the human population. Vaccination is a viable preventive measure in light of the escalating issue of antibiotic resistance. The use of DNA vaccines presents a potentially effective approach. This study used the utilization of antigenic H. pylori urease E subunit (UreE) for the development of a DNA vaccine. The UreE gene was chemically cloned into pIRES2-DsRed-Express (pDNA), and PCR and restriction enzyme digestion verified the cloning. The immunogenicity and immune-protective efficacy of the vaccination were assessed in BALB/c mice. In contrast, blood samples from BALB/c mice inoculated with pDNA-UreE showed higher levels of IgG, IFN-γ, IL- 4, and IL- 17. Furthermore, stomach damage and bacterial loads were reduced, and BALB/c mice inoculated with pDNA-UreE exhibited a significant protection rate (87.5%) against the H. pylori challenge. pDNA-UreE generated a combination of Th1-Th2-Th17 immune responses, perhaps contributing to adequate protection. Based on our findings, using this DNA immunization as a preventive measure against H. pylori infection is a viable approach.

Assessment of the bidirectional causal association between Helicobacter pylori infection and allergic diseases by mendelian randomization analysis

This article employed a bidirectional Mendelian randomization (MR) analysis to deduce the causal relationship between H. pylori infection (Seven H. pylori antibodies: CagA, Catalase, GroEL, IgG, OMP, UREA, and VacA) and allergic diseases. This study primarily employed the Inverse-Variance Weighted (IVW)method, supplemented by MR-Egger regression and the Weighted median (WM) method approach, to comprehensively assess the causal relationship between exposure and outcome. Sensitivity analysis, including Cochran's Q test, MR-Egger regression intercept, MR-PRESSO test, and leave-one-out analysis, verified the reliability of the results. In the forward MR analysis, the IVW analysis outcomes showed the causal relationship existed between the allergic urticaria (AU) and Catalase antibody, allergic asthma (AA) and allergic rhinitis (AR) with OMP antibody, and allergic conjunctivitis (AC) and VacA antibody; in the reverse MR analysis, the results of the IVW analysis revealed that CagA antibody was positively associated with AU. Sensitivity analysis indicated that the causal relationship was robust. Higher levels of Catalase antibody may potentially increase the risk of AU development; increased OMP antibody levels might be associated with a higher risk for AA, yet could potentially be a protective factor against AR; greater VacA antibody levels might possibly decrease the incidence of AC; individuals with AU might have a higher likelihood of exhibiting elevated CagA antibody levels. It is suggested that H. pylori infection could potentially influence the onset and progression of allergic diseases via the "gut-skin", "gut-lung", "gut-nose", and "gut-eye" axis; moreover, skin diseases may potentially impact the gut microbiota imbalance through the "skin-gut" axis.

Mast cells: key players in digestive system tumors and their interactions with immune cells

Mast cells (MCs) are critical components of both innate and adaptive immune processes. They play a significant role in protecting human health and in the pathophysiology of various illnesses, including allergies, cardiovascular diseases and autoimmune diseases. Recent studies in tumor-related research have demonstrated that mast cells exert a substantial influence on tumor cell behavior and the tumor microenvironment, exhibiting both pro- and anti-tumor effects. Specifically, mast cells not only secrete mediators related to pro-tumor function such as trypsin-like enzymes, chymotrypsin, vascular endothelial cell growth factor and histamine, but also mediators related to anti-tumor progression such as cystatin C and IL-17F. This dual role of mast cells renders them an under-recognized but very promising target for tumor immunotherapy. Digestive system tumors, characterized by high morbidity and associated mortality rates globally, are increasingly recognized as a significant healthcare burden. This paper examines the influence of mast cell-derived mediators on the development of tumors in the digestive system. It also explores the prognostic significance of mast cells in patients with various gastrointestinal cancers at different stages of the disease. Additionally, the article investigates the interactions between mast cells and immune cells, as well as the potential relationships among intratumoral bacteria, immune cells, and mast cell within digestive system microenvironment. The aim is to propose new strategies for the immunotherapy of digestive system tumors by targeting mast cells.

Pivotal role of Helicobacter pylori virulence genes in pathogenicity and vaccine development

One of the most prevalent human infections is Helicobacter pylori (H. pylori), which affects more than half of the global population. Although H. pylori infections are widespread, only a minority of individuals develop severe gastroduodenal disorders. The global resistance of H. pylori to antibiotics has reached concerning levels, significantly impacting the effectiveness of treatment. Consequently, the development of vaccines targeting virulence factors may present a viable alternative for the treatment and prevention of H. pylori infections. This review aims to provide a comprehensive overview of the current understanding of H. pylori infection, with a particular focus on its virulence factors, pathophysiology, and vaccination strategies. This review discusses various virulence factors associated with H. pylori, such as cytotoxin-associated gene A (cagA), vacuolating cytotoxin gene (vacA), outer membrane proteins (OMPs), neutrophil-activated protein (NAP), urease (ure), and catalase. The development of vaccines based on these virulence characteristics is essential for controlling infection and ensuring long-lasting protection. Various vaccination strategies and formulations have been tested in animal models; however, their effectiveness and reproducibility in humans remain uncertain. Different types of vaccines, including vector-based vaccines, inactivated whole cells, genetically modified protein-based subunits, and multiepitope nucleic acid (DNA) vaccines, have been explored. While some vaccines have demonstrated promising results in murine models, only a limited number have been successfully tested in humans. This article provides a thorough evaluation of recent research on H. pylori virulence genes and vaccination methods, offering valuable insights for future strategies to address this global health challenge.

Helicobacter pylori Inhibition, Gastritis Attenuation, and Gut Microbiota Protection in C57BL/6 Mice by Ligilactobacillus salivarius NCUH062003

Helicobacter pylori (H. pylori), one of the most prevalent pathogenic bacteria worldwide, is the leading cause of gastritis, gastric intestinal metaplasia, and gastric cancer. Antibiotics, the conventional treatment for eliminating H. pylori, often lead to severe bacterial resistance, gut dysbiosis, and hepatic insufficiency and fail to address the inflammatory response or gastric mucosal damage caused by H. pylori infection. In this study, based on 10-week animal experiments, two models of L. salivarius NCUH062003 for the prophylaxis and therapy of H. pylori infection in C57BL/6 mice were established; a comprehensive comparative analysis was performed to investigate the anti-H. pylori effect of probiotics, the reduction in inflammation, and repair of gastric mucosal damage. ELISA, immunohistochemistry, and pathology analyses showed that NCUH062003 decreased the expression of pro-inflammatory cytokine interleukins (IL-1β, IL-6) and myeloperoxidase (MPO) and reduced neutrophil infiltration in the gastric mucosa lamina propria. Immunofluorescence and biochemical analysis showed that NCUH062003 resisted gastric epithelial cell apoptosis, increased the level of superoxide dismutase (SOD) in gastric mucosa, and promoted the expression of tight junction protein ZO1 and Occludin. In addition, through high-throughput sequencing, in the probiotic therapy and prophylactic mode, the diversity and composition of the gut microbiota of HP-infected mice were clarified, the potential functions of the gut microbiota were analyzed, the levels of short-chain fatty acids (SCFAs) were measured, and the effects of L. salivarius NCUH062003 on the gut microbiota and its metabolites in HP-infected mice treated with amoxicillin/metronidazole were revealed. This study provides functional strain resources for the development and application of microbial agents seeking to antagonize H. pylori beyond antibiotics.

Candidate Antigens and the Development of Helicobacter pylori Vaccines

BACKGROUND

Infection with Helicobacter pylori (Hp) mostly occurs during childhood, and persistent infection may lead to severe gastric diseases and even gastric cancer. Currently, the primary method for eradicating Hp is through antibiotic treatment. However, the increasing multidrug resistance in Hp strains has diminished the effectiveness of antibiotic treatments. Vaccination could potentially serve as an effective intervention to resolve this issue.

AIMS

Through extensive research and analysis of the vital protein characteristics involved in Hp infection, we aim to provide references for subsequent vaccine antigen selection. Additionally, we summarize the current research and development of Hp vaccines in order to provide assistance for future research.

MATERIALS AND METHODS

Utilizing the databases PubMed and the Web of Science, a comprehensive search was conducted to compile articles pertaining to Hp antigens and vaccines. The salient aspects of these articles were then summarized to provide a detailed overview of the current research landscape in this field.

RESULTS

Several potential antigens have been identified and introduced through a thorough understanding of the infection process and pathogenic mechanisms of Hp. The conserved and widely distributed candidate antigens in Hp, such as UreB, HpaA, GGT, and NAP, are discussed. Proteins such as CagA and VacA, which have significant virulence effects but relatively poor conservatism, require further evaluation. Emerging antigens like HtrA and dupA have significant research value. In addition, vaccines based on these candidate antigens have been compiled and summarized.

CONCLUSIONS

Vaccines are a promising method for preventing and treating Hp. While some Hp vaccines have achieved promising results, mature products are not yet available on the market. Great efforts have been directed toward developing various types of vaccines, underscoring the need for developers to select appropriate antigens and vaccine formulations to improve success rates.

Impact of Helicobacter pylori and metabolic syndrome on mast cell activation-related pathophysiology and neurodegeneration

Both Helicobacter pylori (H. pylori) infection and metabolic syndrome (MetS) are highly prevalent worldwide. The emergence of relevant research suggesting a pathogenic linkage between H. pylori infection and MetS-related cardio-cerebrovascular diseases and neurodegenerative disorders, particularly through mechanisms involving brain pericyte deficiency, hyperhomocysteinemia, hyperfibrinogenemia, elevated lipoprotein-a, galectin-3 overexpression, atrial fibrillation, and gut dysbiosis, has raised stimulating questions regarding their pathophysiology and its translational implications for clinicians. An additional stimulating aspect refers to H. pylori and MetS-related activation of innate immune cells, mast cells (MC), which is an important, often early, event in systemic inflammatory pathologies and related brain disorders. Synoptically, MC degranulation may play a role in the pathogenesis of H. pylori and MetS-related obesity, adipokine effects, dyslipidemia, diabetes mellitus, insulin resistance, arterial hypertension, vascular dysfunction and arterial stiffness, an early indicator of atherosclerosis associated with cardio-cerebrovascular and neurodegenerative disorders. Meningeal MC can be activated by triggers including stress and toxins resulting in vascular changes and neurodegeneration. Likewise, H.pylori and MetS-related MC activation is linked with: (a) vasculitis and thromboembolic events that increase the risk of cardio-cerebrovascular and neurodegenerative disorders, and (b) gut dysbiosis-associated neurodegeneration, whereas modulation of gut microbiota and MC activation may promote neuroprotection. This narrative review investigates the intricate relationship between H. pylori infection, MetS, MC activation, and their collective impact on pathophysiological processes linked to neurodegeneration. Through a comprehensive search of current literature, we elucidate the mechanisms through which H. pylori and MetS contribute to MC activation, subsequently triggering cascades of inflammatory responses. This highlights the role of MC as key mediators in the pathogenesis of cardio-cerebrovascular and neurodegenerative disorders, emphasizing their involvement in neuroinflammation, vascular dysfunction and, ultimately, neuronal damage. Although further research is warranted, we provide a novel perspective on the pathophysiology and management of brain disorders by exploring potential therapeutic strategies targeting H. pylori eradication, MetS management, and modulation of MC to mitigate neurodegeneration risk while promoting neuroprotection.

The Role of Helicobacter pylori and Metabolic Syndrome-Related Mast Cell Activation Pathologies and Their Potential Impact on Pregnancy and Neonatal Outcomes

Helicobacter pylori infection, a significant global burden beyond the gastrointestinal tract, has long been implicated in various systemic pathologies. Rising evidence suggests that the bacterium's intricate relationship with the immune system and its potential to induce chronic inflammation impact diverse pathophysiological processes in pregnant women that may in turn affect the incidence of several adverse pregnancy and neonate outcomes. Helicobacter pylori infection, which has been linked to metabolic syndrome and other disorders by provoking pericyte dysfunction, hyperhomocysteinemia, galectin-3, atrial fibrillation, gut dysbiosis, and mast cell activation pathologies, may also contribute to adverse pregnancy and neonatal outcomes. Together with increasing our biological understanding of the individual and collective involvement of Helicobacter pylori infection-related metabolic syndrome and concurrent activation of mast cells in maternal, fetus, and neonatal health outcomes, the present narrative review may foster related research endeavors to offer novel therapeutic approaches and informed clinical practice interventions to mitigate relevant risks of this critical topic among pregnant women and their offspring.

Global status and trends of gastric cancer and gastric microbiota research: a bibliometric analysis

Background

Numerous studies have cast light on the relationship between the gastric microbiota and gastric carcinogenesis. In this study, we conducted a bibliometric analysis of the relevant literature in the field of gastric cancer and the gastric microbiota and clarified its research status, hotspots, and development trends.

Materials and methods

Publications were retrieved from the Web of Science Core Collection on 18 July 2023. CiteSpace 6.2.R4, VOSviewer 1.6.19.0, and Biblioshiny were used for the co-occurrence and cooperation analyses of countries, institutions, authors, references, and keywords. A keyword cluster analysis and an emergence analysis were performed, and relevant knowledge maps were drawn.

Results

The number of published papers in this field totaled 215 and showed an increasing trend. The analysis of funding suggested that the input in this field is increasing steadily. China had the highest number of publications, while the United States had the highest betweenness centrality. Baylor College of Medicine published the most articles cumulatively. Both Ferreira RM and Cooker OO had the highest citation frequency. The journal Helicobacter showed the most interest in this field, while Gut provided a substantial research foundation. A total of 280 keywords were obtained using CiteSpace, which were primarily focused on the eradication and pathogenic mechanisms of Helicobacter pylori, as well as the application of the gastric microbiota in the evaluation and treatment of gastric cancer. The burst analysis suggested that in the future, research may focus on the application of gastric microorganisms, particularly Fusobacterium nucleatum, in the diagnosis and treatment of gastric cancer, along with their pathogenic mechanisms.

Conclusion

Current studies have been tracking the eradication of Helicobacter pylori and its pathogenic mechanisms, as well as changes in the gastric microbiota during gastric carcinogenesis. Future research may focus on the clinical application and pathogenesis of stomach microorganisms through bacteria such as Fusobacterium nucleatum.

Sodium sulfite-driven Helicobacter pylori eradication: Unraveling oxygen dynamics through multi-omics investigation

Due to the emergence and spread of multidrug resistance in Helicobacter pylori (H. pylori), its eradication has become difficult. Sodium sulfite (SS), a widely used food additive for ensuring food safety and storage, has been recognized as an effective nonbactericidal agent for H. pylori eradication. However, the mechanism by which H. pylori adapts and eventually succumbs under low- or no-oxygen conditions remains unknown. In this study, we aimed to evaluate the anti-H. pylori effect of SS and investigated the multiomics mechanism by which SS kills H. pylori. The results demonstrated that SS effectively eradicated H. pylori both in vitro and in vivo. H. pylori responds to the oxygen changes regulated by SS, downregulates the HcpE gene, which is responsible for redox homeostasis in bacteria, decreases the activities of enzymes related to oxidative stress, and disrupts the outer membrane structure, increasing susceptibility to oxidative stress. Furthermore, SS downregulates the content of cytochrome C in the microaerobic respiratory chain, leading to a sharp decrease in ATP synthesis. Consequently, the accumulation of triglycerides (TGs) in bacteria due to oxidative stress supports anaerobic respiration, meeting their energy requirements. The multifaceted death of H. pylori caused by SS does not result in drug resistance. Thus, screening of the redox homeostasis of HcpE as a new target for H. pylori infection treatment could lead to the development of a novel approach for H. pylori eradication therapy.

Impact of Helicobacter pylori and metabolic syndrome-related mast cell activation on cardiovascular diseases

Helicobacter pylori, a widely renowned bacterium, has recently gained attention owing to its potential impact on extragastric health. The emergence of research linking H. pylori infection with metabolic syndrome (MetS)-related cardiovascular diseases (CVDs) has raised intriguing questions about the pathogenic linkage and its translational implications for clinicians. MetS encompasses a collection of metabolic abnormalities that considerably elevate the risk of CVDs and cerebrovascular diseases. Emerging evidence supports a potential pathogenetic role of H. pylori for MetS-related disorders through mechanisms implicating chronic smoldering inflammation, insulin resistance (IR), and modulation of immune responses. One intriguing aspect of this possible connection is the role of mast cells (MCs), a subset of immune cells representing innate immune system effector cells. They play a fundamental role in innate immune responses and the modulation of adaptive immunity. Activated MCs are commonly found in patients with MetS-related CVD. Recent studies have also suggested that H. pylori infection may activate MCs, triggering the release of pro-inflammatory mediators that contribute to IR and atherosclerosis. Understanding these intricate interactions at the cellular level provides new insights into the development of therapeutic strategies targeting both H. pylori infection and MetS-related MCs activation. This review investigates the current state of research regarding the potential impact of H. pylori infection and MetS-related MCs activation on the pathophysiology of CVD, thereby opening up new avenues for related research and paving the way for innovative approaches to prevention and treatment in clinical practice

Strategies of Helicobacter pylori in evading host innate and adaptive immunity: insights and prospects for therapeutic targeting

Helicobacter pylori (H. pylori) is the predominant pathogen causing chronic gastric mucosal infections globally. During the period from 2011 to 2022, the global prevalence of H. pylori infection was estimated at 43.1%, while in China, it was slightly higher at approximately 44.2%. Persistent colonization by H. pylori can lead to gastritis, peptic ulcers, and malignancies such as mucosa-associated lymphoid tissue (MALT) lymphomas and gastric adenocarcinomas. Despite eliciting robust immune responses from the host, H. pylori thrives in the gastric mucosa by modulating host immunity, particularly by altering the functions of innate and adaptive immune cells, and dampening inflammatory responses adverse to its survival, posing challenges to clinical management. The interaction between H. pylori and host immune defenses is intricate, involving evasion of host recognition by modifying surface molecules, manipulating macrophage functionality, and modulating T cell responses to evade immune surveillance. This review analyzes the immunopathogenic and immune evasion mechanisms of H. pylori, underscoring the importance of identifying new therapeutic targets and developing effective treatment strategies, and discusses how the development of vaccines against H. pylori offers new hope for eradicating such infections.

Exploring the association between inflammatory biomarkers and gastric cancer development: A two-sample mendelian randomization analysis

This study aimed to elucidate the potential causative links between inflammatory biomarkers and gastric cancer risk via a two-sample Mendelian randomization approach. Leveraging genome-wide association study (GWAS) data, we conducted a two-sample Mendelian randomization analysis. Instrumental variable selection for inflammatory markers - namely, tissue factor, monocyte chemotactic protein-1, E-selectin, interleukin 6 receptor, and fatty acid-binding protein 4 - was informed by SNP data from the IEU database. Strongly associated SNPs served as instrumental variables. We applied a suite of statistical methods, including Inverse Variance Weighted (IVW), Weighted Median Estimator (WME), MR-Egger, and mode-based estimates, to compute the odds ratios (ORs) that articulate the impact of these markers on gastric cancer susceptibility. The IVW method revealed that the interleukin 6 receptor was inversely correlated with gastric cancer progression (OR = 0.86, 95% CI = 0.74-0.99, P = .03), whereas fatty acid-binding protein 4 was found to elevate the risk (OR = 1.21, 95% CI = 1.05-1.39, P = .03). Instrumental variables comprised 5, 4, 7, 2, and 3 SNPs respectively. Convergent findings from WME, MR-Egger, and mode-based analyses corroborated these associations. Sensitivity checks, including heterogeneity, horizontal pleiotropy assessments, and leave-one-out diagnostics, affirmed the robustness and reliability of our instruments across diverse gastric malignancy tissues without substantial bias. Our research suggests that the interleukin 6 receptor potentially mitigates, while fatty acid-binding protein 4 may contribute to the pathogenesis of gastric cancer (GC). Unraveling the intricate biological interplay between inflammation and oncogenesis offers valuable insights for preemptive strategies and therapeutic interventions in gastric malignancy management.

A Mini-review on Helicobacter pylori with Gastric Cancer and Available Treatments

Helicobacter pylori (H. pylori) is the most thoroughly researched etiological component for stomach inflammation and malignancies. Even though there are conventional recommendations and treatment regimens for eradicating H. pylori, failure rates continue to climb. Antibiotic resistance contributes significantly to misdiagnoses, false positive results, and clinical failures, all of which raise the chance of infection recurrence. This review aims to explore the molecular mechanisms underlying drug resistance in H. pylori and discuss novel approaches for detecting genotypic resistance. Modulation of drug uptake/ efflux, biofilm, and coccoid development. Newer genome sequencing approaches capable of detecting H. pylori genotypic resistance are presented. Prolonged infection in the stomach causes major problems such as gastric cancer. The review discusses how H. pylori causes stomach cancer, recent biomarkers such as miRNAs, molecular pathways in the development of gastric cancer, and diagnostic methods and clinical trials for the disease. Efforts have been made to summarize the recent advancements made toward early diagnosis and novel therapeutic approaches for H. pylori-induced gastric cancer.

Microbiome in Cancer Development and Treatment

Targeting the microbiome, microbiota-derived metabolites, and related pathways represents a significant challenge in oncology. Microbiome analyses have confirmed the negative impact of cancer treatment on gut homeostasis, resulting in acute dysbiosis and severe complications, including massive inflammatory immune response, mucosal barrier disruption, and bacterial translocation across the gut epithelium. Moreover, recent studies revealed the relationship between an imbalance in the gut microbiome and treatment-related toxicity. In this review, we provide current insights into the role of the microbiome in tumor development and the impact of gut and tumor microbiomes on chemo- and immunotherapy efficacy, as well as treatment-induced late effects, including cognitive impairment and cardiotoxicity. As discussed, microbiota modulation via probiotic supplementation and fecal microbiota transplantation represents a new trend in cancer patient care, aiming to increase bacterial diversity, alleviate acute and long-term treatment-induced toxicity, and improve the response to various treatment modalities. However, a more detailed understanding of the complex relationship between the microbiome and host can significantly contribute to integrating a microbiome-based approach into clinical practice. Determination of causal correlations might lead to the identification of clinically relevant diagnostic and prognostic microbial biomarkers. Notably, restoration of intestinal homeostasis could contribute to optimizing treatment efficacy and improving cancer patient outcomes.

Reactive oxygen species and gastric carcinogenesis: The complex interaction between Helicobacter pylori and host

Helicobacter pylori (H. pylori) is a highly successful human pathogen that colonizes stomach in around 50% of the global population. The colonization of bacterium induces an inflammatory response and a substantial rise in the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), mostly derived from host neutrophils and gastric epithelial cells, which play a crucial role in combating bacterial infections. However, H. pylori has developed various strategies to quench the deleterious effects of ROS, including the production of antioxidant enzymes, antioxidant proteins as well as blocking the generation of oxidants. The host's inability to eliminate H. pylori infection results in persistent ROS production. Notably, excessive ROS can disrupt the intracellular signal transduction and biological processes of the host, incurring chronic inflammation and cellular damage, such as DNA damage, lipid peroxidation, and protein oxidation. Markedly, the sustained inflammatory response and oxidative stress during H. pylori infection are major risk factor for gastric carcinogenesis. In this context, we summarize the literature on H. pylori infection-induced ROS production, the strategies used by H. pylori to counteract the host response, and subsequent host damage and gastric carcinogenesis.

Recombinant outer membrane vesicles delivering eukaryotic expression plasmid of cytokines act as enhanced adjuvants against Helicobacter pylori infection in mice

The widespread prevalence of Helicobacter pylori (H. pylori) infection remains a great challenge to human health. The existing vaccines are not ideal for preventing H. pylori infection; thus, exploring highly effective adjuvants may improve the immunoprotective efficacy of H. pylori vaccines. In a previous study, we found that the outer membrane vesicles (OMVs), a type of nanoscale particle spontaneously produced by Gram-negative bacteria, could act as adjuvants to boost the immune responses to vaccine antigens. In this study, we explored the potential application of OMVs as delivery vectors for adjuvant development. We constructed recombinant OMVs containing eukaryotic expression plasmid of cytokines, including interleukin 17A or interferon-γ, and evaluated their function as adjuvants in combination with inactivated whole-cell vaccine (WCV) or UreB as vaccine antigens. Our results showed that recombinant OMVs as adjuvants could induce stronger humoral and mucosal immune responses in mice than wild-type H. pylori OMVs and the cholera toxin (CT) adjuvant. Additionally, the recombinant OMVs significantly promoted Th1/Th2/Th17-type immune responses. Furthermore, the recombinant OMV adjuvant induced more potent clearance of H. pylori than CT and wild-type OMVs. Our findings suggest that the recombinant OMVs coupled with cytokines may become potent adjuvants for the development of novel and effective vaccines against H. pylori infection.

The role of microbiota in the development and treatment of gastric cancer

The stomach was once considered a sterile organ until the discovery of Helicobacter pylori (HP). With the application of high-throughput sequencing technology and macrogenomics, researchers have identified fungi and fivemajor bacterial phyla within the stomachs of healthy individuals. These microbial communities exert regulatory influence over various physiological functions, including energy metabolism and immune responses. HP is a well-recognized risk factor for gastric cancer, significantly altering the stomach's native microecology. Currently, numerous studies are centered on the mechanisms by which HP contributes to gastric cancer development, primarily involving the CagA oncoprotein. However, aside from exogenous infections such as HP and EBV, certain endogenous dysbiosis can also lead to gastric cancer through multiple mechanisms. Additionally, gut microbiota and its metabolites significantly impact the development of gastric cancer. The role of microbial therapies, including diet, phages, probiotics and fecal microbiota transplantation, in treating gastric cancer should not be underestimated. This review aims to study the mechanisms involved in the roles of exogenous pathogen infection and endogenous microbiota dysbiosis in the development of gastric cancer. Also, we describe the application of microbiota therapy in the treatment and prognosis of gastric cancer.

Recent trends in Helicobacter pylori management: harnessing the power of AI and other advanced approaches

Background

Helicobacter pylori (H. pylori) is a bacterial infection that is prevalent and affects more than half of the world's population, causing stomach disorders such as gastritis, peptic ulcer disease, and gastric cancer.

Main body

The diagnosis of H. pylori infection relies on invasive and non-invasive techniques emerging artificial intelligence, and antibiotic therapy is available, but antibiotic resistance is a growing concern. The development of a vaccine is crucial in preventing H. pylori-associated diseases, but it faces challenges due to the bacterium's variability and immune escape mechanisms. Despite the challenges, ongoing research into H. pylori's virulence factors and immune escape mechanisms, as well as the development of potential vaccine targets, provides hope for more effective management and prevention of H. pylori-associated diseases. Recent research on H. pylori's immune escape mechanisms and novel immune checkpoint inhibitors could also lead to biomarkers for early cancer detection. Therefore, experts have suggested a combination of traditional and herbal medicine with artificial intelligence to potentially eradicate H. pylori.

Short conclusion

H. pylori infection remains a significant global health problem, but ongoing research into its properties and advanced technologies in addition to the combination of traditional and herbal medicine with artificial intelligence may also lead to the eradication of H. pylori-associated diseases.

Graphical abstract

Reactive Oxygen Species and H. pylori Infection: A Comprehensive Review of Their Roles in Gastric Cancer Development

Gastric cancer (GC) is the fifth most common cancer worldwide and makes up a significant component of the global cancer burden. Helicobacter pylori (H. pylori) is the most influential risk factor for GC, with the International Agency for Research on Cancer classifying it as a Class I carcinogen for GC. H. pylori has been shown to persist in stomach acid for decades, causing damage to the stomach's mucosal lining, altering gastric hormone release patterns, and potentially altering gastric function. Epidemiological studies have shown that eliminating H. pylori reduces metachronous cancer. Evidence shows that various molecular alterations are present in gastric cancer and precancerous lesions associated with an H. pylori infection. However, although H. pylori can cause oxidative stress-induced gastric cancer, with antioxidants potentially being a treatment for GC, the exact mechanism underlying GC etiology is not fully understood. This review provides an overview of recent research exploring the pathophysiology of H. pylori-induced oxidative stress that can cause cancer and the antioxidant supplements that can reduce or even eliminate GC occurrence.

Helicobacter pylori in the post-antibiotics era: from virulence factors to new drug targets and therapeutic agents

Helicobacter pylori is considered one of the most prevalent human pathogenic microbes globally. It is the main cause of a number of gastrointestinal ailments, including peptic and duodenal ulcers, and gastric tumors with high mortality rates. Thus, eradication of H. pylori is necessary to prevent gastric cancer. Still, the rise in antibiotic resistance is the most important challenge for eradication strategies. Better consideration of H. pylori virulence factors, pathogenesis, and resistance is required for better eradication rates and, thus, prevention of gastrointestinal malignancy. This article is aimed to show the role of virulence factors of H. pylori. Some are involved in its survival in the harsh environment of the human gastric lumen, and others are related to pathogenesis and the infection process. Furthermore, this work has highlighted the recent advancement in H. pylori treatment, as well as antibiotic resistance as a main challenge in H. pylori eradication. Also, we tried to provide an updated summary of the evolving H. pylori control strategies and the potential alternative drugs to fight this lethal resistant pathogen. Recent studies have focused on evaluating the efficacy of alternative regimens (such as sequential, hybrid, concomitant treatment, vonoprazan (VPZ)-based triple therapy, high-dose PPI-amoxicillin dual therapy, probiotics augmented triple therapy, or in combination with BQT) in the effective eradication of H. pylori. Thus, innovating new anti-H. pylori drugs and establishing H. pylori databanks are upcoming necessities in the near future.

Pathogenomics of Helicobacter pylori

The human stomach bacterium Helicobacter pylori, the causative agent of gastritis, ulcers and adenocarcinoma, possesses very high genetic diversity. H. pylori has been associated with anatomically modern humans since their origins over 100,000 years ago and has co-evolved with its human host ever since. Predominantly intrafamilial and local transmission, along with genetic isolation, genetic drift, and selection have facilitated the development of distinct bacterial populations that are characteristic for large geographical areas. H. pylori utilizes a large arsenal of virulence and colonization factors to mediate the interaction with its host. Those include various adhesins, the vacuolating cytotoxin VacA, urease, serine protease HtrA, the cytotoxin-associated genes pathogenicity island (cagPAI)-encoded type-IV secretion system and its effector protein CagA, all of which contribute to disease development. While many pathogenicity-related factors are present in all strains, some belong to the auxiliary genome and are associated with specific phylogeographic populations. H. pylori is naturally competent for DNA uptake and recombination, and its genome evolution is driven by extraordinarily high recombination and mutation rates that are by far exceeding those in other bacteria. Comparative genome analyses revealed that adaptation of H. pylori to individual hosts is associated with strong selection for particular protein variants that facilitate immune evasion, especially in surface-exposed and in secreted virulence factors. Recent studies identified single-nucleotide polymorphisms (SNPs) in H. pylori that are associated with the development of severe gastric disease, including gastric cancer. Here, we review the current knowledge about the pathogenomics of H. pylori.