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Mycobacterium bovis (M. bovis) Bacillus Calmette-Guerin (BCG) strain used in immunotherapy of bladder cancer (onco-BCG) due to its acid tolerance can be a candidate for prevention or reversion of deleterious effects towards gastric cell barrier initiated by gastric pathogen Helicobacter pylori (Hp) with high resistance to commonly used antibiotics. Colonization of gastric mucosa by Hp promotes oxidative stress, apoptosis resulting in the gastric barrier damage. The aim of this study was to examine the ability of onco-BCG bacilli to control the Hp driven gastric damage using the model of Cavia porcellus primary gastric epithelial cells or fibroblasts in vitro. These cells were treated with Hp surface antigens (glycine acid extract-GE or lipopolysaccharide-LPS) alone or with onco-BCG bacilli and evaluated for cell apoptosis and proliferation in conjunction with the level of soluble lipid peroxidation marker (s4HNE). The cell migration was determined by "wound healing assay", while cytokine response of cells, including interleukin (IL)-33, IL-1β, IL-8 and tumor necrosis factor alpha (TNF-α), by the ELISA. The apoptosis of cells pulsed in vitro with Hp surface components present in GE or with LPS was reduced after exposure of cells to mycobacteria. Similarly, the cell regeneration which was diminished by Hp LPS has been improved in response to mycobacteria. This study reveals that vaccine mycobacteria may reduce gastric barrier damage induced by Hp infection., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Background: Changes in gastric microbiome are associated with gastric carcinogenesis. Studies on the association between gastric mucosa-associated gastric microbiome (MAM) and metachronous gastric cancer are limited. This study aimed to identify gastric MAM as a predictive factor for metachronous recurrence following endoscopic resection of gastric neoplasms., Method: Microbiome analyses were conducted for 81 patients in a prospective cohort to investigate surrogate markers to predict metachronous recurrence. Gastric MAM in non-cancerous corporal biopsy specimens was evaluated using Illumina MiSeq platform targeting 16S ribosomal DNA., Results: Over a median follow-up duration of 53.8 months, 16 metachronous gastric neoplasms developed. Baseline gastric MAM varied with Helicobacter pylori infection status, but was unaffected by initial pathologic diagnosis, presence of atrophic gastritis, intestinal metaplasia, or synchronous lesions. The group with metachronous recurrence did not exhibit distinct phylogenetic diversity compared with the group devoid of recurrence but showed significant difference in β-diversity. The study population could be classified into two distinct gastrotypes based on baseline gastric MAM: gastrotype 1, Helicobacter-abundant; gastrotype 2: Akkermansia-abundant. Patients in gastrotype 2 showed higher risk of metachronous recurrence than gastrotype (Cox proportional hazard analysis, adjusted hazard ratio [95% confidence interval]: 5.10 [1.09-23.79])., Conclusions: Gastric cancer patients can be classified into two distinct gastrotype groups by their MAM profiles, which were associated with different risk of metachronous recurrence., (© 2024. The Author(s) under exclusive licence to The International Gastric Cancer Association and The Japanese Gastric Cancer Association.)

The escalating challenges of Helicobacter pylori-induced gastric complications, driven by rising antibiotic resistance and persistent cancer risks, underscore the demand for innovative therapeutic strategies. This study addresses this urgency through the development of tailored semi-interpenetrating polymer networks (semi-IPN) serving as gastroretentive matrices for amoxicillin (AMOX). They are biodegradable, absorb significant volume of simulated gastric fluid (swelling index > 360 %) and exhibit superporous microstructures, remarkable mucoadhesion, and buoyancy. The investigation includes assessment at pH 1.2 for comparative analysis with prior studies and, notably, at pH 5.0, reflecting the acidic environment in H. pylori-infected stomachs. The semi-IPN demonstrated gel-like structures, maintaining integrity throughout the 24-hour controlled release study, and disintegrating upon completing their intended function. Evaluated in gastroretentive drug delivery system performance, AMOX release at pH 1.2 and pH 5.0 over 24 h (10 %-100 %) employed experimental design methodology, elucidating dominant release mechanisms. Their mucoadhesive, buoyant, three-dimensional scaffold stability, and gastric biodegradability make them ideal for accommodating substantial AMOX quantities. Furthermore, exploring the inclusion of the potassium-competitive acid blocker (P-CAB) vonoprazan (VONO) in AMOX-loaded formulations shows promise for precise and effective drug delivery. This innovative approach has the potential to combat H. pylori infections, thereby preventing the gastric cancer induced by this pathogen., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

A bibliometric analysis of studies dedicated to autoimmune gastritis (AIG) recently published demonstrated a noteworthy surge in publications over the last three years. This can be explained by numerous publications from different regions of the world reporting the results of several studies that stimulated reassessment of our view of AIG as a precancerous condition. Follow-up studies and retrospective analyses showed that the risk of gastric cancer (GC) in AIG patients is much lower than expected if the patients ever being infected with Helicobacter pylori ( H. pylori ) were excluded. The low prevalence of precancerous lesions, such as the incomplete type of intestinal metaplasia, may explain the low risk of GC in AIG patients because the spasmolytic polypeptide-expressing metaplasia commonly observed in AIG does not involve clonal reprogramming of the gastric gland and can be considered as an adaptive change rather than a true precancerous lesion. However, changes in gastric secretion due to the progression of gastric atrophy during the course of AIG cause changes in the gastric mic-robiome, stimulating the growth of bacterial species such as streptococci, which may promote the development of precancerous lesions and GC. Thus, Streptococcus anginosus exhibited a robust proinflammatory response and induced the gastritis-atrophy-metaplasia-dysplasia sequence in mice, reproducing the well-established process for carcinogenesis associated with H. pylori . Prospective studies in H. pylori -naïve patients evaluating gastric microbiome changes during the long-term course of AIG might provide an explanation for the enigmatic increase in GC incidence in the last decades in younger cohorts, which has been reported in economically developed countries., Competing Interests: Conflict-of-interest statement: The authors declare that they have no conflict of interest., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Helicobacter pylori infection predisposes carriers to a high risk of developing gastric cancer. The cell-of-origin of antral gastric cancer is the Lgr5 + stem cell. Here, we show that infection of antrum-derived gastric organoid cells with H. pylori increases the expression of the stem cell marker Lgr5 as determined by immunofluorescence microscopy, qRT-PCR, and Western blotting, both when cells are grown and infected as monolayers and when cells are exposed to H. pylori in 3D structures. H. pylori exposure increases stemness properties as determined by spheroid formation assay. Lgr5 expression and the acquisition of stemness depend on a functional type IV secretion system (T4SS) and at least partly on the T4SS effector CagA. The pharmacological inhibition or genetic ablation of NF-κB reverses the increase in Lgr5 and spheroid formation. Constitutively active Wnt/β-catenin signaling because of Apc inactivation exacerbates H. pylori -induced Lgr5 expression and stemness, both of which persist even after eradication of the infection. The combined data indicate that H. pylori has stemness-inducing properties that depend on its ability to activate NF-κB signaling., (© 2024 Nascakova et al.)

Helicobacter pylori (Hp) is a Gram-negative bacterium that colonizes in the gastric mucosa. Hp induces the production of cancer-associated fibroblasts (CAF) in the stomach. The virulence factors of Hp and CAF trigger epithelial-mesenchymal transition (EMT), leading to local inflammation, damage to the gastric mucosa, and the occurrence of chronic gastritis. Here, we summarize the molecular mechanisms of CAF mediated gastric EMT after Hp infection, providing new insights into potential molecular targets and strategies for the future treatment of Hp infection associated gastric cancer.

Background: Helicobacter pylori (H. pylori) infection is critical in the development and occurrence of gastric cancer. H. pylori secretes gamma-glutamyl transferase (GGT), which affects energy metabolism and histone methylation in mesenchymal stem cells. However, its effect on human gastric epithelial cells remains unclear. This study aimed to investigate the effects of GGT on energy metabolism and histone methylation in gastric epithelial cells and determine its role in the development and progression of H. pylori-induced gastric cancer., Methods: A GGT knockout H. pylori strain and mouse gastric cancer model were constructed, and alpha-ketoglutarate (α-KG) was added. The underlying mechanism was investigated using proteomics, immunohistochemistry, Western blotting, and other experimental assays., Results: H. pylori can colonize the host's stomach and destroy the gastric epithelium. GGT secreted by H. pylori decreased the concentration of glutamine in the stomach and increased H3K9me3 and H3K27me3 expression, which promoted the proliferation and migration of gastric epithelial cells. Additionally, α-KG reversed this effect. GGT increased the tumorigenic ability of nude mice. GGT, secreted by H. pylori, promoted the expression of ribosomal protein L15 (RPL15), while GGT knockout and supplementation with α-KG and trimethylation inhibitors reduced RPL15 expression and Wnt signaling pathway expression., Conclusions: H. pylori secreted GGT decreased the expression of glutamine and α-KG in gastric epithelial cells, increased the expression of histones H3K9me3 and H3K27me3, and activated the Wnt signaling pathway through RPL15 expression, ultimately changing the biological characteristics of the gastric epithelium and promoting the occurrence of gastric cancer. Altered energy metabolism and histone hypermethylation are important factors involved in this process., (© 2024. The Author(s).)

Gastrointestinal mucosal surface is frequently under challenge due to it's the large surface area and most common entry of microbes. IL-37, an anti-inflammatory cytokine, regulates local and systemic host immunity. H. pylori infection leads to the inhibition of IL-37 in the gastric mucosa, contributing to heightened mucosal inflammation and destruction, thereby facilitating increased proliferation of H. pylori . Food allergy, due to immune dysregulation, also contribute to GI injury. On the other hand, elevated levels of IL-37 observed in gastric cancer patients align with reduced host immunity at the cellular and humoral levels, indicating that IL-37 may contribute to the development of gastric cancer via suppressing pro-inflammatory responses. While IL-37 provides protection in an IBD animal model, the detection of highly produced IL-37 in IBD patients suggests a stage-dependent role, being protective in acute inflammation but potentially exacerbates the development of IBD in chronic conditions. Moreover, elevated colonic IL-37 in CRC correlates with overall survival time and disease time, indicating a protective role for IL-37 in CRC. The differential regulation and expression of IL-37 between upper- and lower-GI organs may be attributed to variations in the microbial flora. This information suggests that IL-37 could be a potential therapeutic agent, depending on the stage and location., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Wang, Zhang, An, Hambly and Bao.)

Background: Theoretically, a rapid urease test (RUT) using a swab of the gastric wall (Swab-RUT) for Helicobacter pylori (H. pylori) is safe. However, the validity and utility of Swab-RUT remain unclear. Therefore, we assessed the validity and utility of Swab-RUT compared to RUT using mucosal forceps of the gastric wall (Forceps-RUT) and 13 C-urea breath test (UBT)., Methods: This study was a multicenter prospective observational study. When the examinees were suspected of H. pylori infection during esophagogastroduodenoscopy, we performed Swab-RUT and Forceps-RUT continuously. When the examinees were not suspected of H. pylori infection, we performed Swab-RUT alone. We validated the status of H. pylori infection using UBT., Results: Ninety-four examinees were enrolled from four institutions between May 2016 and December 2020 (median age [range], 56.5 [26-88] years). In this study, the sensitivity, specificity, and accuracy of Swab-RUT to UBT were 0.933 (95% confidence interval: 0.779-0.992), 0.922 (0.827-0.974), and 0.926 (0.853-0.970), respectively. The Kappa coefficient of Swab-RUT to UBT was 0.833, and that of Swab-RUT to forceps-RUT was 0.936. No complications were observed in this study., Conclusions: Swab-RUT is a valid examination for the status of H. pylori infection compared to the conventional Forceps-RUT., (© 2024. The Author(s).)

Background: Helicobacter pylori infection is one of the most common chronic bacterial infections, especially in developing countries. MicroRNA-148a is involved in the regulation of various genes, including Rock1, which is altered in gastric cancer. Decreased expression of mir-148a leads to tumor metastasis and increased Rock1 gene expression in gastric cancer. This study aimed to investigate the expression of these genes in biopsies collected from patients with H. pylori induced gastritis., Methods: Informed consent forms were gotten from the studied patients with gastritis who needed endoscopy. Gastric biopsies were taken by a gastroenterologist from patients with inflammation. Rapid urease test, stool antigen detection, and histopathological staining were used to determine the H. pylori infected patients. Real time PCR was used to evaluate the miRNA and Rock1 expression levels., Results: The Rock1 expression level in biopsies that were positive for H. pylori was significantly increased compared to our control gastritis group that were H. pylori-negative, but the results were not statistically significant. Moreover, the mir-148a expression level in H. pylori-positive patients with gastritis was increased compared to our control group. However, the results were not statistically significant. We did not find a significant relation between the expression levels of Rock1 and mir-148a in samples with gastritis infected or uninfected by H. pylori. This result may be due to the small sample size., Conclusion: We suggest that this test should be carried out with more samples, and the comparison should be done between biopsies with inflammation and no inflammation in a patient., (© 2024. The Author(s).)

Helicobacter pylori is a microaerophilic Gram-negative bacterium that resides in the human stomach and is classified as a class I carcinogen for gastric cancer. Numerous studies have demonstrated that H. pylori infection plays a role in regulating the function of host cells, thereby contributing to the malignant transformation of these cells. However, H. pylori infection is a chronic process, and short-term cellular experiments may not provide a comprehensive understanding of the in vivo situation, especially when considering the lower oxygen levels in the human stomach. In this study, we aimed to investigate the mechanisms underlying gastric cell dysfunction after prolonged exposure to H. pylori under hypoxic conditions. We conducted a co-culture experiment using the gastric cell line GES-1 and H. pylori for 30 generations under intermittent hypoxic conditions. By closely monitoring cell proliferation, migration, invasion, autophagy, and apoptosis, we revealed that sustained H. pylori stimulation under hypoxic conditions significantly influences the function of GES-1 cells. This stimulation induces epithelial-mesenchymal transition and contributes to the propensity for malignant transformation of gastric cells. To confirm the in vitro results, we conducted an experiment involving Mongolian gerbils infected with H. pylori for 85 weeks. All the results strongly suggest that the Nod1 receptor signaling pathway plays a crucial role in H. pylori -related apoptosis and autophagy. In summary, continuous stimulation by H. pylori affects the functioning of gastric cells through the Nod1 receptor signaling pathway, increasing the likelihood of cell carcinogenesis. The presence of hypoxic conditions further exacerbates this process.IMPORTANCEDeciphering the collaborative effects of Helicobacter pylori infection on gastric epithelial cell function is key to unraveling the development mechanisms of gastric cancer. Prior research has solely examined the outcomes of short-term H. pylori stimulation on gastric epithelial cells under aerobic conditions, neglecting the bacterium's nature as a microaerophilic organism that leads to cancer following prolonged stomach colonization. This study mimics a more genuine in vivo infection scenario by repeatedly exposing gastric epithelial cells to H. pylori under hypoxic conditions for up to 30 generations. The results show that chronic exposure to H. pylori in hypoxia substantially increases cell migration, invasion, and epithelial-mesenchymal transition, while suppressing autophagy and apoptosis. This highlights the significance of hypoxic conditions in intensifying the carcinogenic impact of H. pylori infection. By accurately replicating the in vivo gastric environment, this study enhances our comprehension of H. pylori 's pathogenic mechanisms in gastric cancer., Competing Interests: The authors declare no conflict of interest.

Objectives: We aimed to identify predictive markers for metachronous gastric cancer (MGC) in early gastric cancer (EGC) patients curatively treated with endoscopic submucosal dissection (ESD)., Materials and Methods: From EGC patients who underwent ESD, bulk RNA sequencing was performed on non-cancerous gastric mucosa samples at the time of initial EGC diagnosis. This included 23 patients who developed MGC, and 23 control patients without additional gastric neoplasms for over 3 years (1:1 matched by age, sex, and Helicobacter pylori infection state). Candidate differentially-expressed genes were identified, from which biomarkers were selected using real-time quantitative polymerase chain reaction and cell viability assays using gastric cell lines. An independent validation cohort of 55 MGC patients and 125 controls was used for marker validation. We also examined the severity of gastric intestinal metaplasia, a known premalignant condition, at initial diagnosis., Results: From the discovery cohort, 86 candidate genes were identified of which KDF1 and CDK1 were selected as markers for MGC, which were confirmed in the validation cohort. CERB5 and AKT2 isoform were identified as markers related to intestinal metaplasia and were also highly expressed in MGC patients compared to controls (p < 0.01). Combining these markers with clinical data (age, sex, H. pylori and severity of intestinal metaplasia) yielded an area under the curve (AUC) of 0.91 (95% CI, 0.85-0.97) for MGC prediction., Conclusion: Assessing biomarkers in non-cancerous gastric mucosa may be a useful method for predicting MGC in EGC patients and identifying patients with a higher risk of developing MGC, who can benefit from rigorous surveillance., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

The Helicobacter pylori infection in the stomach is the key reason for gastric mucosal bleeding. Eliminating gastric Helicobacter pylori by oral treatment remains difficult due to the presence of the gastric mucosal layer, which acts as a physical barrier to drugs via oral administration. In this study, a magnetic-navigable microneedle drug delivery platform (MNsD) for oral administration, featuring differential dual-mode drug release rate, was designed to fulfil rapid gastric hemostasis and overcome the gastric barriers for long-lasting Helicobacter pylori inhibition in stomach. MNs-D was created by rationally loading the carrier substrate, which was composed of silk fibroin with variable solubility, with antibiotics and hemostats. In vitro experiments showed MNs-D may sustainably eradicate Helicobacter pylori in stimulated gastric juices with long-lasting drug release (79 % in 24 h) and quickly establish hemostasis with instant drug release (92 % within 60 s). Most importantly, in vivo studies demonstrated MNs-D overcame the unsettling gastric mucosal barrier in traditional therapies of oral administration by insertion into the GML under magnetic navigation, resulting in sustained antibiotic release for long-lasting Helicobacter pylori eradiation (99 %). For differential dual-mode medication release against gastric Helicobacter pylori infections, this study may have firstly examined the effects of magnetic navigated microneedles administered orally., Competing Interests: Declaration of competing interest There are no conflicts of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Reports of Helicobacter pylori (Hp)-naïve gastric neoplasm (HpNGN) cases have been rapidly increasing due to the recent increase in the Hp-naïve population in Japan. Most HpNGNs exhibit the gastric immunophenotype and a low malignant potential regardless of histological type. Especially, foveolar-type gastric adenoma (FGA) and intestinal-type gastric dysplasia (IGD) rarely progress to invasive carcinoma. FGA is a foveolar epithelial neoplasm that occurs in the fundic gland (oxyntic gland) mucosa and is classified as the flat type or raspberry type (FGA-RA). The flat type is a large, whitish flatly elevated lesion while FGA-RA is a small reddish polyp. Genomically, the flat type is characterized by APC and KRAS gene mutations and FGA-RA by a common single nucleotide variant in the KLF4 gene. This KLF4 single-nucleotide variant reportedly induces gastric foveolar epithelial tumorigenesis and activates both cell proliferation and apoptosis, leading to its slow-growing nature. IGD consists of an intestinalized epithelial dysplasia that develops in the pyloric gland mucosa, characterized as a superficial depressed lesion surrounded by raised mucosa showing a gastritis-like appearance. Immunohistochemically, it exhibits an intestinal or gastrointestinal phenotype and, frequently, p53 overexpression. Thus, IGD shows unique characteristics in HpNGNs and a potential multistep tumorigenic process., (© 2024 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

About half of the world's population is infected with the bacterium Helicobacter pylori. For colonization, the bacterium neutralizes the low gastric pH and recruits immune cells to the stomach. The immune cells secrete cytokines, i.e., the pro-inflammatory IL-17A, which directly or indirectly damage surface epithelial cells. Since (I) dietary proteins are known to be digested into bitter tasting peptides in the gastric lumen, and (II) bitter tasting compounds have been demonstrated to reduce the release of pro-inflammatory cytokines through functional involvement of bitter taste receptors (TAS2Rs), we hypothesized that the sweet-tasting plant protein thaumatin would be cleaved into anti-inflammatory bitter peptides during gastric digestion. Using immortalized human parietal cells (HGT-1 cells), we demonstrated a bitter taste receptor TAS2R16-dependent reduction of a H. pylori-evoked IL-17A release by up to 89.7 ± 21.9% (p ≤ 0.01). Functional involvement of TAS2R16 was demonstrated by the study of specific antagonists and siRNA knock-down experiments., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Phil Richter (co-author), Veronika Somoza (corresp. author) reports financial support, administrative support, article publishing charges, and equipment, drugs, or supplies were provided by Leibniz-Institute for Food Systems Biology at the Technical University of Munich. Veronika Somoza reports a relationship with Leibniz-Institute for Food Systems Biology at the Technical University of Munich that includes: employment. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Helicobacter pylori ( H. pylori ) infection is the primary risk factor for the progress of gastric diseases. The persistent stomach colonization of H. pylori is closely associated with the development of gastritis and malignancies. Although the involvement of progranulin (PGRN) in various cancer types has been well-documented, its functional role and underlying mechanisms in gastric cancer (GC) associated with H. pylori infection remain largely unknown. This report demonstrated that PGRN was up-regulated in GC and associated with poor prognosis, as determined through local and public database analysis. Additionally, H. pylori induced the up-regulation of PGRN in gastric epithelial cells both in vitro and in vivo . Functional studies have shown that PGRN promoted the intracellular colonization of H. pylori . Mechanistically, H. pylori infection induced autophagy, while PGRN inhibited autophagy to promote the intracellular colonization of H. pylori . Furthermore, PGRN suppressed H. pylori -induced autophagy by down-regulating decorin (DCN) through the mTOR pathway. In general, PGRN inhibited autophagy to facilitate intracellular colonization of H. pylori via the PGRN/mTOR/DCN axis. This study provides new insights into the molecular mechanisms underlying the progression of gastric diseases, suggesting PGRN as a potential therapeutic target and prognostic predictor for these disorders., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Liu, Xiang, Zhou, Ren, Shi, Du, Fu, Li and Wang.)

Introduction: Cytokeratins (CKs) have been associated with precancerous and cancerous gastric lesions in patients with Helicobacter pylori-associated chronic gastritis, making them useful for diagnosing epithelial tumors., Methodology: A retrospective study was conducted utilizing 200 formalin-fixed paraffin-embedded gastric biopsy samples collected from the lesser curvature of the stomach. Samples from the control group, patients with H. pylori infection, and patients with H. pylori-associated gastritis, with complete and incomplete intestinal metaplasia (IM) were immunostained. Monoclonal antibodies were utilized to determine the expression of CK7, CK20, and Ki-67., Results: Patients infected with H. pylori had strong CK20 expression on the surface, and weak CK7 expression on the surface and deep glands; while non-specific chronic gastritis patients had weak focal CK7 expression and strong CK20 expression. The normal gastric mucosa of patients in the control group had relatively weak CK7 expression, restricted to a few cells in the neck and deep glands. CK20 showed diffuse strong reactivity on the surface. On the other hand, patients with complete IM showed a CK7 staining pattern that was either negative or weakly focal on the surface and crypts associated with diffuse surface CK20 and focal crypt staining corresponding to gastric type IM. The Ki67 proliferating index was low (≤ 15%) in H. pylori infected patients, high (> 30%) in patients with incomplete IM, and intermediate (16-30%) in patients with complete IM., Conclusions: These results indicate a significant link between the expressions of CK7/CK20 and Ki67 in patients afflicted with H. pylori and IM., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2024 Ava T Ismael, Rafal A Abdulhameed, Jalal A Jalal, Rawaz D Tawfeeq, Aram Ommar, Aveen Jalal.)

Gastric cancer is one of the major causes of cancer-related deaths worldwide, and infection with Helicobacter pylori and EBV, smoking and a salt-heavy diet have been shown to be risk factors for the development of gastric cancer. Currently, numerous research has demonstrated that differences in the structure of the gastric flora can be exploited to distinguish the different stages of gastric mucosal lesions and to predict the progression of gastric cancer. Therefore, a new biomarker is presented for the diagnosis of gastric cancer based on the structural differences of the gastric flora. Gastric flora has also potential in the treatment of gastric cancer. The application of non-H. pylori flora to modulate immune cells may increase the sensitivity of tumour cells for chemotherapy, improve the efficacy of immune checkpoint inhibitors and significantly prolong the survival of patients. This review of advances in the application of gastric flora in the diagnosis and treatment of gastric cancer is aimed at providing a reference and basis for future research in this field.

Indole-3-lactic acid (ILA) has exhibited antimicrobial properties. However, its role in inhibiting Helicobacter pylori infection remains elusive. This study investigated the inhibitory effect of ILA produced by Lacticaseibacillus paracasei on H. pylori , which was further confirmed by cell and animal experiments. 5 mg/mL ILA was sufficient to directly inhibit the growth of H. pylori in vitro, with a urease inhibitory activity reaching 60.94 ± 1.03%, and the cell morphology and structure were destroyed. ILA inhibited 56.5% adhesion of H. pylori to GES-1 and significantly reduced the number of apoptotic cells. Furthermore, ILA suppresses H. pylori colonization by approximately 38% to 63%, reduced inflammation and oxidative stress in H. pylori -infected mice, and enhanced the enrichment and variety of gut microbiota, notably fostering the growth of beneficial bacteria such as Lactobacillus and Bifidobacterium strains. The results support that ILA derived from Lactobacillus can be applicated as a novel prebiotic in anti- H. pylori functional foods.

Background/aims: While DNA methylation and gastric microbiome are each associated with gastric cancer (GC), their combined role in predicting GC remains unclear. This study investigated the potential of a combined DNA methylation and gastric microbiome signature to predict Helicobacter pylori -negative GC., Methods: In this case-control study, we conducted quantitative methylation-specific polymerase chain reaction to measure the methylation levels of DKK3 , SFRP1 , EMX1 , NKX6-1 , MIR124-3 , and TWIST1 in the gastric mucosa from 75 H. pylori -negative patients, including chronic gastritis (CG), intestinal metaplasia (IM), and GC. A combined analysis of DNA methylation and gastric microbiome, using 16S rRNA gene sequencing, was performed in 30 of 75 patients., Results: The methylation levels of DKK3 , SFRP1 , EMX1 , MIR124-3 , and TWIST1 were significantly higher in patients with GC than in controls (all q<0.05). MIR124-3 and TWIST1 methylation levels were higher in patients with IM than those with CG and also in those with GC than in those with IM (all q<0.05). A higher methylation level of TWIST1 was an independent predictor for H. pylori -negative GC after adjusting for age, sex, and atrophy (odds ratio [OR], 15.15; 95% confidence interval [CI], 1.58 to 145.46; p=0.018). The combination of TWIST1 methylation and GC microbiome index (a microbiome marker) was significantly associated with H. pylori -negative GC after adjusting for age, sex, and atrophy (OR, 50.00; 95% CI, 1.69 to 1,476; p=0.024)., Conclusions: The combination of TWIST1 methylation and GC microbiome index may offer potential as a biomarker for predicting H. pylori -negative GC.

H. pylori infection is gaining increasing attention, but detailed investigations into its impact on gastric microbiota remain limited. We collected gastric mucosa samples from 47 individuals divided into three groups: 1. Group HP: patients with initial positive H. pylori infection (25 cases); 2. Group ck: H. pylori-negative patients (14 cases); 3. Group DiffHP: patients with refractory H. pylori infection (8 cases). The samples were analyzed using 16S rDNA sequencing and functional prediction with PICRUSt. Group HP showed differences in flora distribution and function compared to Group ck, while Group DiffHP overlapped with Group HP. The abundances of Aeromonas piscicola, Shewanella algae, Vibrio plantisponsor, Aeromonas caviae, Serratia marcescens, Vibrio parahaemolyticus, Microbacterium lacticum, and Prevotella nigrescens were significantly reduced in both Group DiffHP and Group HP compared to Group ck. Vibrio shilonii was reduced only in Group DiffHP compared to Group ck, while Clostridium perfringens and Paracoccus marinus were increased only in Group DiffHP. LEfSe analysis revealed that Clostridium perfringens and Paracoccus marinus were enriched, whereas Vibrio shilonii was reduced in Group DiffHP compared to Group ck at the species level. In individuals with refractory H. pylori infection, the gastric microbiota exhibited enrichment in various human diseases, organic systems, and metabolic pathways (amino acid metabolism, carbohydrate metabolism, transcription, replication and repair, cell cycle pathways, and apoptosis). Patients with multiple failed H. pylori eradication exhibited significant changes in the gastric microbiota. An increase in Clostridium perfringens and Paracoccus marinus and a decrease in Vibrio shilonii appears to be characteristic of refractory H. pylori infection., (© 2024. The Author(s).)

Background: Chronic gastritis caused by Helicobacter pylori (Hp) infection is a common gastrointestinal disorder. Despite the high prevalence of Hp infection and chronic gastritis in the Tibetan Plateau, there is a lack of studies elucidating the influence of plateau hypoxia on Hp-induced gastritis. This study aimed to investigate the impact of high-altitude hypoxia on Hp-induced gastritis, particularly focusing on pathological manifestations and inflammatory responses., Methods: This study was conducted from July 2023 to March 2024 at the Department of Gastroenterology, Affiliated Hospital of Qinghai University. Ninety patients diagnosed with chronic gastritis were enrolled in the study and divided into four groups based on their residential altitude and Hp infection status. Data on endoscopic and pathological characteristics were collected, along with serum oxidative stress and inflammatory markers., Results: Patients with Hp gastritis exhibit distinctive features in the gastric mucosa, including diffuse erythema, enlarged folds, and white turbid mucus during endoscopy. Notably, individuals with Hp gastritis at high altitudes show a higher prevalence of diffuse erythema and enlarged folds. Pathological analysis reveals that these patients have elevated gastric mucosal inflammation scores and increased chronic and active inflammation. Furthermore, individuals with Hp gastritis at high altitudes demonstrate elevated levels of serum TNF-α, IL-1β, IL-6, and MDA, as well as reduced serum SOD and GSH-Px activities., Conclusions: High-altitude hypoxia may exacerbate gastric mucosal damage by enhancing oxidative stress and inflammatory response induced by Hp infection., (© 2024. The Author(s).)

BRCA1 and BRCA2 carriers may be at increased risk for gastric cancer; however, the mechanisms of gastric carcinogenesis remain poorly understood. We sought to determine the prevalence of gastric cancer risk factors Helicobacter pylori (H. pylori) infection and gastric intestinal metaplasia (GIM) among BRCA1/2 carriers to gain insight into the pathogenesis of gastric cancer in this population. A total of 100 unselected BRCA1/2 carriers who underwent endoscopic ultrasound from March 2022 to March 2023 underwent concomitant upper endoscopy with nontargeted gastric antrum and body biopsies. The study population (70% women; mean age 60.1 years) included 66% BRCA2 carriers. H. pylori was detected in one (1%) individual, 7 (7%) had GIM, 2 (2%) had autoimmune atrophic gastritis, and no gastric cancers were diagnosed. Among BRCA1/2 carriers, H. pylori prevalence was low and GIM prevalence was similar to that in the general population; however, identification of H. pylori or GIM may help inform future gastric cancer risk management strategies in BRCA1/2 carriers. Prevention Relevance: Evaluating the burden of H. pylori infection and GIM among BRCA1/2 carriers is warranted to better understand the mechanisms of gastric carcinogenesis and to help inform risk management strategies for gastric cancer among this at-risk population., (©2024 American Association for Cancer Research.)

Emerging evidence suggests differential antagonism of lactic acid-producing bacteria (LAB) to Helicobacter pylori, posing challenges to human health and food safety due to unclear mechanisms. This study assessed 21 LAB strains from various sources on H. pylori growth, urease activity, and coaggregation. Composite scoring revealed that Latilactobacillus sakei LZ217, derived from fresh milk, demonstrates strong inhibitory effects on both H. pylori growth and urease activity. L. sakei LZ217 significantly reduced H. pylori adherence of gastric cells in vitro, with inhibition ratios of 47.62%. Furthermore, in vivo results showed that L. sakei LZ217 alleviated H. pylori-induced gastric mucosa damage and inflammation in mice. Metabolomic exploration revealed metabolic perturbations in H. pylori induced by L. sakei LZ217, including reduced amino acid levels (e.g., isoleucine, leucine, glutamate, aspartate, and phenylalanine) and impaired carbohydrate and nucleotide synthesis, contributing to the suppression of ureA (28.30%), ureE (84.88%), and ureF (59.59%) expressions in H. pylori. This study underscores the efficacy of LAB against H. pylori and highlights metabolic pathways as promising targets for future interventions against H. pylori growth and colonization., (© 2024 John Wiley & Sons Ltd.)

Objective: Data regarding Helicobacter pylori (H. pylori)-associated mucosa-associated lymphoid tissue (MALT) lymphoma in children are lacking. We aimed to characterize the diagnosis, management, and outcome of H. pylori-associated MALT lymphoma in pediatric patients., Study Design: A retrospective multicenter case series of the pediatric patients with H. pylori-associated MALT lymphoma who were diagnosed during 2010-2022., Results: Five children, of them three females, were identified. The mean age at diagnosis was 14.6 ± 2.4 years. The clinical presentation included abdominal pain (5/5), nausea (3/5), weight loss, night sweats, recurrent fever (1/5), and iron deficiency anemia (2/5). Endoscopic findings in both the stomach antrum and body included a fragile and hyperemic mucosa, large ulcers, extensive nodularity, and exudate. All the biopsies from the gastric mucosa were consistent with MALT lymphoma, and positive for H. pylori (by Giemsa stain). All the patients received triple therapy (amoxicillin, nitroimidazole, or a macrolide, and a proton pump inhibitor, for 14 days), and achieved H. pylori eradication. All had complete resolution of histological findings at the last follow-up. In one patient, the histology of MALT lymphoma persisted 12 months after H. pylori eradication, and only the 18-month-biopsy was free of residual disease., Conclusions: In this series of pediatric MALT lymphoma, complete resolution of disease occurred in all the patients, yet histological remission was delayed in one. This supports the importance of endoscopic follow-up., (© 2024 John Wiley & Sons Ltd.)

Background/aims: Recent research has increasingly focused on the role of the gastric microbiome in the development of gastric cancer. We aimed to investigate the changes in the microbiome during gastric carcinogenesis in structural and functional aspects, with a specific focus on the association between oral and gastric microbiomes., Methods: We collected saliva, gastric juice, and gastric tissue samples from 141 patients at different stages of gastric carcinogenesis and processed them for microbiome analysis using 16S rRNA gene profiling. The alpha and beta diversities were analyzed, and the differences in microbiome composition and function profiles were analyzed among the groups, as well as the correlation between changes in the oral and gastric microbiomes during carcinogenesis., Results: We observed significant differences in microbial diversity and composition between the disease and control groups, primarily in the gastric juice. Specific bacterial strains, including Schaalia odontolytica, Streptococcus cristatus, and Peptostreptococcus stomatis, showed a significant increase in abundance in the gastric juice in the low-grade dysplasia and gastric cancer groups. Notably, the correlation between the oral and gastric microbiota compositions, increased as the disease progressed. Predictive analysis of the metagenomic functional profiles revealed changes in functional pathways that may be associated with carcinogenesis (ABC transport and two-component systems)., Conclusion: During gastric carcinogenesis, the abundance of oral commensals associated with cancer increased in the stomach. The similarity in microbial composition between the stomach and oral cavity also increased, implying a potential role of oral-gastric bacterial interactions in gastric cancer development.

Context: Helicobacter pylori ( H. pylori ), a spiral-shaped bacterium, is closely associated with chronic, progressive gastric mucosal damage, gastric atrophy, and even gastric cancer (GC). An increasing number of studies have addressed the correlation between long noncoding RNAs (lncRNAs) and H. pylori pathogenicity in GC., Objective: In this study, we found that the expression level of LINC00659 gradually increased in the progression from atrophic gastritis, intestinal metaplasia, and dysplasia to GC in H. pylori -infected patients. Thus, we aimed to further explore the function of LINC00659 in the progression of gastritis to cancer under H. pylori infection., Materials and Methods: StarBase predictions, ribonucleic acid (RNA)-binding protein immunoprecipitation assays, and gene ontology functional annotation (GO)/Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis were performed to identify the RNA-binding proteins of LINC00659; moreover, qRT‒PCR, western blotting, RNA interference, and immunofluorescence assays were used to investigate the function of LINC00659., Results: LINC00659 bound directly to the RNA-binding protein polypyrimidine tract-binding protein (PTBP1). Importantly, qRT‒PCR and western blot assays demonstrated that PTBP1 expression increased in the progression from inflammation to cancer in the stomach of H. pylori -infected patients and H. pylori -infected GES-1 cells. However, LINC00659 knockdown downregulated PTBP1 expression and inhibited PTBP1 binding under H. pylori infection. Finally, LINC00659 knockdown significantly reduced H. pylori -induced human gastric epithelial cell senescence and suppressed interleukin (IL)-6 and IL-8 secretion by reducing the phosphorylation level of NF-κB p65., Conclusions: This study indicated that LINC00659 may have the potential to be a novel promising prognostic and therapeutic marker for H. pylori -associated gastric diseases., (Copyright © 2023 Copyright: © 2023 Indian Journal of Pathology and Microbiology.)

Background: Chronic atrophic gastritis (CAG) is a global digestive system disease and one of the important causes of gastric cancer. The incidence of CAG has been increasing yearly worldwide., Purpose: This article reviews the latest research on the common causes and future therapeutic targets of CAG as well as the pharmacological effects of corresponding clinical drugs. We provide a detailed theoretical basis for further research on possible methods for the treatment of CAG and reversal of the CAG process., Results: CAG often develops from chronic gastritis, and its main pathological manifestation is atrophy of the gastric mucosa, which can develop into gastric cancer. The drug treatment of CAG can be divided into agents that regulate gastric acid secretion, eradicate Helicobacter. pylori (H. pylori), protect gastric mucous membrane, or inhibit inflammatory factors according to their mechanism of action. Although there are limited specific drugs for the treatment of CAG, progress is being made in defining the pathogenesis and therapeutic targets of the disease. Growing evidence shows that NF-κB, PI3K/AKT, Wnt/ β-catenin, MAPK, Toll-like receptors (TLRs), Hedgehog, and VEGF signaling pathways play an important role in the development of CAG., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Conflict of Interest None., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Background and Aims: Early gastric cancers (EGCs) after Helicobacter pylori (H. pylori) eradication often appear as reddish depressed lesions (RDLs); the same features are also appeared in benign stomachs after eradication. We compared clinic-pathological and endoscopic features of benign and neoplastic RDLs after H. pylori eradication., Methods: 228 neoplastic RDLs after H. pylori eradication were studied. All lesions were divided into neoplastic RDLs (differentiated carcinoma or adenoma, n=114) and benign RDLs (n=114) according to the histology. Clinical and pathological characteristics were compared in neoplastic and benign groups. Endoscopic diagnostic yields using the white light (WL) endoscopy, chromoendoscopy (CE) using indigo carmine dye and the magnifying endoscopy with narrow-band imaging (ME-NBI) were also evaluated in relation to the pathological diagnosis., Results: Size of neoplastic RDLs was larger than that of benign RDLs (p<0.01). Sensitivity, specificity and accuracy for predicting pathological types of RDLs was 70.1%, 52.6% and 61.4% for the WL, 65.8%, 63.1% and 65.4% for the CE, while the ME-NBI scored better with the 88.6%, 88.6%, 99.1% and 93.9% of sensitivity, specificity and accuracy. The accuracy of the ME-NBI was 99.9% (113/114) in the benign RDLs and 89.4% (101/114) for the neoplastic RDLs. Undiagnosed neoplastic RDLs using the ME-NBI were associated with more differentiated tumors such as adenoma and well-differentiated adenocarcinoma (tub1) and the presence of an unclear demarcation line., Conclusions: ME-NBI is useful to diagnose RDLs after H. pylori eradiation, while some of neoplastic lesions are difficult to diagnose using the ME-NBI.

Helicobacter pylori is a highly prevalent human gastric pathogen that causes gastritis, ulcer disease, and gastric cancer. It is not yet fully understood how H. pylori injures the gastric epithelium. The Na,K-ATPase, an essential transporter found in virtually all mammalian cells, has been shown to be important for maintaining the barrier function of lung and kidney epithelia. H. pylori decreases levels of Na,K-ATPase in the plasma membrane of gastric epithelial cells, and the aim of this study was to demonstrate that this reduction led to gastric injury by impairing the epithelial barrier. Similar to H. pylori infection, the inhibition of Na,K-ATPase with ouabain decreased transepithelial electrical resistance and increased paracellular permeability in cell monolayers of human gastric cultured cells, 2D human gastric organoids, and gastric epithelium isolated from gerbils. Similar effects were caused by a partial shRNA silencing of Na,K-ATPase in human gastric organoids. Both H. pylori infection and ouabain exposure disrupted organization of adherens junctions in human gastric epithelia as demonstrated by E-cadherin immunofluorescence. Functional and structural impairment of epithelial integrity with a decrease in Na,K-ATPase amount or activity provides evidence that the H. pylori -induced downregulation of Na,K-ATPase plays a role in the complex mechanism of gastric disease induced by the bacteria.

Background: Helicobacter pylori (H. pylori) infection is closely associated with gastrointestinal diseases. Our preliminary studies have indicated that H. pylori infection had a significant impact on the mucosal microbiome structure in patients with gastric ulcer (GU) or duodenal ulcer (DU)., Aim: To investigate the contributions of H . pylori infection and the mucosal microbiome to the pathogenesis and progression of ulcerative diseases., Methods: Patients with H . pylori infection and either GU or DU, and healthy individuals without H . pylori infection were included. Gastric or duodenal mucosal samples was obtained and subjected to metagenomic sequencing. The compositions of the microbial communities and their metabolic functions in the mucosal tissues were analyzed., Results: Compared with that in the healthy individuals, the gastric mucosal microbiota in the H . pylori -positive patients with GU was dominated by H . pylori , with significantly reduced biodiversity. The intergroup differential functions, which were enriched in the H . pylori -positive GU patients, were all derived from H . pylori , particularly those concerning transfer RNA queuosine-modification and the synthesis of demethylmenaquinones or menaquinones. A significant enrichment of the uibE gene was detected in the synthesis pathway. There was no significant difference in microbial diversity between the H. pylori -positive DU patients and healthy controls., Conclusion: H . pylori infection significantly alters the gastric microbiota structure, diversity, and biological functions, which may be important contributing factors for GU., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Impaired E-cadherin (Cdh1) functions are closely associated with cellular dedifferentiation, infiltrative tumor growth and metastasis, particularly in gastric cancer. The class-I carcinogen Helicobacter pylori ( H. pylori ) colonizes gastric epithelial cells and induces Cdh1 shedding, which is primarily mediated by the secreted bacterial protease high temperature requirement A (HtrA). In this study, we used human primary epithelial cell lines derived from gastroids and mucosoids from different healthy donors to investigate HtrA-mediated Cdh1 cleavage and the subsequent impact on bacterial pathogenesis in a non-neoplastic context. We found a severe impairment of Cdh1 functions by HtrA-induced ectodomain cleavage in 2D primary cells and mucosoids. Since mucosoids exhibit an intact apico-basal polarity, we investigated bacterial transmigration across the monolayer, which was partially depolarized by HtrA, as indicated by microscopy, the analyses of the transepithelial electrical resistance (TEER) and colony forming unit (cfu) assays. Finally, we investigated CagA injection and observed efficient CagA translocation and tyrosine phosphorylation in 2D primary cells and, to a lesser extent, similar effects in mucosoids. In summary, HtrA is a crucially important factor promoting the multistep pathogenesis of H. pylori in non-transformed primary gastric epithelial cells and organoid-based epithelial models., Competing Interests: The authors declare no conflicts of interest.

A major worldwide health problem, Helicobacter Pylori (H. pylori) infection is associated with a number of gastrointestinal disorders, such as gastric cancer and peptic ulcers. The shortcomings of traditional treatment plans often include adverse effects, low patient compliance, and the emergence of antibiotic resistance. Investigating different delivery methods is thus necessary to improve the effectiveness of treatment. Mucoadhesive microspheres show promise as a method for delivering anti H. pylori drugs in a targeted and sustained manner. With their ability to stick to the stomach mucosa, these microspheres increase the local concentration of the medication and guarantee a more thorough removal of the pathogen. The potential of Mucoadhesive microspheres in the management of H. pylori infection is examined in this review. We explore the properties and benefits of Mucoadhesive polymers, the production techniques for microspheres, and the variables affecting their functionality. To provide a thorough grasp of this delivery system, a variety of drug-loading strategies, release mechanisms, and in vitro and in vivo assessment methodologies are covered. The potential of Mucoadhesive microspheres to overcome the drawbacks of traditional therapy is shown by highlighting recent developments in their formulation and their therapeutic consequences. Mucoadhesive microspheres constitute an important advancement in the treatment of Helicobacter pylori because they guarantee a regulated release of antibiotics and improve medication absorption at the site of infection. In order to fully appreciate the advantages of this novel delivery method, further study is necessary. Future research paths and the difficulties in the clinical translation of this technology are also discussed.

Helicobacter pylori eradication therapy reduces the risk of gastric cancer. However, it is unclear whether the severity of risk factors for gastric cancer such as atrophy and intestinal metaplasia are reduced after eradication in the long term. We aimed to study long-term changes in endoscopic risk factors for gastric cancer up to 20 years post-eradication. The endoscopic severity of gastritis according to the Kyoto Classification of Gastritis in 167 patients was retrospectively evaluated over an average follow-up 15.7 years. A significant improvement in mean total gastric cancer risk score (4.36 ± 1.66 to 2.69 ± 1.07, p < 0.001), atrophy (1.73 ± 0.44 to 1.61 ± 0.49, p = 0.004), and diffuse redness (1.22 ± 0.79 to 0.02 ± 0.13, p < 0.001) was observed compared to baseline in the Eradication group. However, there was no change in the never infection and current infection groups. The frequency of map-like redness increased over time until 15 years (3.6% to 18.7%, p = 0.03). The Cancer group had significantly higher risk scores at all time points. Endoscopic atrophy significantly improved in eradicated patients over long-term, suggested that eradication is one of the key elements in gastric cancer prevention. Individualized surveillance strategies based on endoscopic gastritis severity before eradication may be important for those at risk of gastric cancer., (© 2024. The Author(s).)

Gastric cancer is the fifth most diagnosed cancer in the world. Infection by the bacteria Helicobacter pylori (HP) is associated with approximately 75% of gastric cancer cases. HP infection induces chronic gastric inflammation, damaging the stomach and fostering carcinogenesis. Most mechanistic studies on gastric cancer initiation are performed in mice and utilize either mouse-adapted strains of HP or the natural mouse pathogen Helicobacter felis (HF). Here, we identified the differences in gastric inflammation, atrophy, and metaplasia associated with HP and HF infection in mice. PMSS1 HP strain or the CS1 HF strain were co-cultured with mouse peritoneal macrophages to assess their immunostimulatory effects. HP and HF induced similar cytokine production from cultured mouse peritoneal macrophages revealing that both bacteria exhibit similar immunostimulatory effects in vitro . Next, C57BL/6J mice were infected with HP or HF and were assessed 2 months post-infection. HP-infected mice caused modest inflammation within both the gastric corpus and antrum, and did not induce significant atrophy within the gastric corpus. In contrast, HF induced significant inflammation throughout the gastric corpus and antrum. Moreover, HF infection was associated with significant atrophy of the chief and parietal cell compartments and induced the expression of pyloric metaplasia (PM) markers. HP is poorly immunogenic compared to HF. HF induces dramatic CD4+ T cell activation, which is associated with increased gastric cancer risk in humans. Thus, HP studies in mice are better suited for studies on colonization, while HF is more strongly suited for studies on the effects of gastric inflammation on tumorigenesis.   ., Importance: Mouse infection models with Helicobacter species are widely used to study Helicobacter pathogenesis and gastric cancer initiation. However, Helicobacter pylori is not a natural mouse pathogen, and mouse-adapted H. pylori strains are poorly immunogenic. In contrast, Helicobacter felis is a natural mouse pathogen that induces robust gastric inflammation and is often used in mice to investigate gastric cancer initiation. Although both bacterial strains are widely used, their disease pathogenesis in mice differs dramatically. However, few studies have directly compared the pathogenesis of these bacterial species in mice, and the contrasting features of these two models are not clearly defined. This study directly compares the gastric inflammation, atrophy, and metaplasia development triggered by the widely used PMSS1 H. pylori and CS1 H . felis strains in mice. It serves as a useful resource for researchers to select the experimental model best suited for their studies., Competing Interests: The authors declare no conflict of interest.

In Japan, accessible Helicobacter pylori (Hp) eradication therapy is associated with an increase in the prevalence of gastric cancers (GCs) in Hp uninfected stomachs. Signet ring cell carcinoma (SRCC) is the most common of these GCs. Intramucosal SRCC with poorly differentiated adenocarcinoma (PDA) occurring in Hp uninfected gastric mucosa is rare; furthermore, many Hp uninfected pure SRCCs exhibit discoloration and flat or slightly depressed lesions, and morphological elevation is relatively rare. We report a case of intramucosal SRCC with PDA with an elevated, verrucous gastritis-like lesion in a 57-year-old male patient. In the present case, the PDA area showed dense tumor cell growth and coexisting desmoplastic and fibrotic reactions. Histopathology and immunohistochemical staining identified extensive fibromuscular obliteration with smooth muscle bundles extending from the muscularis mucosa into the lamina propria. The patient underwent curative endoscopic submucosal dissection. The reporting and analysis of such rare cases may lead to a better understanding of the characteristics of advanced Hp uninfected GCs., (© 2024. The Author(s).)

Objective: Our paper aimed to elucidate the mechanism of Weiwei granules in the treatment of Helicobacter pylori (Hp)-positive chronic atrophic gastritis (CAG) based on the TLR4/NF-κB/COX-2 inflammatory signaling pathway., Methods: Hp-positive CAG patients were randomized into the control group (treated with quadruple therapy) or the observation group (treated with Weiwei granules based on the control group). The clinical efficacy, Hp clearance rate, and efficacy of traditional Chinese medicine (TCM) symptoms were compared between the two groups after six months of treatment. The scores of various histopathology variables, serum levels of inflammatory factors (interleukin-6 [IL-6], interleukin-8 [IL-8], and tumor necrosis factor-alpha [TNF-α]), gastrin-17 (G-17) and motilin (MTL), pepsinogen (PG) I and PG II, as well as serum levels of gastrointestinal hormone endothelin (ET), epidermal growth factor (EGF), and calcitonin gene-related peptide (CGRP), were compared between the two groups before and after treatment. TLR4, NF-κB, and COX-2 mRNA levels were compared in gastric mucosal tissues before and after treatment in the two groups., Results: After treatment, the clinical efficacy, Hp clearance rate, and efficacy of TCM symptoms of patients in the observation group were higher than those in the control group. After treatment, the scores of various histopathology variables, serum levels of inflammatory factors (IL-6, IL-8, and TNF-α), gastrointestinal hormones (ET and EGF), and the expression levels of TLR4, NF-κB, and COX-2 mRNA in the gastric mucosal tissues were lower and G-17, MTL, CGRP, and PG I levels were higher in the observation group than in the control group., Conclusion: Weiwei granules can effectively improve Hp-positive CAG patients and reduce the expression levels of TLR4, NF-κB, and COX-2., (©The Author(s) 2024. Open Access. This article is licensed under a Creative Commons CC-BY International License.)

Introduction: We designed a race-conscious study to assess the presence of Helicobacter pylori v irulence factor cagA in a retrospective cohort of patients with active H. pylori infection., Methods: We compared cagA status by race in gastric tissue samples from 473 patients diagnosed with active H. pylori infection from 2015 to 2019., Results: H. pylori + Black patients were 2 times more likely to be cagA + than H. pylori + White patients (82% vs 36%, P < .0001)., Discussion: Presence of cagA is common among endoscopy patients with active H. pylori infection; appropriate testing and treatment of H. pylori can both reduce gastric cancer risk and address health disparities., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

Bactrian camels inhabiting desert and semi-desert regions of China are valuable animal models for studying adaptation to desert environments and heat stress. In this study, 16S rRNA technology was employed to investigate the distribution characteristics and differences of mucosal microorganisms in the anterior gland area, posterior gland area, third gland area, cardia gland area, gastric fundic gland area and pyloric gland area of 5-peak adult healthy Bactrian camels. We aimed to explore the possible reasons for the observed microbial distribution from the aspects of histological structure and mucosal immunity. Bacteroides and Fibrobacteria accounted for 59.54% and 3.22% in the gland area, respectively, and 52.37% and 1.49% in the wrinkled stomach gland area, respectively. The gland area showed higher abundance of Bacteroides and Fibrobacteria than the wrinkled stomach gland area. Additionally, the anterior gland area, posterior gland area, third gland area, and cardia gland area of Bactrian camels mainly secreted acidic mucus, while the gastric fundic gland area mainly secreted neutral mucus and the pyloric region mainly secreted a mixture of acidic and neutral mucus. The results of immunohistochemistry techniques demonstrated that the number of IgA+ cells in the anterior glandular area, posterior glandular area, third glandular area, and cardia gland area was significantly higher than that in the fundic and pyloric gland area (p < 0.05), and the difference in IgA+ between the fundic and pyloric gland area was not significant (p > 0.05). The study revealed a large number of bacteria that can digest and degrade cellulose on the mucosa of the gastric gland area of Bactrian camels. The distribution of IgA+ cells, the structure of the mucosal tissue in the glandular region, and the composition of the mucus secreted on its surface may have a crucial influence on microbial fixation and differential distribution., Competing Interests: The author declared no potential conflicts of interest with respect to the research, authorship, and publication of this article., (Copyright: © 2024 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Trained immunity is a concept in immunology in which innate immune cells, such as monocytes and macrophages, exhibit enhanced responsiveness and memory-like characteristics following initial contact with a pathogenic stimulus that may promote a more effective immune defense following subsequent contact with the same pathogen. Helicobacter pylori , a bacterium that colonizes the stomach lining, is etiologically associated with various gastrointestinal diseases, including gastritis, peptic ulcer, gastric adenocarcinoma, MALT lymphoma, and extra gastric disorders. It has been demonstrated that repeated exposure to H. pylori can induce trained immunity in the innate immune cells of the gastric mucosa, which become more responsive and better able to respond to subsequent H. pylori infections. However, interactions between H. pylori and trained immunity are intricate and produce both beneficial and detrimental effects. H. pylori infection is characterized histologically as the presence of both an acute and chronic inflammatory response called acute-on-chronic inflammation, or gastritis. The clinical outcomes of ongoing inflammation include intestinal metaplasia, gastric atrophy, and dysplasia. These same mechanisms may also reduce immunotolerance and trigger autoimmune pathologies in the host. This review focuses on the relationship between trained immunity and H. pylori and underscores the dynamic interplay between the immune system and the pathogen in the context of gastric colonization and inflammation.

Objective: To prepare a postbiotic using soybean fermentation product of Lactobacillus paracasei TK1501 and evaluate its inhibitory effect against Helicobacter pylori ( Hp ) infection in mice., Methods: L. paracasei TK1501 was cultured for 32 h at 37 ℃ in an anaerobic condition for solid substrate fermentation with a solid to water ratio of 1:1.5 in the substrate and an inoculation density of 5×10 7 CFU/mL. The postbiotic was isolated and purified using macroporous resin XAD-16N adsorption, cation exchange chromatography and HPLC, and its stability and antibacterial activity were assessed. The inhibitory effect of this postbiotic against Hp infection was evaluated in a mouse model with gastric mucosal Hp infection, which were treated with the postbiotic via gavage for 4 weeks at the dose of 0.02 or 0.1 mL. Serum levels of TNF-α and IL-1β of the mice were analyzed after the treatments, and gastric tissues of the mice were collected for HE staining., Results: L. paracasei TK1501 postbiotic could be easily degraded by protease and had good thermal stability and tolerance to exposures to acid, base, and organic solvents. In the in vitro experiment, the postbiotic showed strong inhibitory effects in bacterial cultures of Staphylococcus aureus , Hp and other common pathogenic bacteria without obviously affecting the resident bacteria in the digestive tract. In the mouse models, treatment with the postbiotic at the dose of 0.1 mL significantly alleviated Hp infection and lowered the serum levels of TNF-α and IL-1β of the mice., Conclusion: L. paracasei TK1501 postbiotic has strong inhibitory effects on Hp and Staphylococcus aureus but not on normal intestinal flora in mice.

Background: Helicobacter pylori (H. pylori) is the predominant etiological agent of gastritis and disrupts the integrity of the gastric mucosal barrier through various pathogenic mechanisms. After H. pylori invades the gastric mucosa, it interacts with immune cells in the lamina propria. Macrophages are central players in the inflammatory response, and H. pylori stimulates them to secrete a variety of inflammatory factors, leading to the chronic damage of the gastric mucosa. Therefore, the study aims to explore the mechanism of gastric mucosal injury caused by inflammatory factors secreted by macrophages, which may provide a new mechanism for the development of H. pylori-related gastritis., Methods: The expression and secretion of CCL3 from H. pylori infected macrophages were detected by RT-qPCR, Western blot and ELISA. The effect of H. pylori-infected macrophage culture medium and CCL3 on gastric epithelial cells tight junctions were analyzed by Western blot, immunofluorescence and transepithelial electrical resistance. EdU and apoptotic flow cytometry assays were used to detect cell proliferation and apoptosis levels. Dual-luciferase reporter assays and chromatin immunoprecipitation assays were used to study CCL3 transcription factors. Finally, gastric mucosal tissue inflammation and CCL3 expression were analyzed by hematoxylin and eosin staining and immunohistochemistry., Results: After H. pylori infection, CCL3 expressed and secreted from macrophages were increased. H. pylori-infected macrophage culture medium and CCL3 disrupted gastric epithelial cells tight junctions, while CCL3 neutralizing antibody and receptor inhibitor of CCL3 improved the disruption of tight junctions between cells. In addition, H. pylori-infected macrophage culture medium and CCL3 recombinant proteins stimulated P38 phosphorylation, and P38 phosphorylation inhibitor improved the disruption of tight junctions between cells. Besides, it was identified that STAT1 was a transcription factor of CCL3 and H. pylori stimulated macrophage to secret CCL3 through the JAK1-STAT1 pathway. Finally, after mice were injected with murine CCL3 recombinant protein, the gastric mucosal injury and inflammation were aggravated, and the phosphorylation level of P38 was increased., Conclusions: In summary, our findings demonstrate that H. pylori infection stimulates macrophages to secrete CCL3 via the JAK1-STAT1 pathway. Subsequently, CCL3 damages gastric epithelial tight junctions through the phosphorylation of P38. This may be a novel mechanism of gastric mucosal injury in H. pylori-associated gastritis., (© 2024. The Author(s).)

Background: At present, eradication regimens for non-Helicobacter pylori Helicobacter (NHPH) have not been established yet. We investigated effectiveness of the standard triple-drug combination therapy for Helicobacter pylori eradication and of a proton pump inhibitor (PPI) monotherapy in eradication of NHPH., Methods: Subjects were the patients who were diagnosed with NHPH-infected gastritis based on microscopic findings, helical-shaped organisms obviously larger than Helicobacter pylori, in the gastric mucosal specimens using Giemsa staining at Kenwakai Hospital between November 2010 and September 2021, whose NHPH species were identified by polymerase chain reaction (PCR) analysis of urease genes in endoscopically-biopsied samples, and who consented to NHPH eradication with either the triple-drug combination therapy for one week or a PPI monotherapy for six months. Six months after the completion of eradication, its result was determined with esophagogastroduodenoscopy, microscopic examination, and PCR analysis. In cases of unsuccessful eradication, a second eradication with the other therapy was suggested to the patient., Results: PCR analysis detected NHPH in 38 patients: 36 as Helicobacter suis and two as Helicobacter heilmannii/Helicobacter ailurogastricus. Fourteen Helicobacter suis-infected and one Helicobacter heilmannii/Helicobacter ailurogastricus-infected patients requested eradication therapy. The triple-drug combination therapy succeeded in four of five patients, while the PPI monotherapy succeeded in five of 10 patients. Three of five patients who had been unsuccessful with the latter therapy requested the triple-drug combination therapy as the second eradication and all three were successful. In total, the triple-drug combination therapy succeeded in seven out of eight (87.5%) attempted cases, while the PPI monotherapy in five out of 10 (50%) attempted cases., Conclusions: In NHPH eradication, the triple-drug combination therapy was considered to be effective to some extent and to become the first-line therapy. While, although less successful, PPI monotherapy appeared to be a potentially promising option particularly for patients with allergy or resistance to antibiotics. Effectiveness of PPI monotherapy may be attributed to hyperacid environment preference of Helicobacter suis and PPI's acid-suppressive effect. Additionally, male predominance in NHPH-infected gastritis patients may be explained by gender difference in gastric acid secretory capacity. However, further evidence needs to be accumulated., Study Registration: This study was approved by the Research Ethics Committee of Kenwakai Hospital (No. 2,017,024)., (© 2024. The Author(s).)

Background/aim: H. pylori infection can promote a systemic inflammatory syndrome, eventually leading to intestinal metaplasia and gastric cancer. The aim of our study was to investigate the possible association between dyslipidemia and histopathological features of H. pylori gastritis., Patients and Methods: An observational, retrospective study was conducted over the period 2017-2022 on symptomatic patients with a positive rapid urease test. A total of 121 patients who underwent upper gastrointestinal endoscopy with stomach biopsy were enrolled in this study. Based on the updated Sydney System, we investigated the association between neutrophils, mononuclear cells, intestinal metaplasia, or gastric atrophy and altered lipid profiles., Results: A high prevalence of H. pylori infection was noticed in the studied group upon the application of the rapid urease test, being associated with dyslipidemia regardless of patient sex. All the endoscopic diagnoses (acute, chronic, or atrophic chronic gastritis, metaplasia) correlated with the histopathological features. Mononuclear cells and metaplasia were more likely to be found in H. pylori-positive patients with dyslipidemia, which is consistent with acute and chronic inflammation caused by H. pylori in the gastric mucosa., Conclusion: Although our study was conducted on a small scale, it offers new insights and details regarding H. pylori infection and histopathological features. Mononuclear cells and metaplasia were associated with an altered lipid profile in H. pylori-positive patients. These findings warrant future investigation, such as the evolution of gastric biopsies and lipid profiles before and after eradication., (Copyright © 2024, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Helicobacter pylori (H. pylori) can evade the host's immune response and persist for a long time on the gastric mucosa. T helper (Th) cells appear to be involved in the control of H. pylori bacteria but promote mucosal inflammation. In contrast, regulatory T cells (Tregs) may reduce inflammation but promote H. pylori persistence. CC motif chemokine receptor 6 (CCR6) is involved in the migration of various cells into inflamed gastric mucosa. In this study, we examined CCR6 + Th cells and CCR6 + Tregs during H. pylori infection in humans., Materials and Methods: Isolation of cells from blood and mucosal biopsies, magnetic separation of В cells, CD4 + and CD4 + CCR6 + CD45RO + T cells, antigen-specific activation, B cell response in vitro, flow cytometry, determination of CD4 + CD25 hi FoxP3 + Tregs and various groups of Th cells., Results: CD4 + CCR6 + blood lymphocytes from healthy donors included Th cells and Tregs. These CCR6 + Th cells produced proinflammatory cytokines and also stimulated plasma cell maturation and antibody production in vitro. H. pylori gastritis and peptic ulcer disease were associated with an increase in the number of circulate CD4 + CCR6 + CD45RO + cells and the percentage of Th1, Th17 and Th1/17 cells in this lymphocyte subgroup. In H. pylori-positive patients, circulating CD4 + CCR6 + cells contained a higher proportion of H. pylori-specific cells compared with their CD4 + CCR6 - counterparts. H. pylori infection strongly increased the content of CD4 + lymphocytes in the inflamed gastric mucosa, with the majority of these CD4 + lymphocytes expressing CCR6. CD4 + CCR6 + lymphocytes from H. pylori-infected stomach included Tregs and in vivo activated T cells, some of which produced interferon-γ without ex vivo stimulation., Conclusion: H. pylori infection causes an increase in the number of mature CD4 + CCR6 + lymphocytes in the blood, with a pro-inflammatory shift in their composition and enrichment of the gastric mucosa with CD4 + CCR6 + lymphocytes, including CCR6 + Th1 cells and Tregs., (© 2024 John Wiley & Sons Ltd.)

The following are our views regarding the "letter to the editor" ( Helicobacter is preserved in yeast vacuoles! Does Koch's postulates confirm it?) by Alipour and Gaeini, and the response "letter to the editor" ( Candida accommodates non-culturable Helicobacter pylori in its vacuole-Koch's postulates aren't applicable) by Siavoshi and Saniee. Alipour and Gaeini rejected the methods, results, discussion, and conclusions summarized in a review article by Siavoshi and Saniee. The present article reviews and discusses evidence on the evolutionary adaptation of Helicobacter pylori ( H. pylori ) to thrive in Candida cell vacuoles and concludes that Candida could act as a Trojan horse, transporting potentially infectious H. pylori into the stomach of humans., Competing Interests: Conflict-of-interest statement: The authors declare no conflicts of interest., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)