CXCL-8 as a signature of severe Helicobacter pylori infection and a stimulator of stomach region-dependent immune response

Helicobacter pylori infection is involved in development of diverse gastro-pathologies. Our aim is to investigate potential signature of cytokines-chemokine levels (IL-17A, IL-1β, and CXCL-8) in H. pylori-infected patients and their impact on immune response in both corpus and antrum. Multivariate level analysis with machine learning model were carried out using cytokines/chemokine levels of infected Moroccan patients. In addition, Geo dataset was used to run enrichment analysis following CXCL-8 upregulation. Our analysis showed that combination of cytokines-chemokine levels allowed prediction of positive H. pylori density score with <5% of miss-classification error, with fundus CXCL-8 being the most important variable for this discrimination. Furthermore, CXCL-8 dependent expression profile was mainly associated to IL6/JAK/STAT3 signaling in the antrum, interferons alpha and gamma responses in the corpus and commonly induced transcriptional /proliferative activities. To conclude, CXCL-8 level might be a signature of Moroccan H. pylori-infected patients and an inducer of regional-dependent immune response at the gastric level. Larger trials must be carried out to validate the relevance of these results for diverse populations.

Factors associated with treatment failure, and possible applications of probiotic bacteria in the arsenal against Helicobacter pylori

INTRODUCTION

Helicobacter pylori is a widespread helical Gram-negative bacterium, which causes a variety of stomach disorders, such as peptic ulcer, chronic atrophic gastritis, and gastric cancer. This microbe frequently colonizes the mucosal layer of the human stomach and survives in the inhospitable microenvironment, by adapting to this hostile milieu.

AREAS COVERED

In this extensive review, we describe conventional antibiotic treatment regimens used against H. pylori including, empirical, tailored, and salvage therapies. Then, we present state-of-the-art information about reasons for treatment failure against H. pylori. Afterward, the latest advances in the use of probiotic bacteria against H. pylori infection are discussed. Finally, we propose a polymeric bio-platform to provide efficient delivery of probiotics for H. pylori infection.

EXPERT OPINION

For effective probiotic delivery systems, it is necessary to avoid the early release of probiotics at the acidic stomach pH, to protect them against enzymes and antimicrobials, and precisely target H. pylori bacteria which have colonized the antrum area of the stomach (basic pH).

Novel Sensitive Electrochemical Immunosensor Development for the Selective Detection of HopQ H. pylori Bacteria Biomarker

Helicobacter pylori (H. pylori) is a highly contagious pathogenic bacterium that can cause gastrointestinal ulcers and may gradually lead to gastric cancer. H. pylori expresses the outer membrane HopQ protein at the earliest stages of infection. Therefore, HopQ is a highly reliable candidate as a biomarker for H. pylori detection in saliva samples. In this work, an H. pylori immunosensor is based on detecting HopQ as an H. pylori biomarker in saliva. The immunosensor was developed by surface modification of screen-printed carbon electrodes (SPCE) with MWCNT-COOH decorated with gold nanoparticles (AuNP) followed by HopQ capture antibody grafting on SPCE/MWCNT/AuNP surface using EDC/S-NHS chemistry. The sensor performance was investigated utilizing various methods, such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX). H. pylori detection performance in spiked saliva samples was evaluated by square wave voltammetry (SWV). The sensor is suitable for HopQ detection with excellent sensitivity and linearity in the 10 pg/mL-100 ng/mL range, with a 2.0 pg/mL limit of detection (LOD) and an 8.6 pg/mL limit of quantification (LOQ). The sensor was tested in saliva at 10 ng/mL, and recovery of 107.6% was obtained by SWV. From Hill's model, the dissociation constant Kd for HopQ/HopQ antibody interaction is estimated to be 4.60 × 10^-10 mg/mL. The fabricated platform shows high selectivity, good stability, reproducibility, and cost-effectiveness for H. pylori early detection due to the proper choice of biomarker, the nanocomposite material utilization to boost the SPCE electrical performance, and the intrinsic selectivity of the antibody-antigen approach. Additionally, we provide insight into possible future aspects that researchers are recommended to focus on.

Updated Epidemiology of Gastric Cancer in Asia: Decreased Incidence but Still a Big Challenge

Despite the decline in incidence and mortality rates, gastric cancer (GC) is the fifth leading cause of cancer deaths worldwide. The incidence and mortality of GC are exceptionally high in Asia due to high H. pylori infection, dietary habits, smoking behaviors, and heavy alcohol consumption. In Asia, males are more susceptible to developing GC than females. Variations in H. pylori strains and prevalence rates may contribute to the differences in incidence and mortality rates across Asian countries. Large-scale H. pylori eradication was one of the effective ways to reduce GC incidences. Treatment methods and clinical trials have evolved, but the 5-year survival rate of advanced GC is still low. Efforts should be put towards large-scale screening and early diagnosis, precision medicine, and deep mechanism studies on the interplay of GC cells and microenvironments for dealing with peritoneal metastasis and prolonging patients' survival.

Using Machine Learning and Molecular Docking to Leverage Urease Inhibition Data for Virtual Screening

Urease is a metalloenzyme that catalyzes the hydrolysis of urea, and its modulation has an important role in both the agricultural and medical industry. Even though numerous molecules have been tested against ureases of different species, their clinical translation has been limited due to chemical and metabolic stability as well as side effects. Therefore, screening new compounds against urease would be of interest in part due to rising concerns regarding antibiotic resistance. In this work, we collected and curated a diverse set of 2640 publicly available small-molecule inhibitors of jack bean urease and developed a classifier using a random forest machine learning method with high predictive performance. In addition, the physicochemical features of compounds were paired with molecular docking and protein-ligand fingerprint analysis to gather insight into the current activity landscape. We observed that the docking score could not differentiate active from inactive compounds within each chemical family, but scores were correlated with compound activity when all compounds were considered. Additionally, a decision tree model was built based on 2D and 3D Morgan fingerprints to mine patterns of the known active-class compounds. The final machine learning model showed good prediction performance against the test set (81% and 77% precision for active and inactive compounds, respectively). Finally, this model was employed, as a proof-of-concept, on an in-house library to predict new hits that were then tested against urease and found to be active. This is, to date, the largest, most diverse dataset of compounds used to develop predictive in silico models. Overall, the results highlight the usefulness of using machine learning classifiers and molecular docking to predict novel urease inhibitors.

Atrophic Gastritis and Autoimmunity: Results from a Prospective, Multicenter Study

Despite a global decrease, gastric cancer (GC) incidence appears to be increasing recently in young, particularly female, patients. The causal mechanism for this "new" type of GC is unknown, but a role for autoimmunity is suggested. A cascade of gastric precancerous lesions, beginning with chronic atrophic gastritis (CAG), precedes GC. To test the possible existence of autoimmunity in patients with CAG, we aimed to analyze the prevalence of several autoantibodies in patients with CAG as compared to control patients. Sera of 355 patients included in our previous prospective, multicenter study were tested for 19 autoantibodies (anti-nuclear antibodies, ANA, anti-parietal cell antibody, APCA, anti-intrinsic factor antibody, AIFA, and 16 myositis-associated antibodies). The results were compared between CAG patients (n = 154), including autoimmune gastritis patients (AIG, n = 45), non-autoimmune gastritis patients (NAIG, n = 109), and control patients (n = 201). ANA positivity was significantly higher in AIG than in NAIG or control patients (46.7%, 29%, and 27%, respectively, p = 0.04). Female gender was positively associated with ANA positivity (OR 0.51 (0.31-0.81), p = 0.005), while age and H. pylori infection status were not. Myositis-associated antibodies were found in 8.9% of AIG, 5.5% of NAIG, and 4.4% of control patients, without significant differences among the groups (p = 0.8). Higher APCA and AIFA positivity was confirmed in AIG, and was not associated with H. pylori infection, age, or gender in the multivariate analysis. ANA antibodies are significantly more prevalent in AIG than in control patients, but the clinical significance of this finding remains to be established. H. pylori infection does not affect autoantibody seropositivity (ANA, APCA, AIFA). The positivity of myositis-associated antibodies is not increased in patients with CAG as compared to control patients. Overall, our results do not support an overrepresentation of common autoantibodies in patients with CAG.

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

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

Gastric microbiota: an emerging player in gastric cancer

Gastric cancer (GC) is a common cancer worldwide with a high mortality rate. Many microbial factors influence GC, of which the most widely accepted one is Helicobacter pylori (H. pylori) infection. H. pylori causes inflammation, immune reactions and activation of multiple signaling pathways, leading to acid deficiency, epithelial atrophy, dysplasia and ultimately GC. It has been proved that complex microbial populations exist in the human stomach. H. pylori can affect the abundance and diversity of other bacteria. The interactions among gastric microbiota are collectively implicated in the onset of GC. Certain intervention strategies may regulate gastric homeostasis and mitigate gastric disorders. Probiotics, dietary fiber, and microbiota transplantation can potentially restore healthy microbiota. In this review, we elucidate the specific role of the gastric microbiota in GC and hope these data can facilitate the development of effective prevention and therapeutic approaches for GC.

Expectations for the Dual Therapy with Vonoprazan and Amoxicillin for the Eradication of H. pylori

Vonoprazan (VPZ) inhibits gastric acid secretion more potently than proton pump inhibitors. Recently, attention has been focused on the dual therapy with VPZ and amoxicillin (AMOX) for the eradication of H. pylori. The dual VPZ/AMOX therapy attains the sufficient eradication rate with lowering the risk of adverse events in comparison with the triple therapy and quadruple therapy. Therefore, the dual VPZ/AMOX therapy is considered a useful eradication regimen for H. pylori infection.

Iatrogenic factors of Helicobacter pylori eradication failure: lessons from the frontline

BACKGROUND

Iatrogenic factors play an important role in H. pylori eradication failure, whereas it can be easily missed. Therefore, we aimed to investigate and analyze these related iatrogenic factors of H. pylori eradication failure.

METHODS

A total of 508 patients who experienced H. pylori eradication failure were included in this study conducted from December 2019 to February 2022. All the patients filled out a questionnaire including demographic characteristics, duration of treatment, regimens, dosage, and time intervals in rescue treatment.

RESULTS

In the first-line treatment, 89 patients (17.5%, 89/508) used at least one antibiotic with high resistance rate in triple therapy and 57 patients (11.2%, 57/508) used two antibiotics with high resistance rates or other not recommended antibiotics in quadruple therapy. In the rescue therapy, 85 regimens were repeatedly used as salvage regimens in 58 patients (22.6%, 58/257) and 178 regimens containing antibiotics with high resistance rates were repeatedly used in 85 patients (33.1%, 85/257).

CONCLUSION

To decrease the risk of H. pylori eradication failure, iatrogenic factors need to gain more attention. Clinicians should enhance their education and training to standardize the treatment regimens, better manage the H. pylori infection, and improve the eradication rate eventually.

Understanding The Regulatory Role of USP32 and SHMT2 in The Progression of Gastric Cancer

OBJECTIVE

Gastric cancer is the fifth most common neoplasm and the fourth reason for mortality globally. Incidence rates are highly variable and dependent on risk factors, epidemiologic and carcinogenesis patterns. Previous studies reported that Helicobacter pylori (H. pylori) infection is one the strongest known risk factor for gastric cancer. USP32 is a deubiquitinating enzyme identified as a potential factor associated with tumor progression and a key player in cancer development. On the other hand, SHMT2 is involved in serine-glycine metabolism to support cancer cell proliferation. Both USP32 and SHMT2 are reported to be upregulated in many cancer types, including gastric cancer, but its complete mechanism is not fully explored yet. The present study explored possible mechanism of action of USP32 and SHMT2 in the progression of gastric cancer.

MATERIALS AND METHODS

In this experimental study, Capsaicin (0.3 g/kg/day) and H. pylori infection combination was used to successfully initiate gastric cancer conditions in mice. It was followed by 40 and 70 days of treatment to establish initial and advanced conditions of gastric cancer.

RESULTS

Histopathology confirmed formation of signet ring cell and initiation of cellular proliferation in the initial gastric cancer. More proliferative cells were also observed. In addition, tissue hardening was confirmed in the advanced stage of gastric cancer. USP32 and SHMT2 showed progressive upregulated expression, as gastric cancer progress. Immunohistologically, it showed signals in abnormal cells and high-intensity signals in the advanced stage of cancer. In USP32 silenced tissue, expression of SHMT2 was completely blocked and reverted cancer development as evident with less abnormal cell in initial gastric cancer. Reduction of SHMT2 level to one-fourth was observed in the advanced gastric cancer stages of USP32 silenced tissue.

CONCLUSION

USP32 had a direct role in regulating SHMT2 expression, which attracted therapeutic target for future treatment.

Immunological Role of Toll-Like Receptor Markers (TLR2 and TLR4) in Patients with Helicobacter pylori infection at Basrah, Iraq

Helicobacter pylori is a spiral-shaped, flagellated, microaerophilic bacteria found in the human gastric sub-mucosa. This study aimed to investigate the association between toll-like receptor markers (TLR2 and TLR4) and the infection with Helicobacter pylori. The study involved 224 participants randomly divided into 2 equal groups (n=112). The patient group (n=112) was involved with several gastrointestinal symptoms. They were compared to a control group (n=112) with negative H. pylori tests. Patients and control were subjected to upper digestive endoscopy with gastric biopsy for the rapid urease test, rapid diagnostic test, and ELISA test for TLR2 and TLR4 detection. The recorded data showed that 36 (32.1 %) patients with H. pylori were in the second to the third decades of their life (25-34 years), while 22 (19.6 %) positive H. pylori-infected individuals were in the age range of 15-24 years, which were very close to the participants in the age range of 35-44 years. On the other hand, it is revealed that 15 (13.4%) participants were in the fourth to fifth decades of life. This rate was very similar to the groups of patients within the sixth to seventh decades of their life (13 (11.6 %)), but the lowest number of cases with H. pylori patients found in the age range of 55-64 years were recorded 7.1%. In conclusion, the concentration of TLR2 and TLR4 is higher in H. pylori-positive participants compared to the control group. This might reflect the response of innate immunity of the body to the presence of H. pylori infection, and thus it may be used as an ancillary tool in the detection of the patient's susceptibility to this type of infection.

[Effect of 6-month S-methylmethionine intake on the quality of life and dyspepsia symptoms in patients with chronic gastritis]

S-methylmethionine (methylmethionine sulfonium chloride), better known as vitamin U, is a metabolic substrate that affects many metabolic processes in the human organism. Since its discovery, a large number of studies has been produced demonstrating its safety and effectiveness in various diseases, especially in diseases of the gastrointestinal tract. The purpose of the study was to evaluate the effect of methylmethionine sulfonium chloride (vitamin U) intake on the symptoms of dyspepsia and the quality of life of patients with chronic gastritis. Material and methods. The study included 37 patients (21 men and 16 women) aged 35-60 years with chronic gastritis of various etiologies. After inclusion in the study, all patients were prescribed S-methylmethionine at a dose of 300 mg per day. Clinical manifestations of dyspepsia were assessed using the GSRS questionnaire (Gastrointestinal Symptom Rating Scale), quality of life was assessed using the SF 36 questionnaire. The survey was conducted before the start of the therapy, after 3 and 6 months of complex diet therapy. Results. The most pronounced manifestations were dyspeptic (from 3 to 9 points) and diarrheal syndromes (from 2 to 5 points). Other indicators of the GSRS scale did not exceed 4 points. The total score was 15 points. By the 3rd month of therapy, there was a statistically significant decrease in the total score to 9 points (p<0.05). By the 6th month of therapy, the total GSRS score averaged 5.5 points (p<0.05). According to the SF 36 questionnaire, by the end of the 3rd month of therapy, indicators such as PF - physical functioning, BP - Bodily pain and SF - social functioning improved. By the end of the 6th month of therapy, several other indicators also improved (RP - role-physical functioning, GH - general perception of health, VT - viability, RE - Role-Emotional; MH - mental health) (p<0.05). Conclusion. The study showed that the appointment of dietary supplements containing methylmethionine sulfonium chloride at a dose of 300 mg per day helps to reduce the severity of dyspeptic symptoms in patients with chronic gastritis and their quality of life.

PHKG2 regulates RSL3-induced ferroptosis in Helicobacter pylori related gastric cancer

Ferroptosis is a newly discovered form of regulatory cell death induced by iron-dependent lipid peroxidation. Infection with Helicobacter pylori (H. pylori) is regarded as a high-risk factor for the development of gastric cancer (GC) and is associated with an increase in the levels of reactive oxygen species with activation of oncogenic signaling pathways. However, whether GC arising in the context of infection with H. pylori is correlated with ferroptosis is still unknown. In this study, we demonstrate that H. pylori infection increased the sensitivity of GC cells to RSL3 (RAS-selective lethal3)-induced ferroptosis. The molecular subtypes mediated by ferroptosis-related genes are associated with tumor microenvironment (TME) cell infiltration and patient survival. Importantly, we identified that the expression of phosphorylase kinase G2 (PHKG2) was remarkably correlated with H. pylori infection, metabolic biological processes, patient survival and therapy response. We further found the mechanism of H. pylori-induced cell sensitivity to ferroptosis, which involves PHKG2 regulation of the lipoxygenase enzyme Arachidonate 5-Lipoxygenase (ALOX5). In conclusion, PHKG2 facilitates RSL3-induced ferroptosis in H. pylori-positive GC cells by promoting ALOX5 expression. These findings may contribute to a better understanding of the unique pathogenesis of H. pylori-induced GC and allow for maximum efficacy of genetic, cellular, and immune therapies for controlling ferroptosis in diverse contexts.

RIDA®GENE Helicobacter pylori PCR on the ELITe InGenius System

PCR detection of Helicobacter pylori infection in gastric biopsies allows the detection of this bacterium and the mutations associated with macrolide resistance. The aim of this study was to evaluate the performance of RIDA®GENE H. pylori PCR (r-Biopharm) on the ELITe InGenius System (Elitech). Two hundred gastric biopsies were obtained. These biopsies were ground in nutrient broth. Two hundred microliters of this suspension was treated with proteinase K, and then, 200 µL was transferred to an ELITe InGenius sample tube and tested using RIDA®GENE H. pylori PCR reagents. In-house H. pylori PCR was used as a reference. The sensitivity of RIDA®GENE H. pylori PCR with ELITe InGenius was 100%, the specificity was 98% (95% confidence interval (CI), 95.3-100%), the PPV was 98% (95% CI, 95.3-100%), and the NPV was 100% for the detection of H. pylori. All of these parameters were 100% for the categorization of macrolide resistance. The adaptation of RIDA®GENE H. pylori PCR reagents on the ELITe InGenius System was successful. This PCR is easy to use on this system.

CYP2C19 gene polymorphism in Ningxia

BACKGROUND

Poor metabolizer (PM) status of CYP2C19 can be a predisposing factor for developing gastric cancer in H. pylori-infected patients. It is unclear whether PM status of CYP2C19 can also be a potential factor for H.pylori infection in healthy people.

METHODS

We used high-throughput sequencing to detect single nucleotide polymorphisms (SNPs) at just three loci, rs4244285 (CYP2C19*2), rs4986893 (CYP2C19*3) and rs12248560 (CYP2C19*17), to identify the exact CYP2C19 alleles corresponding to the mutated sites. We determined CYP2C19 genotypes of 1050 subjects from 5 cities of Ningxia from September 2019 to September 2020 and evaluated the potential correlation between H.pylori and CYP2C19 gene polymorphisms. Clinical data were analyzed using χ2 tests.

RESULTS

The frequency of CYP2C19*17 in Hui (3.7%) was higher as compared to Han (1.4%) in Ningxia (p = 0.001). The frequency of CYP2C19*1/*17 of Hui (4.7%) was higher as compared to Han (1.6%) in Ningxia (p = 0.004). The frequency of CYP2C19*3/*17 of Hui (1%) was higher as compared to Han (0%) in Ningxia (p = 0.023). The frequencies of alleles (p = 0.142) and genotypes (p = 0.928) were not found to be significantly different among the different BMI groups. The frequencies of four alleles between H. pylori positive and negative groups were not found to be statistically different (p = 0.794). The frequencies of the different genotypes between H. pylori positive and negative groups were not statistically different (p = 0.974), and no statistical difference was observed between the different metabolic phenotypes (p = 0.494).

CONCLUSION

There were regional differences observed in CYP2C19*17 distribution in Ningxia. The frequency of CYP2C19*17 in Hui was higher than in Han of Ningxia. No significant relationship was found between CYP2C19 gene polymorphism and susceptibility to H. pylori infection.

Novel approach for the inhibition of Helicobacter pylori contamination in yogurt using selected probiotics combined with eugenol and cinnamaldehyde nanoemulsions

Different strains of probiotics were screened in vitro to select the one with the highest anti-H. pylori activity. Three nanoemulsions of eugenol, cinnamaldehyde and their mixture were fabricated and tested also in vitro against the same pathogen. The selected probiotic strains, the nanoemulsion mixture and their combination were imbedded in a lab-manufactured yogurt which is deliberately contaminated with 6.0 log cfu/g H. pylori during manufacture. The inhibitory activity of all treatments on the growth of H. pylori and the other microorganisms in yogurt was evaluated during 21 days. Combining the selected probiotic strains with the nanoemulsion mixture in the contaminated yogurt reduced the count of H. pylori by 3.9 log cycle. The nanoemulsion showed lower inhibitory effect against the other microorganisms like probiotics, starter culture and total bacterial count in the tested yogurt, where their enumeration did not fall below 10⁶ cfu/g at the end of yogurt storage period.

Effectiveness of eradication therapy for Helicobacter pylori infection in Africa: a systematic review and meta-analysis

BACKGROUND

The effectiveness of Helicobacter pylori (H. pylori) eradication depends on the treatment protocol. This study investigates the H. pylori eradication rate in Africa using the best available evidence from databases.

METHODS

Databases were searched and results were pooled together. Heterogeneity between studies was assessed using I² test statistics. Stata version 13 software was employed to compute the pooled eradication rate. In the subgroup analysis comparison, the finding is considered significant when the confidence intervals did not overlap.

RESULTS

Twenty-two studies from 9 African countries with a total population of 2,163 were included in this study. The pooled eradication rate of H. pylori was 79% (95% CI: 75%-82%), heterogeneity (I² = 93.02%). In the subgroup analysis by study design, a higher eradication rate was reported from observational studies (85%, 95% CI: 79%-90%), compared to randomized control trials (77%, 95% CI: 73%-82%); by the duration of therapy, higher eradication rate was reported in 10-days regimen (88%, 95% CI: 84%-92%), compared to 7-days regimen (66%, 95% CI: 55%-77%); by country, the highest eradication rate was found in Ethiopia (90%; 95% CI: 87%-93%) and the lowest eradication rate was reported in Ivory Coast (22.3%; 95% CI:15%-29%); by type of H. pylori test, the highest eradication rate was reported when rapid urease test coupled with histology (88%, 95% CI: 77%-96%), and the lowest eradication rate was reported with histology alone (22.3%; 95% CI:15%-29%). Significant heterogeneity was observed with pooled prevalence (I² = 93.02%, P < 0.000).

CONCLUSIONS

In Africa, the first-line therapy showed a variable eradication rate for H. pylori. This study demonstrates the necessity to optimize current H. pylori treatment regimens in each country, taking into account the antibiotic susceptibility. Future RCT studies with standardized regimens are warranted.

Motility of Different Gastric Helicobacter spp

Helicobacter spp., including the well-known human gastric pathogen H. pylori, can cause gastric diseases in humans and other mammals. They are Gram-negative bacteria that colonize the gastric epithelium and use their multiple flagella to move across the protective gastric mucus layer. The flagella of different Helicobacter spp. vary in their location and number. This review focuses on the swimming characteristics of different species with different flagellar architectures and cell shapes. All Helicobacter spp. use a run-reverse-reorient mechanism to swim in aqueous solutions, as well as in gastric mucin. Comparisons of different strains and mutants of H. pylori varying in cell shape and the number of flagella show that their swimming speed increases with an increasing number of flagella and is somewhat enhanced with a helical cell body shape. The swimming mechanism of H. suis, which has bipolar flagella, is more complex than that of unipolar H. pylori. H. suis exhibits multiple modes of flagellar orientation while swimming. The pH-dependent viscosity and gelation of gastric mucin significantly impact the motility of Helicobacter spp. In the absence of urea, these bacteria do not swim in mucin gel at pH < 4, even though their flagellar bundle rotates.

Lacticaseibacillus casei T1 attenuates Helicobacter pylori-induced inflammation and gut microbiota disorders in mice

Probiotics are defined as live microbial food elements that are beneficial to human health. Lacticaseibacillus casei T1 was considered to have potential as a bioactive ingredient in functional foods, which was isolated from kurut. Previous research by our group proved that L. casei T1 could prevent inflammatory responses caused by Helicobacter pylori. This study aimed to investigate whether treatment with L. casei T1 resulted in a suppressive effect on H. pylori-induced oxidative stress and inflammatory responses. The results showed that treatment with L. casei T1 could relieve H. pylori-induced overexpression of inflammatory cytokines in GES-1 cells. Experiments in animals suggested that taking long-term L. casei T1 could reduce oxidative stress and inflammatory cytokines and improve H. pylori-induced gastric mucosal damage. Furthermore, taking L. casei T1 could increase the relative abundance of beneficial intestinal bacterium (Lachnospiraceae and Odoribacter) of H. pylori-infected mice and help in maintaining the balance of intestinal microflora.Collectively, L. casei T1 had certain degrees of therapeutic effect against H. pylori. In the future, it combined with antibiotics for H. pylori eradication deserves further study.

Short Telomere Lesions with Dysplastic Metaplasia Histology May Represent Precancerous Lesions of Helicobacter pylori-Positive Gastric Mucosa

Gastric cancers are strongly associated with Helicobacter pylori infection, with intestinal metaplasia characterizing the background mucosa in most cases. However, only a subset of intestinal metaplasia cases proceed to carcinogenesis, and the characteristics of high-risk intestinal metaplasia that link it with gastric cancer are still unclear. We examined telomere reduction in five gastrectomy specimens using fluorescence in situ hybridization, and identified areas with localized telomere loss (outside of cancerous lesions), which were designated as short telomere lesions (STLs). Histological analyses indicated that STLs were characteristic of intestinal metaplasia accompanied by nuclear enlargement but lacking structural atypia, which we termed dysplastic metaplasia (DM). A review of gastric biopsy specimens from 587 H. pylori-positive patients revealed 32 cases of DM, 13 of which were classified as high-grade based on the degree of nuclear enlargement. All high-grade DM cases exhibited a telomere volume reduced to less than 60% of that of lymphocytes, increased stemness, and telomerase reverse transcriptase (TERT) expression. Two patients (15%) exhibited low levels of p53 nuclear retention. After a 10-year follow-up, 7 (54%) of the high-grade DM cases had progressed to gastric cancer. These results suggest that DM is characterized by telomere shortening, TERT expression, and stem cell proliferation, and high-grade DM is a high-grade intestinal metaplasia that likely represents a precancerous lesion of gastric cancer. High-grade DM is expected to effectively prevent progression to gastric cancer in H. pylori-positive patients.

A visual denaturation bubble-mediated strand exchange amplification and RGB visual analysis-based assay for quantitative detection of Helicobacter pylori in saliva

Helicobacter pylori (H. pylori) is a class I carcinogen causing gastric cancer. Almost 50% of people on earth have been infected and it is worse in developing countries. Early diagnosis of H. pylori infection is the most important strategy for preventing the spread and worse consequences. H. pylori can be isolated from human saliva, and the sampling of saliva is easy and convenient. Therefore, we developed a visual denaturation bubble-mediated strand exchange amplification and RGB visual analysis-based assay for quantitative detection of H. pylori in saliva in this study. Under the optimized reaction temperature and time, the SEA reaction could be finished in 30 min with a simple reaction system and low dependency on equipment. The detection results could be qualitatively identified by the naked eye and quantitatively analyzed by a developed RGB visual analysis method. The limit of detection (LOD) of RGB visual analysis was 10.8 CFU/mL. This assay had good specificity and anti-interference capacity. In the artificial contamination test, the recovery rate of our assay was between 99.3% and 111.5%, with RSD values ranging from 1.7% to 3.5%. These indicated our assay also had good reliability in the detection of saliva. We believe this assay showed good potential for better non-invasive diagnosis of H. pylori infection.

Low-grade duodenal eosinophilia is associated with cagA in Helicobacter pylori-related dyspepsia

BACKGROUND AND AIM

Functional dyspepsia (FD) is a multifactorial disorder. Helicobacter pylori (H. pylori)-related dyspepsia (HpD) may be considered a separate entity. Duodenal eosinophilia is a potential pathogenic mechanism in FD. However, the impact of duodenal eosinophilia and H. pylori virulence genes in HpD was not explored. We aim to evaluate the association of H. pylori virulence genes and low-grade duodenal eosinophilia in HpD.

METHODS

A multi-center cross-sectional study was conducted. A total of 301 patients who meet Rome-III criteria were selected before upper endoscopy, and 95 patients were included after normal endoscopy and positive H. pylori in gastric biopsies were assessed. Clinical parameters, H. pylori virulence genes (cagA, oipA, and vacA) and duodenal histology were evaluated.

RESULTS

Sixty-nine (72%) patients had epigastric pain syndrome (EPS), 17 (18%) post-prandial distress syndrome (PDS) and 9 (10%) EPS/PDS overlap. FD syndromes were not associated with cagA or oipA strains. A significantly trend of vacA s1/m1 (78%) and s1/m2 (80%) positive strains in EPS was observed. Histological duodenal grading of chronic inflammation, low-grade duodenal eosinophilia and intra-epithelial lymphocytes showed no difference in oipA and vacA strains. Low-grade duodenal eosinophilia was significant in cagA positive strain, and the OR for low-grade duodenal eosinophilia with H. pylori cagA positive strain was 4.2 (95% CI, 1.78-9.93). Adjusting for age, gender, smoking, diabetes, alcohol, PPI, and NSAID, the OR was 5.44 (1.989-14.902).

CONCLUSION

Our findings suggest that low-grade duodenal eosinophilia is significantly associated with cagA strain in HpD.

Multiple amino acid substitutions in penicillin-binding protein-1A confer amoxicillin resistance in refractory Helicobacter pylori infection

BACKGROUND

Amoxicillin resistance in Helicobacter pylori is mainly associated with mutations in penicillin-binding protein-1A (PBP-1A). However, the specific amino acid substitutions in PBP-1A that confer amoxicillin resistance in H. pylori remain to be investigated.

OBJECTIVE

This study aimed to investigate the molecular mechanism underlying amoxicillin resistance in patients with refractory H. pylori infection.

METHODS

Esophagogastroduodenoscopy (EGD) was performed in patients with persistent H. pylori infection after at least two courses of H. pylori eradication therapy between January-2018 to March-2021. Refractory H. pylori was cultured from the gastric biopsy specimens. Antibiotic susceptibility testing was conducted to determine the minimum inhibitory concentrations (MICs). Sequence analysis of pbp-1A was performed for amoxicillin-resistant strains.

RESULTS

Thirty-nine successfully cultured isolates were classified as refractory H. pylori isolates, and seventeen isolates were resistant to amoxicillin (MIC > 0.125 mg/L). Sequence analysis of resistant strains showed multiple mutations in the C-terminal region of PBP-1A that conferred amoxicillin resistance in H. pylori. However, the number of PBP-1A mutations did not correlate with the high MICs of amoxicillin-resistant isolates. Notably, some amino acid substitutions were identified in all Taiwanese isolates with history of eradication failure but not in published amoxicillin-susceptible strains, suggesting that the mutations may play a role in conferring antibiotic resistance to these strains.

CONCLUSIONS

Our results show that amoxicillin resistance in refractory H. pylori is highly correlated with numerous PBP-1A mutations that are strain specific. Continuous improvements in diagnostic tools, particularly molecular analysis approaches, can help to optimize current antimicrobial regimens.

The efficacy and safety of Saccharomyces boulardii in addition to antofloxacin-based bismuth quadruple therapy for Helicobacter pylori eradication: a single-center, prospective randomized-control study

Background

We previously reported that antofloxacin-based bismuth quadruple therapy was safe and effective for Helicobacter pylori (H. pylori) eradication. It is not clear whether the addition of Saccharomyces boulardii (S. boulardii) to antofloxacin-based quadruple therapy can improve the eradication rate of H. pylori and reduce adverse events.

Objective

To investigate the effect of adding S. boulardii to antofloxacin-based quadruple therapy on the eradication rate of H. pylori and the adverse events.

Design

Single-center, prospective randomized controlled study.

Methods

A total of 172 patients with H. pylori infection were randomly assigned to the test and control groups. Patients in the control group (n = 86) received antofloxacin-based bismuth quadruple therapy for 14 days. On this basis, cases in the test group (n = 86) received S. boulardii 500 mg b.i.d. The eradication rate of H. pylori and adverse events were observed 4 weeks after the treatment.

Results

There were no statistically significant differences in the eradication rates of H. pylori and frequency of diarrhea between the test group and control group (p > 0.05). The duration of diarrhea in the test group was significantly shorter than in the control group (p < 0.001). In addition, the two groups exhibited similar adverse event rates for epigastric pain, abdominal distention, dizzy, vomiting, and rash (p > 0.05). The severity of adverse reactions was similar between the two groups (p > 0.05), and most of them had mild adverse events.

Conclusion

Although the addition of S. boulardii to antofloxacin-based quadruple therapy could not improve the eradication rate of H. pylori, it could shorten the time of antibiotic-associated diarrhea and reduce the incidence of diarrhea.

Trial registration number

ChiCTR2200056931.