The pathogenesis of Helicobacter pylori-induced gastro-duodenal diseases

Subdomains of the Helicobacter pylori Cag T4SS outer membrane core complex exhibit structural independence

The Helicobacter pylori Cag type IV secretion system (Cag T4SS) has an important role in the pathogenesis of gastric cancer. The Cag T4SS outer membrane core complex (OMCC) is organized into three regions: a 14-fold symmetric outer membrane cap (OMC) composed of CagY, CagX, CagT, CagM, and Cag3; a 17-fold symmetric periplasmic ring (PR) composed of CagY and CagX; and a stalk with unknown composition. We investigated how CagT, CagM, and a conserved antenna projection (AP) region of CagY contribute to the structural organization of the OMCC. Single-particle cryo-EM analyses showed that complexes purified from ΔcagT or ΔcagM mutants no longer had organized OMCs, but the PRs remained structured. OMCCs purified from a CagY antenna projection mutant (CagY∆AP) were structurally similar to WT OMCCs, except for the absence of the α-helical antenna projection. These results indicate that CagY and CagX are sufficient for maintaining a stable PR, but the organization of the OMC requires CagY, CagX, CagM, and CagT. Our results highlight an unexpected structural independence of two major subdomains of the Cag T4SS OMCC.

Helicobacter pylori Eradication Reverses DNA Damage Response Pathway but Not Senescence in Human Gastric Epithelium

Helicobacter pylori (H. pylori) infection induces DNA Double-Strand Breaks (DSBs) and consequently activates the DNA Damage Response pathway (DDR) and senescence in gastric epithelium. We studied DDR activation and senescence before and after the eradication of the pathogen. Gastric antral and corpus biopsies of 61 patients with H. pylori infection, prior to and after eradication treatment, were analyzed by means of immunohistochemistry/immunofluorescence for DDR marker (γH2AΧ, phosporylated ataxia telangiectasia-mutated (pATM), p53-binding protein (53BP1) and p53) expression. Samples were also evaluated for Ki67 (proliferation index), cleaved caspase-3 (apoptotic index) and GL13 staining (cellular senescence). Ten H. pylori (-) dyspeptic patients served as controls. All patients were re-endoscoped in 72-1361 days (mean value 434 days), and tissue samples were processed in the same manner. The eradication of the microorganism, in human gastric mucosa, downregulates γH2AΧ expression in both the antrum and corpus (p = 0.00019 and p = 0.00081 respectively). The expression of pATM, p53 and 53BP1 is also reduced after eradication. Proliferation and apoptotic indices were reduced, albeit not significantly, after pathogen clearance. Moreover, cellular senescence is increased in H. pylori-infected mucosa and remains unaffected after eradication. Interestingly, senescence was statistically increased in areas of intestinal metaplasia (IM) compared with adjacent non-metaplastic mucosa (p < 0.001). In conclusion, H. pylori infection triggers DSBs, DDR and senescence in the gastric epithelium. Pathogen eradication reverses the DDR activation but not senescence. Increased senescent cells may favor IM persistence, thus potentially contributing to gastric carcinogenesis.

Transcriptomic remodeling of gastric cells by Helicobacter pylori outer membrane vesicles

BACKGROUND

Outer membrane vesicles (OMVs) are spontaneously released by Gram-negative bacteria and influence bacteria-host interactions by acting as a delivery system for bacterial components and by interacting directly with host cells. Helicobacter pylori, a pathogenic bacterium that chronically colonizes the human stomach, also sheds OMVs, and their impact on bacterial-mediated diseases is still being elucidated.

MATERIALS AND METHODS

Transcriptomic profiling of the human gastric cell line MKN74 upon challenge with H. pylori OMVs compared to control and infected cells was performed using the Ion AmpliSeq™ Transcriptome Human Gene Expression Panel to understand the gene expression changes that human gastric epithelial cells might undergo when exposed to H. pylori OMVs.

RESULTS

H. pylori OMVs per se modify the gene expression profile of gastric epithelial cells, adding another layer of (gene) regulation to the already complex host-bacteria interaction. The most enriched pathways include those related to amino acid metabolism, mitogen-activated protein kinase signaling, autophagy, and ferroptosis, whereas the cell cycle, DNA replication, and DNA repair were the most downregulated. The transcriptomic changes induced by OMVs were mostly similar to those induced by the parental bacteria, likely amplifying the effects of the bacterium itself.

CONCLUSIONS

Our data provide a valuable portrayal of the transcriptomic remodeling of gastric cells induced by H. pylori OMVs. It demonstrates the breadth of cellular pathways and genes affected by OMVs, most previously unreported, which can be further dissected for the underlying molecular mediators and explored to understand the pathobiology of the full spectrum of H. pylori-mediated diseases.

Treatment of Chronic Gastritis with Traditional Chinese Medicine: Pharmacological Activities and Mechanisms

Chronic gastritis (CG) is a common clinical digestive system disease, which is not easyily cured and is prone to recurrence. Traditional Chinese medicine (TCM) plays a significant role in the treatment of CG and has attracted increasing attention for clinical applications. In recent years, a large number of reports have shown that TCM has good therapeutic effect on CG. The aim of this paper is to investigate the pharmacological activities and mechanism of action of TCM in the treatment of CAG. Therefore, by searching the databases of Pubmed, China National Knowledge Infrastructure, Wanfang, and Baidu academic databases, this paper has summarized the molecular mechanisms of TCM in improving CG. The results show that the improvement of GC by TCM is closely related to a variety of molecular mechanisms, including the inhibition of Helicobacter pylori (Hp) infection, alleviation of oxidative stress, improvement of gastric function, repair of gastric mucosa, inhibition of inflammatory response, and apoptosis. More importantly, IRF8-IFN-γ, IL-4-STAT6, Hedgehog, pERK1/2, MAPK, PI3K-Akt, NF-κB, TNFR-c-Src-ERK1/2-c-Fos, Nrf2/HO-1, and HIF-1α/VEGF signaling pathways are considered as important molecular targets for TCM in the treatment of GC. These important findings will provide a direction and a basis for further exploring the pathogenesis of GC and tapping the potential of TCM in clinical treatment. This review also puts forward a bright prospect for future research of TCM in the treatment of CG.

Helicobacter pylori Infections in Children

In the context of epidemiology, host response, disease presentation, diagnosis, and treatment management, the manifestation of Helicobacter pylori (H. pylori) infection diverges between children and adults. H. pylori infection stands out as one of the most prevalent bacterial infections globally, and its prevalence in both children and adults is decreasing in many developing countries but some still struggle with a high prevalence of pediatric H. pylori infection and its consequences. The majority of infected children are asymptomatic and pediatric studies do not support the involvement of H. pylori in functional disorders such as recurrent abdominal pain. The pathophysiology of H. pylori infection relies on complex bacterial virulence mechanisms and their interaction with the host immune system and environmental factors. This interaction gives rise to diverse gastritis phenotypes, which subsequently influence the potential development of various gastroduodenal pathologies. In clinical settings, the diagnosis of this infection in childhood requires an upper gastrointestinal endoscopic exam with mucosal biopsy samples for histology and culture, or Polymerase Chain Reaction (PCR) at the very least. When warranted, eradication treatment should be given when good compliance is expected, and there should be systematic use of a treatment adapted to the antimicrobial susceptibility profile. To combat the burgeoning threat of multidrug resistance, vigilant surveillance of resistance patterns and strategic antibiotic management are paramount.

Helicobacter pylori infection induces abnormal expression of pro-angiogenic gene ANGPT2 and miR-203a in AGS gastric cell line

Helicobacter pylori colonizes the stomach and induces an inflammatory response that can develop into gastric pathologies including cancer. The infection can alter the gastric vasculature by the deregulation of angiogenic factors and microRNAs. In this study, we investigate the expression level of pro-angiogenic genes (ANGPT2, ANGPT1, receptor TEK), and microRNAs (miR-135a, miR-200a, miR-203a) predicted to regulate those genes, using H. pylori co-cultures with gastric cancer cell lines. In vitro infections of different gastric cancer cell lines with H. pylori strains were performed, and the expression of ANGPT1, ANGPT2, and TEK genes, and miR-135a, miR-200a, and miR-203a, was quantified after 24 h of infection (h.p.i.). We performed a time course experiment of H. pylori 26695 infections in AGS cells at 6 different time points (3, 6, 12, 28, 24, and 36 h.p.i.). The angiogenic response induced by supernatants of non-infected and infected cells at 24 h.p.i. was evaluated in vivo, using the chicken chorioallantoic membrane (CAM) assay. In response to infection, ANGPT2 mRNA was upregulated at 24 h.p.i, and miR-203a was downregulated in AGS cells co-cultured with different H. pylori strains. The time course of H. pylori 26695 infection in AGS cells showed a gradual decrease of miR-203a expression concomitant with an increase of ANGPT2 mRNA and protein expression. Expression of ANGPT1 and TEK mRNA or protein could not be detected in any of the infected or non-infected cells. CAM assays showed that the supernatants of AGS-infected cells with 26695 strain induced a significantly higher angiogenic and inflammatory response. Our results suggest that H. pylori could contribute to the process of carcinogenesis by downregulating miR-203a, which further promotes angiogenesis in gastric mucosa by increasing ANGPT2 expression. Further investigation is needed to elucidate the underlying molecular mechanisms.

Helicobacter pylori infection may influence prevalence and disease course in myelin oligodendrocyte glycoprotein antibody associated disorder (MOGAD) similar to MS but not AQP4-IgG associated NMOSD

Background

Helicobacter pylori (Hp) persists after colonizing the gut in childhood, and potentially regulates host immune system through this process. Earlier studies have shown that Hp infection in childhood, may protect against MS in later life. Such an association was not seen with AQP4-IgG positive NMOSD, while the association with MOGAD is unclear.

Objective

To evaluate frequency of Hp IgG among patients with MOGAD, MS, NMOSD and matched controls and its effect on disease course. To ascertain whether childhood socio economic factors were linked to prevalence of Hp infection.

Methods

In all, 99 patients diagnosed to have MOGAD, 99 AQP4 IgG+ NMOSD, 254MS and 243 matched controls were included. Patient demographics, diagnosis, age at disease onset, duration and the last recorded expanded disability status scale (EDSS) were obtained from our records. Socioeconomic and educational status was queried using a previously validated questionnaire. Serum HpIgG was detected using ELISA kits (Vircell, Spain).

Result

Frequency of Hp IgG was significantly lower among MOGAD (28.3% vs 44%, p-0.007) and MS (21.2% vs 44%, p-0.0001) but not AQP4-IgG+ NMOSD patients (42.4% vs 44%, p-0.78) when compared to controls. Frequency of Hp IgG in MOGAD & MS patients combined (MOGAD-MS) was significantly lower than those with NMOSD (23.2% vs 42.4%, p- 0.0001). Seropositive patients with MOGAD- MS were older (p-0.001. OR -1.04, 95% CI- 1.01- 1.06) and had longer disease duration (p- 0.04, OR- 1.04, 95% CI- 1.002- 1.08) at time of testing. Educational status was lower among parents/caregivers of this study cohort (p- 0.001, OR -2.34, 95% CI- 1.48-3.69) who were Hp IgG+.

Conclusions

In developing countries Hp infection may be a significant environmental factor related to autoimmune demyelinating CNS disease. Our preliminary data suggests that Hp may exert a differential influence - a largely protective role for MS-MOGAD but not NMOSD and may influence disease onset and course. This differential response maybe related to immuno-pathological similarities between MOGAD and MS in contrast to NMOSD. Our study further underscores the role of Hp as a surrogate marker for poor gut hygiene in childhood and its association with later onset of autoimmune diseases.

Susceptibility patterns and virulence genotypes of Helicobacter pylori affecting eradication therapy outcomes among Egyptian patients with gastroduodenal diseases

BACKGROUND

Helicobacter pylori (H. pylori) is a significant human pathogen that is responsible for a variety of illnesses, including mucosa-associated lymphoid tissue lymphoma, gastric cancer, peptic ulcers, and gastritis.

AIM

To investigate the frequency of H. pylori infection and its resistance patterns among Egyptian patients and to determine the influence of H. pylori virulence genetic determinants on the eradication success of 14-d triple therapy regimen.

METHODS

H. pylori infections were investigated in 72 patients with gastroduodenal complications suggestive of H. pylori infection. The cagA and vacA genotypes of cultured strains were studied using polymerase chain reaction. The patients underwent 14 d of triple-therapy treatment. The treatment response was examined using histology and a rapid urease test 6 wk after therapy discontinuation.

RESULTS

The intention-to-treat eradication rate was 59.2% (95%CI: 48.2%–70.3%). Rates of H. pylori resistance to clarithromycin, amoxicillin, and metronidazole were 52.8%, 81.9%, and 100%, respectively. Successful eradication of H. pylori was more significantly associated with vacA s1-positive strains [adjusted odds ratio (aOR) = 0.507, 95%CI: 0.175–0.822]. A significant association was found between failed eradication rate and H. pylori strains resistant to clarithromycin (aOR = 0.204, 95%CI: –0.005 to 0.412) and amoxicillin (aOR = 0.223, 95%CI: 0.026–0.537).

CONCLUSION

This study’s low H. pylori eradication rate following 14-d triple therapy is concerning and worrying. H. pylori pan-resistance to metronidazole followed by the high resistance to ciprofloxacin, amoxicillin, and clarithromycin in this research is challenging and of great concern.

Unwelcome guests - the role of gland-associated Helicobacter pylori infection in gastric carcinogenesis

Helicobacter pylori (H. pylori) are Gram-negative bacteria that cause chronic gastritis and are considered the main risk factor for the development of gastric cancer. H. pylori have evolved to survive the harsh luminal environment of the stomach and are known to cause damage and signaling aberrations in gastric epithelial cells, which can result in premalignant and malignant pathology. As well as colonizing the gastric mucus and surface epithelial cells, a subpopulation of H. pylori can invade deep into the gastric glands and directly interact with progenitor and stem cells. Gland colonization therefore bears the potential to cause direct injury to long-lived cells. Moreover, this bacterial subpopulation triggers a series of host responses that cause an enhanced proliferation of stem cells. Here, we review recent insights into how gastric gland colonization by H. pylori is established, the resulting pro-carcinogenic epithelial signaling alterations, as well as new insights into stem cell responses to infection. Together these point towards a critical role of gland-associated H. pylori in the development of gastric cancer.

Relationship between Helicobacter pylori virulence genes and gastroduodenal disease

OBJECTIVE

This study aimed to identify Helicobacter pylori virulence factors and examine their associations with clinical outcomes in Thai patients. Moreover, the association between these genotypes and gastric mucosa morphological patterns was investigated.

METHODS

This retrospective study enrolled patients who underwent esophagogastroduodenoscopy at Suranaree University of Technology Hospital. The presence of the cagA and vacA genes was investigated by real-time polymerase chain reaction.

RESULTS

The H. pylori-specific genes ureA and 16S rRNA were detected in all 698 gastric biopsy specimens. In total, 567 (81.23%) patients with H. pylori infection were positive for the cagA gene, 443 (63.46%) were positive for the vacA gene, and 370 (53.0%) were positive for both. The cagA genotype was significantly more common in patients with chronic gastritis and peptic ulcers (78.99% and 79.41%, respectively) than the vacA gene (51.48% and 55.88%, respectively) and combined genotypes (32.34% and 47.05%, respectively). Moreover, the cagA genotype was significantly more common in patients with type 4 or 5 gastric mucosa patterns (69.49% and 76.31%, respectively).

CONCLUSIONS

The cagA genotype is the main cause of serious inflammation of the gastric mucosa. The cagA gene is possibly an important factor explaining gastroduodenal disease outcomes in Thai patients with H. pylori infection.

Population- and Gender-Based Investigation for Prevalence of Helicobacter pylori in Dhamar, Yemen

Among 35 species of genus Helicobacter, H. pylori is the most common causative agent of human gastritis, peptic ulcer, and gastric cancer. The infection can spread through direct human-to-human contact, fecal-oral route, and contaminated water. The study was designed to investigate the rate of prevalence of H. pylori in the population of Dhamar, Yemen. In this one-year study, 460 including 250 male and 210 female stool specimens were collected between January to December 2020 in Dhamar Governorate, Yemen. Of the total 460, 215 rural (male: n = 120 and female: n = 95) and 245 urban (male: n = 130 and female: n = 115) specimens were investigated for identification of H. pylori by serological test using Helicobacter pylori stool antigen (HpSA) test. In addition, for comparing an improved recovery of H. pylori, conventional culture-based isolation was also carried out using three selective media. Modified Campy-blood Agar (MCA), Belo Horizonte Agar (BHA), and Egg yolk Emulsion (EYE) medium supplemented with antimicrobial agents including vancomycin (10 mg/L), cefsulodin (5 mg/L), trimethoprim (5 mg/L), and amphotericin B (5 mg/L) and isolates were phenotypically characterized. The HpSA test results revealed that of the total 460 specimens, 89 (19.3%) were positive for H. pylori with relatively low in male (n = 43; 17.2%) as compared to the female (n = 46; 21.9%) specimens. After 3-10 days of incubation, H. pylori was recovered at a variable rate on each selective (MCA: 16.5%; BHA: 15.0%; EYE: 13.0%) media. However, culture-based assay results showed less recovery (n = 81; 17.6%) with no significant difference among all selective media tested and between genders (male: n = 39; 15.6%; female: n = 42; 20.0%). The infection rate was comparatively higher in rural (n = 45; 20.9%) as compared to urban (n = 36; 14.7%) population. Overall, the study data showed the prevalence of infection in both genders of all age groups. The present study showed a relatively high rate of infection of H. pylori in the Dhamar population. The serological identification and culture-based methods are important for rapid detection, aid in treatment, and developing policies for the control and eradication of H. pylori infection and to prevent the disease in different age groups in Yemen.

Helicobacter pylori infection induces gastric precancerous lesions and persistent expression of Angpt2, Vegf-A and Tnf-A in a mouse model

Introduction

Helicobacter pylori colonizes the gastric mucosa and induces chronic inflammation.

Methods

Using a mouse model of H. pylori-induced gastritis, we evaluated the mRNA and protein expression levels of proinflammatory and proangiogenic factors, as well as the histopathological changes in gastric mucosa in response to infection. Five- to six-week-old female C57BL/6N mice were challenged with H. pylori SS1 strain. Animals were euthanized after 5-, 10-, 20-, 30-, 40- and 50-weeks post infection. mRNA and protein expression of Angpt1, Angpt2, VegfA, Tnf-α, bacterial colonization, inflammatory response and gastric lesions were evaluated.

Results

A robust bacterial colonization was observed in 30 to 50 weeks-infected mice, which was accompanied by immune cell infiltration in the gastric mucosa. Compared to non-infected animals, H. pylori-colonized animals showed an upregulation in the expression of Tnf-A, Angpt2 and VegfA at the mRNA and protein levels. In contrast, Angpt1 mRNA and protein expression was downregulated in H. pylori-colonized mice.

Conclusion

Our data show that H. pylori infection induces the expression of Angpt2, Tnf-A and Vegf-A in murine gastric epithelium. This may contribute to the pathogenesis of H. pylori-associated gastritis, however the significance of this should be further addressed.

Phospholipase C: underrated players in microbial infections

During bacterial infections, one or more virulence factors are required to support the survival, growth, and colonization of the pathogen within the host, leading to the symptomatic characteristic of the disease. The outcome of bacterial infections is determined by several factors from both host as well as pathogen origin. Proteins and enzymes involved in cellular signaling are important players in determining the outcome of host-pathogen interactions. phospholipase C (PLCs) participate in cellular signaling and regulation by virtue of their ability to hydrolyze membrane phospholipids into di-acyl-glycerol (DAG) and inositol triphosphate (IP3), which further causes the activation of other signaling pathways involved in various processes, including immune response. A total of 13 PLC isoforms are known so far, differing in their structure, regulation, and tissue-specific distribution. Different PLC isoforms have been implicated in various diseases, including cancer and infectious diseases; however, their roles in infectious diseases are not clearly understood. Many studies have suggested the prominent roles of both host and pathogen-derived PLCs during infections. PLCs have also been shown to contribute towards disease pathogenesis and the onset of disease symptoms. In this review, we have discussed the contribution of PLCs as a determinant of the outcome of host-pathogen interaction and pathogenesis during bacterial infections of human importance.

The Effect of Quadruple Therapy with Polaprezinc or Bismuth on Gut Microbiota after Helicobacter pylori Eradication: A Randomized Controlled Trial

Background: Quadruple therapy with polaprezinc provided an alternative to Helicobacter pylori eradication; however, the effect on gut microbiota remains uncertain. This study aims to identify whether polaprezinc-containing quadruple therapy causes adverse microbiota effects among asymptomatic adults, compared with bismuth therapy. Methods: This was a randomized control trial. One hundred asymptomatic H. pylori-infected adults were randomly (1:1) assigned to two treatment groups (polaprezinc-containing therapy, PQT; or bismuth-containing therapy, BQT). Fecal samples were collected from subjects before and 4−8 weeks after therapy. Samples were sequenced for the V4 regions of the 16S rRNA gene. Results: The relative abundance of the three dominant bacterial phyla (Bacteroidota, Firmicutes, and Proteobacteria) accounted for more than 95% of each treatment group. The alpha diversity between eradications that succeeded and those that failed had no significant difference (p > 0.05). After successful eradication, the alpha diversity in the BQT group decreased in comparison with the baseline (p < 0.05). Subjects who were successfully eradicated by BQT showed considerably lower alpha diversity indices than those of the PQT at follow-up (p < 0.05). The abundance of Parasutterella in subjects who were successfully eradicated by PQT was four times greater than that of BQT (q < 0.05). Conclusion: A 14-day PQT may be superior to BQT in maintaining short-term gut microbiota homeostasis after H. pylori treatment. Our findings preliminarily provide evidence of the short-term impacts of the gut microbiota after PQT treatment of H. pylori infection.

Effect of Helicobacter pylori Infection on Macromineral and Trace Element Status-Systematic Review and Meta-Analysis

OBJECTIVES

To explore the effect of Helicobacter pylori (Hp ) infection on zinc, copper, calcium, magnesium, phosphorus, and iodine status in the pediatric population.

METHODS

A protocol was registered on PROSPERO. A literature search was conducted on Embase, PubMed MEDLINE, and Web of Science, from inception to September 2020, including all studies in English, Spanish, and Portuguese languages. Reference lists were manually searched. Primary studies describing at least one micronutrient status in Hp -positive and Hp -negative or control children were included. PRISMA recommendations were applied. Pooled mean differences (MDs) and 95% confidence intervals were estimated using a random-effects model. A total of 1011 citations were screened. Six cross- sectional studies were included. No publications regarding phosphorus and iodine were identified.

RESULTS

Included studies in meta-analyses comprised an overall age range of 4-18 years, with Hp positivity ranging between 29.5% and 72.3%. These meta-analyses demonstrated a lack of evidence of an association between Hp -positive and Hp -negative or control children regarding serum zinc (vs Hp -negative: MD -1.36 µg/dL; vs control: MD 326.22 µg/dL), copper (MD -0.83 µg/dL), and calcium (MD 0.09 mg/dL) status. Considerable heterogeneity was recognized, except for calcium analysis (I 2 = 0%). Meta-analysis for magnesium was not performed. Five studies presented a low risk of bias.

CONCLUSIONS

The study demonstrated a lack of evidence of an effect of Hp infection on serum zinc, copper, and calcium status. Studies concerning magnesium, phosphorus, and iodine status are warranted. Furthermore, larger and well-controlled studies are recommended.

A Complex Connection Between the Diversity of Human Gastric Mucin O-Glycans, Helicobacter pylori Binding, Helicobacter Infection and Fucosylation

Helicobacter pylori colonizes the stomach of half of the human population. Most H. pylori are located in the mucus layer, which is mainly comprised by glycosylated mucins. Using mass spectrometry, we identified 631 glycans (whereof 145 were fully characterized and the remainder assigned as compositions) on mucins isolated from 14 Helicobacter spp.-infected and 14 Helicobacter spp.-noninfected stomachs. Only six identified glycans were common to all individuals, from a total of 60 to 189 glycans in each individual. An increased number of unique glycan structures together with an increased intraindividual diversity and larger interindividual variation were identified among O-glycans from Helicobacter spp.-infected stomachs compared with noninfected stomachs. H. pylori strain J99, which carries the blood group antigen-binding adhesin (BabA), the sialic acid-binding adhesin (SabA), and the LacdiNAc-binding adhesin, bound both to Lewis b (Leb)-positive and Leb-negative mucins. Among Leb-positive mucins, H. pylori J99 binding was higher to mucins from Helicobacter spp.-infected individuals than noninfected individuals. Statistical correlation analysis, binding experiments with J99 wt, and J99ΔbabAΔsabA and inhibition experiments using synthetic glycoconjugates demonstrated that the differences in H. pylori-binding ability among these four groups were governed by BabA-dependent binding to fucosylated structures. LacdiNAc levels were lower in mucins that bound to J99 lacking BabA and SabA than in mucins that did not, suggesting that LacdiNAc did not significantly contribute to the binding. We identified 24 O-glycans from Leb-negative mucins that correlated well with H. pylori binding whereof 23 contained α1,2-linked fucosylation. The large and diverse gastric glycan library identified, including structures that correlated with H. pylori binding, could be used to select glycodeterminants to experimentally investigate further for their importance in host-pathogen interactions and as candidates to develop glycan-based therapies.

Helicobacter pylori infection in the stomach induces neuroinflammation: the potential roles of bacterial outer membrane vesicles in an animal model of Alzheimer's disease

Helicobacter pylori (HP) is a Gram-negative bacterium that colonizes the human stomach chronically. Colonization of HP in the gastric mucosa not only causes gastrointestinal diseases, but also is associated with extra-gastric diseases, such as idiopathic thrombocytopenic purpura and neurological diseases. Among neurological diseases, epidemiological studies have shown that HP infection increases the prevalence of Alzheimer's disease (AD) and Parkinson's disease (PD). Since HP does not invade the central nervous system (CNS), it has been considered that systemic immunological changes induced by HP infection may play pathogenic roles in AD and PD. Here, we investigated the effects of HP infection on the CNS in vivo and in vitro. In the CNS, chronically HP-infected mice had microglial activation without HP colonization, although systemic immunological changes were not observed. This led us to explore the possibility that HP-derived outer membrane vesicles (HP-OMVs) could cause neuroinflammation. OMVs are small, spherical bilayer vesicles (20-500 nm) released into the extracellular space from the outer membrane of Gram-negative bacteria; OMVs contain lipopolysaccharide, proteins, peptidoglycan, DNA, and RNA. OMVs have also been shown to activate both innate and acquired immune cells in vitro, and to disrupt the tight junctions of the gastric epithelium ("leaky gut") as well as cross the blood-brain barrier in vivo. Thus, in theory, OMVs can activate immune responses in the remote organs, including the lymphoid organs and CNS, if only OMVs enter the systemic circulation. From the exosome fraction of sera from HP-infected mice, we detected HP-specific DNA, suggesting the presence of HP-OMVs. We also found that microglia incubated with HP-OMVs in vitro increased the cell proliferation, inflammatory cytokine production, and migration. On the other hand, HP-OMVs suppressed the cell proliferation of neuroblastoma in vitro. Lastly, we found that AD model mice infected with HP had amyloid plaques adjacent to activated microglia and astrocytes in vivo. Based on the literature review and our experimental data, we propose our working hypothesis that OMVs produced in chronic HP infection in the gut induce neuroinflammation in the CNS, explaining the higher prevalence of AD in HP-infected people.

Chemical Synthesis of the Highly Sterically Hindered Core Undecasaccharide of Helicobacter pylori Lipopolysaccharide for Antigenicity Evaluation with Human Serum

Helicobacter pylori, listed as a human carcinogen by the Department of Health and Human Services, colonizes the gastric mucosa of more than half of the world's population. The individuals infected with H. pylori have a high risk to develop chronic gastritis, peptic ulcers, and even gastric cancer. The conserved core structure of H. pylori lipopolysaccharide (LPS) has been regarded as a promising candidate structure for development of a glycoconjugate vaccine targeting multiple serotypes. Here, we report a total synthesis of the core undecasaccharide of H. pylori LPS and its subunit antigens. The match and mismatch between the glycosyl donor and acceptor caused by the inert hydroxyl groups were addressed by a judicious choice of orthogonal protection strategies and glycosylation conditions. A combination of acyl remote participation and solvent effects has been applied for selective formation of the five 1,2-cis-glucosidic bonds. The high steric hindrance induced by the high carbon sugars and trinacriform architecture required that the core undecasaccharide was synthesized through a finely tuned linear assembly [2 + (1 + (3 + (1 + (1 + 3))))] rather than convergent strategies. An antigenicity evaluation using glycan microarrays showed that an α-(1 → 6)-glucan trisaccharide is recognized by IgG antibodies in sera of H. pylori-infected patients. The phosphate group of the inner core trisaccharide key epitope is very important for IgG recognition. These findings are an important step toward designing carbohydrate-based vaccines against H. pylori.

Prevalence, Virulence Genes, Phylogenetic Analysis, and Antimicrobial Resistance Profile of Helicobacter Species in Chicken Meat and Their Associated Environment at Retail Shops in Egypt

Helicobacter pylori (H. pylori) and Helicobacter pullorum (H. pullorum) are frequently reported pathogens in humans and poultry, respectively. Nevertheless, the source of H. pylori is still unclear. This study aimed to detect Helicobacter spp. in chicken carcasses and to assess the antibiogram and the virulence genes of Helicobacter isolates. Three hundred chicken meat samples (100 each of chicken breast, liver, and gizzard), besides 60 swab samples from chicken processing surfaces, were collected from retail shops in Qalyubia Governorate, Egypt, and examined for the prevalence of H. pylori and H. pullorum. The 16S rRNA of three H. pylori and two H. pullorum isolates were sequenced to determine the genetic relationship between these two Helicobacter spp. Of the 300 chicken samples tested, 16 (5.33%) and 14 (4.67%) were positive for H. pylori and H. pullorum, respectively. Multiplex PCR revealed that the virulence genes vacuolating cytotoxin A (vacA)s1, cytotoxin-associated gene A (cagA), and restriction endonuclease-replacing gene A (hrgA) were detected in 66.7%, 77.8%, and 100% of H. pylori strains tested, respectively. H. pylori showed the highest resistance for clarithromycin, while H. pullorum exhibited the highest resistance towards erythromycin and ciprofloxacin. The study concluded that the chicken meat and giblets are potential sources of the virulent and antimicrobial-resistant strains of H. pylori of human origin.

Oral Administration of a Shigella 2aT32-Based Vaccine Expressing UreB-HspA Fusion Antigen With and Without Parenteral rUreB-HspA Boost Confers Protection Against Helicobacter pylori in Mice Model

Helicobacter pylori (H. pylori) is a gram-negative pathogen classified as a class I carcinogen. The H. pylori urease B subunit (UreB) and heat shock protein A (HspA) are two important vaccine candidate antigens. In this study, we evaluated the immunogenicity and immunoprotective effect of the attenuated Shigella vector vaccine SH02 expressing the UreB-HspA fusion protein of H. pylori in a mouse model. Oral SH02 with or without subcutaneous injection of rUreB-HspA induced antigen-specific serum IgG, mucosal sIgA, and T cells immune response. Subcutaneous injection of the candidate antigen rUreB-HspA enhanced the level of serum antigen-specific IgG antibodies (p &lt; 0.0001) and the levels of IgG1/IgG2a/IgG2b subtypes. In addition, injection boost also increased the proportion of spleen antigen-specific CD4+CD154+ T cells (p &lt; 0.001), and the proportion of CD4+CD154+ T cells that secrete IFN-γ and IL-17A. Following the H. pylori challenge, the levels of H. pylori colonization in the two experimental groups (Groups A and B) significantly reduced compared with the control group (p &lt; 0.001), indicating that the candidate vaccine yielded a preventive effect of anti-H.pylori infection. Compared with the non-subcutaneous booster injection group (Group A), the subcutaneous booster injection group (Group B) exhibited less gastric inflammation, but there was no significant difference in the level of colonization (p &gt; 0.05). These results lay a foundation for the development of a vaccine against H. pylori and the optimization of immunization methods and procedures to prevent H. pylori infection.

Cancer-Associated Microbiota: From Mechanisms of Disease Causation to Microbiota-Centric Anti-Cancer Approaches

Helicobacter pylori infection is the only well-established bacterial cause of cancer. However, due to the integral role of tissue-resident commensals in maintaining tissue-specific immunometabolic homeostasis, accumulated evidence suggests that an imbalance of tissue-resident microbiota that are otherwise considered as commensals, can also promote various types of cancers. Therefore, the present review discusses compelling evidence linking tissue-resident microbiota (especially gut bacteria) with cancer initiation and progression. Experimental evidence supporting the cancer-causing role of gut commensal through the modulation of host-specific processes (e.g., bile acid metabolism, hormonal effects) or by direct DNA damage and toxicity has been discussed. The opportunistic role of commensal through pathoadaptive mutation and overcoming colonization resistance is discussed, and how chronic inflammation triggered by microbiota could be an intermediate in cancer-causing infections has been discussed. Finally, we discuss microbiota-centric strategies, including fecal microbiota transplantation, proven to be beneficial in preventing and treating cancers. Collectively, this review provides a comprehensive understanding of the role of tissue-resident microbiota, their cancer-promoting potentials, and how beneficial bacteria can be used against cancers.

Association of Progranulin Gene Expression from Dyspeptic Patients with Virulent Helicobacter pylori Strains; In Vivo Model

(1) Background: Gastric cancer, the fourth most common cause of death from tumors in the world, is closely associated with Helicobacter pylori. Timely diagnosis, therefore, is essential to achieve a higher survival rate. In Chile, deaths from gastric cancer are high, mainly due to late diagnosis. Progranulin has reflected the evolution of some cancers, but has been poorly studied in gastric lesions. Aiming to understand the role of progranulin in H. pylori infection and its evolution in development of gastric lesions, we evaluated the genic expression of progranulin in gastric tissue from infected and non-infected patients, comparing it according to the epithelial status and virulence of H. pylori strains. (2) Methods: The genic expression of progranulin by q-PCR was quantified in gastric biopsies from Chilean dyspeptic patients (n = 75) and individuals who were uninfected (n = 75) by H. pylori, after receiving prior informed consent. Bacteria were grown on a medium Columbia agar with equine-blood 7%, antibiotics (Dent 2%, Oxoid^TM), in a microaerophilic environment, and genetically characterized for the ureC, vacA, cagA, and iceA genes by PCR. The status of the tissue was determined by endoscopic observation. (3) Results: Minor progranulin expression was detected in atrophic tissue, with a sharp drop in the tissue colonized by H. pylori that carried greater virulence, VacAs1m1⁺CagA⁺IceA1⁺. (4) Conclusions: Progranulin shows a differential behavior according to the lesions and virulence of H. pylori, affecting the response of progranulin against gastric inflammation.

The association of Helicobacter Pylori infection with dyslipidaemia and other atherogenic factors in dyspeptic patients at St. Paul's Hospital Millennium Medical College

Background

Studies showed that more than half of Ethiopians were presumed to be chronically infected with H. pylori. Nowadays, evidence has come to the literature strongly suggesting the potential association between H. pylori and extra gastric disorders including atherosclerosis.

Objective

To assess the association of helicobacter pylori infection with dyslipidaemia and other atherogenic factors in dyspeptic patients at St. Paul's Hospital Millennium Medical College, from November 2019 to June 2020.

Materials and methods

This institution-based cross-sectional study was examining 346 dyspeptic patients at SPHMMC from November 2019 to June 2020. A structured questionnaire was used to collect socio-demography data and anthropometric measurement was taken. Biochemical parameters were measured in serum samples by using Cobas 6000 clinical chemistry analyzer. Data were coded and entered into a statistical package for social sciences (SPSS) version 23 for analysis. Risk factors were identified using logistic regression. Hence, a bivariate logistic regression analysis test was conducted and variables with a p < 0.25 were included in the multivariate logistic regression model. P-values ≤0.05 were considered as a cut point for statistical significance in the final model.

Results

An overall prevalence of dyslipidemia among study participants was 253 (73.12 %). Among those who tested positive for H. pylori, 119/174 (68.39 %) had dyslipidemia in at least one lipid profile, while 8 (4.60%) had dyslipidemia in all four lipid profiles. After adjusting for traditional dyslipidemia risk factors, age >45 (AOR 4.864, 95% CI 2.281–4.080, P < 0.001), systolic blood pressure >120mmHg (AOR 1.036, 95% CI 1.009–1.065, P = 0.036) and being H. Pylori seropositive (AOR 0.555, 95% CI 0.318–0.967, P = 0.038) were an independent predictors of dyslipidemia.

Conclusion

This study reported that more than two-thirds of the H. pylori seropositive groups had exhibited dyslipidemia in at least one lipid profile, which can accelerate the incidence of atherosclerosis process.

Differential H. pylori-Induced MAPK Responses Regulate Lewis Antigen Expression and Colonization Density on Gastric Epithelial Cells Between Children and Adults

Helicobacter pylori causes gastrointestinal diseases, the manifestations of diseases are more serious in adults than in children. Lewis antigen expressions on the gastric epithelium serves as receptors targeted by H. pylori. Moreover, the MAPK signaling pathway involves glycoprotein synthesis of Lewis antigens. We aimed to investigate whether differences in H. pylori-induced MAPK responses mediate gastric Lewis antigens expression and colonization density differently in children and adults. We used human stomach fetal epithelium (HSFE) and SV40-immortalized human normal gastric epithelial (GES-1) cell lines to mimic primary gastric epithelium of children and adults, respectively. H. pylori colonization intensity and Lewis antigens were significantly higher in GES-1 than in HSFE cells, whereas IL-8 and IL-6 levels were significantly higher in HSFE than in GES-1 cells after infection. c-Jun N-terminal kinase (JNK) siRNA and inhibitor (SP600125) experiments showed that Lewis antigen expression and H. pylori colonization were reduced in GES-1 cells but increased in HSFE cells. Furthermore, p-p38 intensity was significantly higher in the superficial epithelium of the children than in the adults with/without H. pylori infection. The overexpression of p38 in GES-1 cells downregulated H. pylori-induced JNK activity mimicking H. pylori infection in children. In conclusion, a higher p38 expression in gastric epithelium counteracting JNK activity in children may contribute to lower Lewis antigen expression and colonization density than in adults after H. pylori infection.

The Association between Helicobacter pylori Seropositivity and Bone Mineral Density in Adults

Objectives

Current evidence on the associations between Helicobacter pylori (H. pylori) infection and bone mineral density (BMD) is conflicting. Therefore, a nationally representative sample of adults was analyzed to investigate the associations of H. pylori seropositivity and BMD in this study.

Methods

A retrospective cross-sectional study was conducted with 2555 subjects aged 40-85 years in the US National Health and Nutrition Examination Survey (NHANES) 1999–2001. Multivariable logistic regression models were performed to evaluate the associations between H. pylori seropositivity and BMD. Subgroup analyses stratified by sex, age, race, and body mass index (BMI) were performed.

Results

No association was found between H. pylori seropositivity and BMD (β = 0.006, 95% CI: -0.003 to 0.015, P = 0.177). In the subgroup analyses stratified by age, a positive association was observed between the H. pylori seropositivity and total BMD among subjects aged 40-55 years (β = 0.018, 95% CI: 0.004 to 0.033, P = 0.012); in the subgroup analyses stratified by sex, a positive association was observed between the H. pylori seropositive and total BMD in male (β = 0.019, 95% CI: 0.007 to 0.032, P = 0.003); in the subgroup analyses stratified by age and sex, the total BMD was higher in men aged 40-55 years with H. pylori seropositive than those with H. pylori seronegative (β = 0.034, 95% CI: 0.013 to 0.056, P = 0.002).

Conclusions

In conclusion, no association between H. pylori seropositive and total BMD was demonstrated among most middle-aged and elderly adults. H. pylori infection may not be one key factor in the loss of BMD.

Targeting and Killing the Ever-Challenging Ulcer Bug

TreatingHelicobacter pylori(H. pylori) infections has been a never-ending challenge, which has contributed to the high incidence of gastric cancer. The antibiotics commonly used are not reaching the infection site in its active state and in a concentration high enough to effectively kill the bacteria. In this context, amoxicillin-loaded lipid nanoparticles with carefully chosen materials were developed, namely dioleoylphosphatidylethanolamine (DOPE) as a targeting agent and Tween®80 and linolenic acid as antimicrobial agents. This work shows the ability of these nanoparticles in (i) targeting the bacteria (imaging flow cytometry) and inhibiting their adhesion to MKN-74 cells (bacteria-gastric cells adhesion model); (ii) killing the bacteria even as an antibiotic-free strategy (time-kill kineticstudies, scanning electron microscopy, and bacterial membrane permeability studies); (iii)overcoming gastrointestinal features using a newly developedin vitroinfection model that includes both physical (epithelial cells and mucus) and the chemical (acid medium) barriers; and in (iv) being incorporated in a floating system that can increase the retention time at the stomach. Overall, this work presents an effective nanosystem to deal with the ulcer-bug. Besides, it also provides two innovative tools transferable to other fields-anin vitroinfection model and a floating system to incorporate nanoparticles.

Identifying the pre-malignant stomach: from guidelines to practice

Gastric adenocarcinoma develops after stepwise progression from normal mucosa through to adenocarcinoma most commonly after being triggered by Helicobacter pylori (H. pylori) infection. As disease is often diagnosed late, the prognosis for gastric adenocarcinoma is poor. Identifying pre-malignant mucosal lesions such as atrophic gastritis, intestinal metaplasia and dysplasia is one strategy adopted by clinicians to reduce cancer related mortality. Surveillance of high-risk individuals and endoscopic resection of dysplastic lesions is recommended by international and UK guidelines. The early detection and endoscopic management reduce the need for invasive surgery. The advancement of image enhanced endoscopy technology, endoscopic training, risk stratification and histological assessment has proven pivotal to the management of pre-malignant lesions. In this review we outline the development of a high-risk stomach, endoscopic assessment and review practical guidelines on identifying pre-malignant gastric mucosa.

Multiple surface interaction mechanisms direct the anchoring, co-aggregation and formation of dual-species biofilm between Candida albicans and Helicobacter pylori

Introduction

Polymicrobial biofilms have a significant impact on pathogenesis of infectious microorganisms. Many human diseases are affected by colonization of multi-species communities affecting negatively the treatments and increase the risks for the health. In particular, in the epithelium of the stomach co-existence between C. albicans and H. pylori has been described, which has been associated to a synergistic effect on ulcer pathogenesis.

Objective

The objective of this work was to advance in the understanding of surface interaction between H. pylori and C. albicans for the formation of polymicrobial biofilms.

Methods

Studies of microbial surfaces both bacterium, yeast and co-cultures of them were carried out by infrared spectroscopy, deconvolution analysis, transmission and scanning electron microscopies, and optic microscopy. Additional methods were used to contrast the results as dynamic light scattering, contact angle, agarose gel electrophoresis and gene amplification.

Results

Several surface interaction mechanisms promote the anchoring of H. pylori on C. albicans, cell co-aggregation, and polymicrobial biofilm formation, main identified interactions were: (i) hydrophobic interactions between non-polar peptide chains and lipid structures, characterized by θ_w among 84.9 ± 1.6 (γ = 22.78 mJ/m² with 95.3 of dispersive contribution) and 76.6 ± 3.8 (γ = 17.34 mJ/m², 40.2 of dispersive contribution) for C. albicans and H. pylori, respectively, (ii) hydrogen bonds between surface components of yeast and bacterium (e.g., -S-H⋅⋅⋅NH₂- or -S-H⋅⋅⋅O[bond, double bond]CO-) and (iii) thiol-mediated surface interactions identified by displacements to lower wavenumbers (Δv = 5 cm^-1). Evidence of internalization and electrostatic interactions were not evidenced. All observations were congruent with the biofilm formation, including the identification of small-size biostructures (i.e., 122-459 nm) associated with extracellular proteins, extracellular DNA, or outer membrane vesicles were observed characteristic of biofilm formation.

Conclusion

It is concluded that biofilm is formed by co-aggregation after anchoring of H. pylori on C. albicans. Several surface interactions were associated with the prevalence of H. pylori, the possibility to find C. albicans in the stomach epithelium infected by H. pylori, but also, strength interactions could be interfering in experimental observations associated with bacterial-DNA detection in culture mixtures.

Association between Helicobacter pylori infection and serum thyroid stimulating hormone in the National Health and Nutrition Examination Survey 1999-2000

OBJECTIVE

Current evidence on the associations between plasma thyroid stimulating hormone and Helicobacter pylori infection is conflicting. Therefore, our study aimed to examine TSH in relation to H. pylori infection.

METHODS

Based on the US National Health and Nutrition Examination Survey (NHANES) 1999-2000, a cross-sectional study was conducted with 948 participants aged 30 to 85 years. The associations between H. pylori seropositivity and TSH were evaluated using binary logistic regression models. A subgroup analysis stratified by sex, age, and body mass index was conducted.

RESULTS

A higher serum TSH level was found in subjects with H. pylori seropositive than in subjects with H. pylori seronegative. A significant positive association was found between H. pylori seropositivity and TSH with increasing quartiles of hormonal levels in univariate regression models (Q4 vs Q1: OR = 1.659; 95% CI, 1.152-2.389) and in multivariate regression models (Q4 vs Q1: OR = 1.604; 95% CI, 1.087-2.367). In stratified analyses, the adjusted association of serum TSH with H. pylori seropositivity was statistically significant in male (Q4 vs Q1: OR = 1.894; 95% CI, 1.109-3.235), normal BMI (Q4 vs Q1: OR = 1.894; 95% CI, 1.109-3.235), overweight (Q4 vs Q1: OR = 2.124; 95% CI, 1.047-4.308);, obese (Q4 vs Q1: OR = 0.429; 95% CI, 0.220-0.837), and age over 60 years (Q4 vs Q1: OR = 1.999; 95% CI, 1.118-3.575).

CONCLUSION

High TSH levels were associated with H. pylori infection, especially among male, overweight and elderly adults.

Visualization of Cytosolic Galectin Accumulation Around Damaged Vesicles and Organelles

Galectins are animal lectins that recognize β-galactoside and bind glycans. Recent studies have indicated that cytosolic galectins recognize cytosolically exposed glycans and accumulate around endocytic vesicles or organelles damaged by various disruptive substances. Accumulated galectins engage other cytosolic proteins toward damaged vesicles, leading to cellular responses, such as autophagy. Disruptive substances include bacteria, viruses, particulate matters, and protein aggregates; thus, this process is implicated in the pathogenesis of various diseases. In this chapter, we describe methods for studying three disruptive substances: photosensitizers, Listeria monocytogenes, and Helicobacter pylori. We summarize the tools used for the detection of cytosolic galectin accumulation around damaged vesicles.

Steamed Ginger Extract Exerts Anti-inflammatory Effects in Helicobacter pylori-infected Gastric Epithelial Cells through Inhibition of NF-κB

Ginger (Zingiber officinale) has traditionally been used as a treatment for inflammatory diseases in the Asian region. Recently, anti-inflammatory effects of steamed ginger extract (GGE03) have been reported, but its association with Helicobacter pylori (H. pylori)-induced gastritis has not been investigated. The purpose of this study was to assess the anti-inflammatory activity of GGE03 in H. pylori-infected gastric epithelial cells. Our studies revealed that the GGE03 suppressed the growth of H. pylori. GGE03 markedly reduced the expression of the H. pylori-induced pro-inflammatory cytokines including interleukin (IL)-8, TNF-α, IL-6, inducible NOS (iNOS) and IFN-γ. We also demonstrated that GGE03 treatment inhibited the H. pylori-activated NF-κB signaling pathway. In addition, the treatment with GGE03 significantly attenuated nitric oxide production and myeloperoxidase activity in H. pylori-infected gastric epithelial cells. These anti-inflammatory effects of GGE03 were more effective than ginger extract. Finally, we investigated the minimum effective concentration of GGE03 to inhibit H. pylori-induced inflammation. Our findings suggest that GGE03 not only inhibits the growth of H. pylori, but also attenuates H. pylori-induced inflammation.

Overview of Helicobacter pylori Infection: Clinical Features, Treatment, and Nutritional Aspects

Helicobacter pylori (H. pylori) is a 0.5-1 µm wide, 2-4 µm long, short helical, S-shaped Gram-negative microorganism. It is mostly found in the pyloric region of the stomach and causes chronic gastric infection. It is estimated that these bacteria infect more than half of the world's population. The mode of transmission and infection of H. pylori is still not known exactly, but the faecal-oral and oral-oral routes via water or food consumption are thought to be a very common cause. In the last three decades, research interest has increased regarding the pathogenicity, microbial activity, genetic predisposition, and clinical treatments to understand the severity of gastric atrophy and gastric cancer caused by H. pylori. Studies have suggested a relationship between H. pylori infection and malabsorption of essential micronutrients, and noted that H. pylori infection may affect the prevalence of malnutrition in some risk groups. On the other hand, dietary factors may play a considerably important role in H. pylori infection, and it has been reported that an adequate and balanced diet, especially high fruit and vegetable consumption and low processed salty food consumption, has a protective effect against the outcomes of H. pylori infection. The present review provides an overview of all aspects of H. pylori infection, such as clinical features, treatment, and nutrition.

Helicobacters and cancer, not only gastric cancer?

The Helicobacter genus actually comprises 46 validly published species divided into two main clades: gastric and enterohepatic Helicobacters. These bacteria colonize alternative sites of the digestive system in animals and humans, and contribute to inflammation and cancers. In humans, Helicobacter infection is mainly related to H. pylori, a gastric pathogen infecting more than half of the world's population, leading to chronic inflammation of the gastric mucosa that can evolve into two types of gastric cancers: gastric adenocarcinomas and gastric MALT lymphoma. In addition, H. pylori but also non-H. pylori Helicobacter infection has been associated with many extra-gastric malignancies. This review focuses on H. pylori and its role in gastric cancers and extra-gastric diseases, as well as malignancies induced by non-H. pylori Helicobacters. Their different virulence factors and their involvement in carcinogenesis is discussed. This review highlights the importance of both gastric and enterohepatic Helicobacters in gastrointestinal and liver cancers.

Anti-Helicobacter pylori Activity of Artemisia ludoviciana subsp. mexicana and Two of Its Bioactive Components, Estafiatin and Eupatilin

Artemisia ludoviciana subsp. mexicana has been traditionally used for the treatment of digestive ailments such as gastritis, whose main etiological agent is Helicobacter pylori. In a previous screening study, the aqueous extract exhibited a good in vitro anti-H. pylori activity. With the aim of determining the efficacy of this species as a treatment for H. pylori related diseases and finding bioactive compounds, its aqueous extract was subjected to solvent partitioning and the fractions obtained were tested for their in vitro anti-H. pylori effect, as well as for their in vivo gastroprotective and anti-inflammatory activities. The aqueous extract showed a MIC = 250 µg/mL. No acute toxicity was induced in mice. A gastroprotection of 69.8 ± 3.8%, as well as anti-inflammatory effects of 47.6 ± 12.4% and 38.8 ± 10.2% (by oral and topical administration, respectively), were attained. Estafiatin and eupatilin were isolated and exhibited anti-H. pylori activity with MBCs of 15.6 and 31.2 µg/mL, respectively. The finding that A. ludoviciana aqueous extract has significant anti-H. pylori, gastroprotective and anti-inflammatory activities is a relevant contribution to the ethnopharmacological knowledge of this species. This work is the first report about the in vivo gastroprotective activity of A. ludoviciana and the anti-H. pylori activity of eupatilin and estafiatin.

Isolation Method and Characterization of Outer Membranes Vesicles of Helicobacter pylori Grown in a Chemically Defined Medium

Outer membrane vesicles (OMVs) are small vesicles constitutively shed by all Gram-negative bacterium, which have been proposed to play a role in Helicobacter pylori persistence and pathogenesis. The methods currently available for the isolation of H. pylori OMVs are diverse and time-consuming, raising the need for a protocol standardization, which was the main aim of this study. Here, we showed that the chemically defined F12 medium, supplemented with cholesterol, nutritionally supports bacterial growth and maintains H. pylori viability for at least 72 h. Additionally, we developed an abridged protocol for isolation of OMVs from these bacterial cultures, which comprises a low-speed centrifugation, supernatant filtration through a 0.45 μm pore, and two ultracentrifugations for OMVs’ recovery and washing. Using this approach, a good yield of highly pure bona fide OMVs was recovered from cultures of different H. pylori strains and in different periods of bacterial growth, as assessed by nanoparticle tracking analysis, transmission electron microscopy (TEM), and proteomic analyses, confirming the reliability of the protocol. Analysis of the proteome of OMVs isolated from H. pylori F12-cholesterol cultures at different time points of bacterial growth revealed differentially expressed proteins, including the vacuolating cytotoxin VacA. In conclusion, this work proposes a time- and cost-efficient protocol for the isolation of H. pylori OMVs from a chemically defined culture medium that is suitable for implementation in research and in the biopharmaceutical field.

Differences in glycated hemoglobin levels and cholesterol levels in individuals with diabetes according to Helicobacter pylori infection

This study examined differences in glycated hemoglobin (HbA1c), fasting plasma glucose and cholesterol levels between H. pylori infected and uninfected persons with diabetes. Anonymized data of Maccabi Healthcare Services in Israel were analyzed, of 12,207 individuals (50.0% H. pylori positive) aged 25–95 years who underwent the urea breath test. The data included HbA1c, fasting plasma glucose and cholesterol levels. The inverse probability of treatment weighting approach was used to account for confounders. Differences between individuals who were H. pylori positive and negative, in HbA1c (> or ≤ 7.0%) and in cholesterol levels were assessed using weighted generalized estimating equations. For men, but not women, the likelihood of having HbA1c > 7.0% was increased in those infected than uninfected with H. pylori: prevalence ratio 1.11 (95% CI 1.00, 1.24), P = 0.04. For both sexes, total cholesterol (P = 0.004) and low-density lipoprotein (LDL) levels (P = 0.006) were higher among those infected than uninfected with H. pylori. No significant differences were found in glucose and HDL levels according to H. pylori infection. The results were consistent in unweighted multivariable analyses. In conclusion, H. pylori infection might be related to worse glycemic control in men, and higher total cholesterol and LDL cholesterol levels in both sexes.

The TNF-A-857*T Polymorphism is Associated with Gastric Adenocarcinoma Risk in a Costa Rican Population

BACKGROUND

Costa Rica is ranked as one of the countries with highest incidence of gastric cancer worldwide. Previous studies in Costa Rican populations have revealed associations between gastric cancer risk and several cytokine polymorphisms that seem to play a role in the regulation of the expression of these proteins. In this study, we assessed associations of the polymorphisms IL-6-174 G/C, IFNGR1-56 C/T, IL-8-251 T/A and TNF-A (-857 C/T, -308 A/G) with gastric pathologies in a high-risk population of Latin America.

METHODS

DNA samples of 47 patients with gastric adenocarcinoma, 53 with chronic gastritis, 56 with duodenal ulcer and 94 healthy controls, were genotyped for the five mentioned SNPs. All participants were ≥50-years-old. Genotyping was performed by PCR-RFLP and 5'-nuclease PCR assay. H. pylori infection, CagA status, pepsinogen (PG) I and II blood levels were determined by ELISA. Logistic regression analysis was used to determine possible associations of the polymorphisms with cancer, gastritis and duodenal ulcer, and linear regression analysis to determine associations with blood PG levels.

RESULTS

A total of 86.6% of the population was positive for H. pylori; of them, 51.6% was CagA+. Patients with the TNF-A-857*T allele had an increased risk for gastritis (OR: 3.67, p = 0.015) and gastric adenocarcinoma (OR:6.15, p = 0.001). Associations between other polymorphisms and gastric diseases, or PG levels, were not found.

CONCLUSIONS

Our results indicate that the TNF-A-857*T SNP is among the risk factors associated with the risk of gastric cancer in Costa Rica.

Gastric Metabolomics Detects Helicobacter pylori Correlated Loss of Numerous Metabolites in Both the Corpus and Antrum

Helicobacter pylori is a chronic bacterial pathogen that thrives in several regions of the stomach, causing inflammation that can vary by site and result in distinct disease outcomes. Whether the regions differ in terms of host-derived metabolites is not known. We thus characterized the regional variation of the metabolomes of mouse gastric corpus and antrum organoids and tissue. The uninfected secreted organoid metabolites differed between the corpus and antrum in only seven metabolites as follows: lactic acid, malic acid, phosphoethanolamine, alanine, uridine, glycerol, and isoleucine. Several of the secreted chemicals were depleted upon H. pylori infection in both regions, including urea, cholesterol, glutamine, fumaric acid, lactic acid, citric acid, malic acid, and multiple nonessential amino acids. These results suggest a model in which H. pylori preferentially uses carboxylic acids and amino acids in complex environments, and these are found in both the corpus and antrum. When organoid metabolites were compared to mouse tissue, there was little overlap. The tissue corpus and antrum metabolomes were distinct, including antrum-elevated 5-methoxytryptamine, lactic acid, and caprylic acid, and corpus-elevated phospholipid products. The corpus and antrum remained distinct over an 8-month infection time course. The antrum displayed no significant changes between the time points in contrast to the corpus, which exhibited metabolite changes that were consistent with stress, tissue damage, and depletion of key nutrients, such as glutamine and fructose-6-phosphate. Overall, our results suggest that the corpus and antrum have largely but not completely overlapping metabolomes that change moderately upon H. pylori infection.

Impact of Helicobacter pylori Infection and Its Major Virulence Factor CagA on DNA Damage Repair

Helicobacter pylori infection induces a plethora of DNA damages. Gastric epithelial cells, in order to maintain genomic integrity, require an integrous DNA damage repair (DDR) machinery, which, however, is reported to be modulated by the infection. CagA is a major H. pylori virulence factor, associated with increased risk for gastric carcinogenesis. Its pathogenic activity is partly regulated by phosphorylation on EPIYA motifs. Our aim was to identify effects of H. pylori infection and CagA on DDR, investigating the transcriptome of AGS cells, infected with wild-type, ΔCagA and EPIYA-phosphorylation-defective strains. Upon RNA-Seq-based transcriptomic analysis, we observed that a notable number of DDR genes were found deregulated during the infection, potentially resulting to base excision repair and mismatch repair compromise and an intricate deregulation of nucleotide excision repair, homologous recombination and non-homologous end-joining. Transcriptome observations were further investigated on the protein expression level, utilizing infections of AGS and GES-1 cells. We observed that CagA contributed to the downregulation of Nth Like DNA Glycosylase 1 (NTHL1), MutY DNA Glycosylase (MUTYH), Flap Structure-Specific Endonuclease 1 (FEN1), RAD51 Recombinase, DNA Polymerase Delta Catalytic Subunit (POLD1), and DNA Ligase 1 (LIG1) and, contrary to transcriptome results, Apurinic/Apyrimidinic Endodeoxyribonuclease 1 (APE1) upregulation. Our study accentuates the role of CagA as a significant contributor of H. pylori infection-mediated DDR modulation, potentially disrupting the balance between DNA damage and repair, thus favoring genomic instability and carcinogenesis.

Efficacy of quadruple regimen with polaprezinc for gastric Helicobacter pylori infection eradication: protocol for a single-centre, single-blind, non-inferiority, randomised clinical trial

INTRODUCTION

Helicobacter pylori (H. pylori) is the most well-known risk factor for gastric cancer. At present, H. pylori shows varying levels of resistance to different treatments, leading to a lower rate of H. pylori eradication. The aim of this study is to evaluate the efficacy of polaprezinc-containing quadruple therapy (PQT) for the eradication of H. pylori infection and, thus, to provide more evidence to inform the clinical treatment of H. pylori infection in China.

METHODS AND ANALYSIS

This is a single-centre, single-blind, non-inferiority, randomised controlled trial, enrolling 158 patients with H. pylori infection. Patients are randomised (1:1) to the two groups for a 14-day therapy. Treatment group: PQT (esomeprazole 20 mg, amoxicillin 1 g, clarithromycin 500 mg, polaprezinc 75 mg) two times per day; control group: bismuth-containing quadruple therapy (esomeprazole 20 mg, amoxicillin 1 g, clarithromycin 500 mg, bismuth potassium citrate 220 mg) two times per day. The primary outcome is the rate of H. pylori eradication. Secondary outcomes are the incidence of adverse events and the gastrointestinal microbiota distribution. The 16S ribosomal RNA (16S rRNA) next-generation sequencing (NGS) is used to evaluate the effect of two different therapies on the distribution of the gastrointestinal microbiota.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Sichuan Cancer Center & Hospital (No. SCCHEC-02-2019-015). Any amendment to the research protocol will be submitted for ethical approval. All participants must provide informed consent. On completion, the results of the study will be published in the appropriate peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ChiCTR1900025800; preresults.

NF-κB/miR-18a-3p and miR-4286/BZRAP1 axis may mediate carcinogenesis in Helicobacter pylori-Associated gastric cancer

Helicobacter pylori infection is an important pathogenic risk factor for gastric cancer, but it is still unclear what tumor markers for gastric cancer induced by H. pylori can be consistently detected. Using an miRNA microarray, we found that miR-18a-3p (6.02-fold) and miR-4286 (5.73-fold) were significantly increased in H. pylori- associated gastric cancer. In a cohort of gastric cancer patients (N = 104), serum expression of miR-18a-3p and miR-4286 was positively and significantly correlated with H. pylori; furthermore, miR-18a-3p was positively correlated with invasion (P = 0.029), and miR-4286 was positively correlated with tumor stage (P = 0.033), tumor size (P = 0.041), and lymph node metastasis (P = 0.009). Overexpression of miR-18a-3p and miR-4286 also increased cancer cell proliferation and motility and both inhibited expression of BZRAP1, resulting in tumor progression in vitro. In addition, lipopolysaccharide co-mediated the expression of miR-18a-3p and miR-4286 by activating the NF-κB transcription factor, but TAK-242 (TLR4 inhibitor) blocked this effect. These results demonstrate that serum miR-18a-3p and miR-4286 levels in H. pylori-associated gastric cancer may be useful prognostic biomarkers and suggest a novel signaling pathway of targeting BZRAP1 in gastric cancer.

Souto E, Cardoso JC. Red Propolis and Its Dyslipidemic Regulator Formononetin: Evaluation of Antioxidant Activity and Gastroprotective Effects in Rat Model of Gastric Ulcer

Propolis has various pharmacological properties of clinical interest, and is also considered a functional food. In particular, hydroalcoholic extracts of red propolis (HERP), together with its isoflavonoid formononetin, have recognized antioxidant and anti-inflammatory properties, with known added value against dyslipidemia. In this study, we report the gastroprotective effects of HERP (50–500 mg/kg, p.o.) and formononetin (10 mg/kg, p.o.) in ethanol and non-steroidal anti-inflammatory drug-induced models of rat ulcer. The volume, pH, and total acidity were the evaluated gastric secretion parameters using the pylorus ligature model, together with the assessment of gastric mucus contents. The anti-Helicobacter pylori activities of HERP were evaluated using the agar-well diffusion method. In our experiments, HERP (250 and 500 mg/kg) and formononetin (10 mg/kg) reduced (p < 0.001) total lesion areas in the ethanol-induced rat ulcer model, and reduced (p < 0.05) ulcer indices in the indomethacin-induced rat ulcer model. Administration of HERP and formononetin to pylorus ligature models significantly decreased (p < 0.01) gastric secretion volumes and increased (p < 0.05) mucus production. We have also shown the antioxidant and anti-Helicobacter pylori activities of HERP. The obtained results indicate that HERP and formononetin are gastroprotective in acute ulcer models, suggesting a prominent role of formononetin in the effects of HERP.

Dissecting the Helicobacter pylori-regulated transcriptome of B cells

Persistent infections with the bacterial group-I carcinogen Helicobacter pylori (H. pylori) have been associated with a broad range of gastric disorders, including gastritis, ulceration, gastric cancer or mucosa-associated lymphoid tissue (MALT) lymphoma. Pathogenesis of H. pylori requires a balance between immune tolerance and defense. Although H. pylori induces inflammatory responses, the immune system cannot eliminate the pathogen. The detailed molecular mechanisms of how H. pylori interferes with cells of the immune system, in particular infiltrated B cells, are not well investigated. Previously, it was shown that the bacterial effector and oncoprotein cytotoxin-associated gene A (CagA) is delivered into B cells followed by its tyrosine-phosphorylation. To investigate the functional consequences in B cells colonized by CagA-positive H. pylori, we analyzed the global transcriptome of H. pylori-infected Mec-1 cells by RNA sequencing. We found 889 differentially expressed genes (DEGs) and validated JUN, FOSL2, HSPA1B, SRC, CXCR3, TLR-4, TNF-α, CXCL8, CCL2, CCL4, MHC class I and MHC class II molecules by qPCR, western blot, flow cytometry and ELISA assays. The H. pylori-specific mRNA expression signature reveals a downregulation of inflammation- and migration-associated genes, whereas central signal transduction regulators of cell survival and death are upregulated.

Risk of subsequent prostate cancer in peptic ulcer patients who received helicobacter pylori eradication therapy: an Asian population-based cohort study

Background

Studies have shown diverse results regarding the association between H. pylori (HP) infection and the risk of malignancy. There is accumulating evidence relating HP infection to urological diseases. We investigated whether there was an association between HP-infected peptic ulcers and the subsequent risk of prostate cancer.

Methods

We collected HP-infected male patients from 1998 to 2008 from the Longitudinal Health Insurance Database (LHID). HP-infected patients were identified as those who had a diagnosis of peptic ulcers upon admission and received HP eradication therapy within 1 year after diagnosis. The date of HP infection diagnosis upon admission was defined as the index date. Patients aged < 20 years or with a cancer history were excluded. For each HP-infected patient, we selected four males without peptic ulcers or a history of HP eradication in the LHID for the comparison cohort according to propensity score matching by age, index year, and comorbidity. The risk of prostate cancer and associated risk factors was assessed by Cox proportional hazard regression.

Results

A total of 2620 HP infection treatment patients and 10,480 matched comparisons were selected. There were 36 patients in the HP-infected treatment cohort and 117 patients in the comparison cohort with documented prostate cancer development (1.52 and 1.21 per 1000 person-years, respectively). Compared to the comparison cohort, the HP infection cohort had a 1.26-fold increased prostate cancer risk in the Cox models after adjusting for matched-pairs (95% CI = 0.87–1.34). There were no significant differences in subsequent prostate cancer development between HP-infected treatment patients and the comparison cohort.

Conclusion

Our findings showed no significant association between HP-infected peptic ulcers and the subsequent risk of prostate cancer. Further studies are warranted to investigate whether this observation is attributable to an HP eradication policy.

Protective effects of Helicobacter pylori membrane vesicles against stress and antimicrobial agents

Outer-membrane vesicles (OMVs) produced by Helicobacter pylori deliver bacterial components to host cells, provide a mechanism for stabilization of secreted components and may allow the bacteria to exert 'long-range' effects in the gastric niche, promoting persistence. In addition to their well-characterized host cell interactions, membrane vesicles improve stress survival in other bacterial species, and are constitutively produced by both pathogenic and non-pathogenic bacteria. We aimed to determine whether OMVs could improve H. pylori survival of a range of stressors. The effects of purified OMVs on the resistance of H. pylori to a range of environmental and antimicrobial stresses were determined using growth curves and survival assays. Addition of purified OMVs to H. pylori cultures provided dose-dependent protection against hydrogen peroxide-mediated killing. Supplementation with OMVs also partially protected H. pylori against the bactericidal effects of the antibiotics clarithromycin and levofloxacin, but not against amoxicillin nor metronidazole. Addition of purified OMVs allowed H. pylori to grow in the presence of inhibitory concentrations of the antimicrobial peptide LL-37. In the presence of 50 µg OMVs ml-1, significantly enhanced H. pylori growth was observed at higher LL-37 concentrations compared with lower LL-37 concentrations, suggesting that OMV-LL-37 interactions might facilitate release of growth-promoting nutrients. Taken together, these data indicate that production of membrane vesicles could help H. pylori to survive exposure to antibiotics and host antimicrobial defences during infection.

Helicobacter pylori infection, a risk factor for Type 2 diabetes mellitus: a hospital-based cross-sectional study among dyspeptic patients in Douala-Cameroon

Diabetic mellitus patients are usually prone to chronic infections. However, there have been contradictory reports about the association between H. pylori infection and type II diabetes. The present study is aimed at evaluating the prevalence of Helicobacter pylori infection among type 2 dyspeptic diabetic patients in the littoral region of Cameroon. This cross sectional study comprised 93 type 2 diabetic dyspeptic patients and 112 non-diabetic dyspeptic patients attending the Gastroenterology Department at two reference hospitals in Douala-Cameroon. The study was approved by the local Ethical Committee of Medical Sciences. Participants were screened for the presence of both type 2 diabetes and H. pylori infection. Body mass index (BMI) of all the participants was also recorded. Data was analyzed using SSPS statistical package. H. pylori infection was found in 73.11% of diabetic patients versus 58.05% in non-diabetic participants, this difference was found to be significant (OR = 1.472, p = 0.0279). This relationship persists even when adjusted to factors such as age and income level of participants. Infected participants from age group ≥ 55 years and those with high income were those with a higher risk to develop diabetes. Infected patients with high BMI were more prone to develops diabetic mellitus compared with infected patients with normal BMI (p = 0.0034). Also, participant with high BMI were more prone to develops diabetic mellitus whether they were infected or not. Patients having both H. pylori + ve and BMI ≥ 25 kg/m2 were significantly more affected by diabetic mellitus than those in the others combined groups (p < 0.0001), suggested that high BMI and H. pylori infection together or not are factors that favor diabetes mellitus development. Separately or not, H. pylori infection and high BMI were risk factor for diabetes mellitus in our milieu.