Pathogenesis of Helicobacter pylori infection

From Primary Data to Ethnopharmacological Investigations on Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson as a Remedy against Gastric Ailments in Valmalenco (Italy)

(1) Background: Within the framework of the European Interreg Italy-Switzerland B-ICE & Heritage project (2018-2022), this study originated from a three-year ethnobotanical survey in Valmalenco (Sondrio, Italy). Following a preliminary work published by our group, this research further explored the folk therapeutic use of Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (Asteraceae) for dyspepsia disorders, specifically its anti-inflammatory potential at a gastrointestinal level. (2) Methods: Semi-structured interviews were performed. The bitter taste was investigated through molecular docking software (PLANTS, GOLD), while the anti-inflammatory activity of the hydroethanolic extract, infusion, and decoction was evaluated based on the release of IL-8 and IL-6 after treatment with TNFα or Helicobacter pylori. The minimum inhibitory concentration and bacterial adhesion on the gastric epithelium were evaluated. (3) Results: In total, 401 respondents were interviewed. Molecular docking highlighted di-caffeoylquinic acids as the main compounds responsible for the interaction with bitter taste receptors. The moderate inhibition of IL-6 and IL-8 release was recorded, while, in the co-culture with H. pylori, stronger anti-inflammatory potential was expressed (29-45 μg/mL). The concentration-dependent inhibition of H. pylori growth was recorded (MIC = 100 μg/mL), with a significant anti-adhesive effect. (4) Conclusions: Confirming the folk tradition, the study emphasizes the species' potentiality for dyspepsia disorders. Future studies are needed to identify the components mostly responsible for the biological effects.

Exploring In Vitro the Combination of Cistus × incanus L. and Castanea sativa Mill. Extracts as Food Supplement Ingredients against H. pylori Infection

Cistus spp. have been traditionally used for inflammatory and infectious disorders, including gastrointestinal ailments, in the Mediterranean area. Among them, Cistus × incanus L. is one of the most frequently cited species in the literature for a variety of biological activities which include inflammatory diseases. Cistus spp. aerial parts are rich in polyphenols such as condensed and hydrolysable tannins, procyanidins, and flavonoids, which show gastroprotective activities. The purpose of the present study is to investigate the biological activities of a hydroalcoholic extract from Cistus × incanus L. aerial parts in gastric epithelial cells (GES-1) infected with H. pylori. The extracts inhibited IL-8 and NF-κB induced by H. pylori and showed antibacterial activity after simulated digestion. Since our previous paper reported interesting results on the ability of Castanea sativa Mill. leaf extract to decrease inflammatory conditions in H. pylori-infected gastric cells, the combination of Castanea sativa and Cistus × incanus extracts was also investigated, showing strong anti-inflammatory activity and inhibition of bacterial adhesion. This association of botanicals is proposed herein as a novel food supplement capable of counteracting gastric inflammatory conditions.

The correlation between helicobacter pylori and idiopathic achalasia: A case control study

Background

Idiopathic achalasia is a common and well-recognized primary esophageal motility disorder with unknown etiology and is characterized by the abnormality of esophageal body peristalsis associated with an impaired relaxation of the lower esophageal sphincter (LES). The aim of this study is to explore the correlation between Helicobacter pylori and idiopathic achalasia.

Methods

This study was conducted on 700 patients, with dysphagia, regurgitation, and non-cardiac chest pain (NCCP), who met our inclusion criteria. The mean ± SD age was 39.8 ± 11 (13-80 years), and 60% (420) of the participants were female. Of the participants, 108 had idiopathic achalasia and 105 were normal participants who were placed in the case and control groups, respectively. They were enrolled in the study based on high-resolution manometry. H. pylori was confirmed by a histological study. In the biopsy, specimens were taken by esophagogastroduodenoscopy.

Results

Our results revealed that 71.3% and 45% of the participants were H. Pylori positive in the case and control groups, respectively. The odds ratio (OR) was 3.3 (95% CI: 1.80-5.99, P < 0.05), indicating a statistically significant association between H. Pylori infection and the group classification. The dominant presenting symptoms in achalasia were dysphagia (97.2%) and NCCP (80.5%), but regurgitation (65.7%) was a dominant symptom in the normal participants.

Conclusions and Inferences

Diverse autoimmune and apoptotic phenomena induced by H. Pylori influence the pathogenesis of idiopathic achalasia, suggesting an underlying link between H. Pylori infection and idiopathic achalasia. This correlation should be confirmed by other clinical and experimental studies.

Helicobacter pylori intragastric colonization and migration: Endoscopic manifestations and potential mechanisms

After being ingested and entering the human stomach, Helicobacter pylori (H. pylori) adopts several effective strategies to adhere to and colonize the gastric mucosa and move to different regions of the stomach to obtain more nutrients and escape from the harsher environments of the stomach, leading to acute infection and chronic gastritis, which is the basis of malignant gastric tumors. The endoscopic manifestations and pathological features of H. pylori infection are diverse and vary with the duration of infection. In this review, we describe the endoscopic manifestations of each stage of H. pylori gastritis and then reveal the potential mechanisms of bacterial intragastric colonization and migration from the perspective of endoscopists to provide direction for future research on the effective therapy and management of H. pylori infection.

The Associations between Helicobacter Pylori immunoglobulin G seropositivity and body mass index in adults

OBJECTIVES

Inconsistent evidence currently exists regarding the associations between Helicobacter Pylori (H. pylori) infection and body mass index (BMI). The goal of the current study was to examine independent associations of H. pylori immunoglobulin G (IgG) seropositivity and BMI in a U.S.-based population sample.

METHODS

The US National Health and Nutrition Examination Survey (NHANES) with 2,576 subjects from 1999 to 2000 were analyzed. Using multivariate logistic regression models, associations between H. pylori IgG seropositivity and BMI were calculated after potential confounders were taken into account. Subgroup analyses were conducted furtherly stratified by sex, age, and race.

RESULTS

H. pylori IgG seropositivity was not associated with BMI in the general population (OR = 0.998; 95% CI = 0.977-1.019; P = 0.842). In the subgroup analyses stratified by race, a negative correction was found between the H. pylori IgG seropositivity and BMI among other races (OR = 0.873; 95% CI = 0.795-0.959; P = 0.004) except non-Hispanic white (OR = 1.006, 95% CI 0.966 to 1.048, P = 0.762), non-Hispanic black (OR = 1.021, 95% CI 0.979 to 1.065, P = 0.335), and Mexican American (OR = 1.010, 95% CI 0.966 to 1.055, P = 0.665).

CONCLUSIONS

In the general population, H. pylori IgG seropositivity is not associated with increased BMI, which provides a new perspective on obesity management.

Ellagitannins from Castanea sativa Mill. Leaf Extracts Impair H. pylori Viability and Infection-Induced Inflammation in Human Gastric Epithelial Cells

Helicobacter pylori (H. pylori) is an etiologic factor of peptic ulcer disease and gastric cancer. Virulent strains of H. pylori are correlated with the severity of gastritis, due to NF-κB activation and IL-8 expression at the epithelial level. Ellagitannins have been documented for antibacterial and anti-inflammatory activities, thus suggesting their potential use in gastritis. Recently, several authors, including our group, demonstrated that tannin-rich extracts from chestnut byproducts, at present considered agricultural waste, display promising biological activities. In this work, we detected high levels of polyphenols in hydroalcoholic extracts from chestnut leaves (Castanea sativa L.). Among polyphenols, the ellagitannin isomers castalagin and vescalagin (about 1% w/w of dry extract) were identified as potential bioactive compounds. In GES-1 cells infected by H. pylori, leaf extract and pure ellagitannins inhibited IL-8 release (IC₅₀ ≈ 28 µg/mL and 11 µM, respectively). Mechanistically, the anti-inflammatory activity was partly due to attenuation of NF-κB signaling. Moreover, the extract and pure ellagitannins reduced bacterial growth and cell adhesion. A simulation of the gastric digestion suggested that the bioactivity might be maintained after oral administration. At the transcriptional level, castalagin downregulated genes involved in inflammatory pathways (NF-κB and AP-1) and cell migration (Rho GTPase). To the best of our knowledge, this is the first investigation in which ellagitannins from plant extracts have demonstrated a potential role in the interaction among H. pylori and human gastric epithelium.

Relationship of Helicobacter pylori Infection with Nonalcoholic Fatty Liver Disease: A Meta-Analysis

BACKGROUND AND AIMS

Helicobacter pylori (H. pylori) and nonalcoholic fatty liver disease (NAFLD) have become increasingly recognized, both of which affect human health globally. The association of H. pylori infection with NAFLD remains unclear.

METHODS

PubMed, EMBASE, and Cochrane Library databases were searched. Only a random-effects model was used. Odds ratios (ORs) and risk ratios (RRs) with 95% confidence intervals (CIs) were calculated for the combined estimates of raw data. Adjusted ORs (aORs) and hazard ratios (aHRs) with 95% CIs were calculated for the combined estimates of data adjusted for confounders.

RESULTS

Thirty-four studies with 218573 participants were included. Based on unadjusted data from 26 cross-sectional studies and 3 case-control studies, H. pylori infection was significantly associated with the presence of NAFLD (OR = 1.26, 95% CI = 1.17-1.36, P < 0.001). Based on adjusted data from 15 cross-sectional studies and 1 case-control study, H. pylori infection was significantly associated with the presence of NAFLD (aOR = 1.25, 95% CI = 1.08-1.44, P < 0.001). Compared with control subjects without NAFLD, patients with moderate (OR = 1.67, 95% CI = 1.17-2.39, P = 0.005) and severe (OR = 1.71, 95% CI = 1.30-2.24, P < 0.001) NAFLD, but not those with mild NAFLD (OR = 1.14, 95% CI = 0.9-1.45, P = 0.286), had significantly higher proportions of H. pylori infection. The association of H. pylori infection with the occurrence of NAFLD was statistically significant based on adjusted data from 3 cohort studies (aHR = 1.18, 95% CI = 1.05-1.34, P = 0.007), but not based on unadjusted data from 3 cohort studies (RR = 1.41, 95% CI = 0.80-2.48, P = 0.237).

CONCLUSION

H. pylori infection is associated with NAFLD, especially moderate and severe NAFLD. The impact of H. pylori eradication on the prevention of NAFLD should be further explored.

AI-2 Induces Urease Expression Through Downregulation of Orphan Response Regulator HP1021 in Helicobacter pylori

Helicobacter pylori causes gastric infections in more than half of the world's population. The bacterium's survival in the stomach is mediated by the abundant production of urease to enable acid acclimation. In this study, our transcriptomic analysis demonstrated that the expression of urease structural proteins, UreA and UreB, is induced by the autoinducer AI-2 in H. pylori. We also found that the orphan response regulator HP1021 is downregulated by AI-2, resulting in the induction of urease expression. HP1021 represses the expression of urease by directly binding to the promoter region of ureAB, ranging from −47 to +3 with respect to the transcriptional start site. The study findings suggest that quorum sensing via AI-2 enhances acid acclimation when bacterial density increases, and might enable bacterial dispersal to other sites when entering gastric acid.

Helicobacter pylori Pathogenicity Islands and Giardia lamblia Cysteine Proteases in Role of Coinfection and Pathogenesis

Helicobacter pylori is a well-known human-specific stomach pathogen that infects more than half of the world’s population. The infection with this bacterium can cause a variety of gastrointestinal problems, including chronic gastritis, peptic ulcers, and even cancer. H. pylori is a highly infectious bacterium. H. pylori causes an increase in gastric mucosa pH or gastric mucosa intestinal metaplasia. These modifications in the stomach environment are necessary for G. lamblia colonization to occur. Giardia lamblia is a flagellate protozoan parasite that can cause giardiasis in humans and other mammals. It dwells in the duodenum and upper jejunum. Globally, over 280 million cases of human giardiasis are predicted to occur each year. Simultaneous human colonization by G. lamblia and H. pylori is a typical occurrence since the viruses’ predisposing factors are similar in both groups. Giardiasis is a parasitic infection that affects both children and adults worldwide. Infection with Giardia is more common in underdeveloped countries. Globally, more than 200 million cases of giardiasis are detected each year. In contrast, the presence of G. lamblia in the host body triggers an immunological response comparable to that of H. pylori, with lymphocytes strongly polarized towards Th1. As a result, their combined presence exacerbates host tissue damage. The major goal of this seminar is to describe the pathophysiology, immunology, and clinical aspects of G. lamblia and H. pylori coinfection using a comprehensive search of PubMed, Lancet, and Google Scholar sources. Upper gastrointestinal problems such as upper abdominal pain, abdominal bloating, nausea, vomiting, epigastric pain/burning, and belching are all caused by both organisms. Differentiation by physical examination is impossible in people infected with both bacteria. For this coinfection distinction, a laboratory diagnosis is required. G. lamblia and H. pylori, when present together, have a synergistic effect on the host and can cause serious damage. As a result, researchers should delve deeper into the mechanics underlying this potential microbial interaction.

Association between Helicobacter pylori infection and irritable bowel syndrome: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori infection and irritable bowel syndrome (IBS) negatively affect the quality of life. Some previous studies found that H. pylori infection should be positively associated with the risk of IBS, but others did not. The present study aims to clarify this association, and to further analyse whether H. pylori treatment can improve IBS symptoms.

MATERIALS AND METHODS

The PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure, China Science and Technology Journal and Wanfang databases were searched. Meta-analysis was performed using a random-effect model. The pooled odds ratios (ORs)/risk ratios (RRs) and their 95% CIs were calculated. Heterogeneity was evaluated using the Cochran's Q test and I² statistics. Meta-regression analysis was used to explore the sources of heterogeneity.

RESULTS

Thirty-one studies with 21 867 individuals were included. Meta-analysis of 27 studies found that patients with IBS had a significantly higher risk of H. pylori infection than those without (OR=1.68, 95% CI 1.29 to 2.18; p<0.001). The heterogeneity was statistically significant (I^²=85%; p<0.001). Meta-regression analyses indicated that study design and diagnostic criteria of IBS might be the potential sources of heterogeneity. Meta-analysis of eight studies demonstrated that H. pylori eradication treatment had a higher improvement rate of IBS symptoms (RR=1.24, 95% CI 1.10 to 1.39; p<0.001). The heterogeneity was not significant (I^²=32%; p=0.170). Meta-analysis of four studies also demonstrated that successful H. pylori eradication had a higher improvement rate of IBS symptoms (RR=1.25, 95% CI 1.01 to 1.53; p=0.040). The heterogeneity was not significant (I^²=1%; p=0.390).

CONCLUSION

H. pylori infection is associated with an increased risk of IBS. H. pylori eradication treatment can improve IBS symptoms.

Colostrum IgA1 antibodies recognize antigens from Helicobacter pylori and prevent cytoskeletal changes in human epithelial cells

Helicobacter pylori is a gram-negative bacterium found on the luminal surface of the gastric mucosa in at least 50% of the world's human population. The protective effect of breastfeeding against H. pylori infection has been extensively reported; however, the mechanisms behind this protection remain poorly understood. Human IgA from colostrum has reactivity against H. pylori antigens. Despite that IgA1 and IgA2 display structural and functional differences, their reactivity against H. pylori had not been previously determined. We attested titers and reactivity of human colostrum-IgA subclasses by ELISA, immunoblot, and flow cytometry. Colostrum samples from healthy mothers had higher titers of IgA; and IgA1 mostly recognized H. pylori antigens. Moreover, we found a correlation between IgA1 reactivity and their neutralizing effect determined by inhibition of cytoskeletal changes in AGS cells infected with H. pylori. In conclusion, colostrum-IgA reduces H. pylori infection of epithelial gastric cells, suggesting an important role in preventing the bacteria establishment during the first months of life. As a whole, these results suggest that IgA1 from human colostrum provides protection that may help in the development of the mucosal immune system of newborn children. This article is protected by copyright. All rights reserved.

Relationship between Helicobacter pylori infection and nonalcoholic fatty liver disease: What should we expect from a meta-analysis?

BACKGROUND

The relationship between Helicobacter pylori (H. pylori) infection and nonalcoholic fatty liver disease (NAFLD) is a matter of debate. Although it has been studied in many observational studies, the results remain controversial. Therefore, we performed a meta-analysis to assess the association between H pylori infection and risk of NAFLD.

METHODS

We searched Pubmed, EMBASE, and Web of Science databases, from inception to September 10, 2020. Odds ratio (OR) and 95% confidence interval (CI) were pooled by random-effects model. The statistical heterogeneity among studies (I2-index), subgroup analyses, regression analyses, sensitivity analysis and the possibility of publication bias were assessed.

RESULTS

A total of seventeen studies involving 91,958 individuals were included in our meta-analysis. Meta-analysis of data from cross-sectional and case-control studies showed that H pylori infection was associated with increased risk of prevalent NAFLD (n = 15; involving 74,561 middle-aged individuals; OR1.38, 95% CI 1.23-1.55, I2 = 86.8%, P < .001). The results of meta-regression implicated that the study type and the case-control ratio impacted the total effect size. Funnel plot did not show significant publication bias. Meta-analysis of data from longitudinal studies showed that H pylori infection was also associated with increased NAFLD incidence (n = 2; involving 17397 individuals; OR 1.21, 95% CI 1.01-1.44, I2 = 6.5%, P = .301).

CONCLUSIONS

The results indicated that a positive association between H pylori infection and the risk of NAFLD. Further studies are required to strengthen the association and clarify the mechanism.

Diagnostic Value of 14C Urea Breath Test for Helicobacter pylori Detection Compared by Histopathology in Indonesian Dyspeptic Patients

PURPOSE

Histopathology method is often used as a gold standard diagnostic for Helicobacter pylori infection in Indonesia. However, it requires an endoscopic procedure which is limited in Indonesia. A non-invasive method, such as 14C Urea Breath Test (UBT), is more favorable; however, this particular method has not been validated yet.

PATIENTS AND METHODS

A total of 55 dyspeptic patients underwent gastroscopy and 14C-UBT test. We used Heliprobe® UBT for UBT test. As for the histology, May-Giemsa staining of two gastric biopsies (from the antrum and corpus) were evaluated following the Updated Sydney System.

RESULTS

The Receiver Operating Characteristics analysis showed that the optimum cut-off value was 57 with excellence Area under Curve = 0.955 (95% CI = 0.861-1.000). By applying the optimum cut-off value, Heliprobe® UBT showed 92.31% for sensitivity, 97.62% for specificity, 92.31% for positive predictive value, 97.62% for negative predictive value, 38.77 for positive likelihood ratio, 0.0788 for negative likelihood ratio, and 96.36% for the accuracy.

CONCLUSION

The 14C-UBT is an accurate test for H. pylori diagnosis with excellent sensitivity, specificity, and accuracy. The different optimum cut-off points suggested that a validation is absolutely necessary for new test prior application to the new population.

Helicobacter pylori knowledge and perception among multi-ethnic Asians

BACKGROUND

Helicobacter pylori (HP) infection is endemic and causes peptic ulcer disease and gastric cancer. There is a lack of data related to awareness of the general public about HP and associated health risks. The objective of this study was to investigate the awareness and public perceptions about HP and the attitudes towards screening.

METHODS

This cross-sectional study included a structured 19-item questionnaire targeting members of the general public at a restructured acute hospital in Singapore.

RESULTS

Out of 504 participants, 152 (30.2%) were aware of HP. Higher education was associated with HP awareness (p < 0.001, OR 7.4, 95% CI 1.6-32.6). A third, 175 (34.7%) of the respondents identified the stomach as the primary site of infection. 131 (26.0%) respondents identified the fecal-oral route as a mode of transmission. 178 (35.3%) respondents were aware of available screening modalities, with around half of them willing to be screened with blood (n = 256, 50.8%) or breath tests (n = 265, 52.6%). 430 (85.3%) participants were keen to learn more about HP, and this was associated with age (p < 0.05, OR 3.9, 95% CI 2.1-7.1).

CONCLUSION

Awareness about HP infection is low, and acceptance of screening tests is high. Educational efforts are needed to improve awareness.

Genome-wide mutation analysis of Helicobacter pylori after inoculation to Mongolian gerbils

Background

Helicobacter pylori is a pathogenic bacterium that causes various gastrointestinal diseases in the human stomach. H. pylori is well adapted to the human stomach but does not easily infect other animals. As a model animal, Mongolian gerbils are often used, however, the genome of the inoculated H. pylori may accumulate mutations to adapt to the new host. To investigate mutations occurring in H. pylori after infection in Mongolian gerbils, we compared the whole genome sequence of TN2 wild type strain (TN2wt) and next generation sequencing data of retrieved strains from the animals after different lengths of infection.

Results

We identified mutations in 21 loci of 17 genes of the post-inoculation strains. Of the 17 genes, five were outer membrane proteins that potentially influence on the colonization and inflammation. Missense and nonsense mutations were observed in 15 and 6 loci, respectively. Multiple mutations were observed in three genes. Mutated genes included babA, tlpB, and gltS, which are known to be associated with adaptation to murine. Other mutations were involved with chemoreceptor, pH regulator, and outer membrane proteins, which also have potential to influence on the adaptation to the new host.

Conclusions

We confirmed mutations in genes previously reported to be associated with adaptation to Mongolian gerbils. We also listed up genes that mutated during the infection to the gerbils, though it needs experiments to prove the influence on adaptation.

Microbial carcinogenesis: Lactic acid bacteria in gastric cancer

While Helicobacter pylori is a fundamental risk factor, gastric cancer (GC) aetiology involves combined effects of microbial (both H. pylori and non-H. pylori), host and environmental factors. Significant differences exist between the gastric microbiome of those with gastritis, intestinal metaplasia and GC, suggesting that dysbiosis in the stomach is dynamic and correlates with progression to GC. Most notably, a consistent increase in abundance of lactic acid bacteria (LAB) has been observed in GC patients including Streptococcus, Lactobacillus, Bifidobacterium and Lactococcus. This review summarises how LAB can influence GC by a number of mechanisms that include supply of exogenous lactate -a fuel source for cancer cells that promotes inflammation, angiogenesis, metastasis, epithelial-mesenchymal transition and immune evasion-, production of reactive oxygen species and N-nitroso compounds, as well as anti-H. pylori properties that enable colonization by other non-H. pylori carcinogenic pathobionts.

Association between Helicobacter pylori infection and nonalcoholic fatty liver disease: A systematic review and meta-analysis of observational studies

BACKGROUND

The association between Helicobacter pylori (H. pylori) infection and nonalcoholic fatty liver disease (NAFLD) has been shown in many observational studies, but these conclusions remain controversial. Hence, we performed a meta-analysis to elucidate the association.

METHODS

A comprehensive search was conducted on relevant studies published from inception to December 31, 2018, in PubMed, EMBASE, and Web of Science databases. Odds ratio (OR) with 95% confidence interval (95% CI) were pooled by random-effect model, generic inverse variance method. Subgroup and sensitivity analyses were also done. Publication bias was estimated by the funnel plot, Begg's test, and Egger's test.

RESULTS

Fifteen studies (eleven cross-sectional, two case-control, and two cohort studies) were included in this meta-analysis. The pooled OR of NAFLD in patients with H. pylori infection was 1.19 (95% CI: 1.11-1.29, P < 0.00001) when compared with the patients without H. pylori infection. Similar results were observed when the subgroup analyses were stratified by different geographical locations, study designs, and confounders adjustment. In subgroup analysis stratified by different H. pylori testing methods, the correlation still exists when using UBT, serology, RUT, or SAT, but there was no statistically significant difference when using multiple detection methods (OR = 2.96, 95% CI: 0.37-23.94, P = 0.31). Sensitivity analyses showed that our results were robust. No evidence of substantial publication bias was detected.

CONCLUSIONS

Current evidence indicated that a positive association between H. pylori infection and the risk of NAFLD. Further prospective studies are warranted to strengthen the association and to clarify whether there is a causative link between them.

Toll-like receptor 2 and 4 polymorphisms associated with Helicobacter pylori susceptibility and gastric cancer

BACKGROUND/AIMS

Genetic polymorphisms in Toll-like receptors (TLRs) are important influence on gastric lesion development and Helicobacter pylori susceptibility.

MATERIALS AND METHODS

TLR2 rs3804099 and rs3804100 and TLR4 rs10759932 were determined in a total of 400 patients. The association among genotypes and the risk of gastric lesion development and H. pylori susceptibility were evaluated by the odds ratios (ORs) and 95% confidence intervals (95% CIs) from logistic regression analyses.

RESULTS

TLR4 rs10759932, C/C homozygous genotype was associated with an increased risk of premalignant/malignant (OR=2.48, 95% CI=1.96-4.62, p=0.015). The recessive model of TLR4 rs10759932 showed a decreased risk of H. pylori susceptibility (adjusted OR=0.52, 95% CI=0.38-0.82, p=0.046). Meanwhile, the recessive model was associated with an increased risk of non-malignant (OR=3.46, 95% CI=2.25-5.67, p=0.001). In subjects with H. pylori infection, the recessive model was associated with an increased risk of non-malignant (OR=2.28, 95% CI=1.24-3.57, p=0.001) and premalignant/malignant (OR=1.83, 95% CI=1.16-2.84, p=0.027).

CONCLUSION

TLR4 rs10759932, but not TLR2 rs3804099 and rs3804100, was associated with risk of premalignant and/or malignant and H. pylori susceptibility. H. pylori infection seems to contribute to chronic gastritis, and premalignant/malignant supported the development of the premalignant/malignant lesions involved in H. pylori infection that is critical to gastric cancer in Thai patients.

Genetic polymorphisms in TLR1, TLR2, TLR4, and TLR10 of Helicobacter pylori-associated gastritis: a prospective cross-sectional study in Thailand

The toll-like receptors (TLRs) mediate the recognition of Helicobacter pylori and initiate the innate immune response to infection. We hypothesized those genetic polymorphisms in the TLR1, TLR2, TLR4, and TLR10 influence bacterial infection, affecting susceptibility H. pylori to disease outcomes. Genomic DNA was extracted and genotypes of TLR1 (rs4833095), TLR2 (rs3804099 and rs3804100), TLR4(rs10759932), and TLR10 (rs10004195) polymorphism were detected by the TagMan single-nucleotide epolymorphisms genotyping assay using the real-time PCR hybridization probe method. The TLR1 (rs4833095), C allele and the TLR10 (rs10004195), A allele frequency was significantly increased risk in the H. pylori infection group (odds ratio=1.76, 95% confidence interval=1.84–2.15, P=0.01 and odds ratio=1.81, 95% confidence interval=1.18–3.26, P=0.04, respectively). The TLR1 (rs4833095), C allele and TLR10 (rs10004195), A allele are susceptible TLRs polymorphisms in the Thai population. These findings suggest that TLR1 rs4833095 and TLR10 rs10004195 may play crucial roles in H. pylori susceptibility and gastric pathogenesis.

Unraveling the Novel Protective Effect of Patchouli Alcohol Against Helicobacter pylori-Induced Gastritis: Insights Into the Molecular Mechanism in vitro and in vivo

Patchouli alcohol (PA), a natural tricyclic sesquiterpene extracted from Pogostemon cablin (Blanco) Benth. (Labiatae), has been found to exhibit anti-Helicobacter pylori and anti-inflammatory properties. In this study, we investigated the protective effect of PA against H. pylori-induced gastritis in vitro and in vivo, and determined the underlying mechanism. In the in vivo experiment, a C57BL/6 mouse model of gastritis was established using H. pylori SS1, and treatments with standard triple therapy or 5, 10, and 20 mg/kg PA were performed for 2 weeks. Results indicated that PA effectively attenuated oxidative stress by decreasing contents of intracellular reactive oxygen species (ROS) and malonyldialdehyde (MDA), and increasing levels of non-protein sulfhydryl (NP-SH), catalase and glutathione (GSH)/glutathione disulphide (GSSG). Additionally, treatment with PA significantly attenuated the secretions of interleukin 1 beta (IL-1β), keratinocyte chemoattractant and interleukin 6 (IL-6). PA (20 mg/kg) significantly protected the gastric mucosa from H. pylori-induced damage. In the in vitro experiment, GES-1 cells were cocultured with H. pylori NCTC11637 at MOI = 100:1 and treated with different doses of PA (5, 10, and 20 μg/ml). Results indicated that PA not only significantly increased the cell viability and decreased cellular lactate dehydrogenase (LDH) leakage, but also markedly elevated the mitochondrial membrane potential and remarkably attenuated GES-1 cellular apoptosis, thereby protecting gastric epithelial cells against injuries caused by H. pylori. PA also inhibited the secretions of pro-inflammatory factors, such as monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor-α (TNF-α) and IL-6. Furthermore, after PA treatment, the combination of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) and cysteine-aspartic proteases 1 (CASPASE-1), the expression levels of NLRP3 inflammasome-related proteins, such as thioredoxin-interacting protein (TXNIP), pro-CASPASE-1, cle-CASPASE-1, and NLRP3 and genes (NLRP3 and CASPASE1) were significantly decreased as compared to the model group. In conclusion, treatment with PA for 2 weeks exhibited highly efficient protective effect against H. pylori-induced gastritis and related damages. The underlying mechanism might involve antioxidant activity, inhibition of pro-inflammatory factor and regulation of NLRP3 inflammasome function. PA exerted anti-H. pylori and anti-gastritis effects and thus had the potential to be a promising candidate for treatment of H. pylori-related diseases.

Helicobacter pylori in metabolic related diseases

Helicobacter pylori is one of the most common gastrointestinal infection affecting humans worldwide. Hp colonizes the stomach with preferential trophism for the antrum. Hp infection is associated with the development of a chronic gastritis and subsequently with several gastric diseases such as peptic disease, gastric carcinoma and MALT lymphoma. Moreover, Helicobacter pylori infection has also been reported in literature to be associated with many other extra-gastric conditions including sideropenic anemia, thrombocytopenia, neurological, liver and cardiovascular diseases. For some conditions the association is supported by solid literature data and also by the identification of the possible physiopathogenetic mechanism involved. In other cases, the link is only reported by association studies often with conflicting results. In this context, diabetes mellitus, cardiovascular disorders and liver steatosis have all been reported to be associated with Helicobacter pylori infection. Interestingly, these conditions share many characteristics and they often overlap as they represent the expression of the so called metabolic syndrome. Aim of the review was to summarize the available data regarding the association between Helicobacter Pylori infection and diabetes mellitus, cardiovascular disorders and liver steatosis.

Helicobacter pylori therapy and clinical perspective

Helicobacter pylori induces chronic gastritis and duodenal ulcer in a small fraction of the colonised population. Three decades after the discovery of H. pylori and disclosure of an urgent need for eliminating the bacterium in patients, it seems that we are still in the first steps of dealing with this mysterious organism. Treatment of H. pylori is a complex dilemma for clinicians, a repeating sentence by many scientists who spend years on this research topic. Apart from many modifications in initial first-line treatment of H. pylori, gastroenterologists are unable to overcome the problem of therapeutic failure. Choosing the best regimen in any region depends on many factors, which have been the focus of many randomised clinical trials. A potential increase in efficacy of future therapies may be influenced by adding the novel potassium-competitive acid blocker vonoprazan. Undeniably, in-depth analysis is necessary to propose more effective therapeutic regimens. Meanwhile, we recommend the performance of antimicrobial susceptibility testing before any antimicrobial prescription.

Helicobacter pylori infection and liver diseases: Epidemiology and insights into pathogenesis

Both Helicobacter pylori (H. pylori) infection and liver diseases, including nonalcoholic fatty liver disease (NAFLD), viral hepatitis, and hepatocellular carcinoma (HCC), have high prevalences worldwide, and the relationship between H. pylori infection and liver disease has been discussed for many years. Although positive correlations between H. pylori and NAFLD have been identified in some clinical and experimental studies, negative correlations have also been obtained in high-quality clinical studies. Associations between H. pylori and the pathogenesis of chronic viral hepatitis, mainly disease progression with fibrosis, have also been suggested in some clinical studies. Concerning HCC, a possible role for H. pylori in hepatocarcinogenesis has been identified since H. pylori genes have frequently been detected in resected HCC specimens. However, no study has revealed the direct involvement of H. pylori in promoting the development of HCC. Although findings regarding the correlations between H. pylori and liver disease pathogenesis have been accumulating, the existing data do not completely lead to an unequivocal conclusion. Further high-quality clinical and experimental analyses are necessary to evaluate the efficacy of H. pylori eradication in ameliorating the histopathological changes observed in each liver disease.

Association between cagA negative Helicobacter pylori status and nonalcoholic fatty liver disease among adults in the United States

We investigated the relationship of H. pylori stratified by cytotoxin-associated gene A (cagA) status with nonalcoholic fatty liver disease (NAFLD) in the general population of the United States (US). We utilized the Third National Health and Nutrition Examination Survey from 1988 to 1994 in this study. NAFLD was defined by ultrasonographic detection of hepatic steatosis in the absence of other known causes of liver diseases and significant alcohol consumption. Hepatic steatosis was assessed by parenchymal brightness, liver to kidney contrast, deep beam attenuation, bright vessel walls and gallbladder wall definition. Antibodies to H. pylori and cagA of participants were measured using H. pylori IgG and anti-cagA IgG enzyme-linked immunosorbent assays. Among 5,404 participants, the prevalence of NAFLD was higher in H. pylori positive subjects (33.5±1.8%) compared to H. pylori negative subjects (26.1±1.7%, p <0.001). In terms of cagA protein status stratification, while cagA positive H. pylori group did not demonstrate an association with NAFLD (OR: 1.05; 95% CI: 0.81-1.37), cagA negative H. pylori group was noted to have a significant association with NAFLD in a multivariable analysis (OR: 1.30; 95% CI: 1.01-1.67). In conclusion, our study demonstrated that cagA negative H. pylori infection was an independent predictor of NAFLD in the US general population.

Helicobacter pylori and extragastric diseases: A review

Helicobacter pylori (H. pylori) infection is very common and affects approximately half of the world population. It causes gastric diseases, but some authors have reported an association of H. pylori infection with other systemic manifestations beginning in 1994. The list of potential effects of H. pylori outside the stomach includes a number of extragastric manifestations and we focused on neurological, dermatological, hematologic, ocular, cardiovascular, metabolic, allergic, and hepatobiliary diseases. This review discusses these important reported manifestations that are not related to the gastrointestinal tract.

Preliminary study and bioinformatics analysis on the potential role of CagQ in type IV secretion system of H.pylori

Helicobacter pylori (H.pylori), is a major causative agent of chronic gastritis, gastric carcinoma and duodenal ulcer. Remarkably, H.pylori carries cytotoxin-associated gene pathogenicity island (CagPAI) which encodes a type IV secretion system (T4SS). T4SS is capable of forming a syringe-like structure to deliver oncoprotein cytotoxin-associated Antigen (CagA) into gastric epithelial cells and resulting in a cascade of events in host cells, such as induction of pro-inflammatory cytokines, alteration of cellular gene expression and cytoskeletal rearrangements. Among of those proteins in T4SS, CagQ still remains unknown functions. In this study, we performed analysis of protein-protein interaction and revealed that CagQ correlated with the most virulence factor CagA in T4SS. Interestingly, our data demonstrated that CagQ-deficient mutant strain had significantly lower expression in both mRNA and protein levels of CagA compared with H.pylori wild-type strain 26695. Moreover, we demonstrated that CagQ deletion also played a vital role in suppressing CagA-induced apoptosis of host gastric epithelial cells. To further investigate the role of CagQ in T4SS, we used bioinformatics analysis to provide a preliminary insight into CagQ. These results showed that CagQ possessed a transmembrane region from amino acid 50-68 which is also consistent with the prediction of hydrophobic scale and structure modeling. Thus, we conclude that CagQ is a membrane protein in T4SS and is crucial for maintaining CagA expression and CagA-induced apoptotic effects. This provides a novel specific therapeutic target for H.pylori CagA-induced gastroduodenal diseases.

Helicobacter pylori infection and prevalence of high blood pressure among Chinese adults

Epidemiological studies demonstrated that Helicobacter pylori (H. pylori) infection was associated with cardiovascular disease and its risk factors. However, the association between H. pylori infection and hypertension remained unclear. The aim of this study was to investigate the association between H. pylori infection and prevalence of hypertension among Chinese adults. We performed a cross-sectional study of 5246 adult participants who were recruited from a health manage center. All participants underwent a ¹³C-urea breath test and a routine health check-up. Logistic and liner regression models were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for hypertension in relation to H. pylori infection. Of the 5168 study participants aged 18-70 years, 2034 (39.4%) were females and 955 (18.5%) had hypertension. After adjustment for potential confounders, H. pylori infection was associated with an increased prevalence of hypertension (OR, 1.23; 95% CI, 1.04, 1.46). In addition, compared with participants not infected with H. pylori, those with H. pylori infection had an increase of 0.735 mmHg (95% CI, 0.101, 1.369) for diastolic blood pressure and 0.723 mmHg (95% CI, 0.034, 1.413) for mean arterial pressure. There was no significant interaction between H. pylori infection and age, sex, and body mass index on the prevalence of hypertension (all P values for interaction >0.05). Findings from this study demonstrate that H. pylori infection was positively associated with prevalence of hypertension among Chinese adults. More well-designed studies are warranted to confirm our findings.

Binding of the Helicobacter pylori OipA causes apoptosis of host cells via modulation of Bax/Bcl-2 levels

The H. pylori outer inflammatory protein A (OipA) is an outer membrane protein that contributes to gastric inflammation. OipA is believed to affect intra-cellular signalling and modulate the host signalling pathways. The aim of the current study was to clarify the role of OipA in H. pylori pathogenesis and its effect on host cell signalling pathways. To this end, the oipA gene was isolated and inserted into cloning and expression vectors. The recombinant plasmid was transferred into an expression host to produce OipA, which was subsequently purified by affinity chromatography and used for antibody production. A confluent monolayer of gastric cell lines was treated with various concentrations of OipA and investigated for attachment, toxicity, and apoptosis and alterations in signalling pathways. OipA bound to gastric cell lines confirming its role in the attachment of H. pylori to host cells. The ratio of Bax/Bcl-2 and caspase3, 8, FasL in the host cells were assessed and the results showed that the Bax/Bcl-2 ratio as well as the level of cleaved-caspase 3 was elevated in OipA-treated cells. These findings suggest that OipA can bind and induce toxic events as well as triggering apoptotic cascade in host gastric cells through intrinsic pathway.

Strategies used by helicobacter pylori to establish persistent infection

Helicobacter pylori (H. pylori) is a Gram-negative and motile bacterium that colonizes the hostile microniche of the human stomach, then persists for the host's entire life, if not effectively treated. Clinically, H. pylori plays a causative role in the development of a wide spectrum of diseases including chronic active gastritis, peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Due to the global distribution of H. pylori, it is no exaggeration to conclude that smart strategies are contributing to adaptation of the bacterium to its permanent host. Thirty-four years after the discovery of this bacterium, there are still many unanswered questions. For example, which strategies help the bacterium to survive in this inhospitable microniche? This question is slightly easier to answer if we presume the same clinical concept for both persistent infection and disease. Understanding the mechanisms governing H. pylori persistence will improve identification of the increased risk of diseases such as gastric cancer in patients infected with this bacterium. A well-defined and long-term equilibrium between the human host and H. pylori allows bacterial persistence in the gastric microniche; although this coexistence leads to a high risk of severe diseases such as gastric cancer. To escape the bactericidal activity of stomach acid, H. pylori secretes large amounts of surface-associated and cytosolic urease. The potential to avoid acidic conditions and immune evasion are discussed in order to explain the persistence of H. pylori colonization in the gastric mucosa, and data on bacterial genetic diversity are included. Information on the mechanisms related to H. pylori persistence can also provide the direction for future research concerning effective therapy and management of gastroduodenal disorders. The topics presented in the current review are important for elucidating the strategies used by H. pylori to help the bacterium persist in relation to the immune system and the many unfavorable features of living in the gastric microniche.

Protein signature characterizing Helicobacter pylori strains of patients with autoimmune atrophic gastritis, duodenal ulcer and gastric cancer

Background

Helicobacter pylori (H. pylori) represents a key factor in the etiology of autoimmune atrophic gastritis (AAG), duodenal ulcer (DU) and gastric cancer (GC). The aim of this study was to characterize the differential protein expression of H. pylori isolated from gastric biopsies of patients affected by either AAG, DU or GC.

Methods

The H. pylori strains were isolated from endoscopic biopsies from the stomach of patients with gastric disease. Protein profiles of H. pylori were compared by two-dimensional difference in gel electrophoresis (2D-DIGE) coupled with mass spectrometry (MS) for the identification of significantly different spots (Student t-test, p < 0.05).

Results

A total of 47 differentially expressed spots were found between H. pylori isolated from patients with either DU or AAG diseases and those isolated from patients with GC (Anova < 0.05, log fold change >1.5). These spots corresponded to 35 unique proteins. The identity of 7 protein spots was validated after one-dimensional electrophoresis and MS/MS analyses of excised gel portions. In H. pylori isolated from DU-patients a significant increase in proteins with antioxidant activity emerged (AroQ, AspA, FldA, Icd, OorA and ScoB), together with a higher content of proteins counteracting the high acid environment (KatA and NapA). In H. pylori isolated from AAG-patients proteins neutralizing hydrogen concentrations through organic substance metabolic processes decreased (GroL, TrxB and Tuf). In addition, a reduction of bacterial motility (FlhA) was found to be associated with AAG-H. pylori isolates. In GC-H. pylori strains it was found an increase in nucleic acid-binding proteins (e.g. DnaG, Tuf, RpoA, RplU) which may be involved in a higher demand of DNA- and protein-related processes.

Conclusion

Our data suggest the presence of specific protein signatures discriminating among H. pylori isolated from either AAG, DU or GC. Changes in protein expression profiles evaluated by DIGE succeeded in deciphering part of the molecular scenarios associated with the different H. pylori-related gastric diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-017-0133-x) contains supplementary material, which is available to authorized users.

Role of Flagella in the Pathogenesis of Helicobacter pylori

This review aimed to investigate the role of Helicobacter pylori flagella on the pathogenicity of this bacterium in humans. Helicobacter pylori is a flagellated pathogen that colonizes the human gastroduodenal mucosa and produces inflammation, and is responsible for gastrointestinal disease. Its pathogenesis is attributed to colonization and virulence factors. The primary function of H. pylori flagella is to provide motility. We believe that H. pylori flagella play an important role in the colonization of the gastrointestinal mucosa. Therefore, we reviewed previous studies on flagellar morphology and motility in order to explore the relationship between H. pylori flagella and pathogenicity. Further investigation is required to confirm the association between flagella and pathogenicity in H. pylori.

Host Determinants of Expression of the Helicobacter pylori BabA Adhesin

Expression of the Helicobacter pylori blood group antigen binding adhesin A (BabA) is more common in strains isolated from patients with peptic ulcer disease or gastric cancer, rather than asymptomatic colonization. Here we used mouse models to examine host determinants that affect H. pylori BabA expression. BabA expression was lost by phase variation as frequently in WT mice as in RAG2−/− mice that do not have functional B or T cells, and in MyD88−/−, TLR2−/− and TLR4−/− mice that are defective in toll like receptor signaling. The presence of other bacteria had no effect on BabA expression as shown by infection of germ free mice. Moreover, loss of BabA expression was not dependent on Le^b expression or the capacity of BabA to bind Le^b. Surprisingly, gender was the host determinant most associated with loss of BabA expression, which was maintained to a greater extent in male mice and was associated with greater bacterial load. These results suggest the possibility that loss of BabA expression is not driven by adaptive immunity or toll-like receptor signaling, and that BabA may have other, unrecognized functions in addition to serving as an adhesin that binds Le^b.

The Gastric Microbiome and Its Influence on Gastric Carcinogenesis: Current Knowledge and Ongoing Research

Gastric malignancies are a leading cause of cancer-related death worldwide. At least 2 microbial species are currently linked to carcinogenesis and the development of cancer within the human stomach. These include the bacterium Helicobacter pylori and the Epstein-Barr virus. In recent years, there has been increasing evidence that within the human gastrointestinal tract it is not only pathogenic microbes that impact human health but also the corresponding autochthonous microbial communities. This article reviews the gastrointestinal microbiome as it relates primarily to mechanisms of disease and carcinogenesis within the upper gastrointestinal tract.

The Association Between Helicobacter pylori Infection and Nonalcoholic Fatty Liver Disease

PURPOSE OF REVIEW

Helicobacter pylori (HP) infection is known to be a significant risk factor in the development of certain gastric conditions, such as ulcers, gastritis, and malignancy. Recently, however, the systemic effect of HP infection on other organ systems has come to be appreciated. In this review, we will explore the association between HP infection and nonalcoholic fatty liver disease (NAFLD), the hepatic component of metabolic syndrome.

RECENT FINDINGS

The possible association between HP infection and NAFLD initially stemmed from the isolation of HP bacteria in the livers of patients with NAFLD. Although there have been conflicting results, several subsequent clinical trials have demonstrated a higher rate of fatty liver and NASH in HP-positive patients compared to HP-negative patients; in addition, small trials examining the effect of HP eradication have shown improvement in markers of NAFLD activity, further supporting a link between these two conditions. The pathophysiology behind the possible association between HP infection and NAFLD has yet to be fully elucidated; several possible mechanisms include induction of a pro-inflammatory state that shifts the body toward a more lipogenic profile, and a hormonal shift that favors progression toward insulin resistance and fibrosis. The association between HP infection and NAFLD has been demonstrated in several clinical trials, including small trials evaluating the effect of HP eradication on NAFLD. Future studies examining the pathophysiology behind this association are the next step in characterizing the relationship between these two conditions.

Vaccine against Helicobacter pylori: Inevitable approach

Over three decades have passed since the discovery of Helicobacter pylori (H. pylori), and yet many questions about its treatment remain unanswered. For example, there is no certainty regarding continued use of current antibiotic therapy against H. pylori. The bad news is that even combined regimens are also unable to eradicate bacterial colonization. The worst problem with H. pylori chemotherapy is that even if we identify the most successful regimen, it cannot eliminate the risk of re-infection. This problem is further complicated by the fact that clinicians have no information as to whether probiotics are useful or not. Moreover, to date, we have no large scale produced vaccine effective against H. pylori. Due to the relatively rapid and abundant dissemination of guidelines globally reported concerning management of gastric cancer prevention and therapeutic regimens, clinicians may choose a vaccine as better effective weapon against H. pylori. Therefore, a radical shift in adopted strategies is needed to guide ultimate decisions regarding H. pylori management. In light of failures in vaccine projects, we should identify better vaccine design targeting conserved/essential genes. The unique character and persistence of H. pylori pose obstacles to making an effective vaccine. Preferably, in developing countries, the best reasonable and logical approach is to recommend prophylactic H. pylori vaccine among children as an obligatory national program to limit primary colonization. Trying to produce a therapeutic vaccine would be postponed until later. In reality, we should not forget to prescribe narrow spectrum antibiotics. In the current review, I draw a route to define the best adopted strategy against this rogue bacterium.

The Helicobacter pylori Cag Pathogenicity Island Protein Cag1 is Associated with the Function of T4SS

The human pathogen Helicobacter pylori is involved in gastric diseases ranging from gastritis to gastric cancer. Virulent strains harboring the cag pathogenicity island (cag PAI) which encode a Type IV Secretion System (T4SS) can induce pro-inflammatory cytokines such as interleukin-8 and deliver their major effector proteins CagA into the gastric cells. While a subset of cag PAI genes have been identified to be the homologues of T4SS genes from Agrobacterium tumefaciens, a majority have unknown functions. We have identified one of such proteins, Cag1, which was predicted to be a non-classically secreted and virulent protein. Our results showed that Cag1 is a membrane-associated protein essential for the induction of multiple cytokine secretions, and cag1-deficient mutant has partial influence on CagA translocation; while the protein itself was not injected into host cells. Our data indicated that Cag1 is located in the bacterial membrane and is associated with the function of T4SS.

Helicobacter pylori infection might have a potential role in hepatocyte ballooning in nonalcoholic fatty liver disease

BACKGROUND

Clinical data regarding Helicobacter pylori (H. pylori) infection in nonalcoholic fatty liver disease (NAFLD) are limited. The aim was to evaluate H. pylori infection in patients with NAFLD and its association with disease severity.

METHODS

One hundred and thirty patients with biopsy-proven NAFLD [43 with nonalcoholic fatty liver (NAFL) and 87 with nonalcoholic steatohepatitis (NASH)] were recruited for blood samples for anti-H. pylori immunoglobulin G (IgG) and standard biochemical tests were obtained after overnight fasting. Glucose tolerance was evaluated by 75-g oral glucose tolerance test. Liver biopsies were scored for NAFLD activity score (NAS), fibrosis and iron deposits.

RESULTS

H. pylori IgG seropositivity was found in 40 % of patients overall. The prevalence of NASH was significantly higher in the patients with H. pylori IgG seropositivity (81 %) than in those without (58 %, p = 0.008). Glucose intolerance was similar between the two groups. The total NAS and the grade of hepatocyte ballooning were higher in the patients with H. pylori IgG seropositivity than in those without, while the hepatic iron grade was lower in the patients with H. pylori IgG seropositivity than in those without. H. pylori infection (p = 0.030), female gender (p = 0.029), and NAFIC score ≥ 2 points (p < 0.001) could independently predict NASH in logistic regression analysis, independent of age, obesity and glucose tolerance.

CONCLUSION

The association of H. pylori seropositivity with hepatocyte ballooning suggests that H. pylori infection may represent another contributing factor in the progression from NAFL to NASH. Eradicating H. pylori infection may have therapeutic prospects in NASH treatment.

From the stomach to other organs: Helicobacter pylori and the liver

Many recent studies have examined the importance of Helicobacter pylori (H. pylori) infection in the pathogenesis of the diseases outside the stomach and explored the significance of this bacterium in the pathogenesis of some metabolic and cardiovascular diseases. Recent studies have provided evidence that H. pylori is also involved in the pathogenesis of some liver diseases. Many observations have proved that H. pylori infection is important in the development of insulin resistance, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, liver fibrosis and cirrhosis. The worsening of liver inflammation of different origins also occurs during H. pylori infection. Some studies have indicated that H. pylori infection induces autoimmunological diseases in the liver and biliary tract. The potential significance of this bacterium in carcinogenesis is unclear, but it is within the scope of interest of many studies. The proposed mechanisms through which H. pylori impacts the development of hepatobiliary diseases are complex and ambiguous. The importance of other Helicobacter species in the development of hepatobiliary diseases is also considered because they could lead to the development of inflammatory, fibrotic and necrotic injuries of the liver and, consequently, to hepatocellular carcinoma. However, many contrary viewpoints indicate that some evidence is not convincing, and further studies of the subject are needed. This review presents the current knowledge about the importance of H. pylori in the pathogenesis of liver and in biliary diseases.

New NCI-N87-derived human gastric epithelial line after human telomerase catalytic subunit over-expression

AIM: To establish a cellular model correctly mimicking the gastric epithelium to overcome the limitation in the study of Helicobacter pylori (H. pylori) infection.

METHODS: Aiming to overcome this limitation, clones of the heterogenic cancer-derived NCI-N87 cell line were isolated, by stably-transducing it with the human telomerase reverse-transcriptase (hTERT) catalytic subunit gene. The clones were first characterized regarding their cell growth pattern and phenotype. For that we measured the clones’ adherence properties, expression of cell-cell junctions’ markers (ZO-1 and E-cadherin) and ability to generate a sustained transepithelial electrical resistance. The gastric properties of the clones, concerning expression of mucins, zymogens and glycan contents, were then evaluated by haematoxylin and eosin staining, Periodic acid Schiff (PAS) and PAS/Alcian Blue-staining, immunocytochemistry and Western blot. In addition, we assessed the usefulness of the hTERT-expressing gastric cell line for H. pylori research, by performing co-culture assays and measuring the IL-8 secretion, by ELISA, upon infection with two H. pylori strains differing in virulence.

RESULTS: Compared with the parental cell line, the most promising NCI-hTERT-derived clones (CL5 and CL6) were composed of cells with homogenous phenotype, presented higher relative telomerase activities, better adhesion properties, ability to be maintained in culture for longer periods after confluency, and were more efficient in PAS-reactive mucins secretion. Both clones were shown to produce high amounts of MUC1, MUC2 and MUC13. NCI-hTERT-CL5 mucins were shown to be decorated with blood group H type 2 (BG-H), Lewis-x (Le^x), Le^y and Le^a and, in a less extent, with BG-A antigens, but the former two antigens were not detected in the NCI-hTERT-CL6. None of the clones exhibited detectable levels of MUC6 nor sialylated Le^x and Le^a glycans. Entailing good gastric properties, both NCI-hTERT-clones were found to produce pepsinogen-5 and human gastric lipase. The progenitor-like phenotype of NCI-hTERT-CL6 cells was highlighted by large nuclei and by the apical vesicular-like distribution of mucin 5AC and Pg5, supporting the accumulation of mucus-secreting and zymogens-chief mature cells functions.

CONCLUSION: These traits, in addition to resistance to microaerobic conditions and good responsiveness to H. pylori co-culture, in a strain virulence-dependent manner, make the NCI-hTERT-CL6 a promising model for future in vitro studies.

Effect of anti-Helicobacter pylori treatment on early diabetic kidney disease

AIM: To assess the effect of anti-Helicobacter pylori (H. pylori) therapy on chronic kidney disease (CKD) associated with type 2 diabetes mellitus (T2DM).

METHODS: Seventy-five T2DM patients with newly diagnosed CKD and H. pylori infection were randomly divided into an anti-H. pylori therapy group (n = 39) and a control group (n = 36). All of the patients received routine treatment for three months. Patients in the anti-H. pylori group were additionally given anti-H. pylori therapy. Clinical indices including fasting blood glucose (FBG), 2-h plasma glucose (2-h PG), hemoglobin A1c (HbA1c), systolic blood pressure (SBP), diastolic blood pressure (DBP), cholesterol (TC), triglyceride (TG), urinary albumin/creatitine ratio (UAlb/Cr), C-reactive protein (CRP), tumor necrosis factor α (TNF-α), plasma endothelin 1 (ET-1), and homocysteine (HCY) were recorded before and three months after treatment.

RESULTS: No significant differences were observed in all clinical indices between the two groups before treatment (P > 0.05). The eradication rate of H. pylori in the anti-H. pylori group was significantly higher than that in the control group three months after treatment (P < 0.01). There were no differences in FBG, 2-h PG, SBP, DBP, HbA1c, TG, or TC between before and after treatment (P > 0.05). At three months after treatment, UAlb/Cr, CRP, ET-1, TNF-α and HCY decreased significantly in both groups (P < 0.05), and changes were statistically significant different between the two groups (P < 0.05).

CONCLUSION: Anti-H. pylori therapy is beneficial for T2DM patients with CKD, because it can help control UAlb/Cr, CRP, ET-1, TNF-α, and HCY and even play an important role in postponing CKD.

Prevalence of Helicobacter pylori infection and its relation with body mass index in a Chinese population

BACKGROUND

Helicobacter pylori infection is highly prevalent worldwide. The association between obesity and H. pylori infection is controversial in the literature. This study aims to investigate the prevalence of H. pylori infection and its relation with body mass index (BMI) in a Chinese population.

MATERIALS AND METHODS

A cross-sectional study was performed among adults who underwent health checkups at the First Affiliated Hospital, College of Medicine, Zhejiang University in 2013. The prevalence of H. pylori infection was examined by (13)C urea breath tests, and the association between prevalence of H. pylori infection and BMI was analyzed.

RESULTS

Of the 8820 participants enrolled, 3859 (43.8%) were positive for H. pylori infection. H. pylori-positive participants had a more unfavorable metabolic profile than H. pylori-negative participants. Overweight/obese participants showed a higher prevalence of H. pylori infection than that of lean participants, and a positive linear correlation between BMI and prevalence of H. pylori infection was observed. Both unadjusted and adjusted analysis revealed that BMI was significantly associated with risk factors of H. pylori infection.

CONCLUSIONS

Our results showed that BMI was significantly and positively associated with H. pylori infection, and a high BMI was associated with an increased risk of the infection.

Role of Helicobacter pylori infection on nutrition and metabolism

Helicobacter pylori (H. pylori) is a gram-negative pathogen that is widespread all over the world, infecting more than 50% of the world’s population. It is etiologically associated with non-atrophic and atrophic gastritis, peptic ulcer and shows a deep association with primary gastric B-cell lymphoma and gastric adenocarcinoma. Recently, the medical research focused on the modification of the gastric environment induced by H. pylori infection, possibly affecting the absorption of nutrients and drugs as well as the production of hormones strongly implicated in the regulation of appetite and growth. Interestingly, the absorption of iron and vitamin B12 is impaired by H. pylori infection, while infected subjects have lower basal and fasting serum levels of ghrelin and higher concentration of leptin compared to controls. Since leptin is an anorexigenic hormone, and ghrelin stimulates powerfully the release of growth hormone in humans, H. pylori infection may finally induce growth retardation if acquired very early in the childhood and in malnourished children. This review is focused on the nutritional effects of H. pylori infection, such as the reduced bioavailability or the malabsorbption of essential nutrients, and of gastrointestinal hormones, as well as on the relationship between H. pylori and the metabolic syndrome.

Association between Helicobacter pylori genotypes and severity of chronic gastritis, peptic ulcer disease and gastric mucosal interleukin-8 levels: Evidence from a study in the Middle East

Background

The varied clinical presentations of Helicobacter pylori (H. pylori) infection are most likely due to differences in the virulence of individual strains, which determines its ability to induce production of interleukin-8 (IL-8) in the gastric mucosa. The aim of this study was to examine association between cagA, vacA-s1 and vacA-s2 genotypes of H. pylori and severity of chronic gastritis and presence of peptic ulcer disease (PUD), and to correlate these with IL-8 levels in the gastric mucosa.

Methods

Gastric mucosal biopsies were obtained from patients during esophagogastroduodenoscopy. The severity of chronic gastritis was documented using the updated Sydney system. H. pylori cagA and vacA genotypes were detected by PCR. The IL-8 levels in the gastric mucosa were measured by ELISA.

Results

H. pylori cagA and/or vacA genotypes were detected in 99 patients (mean age 38.4±12.9; 72 males), of whom 52.5% were positive for cagA, 44.4% for vacA-s1 and 39.4% for vacA-s2; and 70.7% patients had PUD. The severity of inflammation in gastric mucosa was increased with vacA-s1 (p=0.017) and decreased with vacA-s2 (p=0.025), while cagA had no association. The degree of neutrophil activity was not associated with either cagA or vacA-s1, while vacA-s2 was significantly associated with decreased neutrophil activity (p=0.027). PUD was significantly increased in patients with cagA (p=0.002) and vacA-s1 (p=0.031), and decreased in those with vacA-s2 (p=0.011). The level of IL-8 was significantly increased in patients with cagA (p=0.011) and vacA-s1 (p=0.024), and lower with vacA-s2 (p=0.004). Higher levels of IL-8 were also found in patients with a more severe chronic inflammation (p=0.001), neutrophil activity (p=0.007) and those with PUD (p=0.001).

Conclusions

Presence of vacA-s1 genotype of H. pylori is associated with more severe chronic inflammation and higher levels of IL-8 in the gastric mucosa, as well as higher frequency of PUD. Patients with vacA-s2 have less severe gastritis, lower levels of IL-8, and lower rates of PUD. The presence of cagA genotype is not associated with the severity of gastritis or IL-8 induction in the gastric mucosa. The association of cagA with PUD may be a reflection of its presence with vacA-s1 genotype.

The return of metabolism: biochemistry and physiology of the pentose phosphate pathway

The pentose phosphate pathway (PPP) is a fundamental component of cellular metabolism. The PPP is important to maintain carbon homoeostasis, to provide precursors for nucleotide and amino acid biosynthesis, to provide reducing molecules for anabolism, and to defeat oxidative stress. The PPP shares reactions with the Entner–Doudoroff pathway and Calvin cycle and divides into an oxidative and non-oxidative branch. The oxidative branch is highly active in most eukaryotes and converts glucose 6-phosphate into carbon dioxide, ribulose 5-phosphate and NADPH. The latter function is critical to maintain redox balance under stress situations, when cells proliferate rapidly, in ageing, and for the ‘Warburg effect’ of cancer cells. The non-oxidative branch instead is virtually ubiquitous, and metabolizes the glycolytic intermediates fructose 6-phosphate and glyceraldehyde 3-phosphate as well as sedoheptulose sugars, yielding ribose 5-phosphate for the synthesis of nucleic acids and sugar phosphate precursors for the synthesis of amino acids. Whereas the oxidative PPP is considered unidirectional, the non-oxidative branch can supply glycolysis with intermediates derived from ribose 5-phosphate and vice versa, depending on the biochemical demand. These functions require dynamic regulation of the PPP pathway that is achieved through hierarchical interactions between transcriptome, proteome and metabolome. Consequently, the biochemistry and regulation of this pathway, while still unresolved in many cases, are archetypal for the dynamics of the metabolic network of the cell. In this comprehensive article we review seminal work that led to the discovery and description of the pathway that date back now for 80 years, and address recent results about genetic and metabolic mechanisms that regulate its activity. These biochemical principles are discussed in the context of PPP deficiencies causing metabolic disease and the role of this pathway in biotechnology, bacterial and parasite infections, neurons, stem cell potency and cancer metabolism.

Helicobacter pylori cell translocating kinase (CtkA/JHP0940) is pro-apoptotic in mouse macrophages and acts as auto-phosphorylating tyrosine kinase

The Helicobacter pylori gene JHP0940 has been shown to encode a serine/threonine kinase which can induce cytokines in gastric epithelial cells relevant to chronic gastric inflammation. Here we demonstrate that JHP0940 can be secreted by the bacteria, triggers apoptosis in cultured mouse macrophages and acts as an auto-phosphorylating tyrosine kinase. Recombinant JHP0940 protein was found to decrease the viability of RAW264.7 cells (a mouse macrophage cell line) up to 55% within 24h of co-incubation. The decreased cellular viability was due to apoptosis, which was confirmed by TUNEL assay and Fas expression analysis by flow-cytometry. Further, we found that caspase-1 and IL-1beta were activated upon treatment with JHP0940. These results point towards possible action through the host inflammasome. Our in vitro studies using tyrosine kinase assays further demonstrated that JHP0940 acts as auto-phosphorylating tyrosine kinase and induces pro-inflammatory cytokines in RAW264.7 cells. Upon exposure with JHP0940, these cells secreted IL-1beta, TNF-alpha and IL-6, in a dose- and time-dependent manner, as detected by ELISA and transcript profiling by q-RT-PCR. The pro-inflammatory, pro-apoptotic and other regulatory responses triggered by JHP0940 lead to the assumption of its possible role in inducing chronic inflammation for enhanced bacterial persistence and escape from host innate immune responses by apoptosis of macrophages.