Helicobacter species in the intestinal mucosa of patients with ulcerative colitis

No potential causal link between HP infection and IBD: A 2way Mendelian randomization study

Recent epidemiological research suggests a possible negative correlation between Helicobacter pylori infection and inflammatory bowel disease (IBD). However, conflicting studies have provided unclear evidence regarding these causal relationships. Therefore, recommending specific prevention and treatment strategies for H. pylori infection and IBD is challenging. We used various antibodies (anti-H. pylori IgG, VacA, and GroEl) related to H. pylori infection as indicators. We acquired relevant genetic variants from public databases within the Genome-wide Association Studies (GWAS) dataset using IBDs tool variables from 2 different GWAS datasets. We thoroughly examined the data and screened for IVs that fulfilled these criteria. Subsequently, Bidirectional Mendelian randomization (MR) was conducted to predict the potential causality between the 2. To ensure the accuracy and robustness of our results, we conducted a series of sensitivity analyses. Based on our comprehensive MR analysis, no potential causal relationship was observed between H. pylori infection and IBD. Across various methodologies, including IVW, MR-Egger, and weighted median, our findings showed P values > .05. The only exception was observed in the reverse MR analysis using the MR-Egger method, which yielded a P value of < .05. However, because the IVW method is considered the most statistically significant method for MR, and its P value was > .05, we do not believe that a potential causal relationship exists between them. Our sensitivity analysis did not suggest significant horizontal pleiotropism. Although heterogeneity was detected in the analysis of IBD (IIBDGC source) versus H. pylori GroEL antibody levels (MR-Egger, Qp = 0.038; IVW, Qp = 0.043), the results remained reliable because we selected IVW as a random-effects model in our MR analysis method. Based on our MR research, no direct correlation was observed between H. pylori infection and IBD risk. This implies that eradicating H. pylori may not provide substantial benefits in preventing or treating regional IBD, and vice versa. Nevertheless, the use of H. pylori serological index substitution has limitations, and further research using histological diagnosis and additional MR studies is required to comprehensively assess the link between H. pylori infection and IBD.

Persistent advanced periductal fibrosis is associated with cagA-positive Helicobacter pylori infection in post-praziquantel treatment of opisthorchiasis

BACKGROUND

Liver fluke infection caused by Opisthorchis viverrini is associated with several hepatobiliary diseases including advanced periductal fibrosis (APF) and cholangiocarcinoma. Recently, we demonstrated a persistent APF in over one-third of opisthorchiasis patients after worm removal by praziquantel (PZQ) treatment. However, the underlying mechanism(s) of this phenomena is unclear. Given a co-infection with Helicobacter pylori (H. pylori) especially cagA-positive strain enhances APF, we hypothesized that H. pylori with CagA virulent factor contributes to persistent APF.

MATERIALS AND METHODS

Seventy-five opisthorchiasis patients who underwent ultrasonography and treatment with PZQ were recruited in the 2-year follow-up study. Helicobacter and its cagA in the feces were examined by conventional and qPCR. Correlations between prevalence or bacterial loads of Helicobacter spp., H. pylori, and cagA-positive H. pylori before and after PZQ treatment were analyzed among resolved, slowly resolved, relapsed, and persistent APF groups.

RESULTS

Overall, prevalence of Helicobacter spp., H. pylori, and cagA-positive H. pylori declined after PZQ treatment. However, only the prevalence and bacterial loads of cagA-positive H. pylori detected at 2-year post-treatment were significantly lower than those before treatment (p < .05). In addition, both prevalence and bacterial loads of cagA-positive H. pylori were significantly lower in the resolved APF group after PZQ treatment, while there were no significant changes in the slowly resolved, relapsed, and persistent APF groups. Among the APF subgroups, cagA-positive H. pylori prevalence in both relapsed and persistent APF groups were significantly higher than the resolved APF group.

CONCLUSION

The results support our hypothesis that H. pylori, especially cagA-positive strain, contributes to the relapsed and persistent APF. A supplementary antibiotic treatment for H. pylori to reduce persistent APF and eventually CCA is warranted.

Proximate Drivers of Population-Level Lizard Gut Microbial Diversity: Impacts of Diet, Insularity, and Local Environment

Diet has been suggested to be an important driver of variation in microbiota composition in mammals. However, whether this is a more general phenomenon and how fast changes in gut microbiota occur with changes in diet remains poorly understood. Forty-nine years ago, ten lizards of the species Podarcis siculus were taken from the island of Pod Kopište and introduced onto the island of Pod Mrčaru (Croatia). The introduced population underwent a significant dietary shift, and their descendants became omnivorous (consuming up to 80% plant material during summer). Variation in their gut microbiota has never been investigated. To elucidate the possible impact on the gut microbiota of this rapid change in diet, we compared the microbiota (V4 region of the 16S rRNA gene) of P. siculus from Pod Mrčaru, Pod Kopište, and the mainland. In addition, we explored other drivers of variation in gut microbiota including insularity, the population of origin, and the year of sampling. Alpha-diversity analyses showed that the microbial diversity of omnivorous lizards was higher than the microbial diversity of insectivorous lizards. Moreover, omnivorous individuals harbored significantly more Methanobrevibacter. The gut microbial diversity of insectivorous lizards was nonetheless more heterogeneous. Insectivorous lizards on the mainland had different gut microbial communities than their counterparts on the island of Pod Kopište. Bacillus and Desulfovibrio were more abundant in the gut microbiota from insular lizards compared to mainland lizards. Finally, we showed that the population of origin was also an important driver of the composition of the gut microbiota. The dietary shift that occurred in the introduced population of P. siculus has had a detectable impact on the gut microbiota, but other factors such as insularity and the population of origin also contributed to differences in the gut microbial composition of these lizards, illustrating the multifactorial nature of the drivers of variation in gut microbiota. Overall, our data show that changes in gut microbiota may take place on ecological timescales. Yet, diet is only one of many factors driving variation in gut microbiota across populations.

The Role of Dihydroresveratrol in Enhancing the Synergistic Effect of Ligilactobacillus salivarius Li01 and Resveratrol in Ameliorating Colitis in Mice

Currently approved therapeutical strategies for inflammatory bowel diseases (IBD) suffer from variable efficacy and association with risk of serious side effects. Therefore, efforts have been made in searching for alternative therapeutics strategies utilizing gut microbiota manipulation. In this study, we show that the probiotic strain Ligilactobacillus salivarius Li01 (Li01) and the phytochemical prebiotic resveratrol (RSV) have synergistic effect in ameliorating colitis in mice. Oral coadministration of Li01 (10⁹ CFU/d) and RSV (1.5 g/kg/d) promoted restoration of various inflammatory injuries and gut microbiota composition, exhibiting a favorable anti-inflammatory effect in DSS-induced colitis mice. The combination treatment was associated with reductions in the levels of proinflammatory cytokines IL-1β and IL-6 and increases in the levels of the anti-inflammatory cytokine IL-17A in mouse serum. Moreover, the combination treatment was found to alter the composition and metabolism of the gut microbiota, especially influencing the production of short chain fatty acids and anti-inflammatory related molecules. The mechanism underlying the improved anti-inflammatory effect from the RSV and Li01 combination treatment was found to be associated with the environmental sensor mammalian aryl hydrocarbon receptor (AHR) and tryptophan metabolism pathway. Administration of RSV in combination with Li01 in different mouse model led to enhanced conversion of RSV into metabolites, including dihydroresveratrol (DHR), resveratrol-sulfate, and resveratrol-glucuronide. DHR was found to be the dominant metabolite of RSV in conventional and colitis mice. An increased DHR/RSV ratio was confirmed to activate AHR and contribute to an enhanced anti-inflammatory effect. DHR is considered as a potential AHR ligand. The DHR/RSV ratio also affected the serotonin pathway by controlling the expression of Tph1, SERT, and 5-HT₇R leading to amelioration of colitis in mice. Our data suggest that treatment with a combination of Li01 and RSV has potential as a therapeutic strategy for IBD; further investigation of this combination in clinical settings is warranted.

The onset of ulcerative colitis upon Helicobacter pylori eradication in a 72-year-old woman: report of a rare case with a 3-year follow-up

BACKGROUND

Epidemiological studies suggest an inverse association between H. pylori infection/exposure and inflammatory bowel disease prevalence/incidence, however, there are no reports of individual patients who developed a "non-transient" ulcerative colitis (UC) following H. pylori eradication.

CASE PRESENTATION

We report a case of a 72-year-old female with an elderly-onset UC developed upon H. pylori eradication and a 3-year follow-up of the progression to steroid-dependent colitis complicated with enteropathic arthritis and final containment of the disease with golimumab. In our patient, H. pylori eradication was associated with the development of pancolitis that evolved into clinically, endoscopically, and pathohistologically confirmed UC.

CONCLUSIONS

The case of our patient provides a unique clinical context for a growing body of literature suggesting molecular mechanisms involved in the interaction of genes, environment, and microbiota to be of critical importance in the etiopathogenesis of UC, and thus, provides a valuable set of complementary translational information for preclinical and epidemiological research on the topic.

Enterohepatic Helicobacter species - clinical importance, host range, and zoonotic potential

The genus Helicobacter defined just over 30 years ago, is a highly diverse and fast-growing group of bacteria that are able to persistently colonize a wide range of animals. The members of this genus are subdivided into two groups with different ecological niches, associated pathologies, and phylogenetic relationships: the gastric Helicobacter (GH) and the enterohepatic Helicobacter (EHH) species. Although GH have been mostly studied, EHH species have become increasingly important as emerging human pathogens and potential zoonotic agents in the last years. This group of bacteria has been associated with the development of several diseases in humans from acute pathologies like gastroenteritis to chronic pathologies that include inflammatory bowel disease, and liver and gallbladder diseases. However, their reservoirs, as well as their routes of transmission, have not been well established yet. Therefore, this review summarizes the current knowledge of taxonomy, epidemiology, and clinical role of the EHH group.

Association Between Helicobacter pylori Colonization and Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Various observational studies have examined a potential relationship between Helicobacter pylori colonization and inflammatory bowel diseases (IBDs); however, results are inconclusive. This systematic review evaluates articles reporting an association between human H. pylori colonization and IBD.

METHODS

A systematic search of studies was conducted to evaluate a possible relationship between H. pylori colonization and IBD. Seven databases and different types of gray literature were searched. After screening for relevant articles, selection and data extraction were done. After that, the data were analyzed, and pooled odds ratios (ORs) were calculated, using meta-analysis. Heterogeneity, sensitivity, and subgroups analyses were conducted. Funnel plots followed by Begg and Egger tests were done to assess the publication bias.

RESULTS

Among 58 studies, including 13,549 patients with IBD and 506,554 controls, the prevalence of H. pylori colonization was 22.74% and 36.30%, respectively. A significant negative association was observed between H. pylori colonization and IBD (pooled OR: 0.45, 95% confidence interval 0.39-0.53, P≤0.001). The random-effect model showed significant statistical heterogeneity in the included studies (I2=79%). No publication bias was observed. Among subgroups, ORs were notably different when the data were stratified by the age difference between patient and control group, and by study regions and/or continent. Finally, the meta-regression analysis showed significant results, in terms of the age difference and region variables.

CONCLUSIONS

In this meta-analysis, all statistical data support the theory that H. pylori has a protective role in IBD. However, more primary studies using proper methodology are needed to confirm this association.

Helicobacter pylori may be an initiating factor in newly diagnosed ulcerative colitis patients: A pilot study

AIM

To directly visualize Helicobacter pylori (H. pylori) by the highly sensitive and specific technique of immunohistochemical staining in colonic tissue from patients newly diagnosed with ulcerative colitis (UC).

METHODS

Colonoscopic biopsies from thirty patients with newly diagnosed UC and thirty controls were stained with Giemsa stain and immunohistochemical stain for detection of H. pylori in the colonic tissue. Results were confirmed by testing H. pylori Ag in the stool then infected patients were randomized to receive either anti H. pylori treatment or placebo.

RESULTS

Twelve/30 (40%) of the UC patients were positive for H. pylori by Giemsa, and 17/30 (56.6%) by immunohistochemistry stain. Among the control group 4/30 (13.3%) and 6/30 (20 %) were positive for H. pylori by Giemsa and immunohistochemistry staining respectively. H. pylori was significantly higher in UC than in controls (P = 0.04 and 0.007). All Giemsa positive patients and controls were positive by immunohistochemical stain. Four cases of the control group positive for H. pylori also showed microscopic features consistent with early UC.

CONCLUSION

H. pylori can be detected in colonic mucosa of patients with UC and patients with histological superficial ulcerations and mild infiltration consistent with early UC. There seems to be an association between UC and presence of H. pylori in the colonic tissue. Whether this is a causal relationship or not remains to be discovered.

STING-Dependent Signaling Underlies IL-10 Controlled Inflammatory Colitis

Intestinal immune homeostasis is preserved by commensal bacteria interacting with the host to generate a balanced array of cytokines that are essential for wound repair and for combatting infection. Inflammatory bowel disease (IBD), which can lead to colitis-associated cancer (CAC), is thought to involve chronic microbial irritation following a breach of the mucosal intestinal epithelium. However, the innate immune pathways responsible for regulating these inflammatory processes remain to be fully clarified. Here, we show that commensal bacteria influence STING signaling predominantly in mononuclear phagocytes to produce both pro-inflammatory cytokines as well as anti-inflammatory IL-10. Enterocolitis, manifested through loss of IL-10, was completely abrogated in the absence of STING. Intestinal inflammation was less severe in the absence of cGAS, possibly suggesting a role for cyclic dinucleotides (CDNs) indirectly regulating STING signaling. Our data shed insight into the causes of inflammation and provide a potential therapeutic target for prevention of IBD.

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.

The association between Helicobacter pylori infection and inflammatory bowel disease based on meta-analysis

BACKGROUND

In humans there are epidemiological data suggesting a protective effect of Helicobacter pylori (H. pylori) infection against the development of autoimmune diseases and in addition, there are laboratory data illustrating H. pylori's ability to induce immune tolerance and limit inflammatory responses. Thus, numerous observational studies have examined the association between H. pylori infection and inflammatory bowel disease (IBD) with various results.

OBJECTIVE

We performed a meta-analysis of available studies to better define the association of H. pylori infection and IBD.

METHODS

Medical literature searches for human studies were performed through September 2014, using suitable keywords. In each study the risk ratio (RR) of H. pylori infection in IBD patients vs controls was calculated and pooled estimates were obtained using fixed- or random-effects models as appropriate. Heterogeneity between studies was evaluated using Cochran Q test and I(2) statistics, whereas the likelihood of publication bias was assessed by constructing funnel plots.

RESULTS

Thirty-three studies were eligible for meta-analysis, including 4400 IBD patients and 4763 controls. Overall 26.5% of IBD patients were positive for H. pylori infection, compared to 44.7% of individuals in the control group. There was significant heterogeneity in the included studies (Q = 137.2, df (Q) =32, I(2) ( )= 77%, p < 0.001) and therefore the random-effects model of meta-analysis was used. The obtained pool RR estimation was 0.62 (95% confidence interval (CI) 0.55-0.71, test for overall effect Z = -7.04, p < 0.001). There was no evidence of publication bias.

CONCLUSION

The results of this meta-analysis showed a significant negative association between H. pylori infection and IBD that supports a possible protective benefit of H. pylori infection against the development of IBD.

Enterohepatic Helicobacter Species as a Potential Causative Factor in Inflammatory Bowel Disease: A Meta-Analysis

The Helicobacter species in the gut microbiota comprise Helicobacter pylori (H pylori) and enterohepatic Helicobacter species (EHS), which can colonize the intestinal mucosa. However, it is unclear whether EHS are associated with inflammatory bowel disease (IBD). Therefore, we conducted this meta-analysis to examine the association between EHS and IBD.PubMed, Scopus, Cochrane Library, and Web of Science databases, as well as abstracts from conference proceedings were searched to identify studies that used polymerase chain reaction to detect Helicobacter species in intestinal samples from patients with IBD.After screening, we carefully reviewed 20 of the 2955 identified studies, and performed a meta-analysis of the findings from 14 studies (11 adult studies and 3 pediatric studies) using STATA v12.0. These studies evaluated 1407 individuals, including 433 patients with Crohn's disease, 306 patients with ulcerative colitis, and 668 controls. The prevalence of Helicobacter species was higher among the patients with IBD, compared to that among the controls, which corresponded to a pooled risk ratio (RR) of 1.59 (95% confidence interval [CI]: 1.12-2.27). The RRs for adult and pediatric patients with IBD were 1.61 (95% CI: 1.03-2.52) and 1.76 (95% CI: 1.17-2.64), respectively. Compared to the controls, the patients with IBD tended to have a higher prevalence of EHS in the intestinal mucosa (RR: 2.01, 95% CI: 1.36-2.98), although the prevalence of H pylori was not significantly higher (RR: 1.22, 95% CI: 0.77-1.95). Compared to the controls, the RRs for EHS in patients with Crohn's disease and ulcerative colitis were 1.72 (95% CI: 1.20-2.47) and 3.27 (95% CI: 0.93-11.44), respectively.It appears that EHS was associated with IBD, while intestinal H pylori infection was not significantly associated with IBD. Further studies are needed to determine the involvement of EHS in the microbiological etiology of IBD.

Association of genetic variants of membrane receptors related to recognition and induction of immune response with Helicobacter pylori infection in Ecuadorian individuals

Helicobacter pylori (Hp) has a worldwide distribution showing its higher prevalence of infection in developing countries. Toll-like receptors (TLRs) and C-type lectin receptors (CLRs) are proteins that recognize pathogen-associated molecular patterns (PAMPs) and initiate an innate immune response by promoting growth and differentiation of specialized hematopoietic cells for host defense. Gastric infections led by Hp induce a Th-1 cellular immune response, regulated mainly by the expression of IFN-γ. In this retrospective case-control study, we evaluated the TLR1 1805T/G, TLR2 2029C/T, TLR4 896A/G, CD209 -336A/G and IFNGR1 -56C/T polymorphisms and their relationship with susceptibility to Hp infection. TLR1 1805T/G showed statistical differences when the control (Hp-) and infected (Hp+) groups (P = 0.041*) were compared; the TLR1 1805G allele had a protective effect towards infection (OR = 0.1; 95% CI = 0.01-0.88, P = 0.033*). Similarly, the IFNGR1 -56C/T polymorphism showed statistical differences between Hp+ and Hp- (P = 0.018*), and the IFNGR1 -56TT genotype exhibited significant risk to Hp infection (OR = 2.9, 95% CI = 1.27-6.54, P = 0.018*). In conclusion, the pro-inflammatory TLR1 1805T and IFNGR1 -56T alleles are related with susceptibility to Hp infection in Ecuadorian individuals. The presence of these polymorphisms in individuals with chronic infection increases the risk of cellular damage and diminishes the cellular immune response efficiency towards colonizing agents.

Role of the gut microbiota in inflammatory bowel disease pathogenesis: What have we learnt in the past 10 years?

Our understanding of the microbial involvement in inflammatory bowel disease (IBD) pathogenesis has increased exponentially over the past decade. The development of newer molecular tools for the global assessment of the gut microbiome and the identification of nucleotide-binding oligomerization domain-containing protein 2 in 2001 and other susceptibility genes for Crohn’s disease in particular has led to better understanding of the aetiopathogenesis of IBD. The microbial studies have elaborated the normal composition of the gut microbiome and its perturbations in the setting of IBD. This altered microbiome or “dysbiosis” is a key player in the protracted course of inflammation in IBD. Numerous genome-wide association studies have identified further genes involved in gastrointestinal innate immunity (including polymorphisms in genes involved in autophagy: ATG16L1 and IGRM), which have helped elucidate the relationship of the local innate immunity with the adjacent luminal bacteria. These developments have also spurred the search for specific pathogens which may have a role in the metamorphosis of the gut microbiome from a symbiotic entity to a putative pathogenic one. Here we review advances in our understanding of microbial involvement in IBD pathogenesis over the past 10 years and offer insight into how this will shape our therapeutic management of the disease in the coming years.

Association between Helicobacter Pylori infection and ulcerative colitis--a case control study from China

AIMS

To investigate the association between H. pylori infection and UC prevalence in China.

MATERIALS AND METHODS

Subjects were selected from patients admitted in Department of Gastroenterology for abdominal pain, hematochezia, diarrhea and other GI symptoms during 2009-2012. UC diagnosis was based on both colonoscopy and biopsy. H. pylori detection was based on (14)C urea breath test (UBT) and biopsy sample culture. Patients' demographic, anthropometric and serologic data were selected. H. pylori infection rate was compared between UC and control groups, followed by a subgroup analysis on the association between H. pylori infection and extent and severity degree of UC.

RESULTS

Totally, 153 and 121 patients were selected and divided into UC and control groups. There were no significant differences in age, gender, BMI, hypertension and diabetes. However, smoking history was significantly lower while WBC and CRP levels were significantly higher in UC group. The H. pylori infection rate in UC group was 30.5%, significantly lower than that of 57.0% in control group. The H. pylori infection rate in UC of left colon and whole colon were 33,9% and 24.2% (p<0.05 between them), both significantly lower than that in control group. In addition, the H. pylori infection rates in mild, moderate and severe UC subgroups were 37.8%, 32.3% and 22.2% (p>0.05 among them), all of which were significantly lower than that in control group.

CONCLUSION

We reported a significantly lower H. pylori infection rate in UC patients with different extent and severity degree, which provides evidence for bacteria involvement in UC pathogenesis and reminder clinicians to keep cautious in considering H. pylori eradication in UC patients.

Molecular analysis of Helicobacter pylori virulent-associated genes in hepatobiliary patients

OBJECTIVES

The Helicobacter pylori virulence-associated genes in hepatobiliary patients, including vacA, iceA, babA2, cagA and cagE, have not been reported. The aim of this study was to investigate these genes and the association of those and the clinical outcomes in hepatobiliary diseases.

METHODS

Eighty H. pylori-PCR-positive cases were obtained from hepatobiliary patients, representing both cholangiocarcinoma (CCA) (n= 58) and cholelithiasis (n= 22). The diversity of virulence genes was examined by polymerase chain reaction and DNA sequencing. Phylogenetic analysis of cagA was determined using the maximum parsimony method.

RESULTS

The vacAs1a + c/m1, iceA1 and babA2 genes were the most predominant genotypes in both CCA and cholelithiasis patients. The cagA and cagE genes were found significantly more frequently in patients with CCA than those with cholelithiasis (P < 0.05). The cagA positive samples were the Western-type cagA and showed that almost all of the detected sequences in Thai hepatobiliary and Thai gastric cancer patients were classified in the same cluster but separated from the cluster of Japan and other countries.

CONCLUSIONS

The cagA and cagE genes may be associated in the pathogenesis of hepatobiliary diseases, especially of CCA. Besides the bacterial variation, other host factors may be involved in the pathogenesis of hepatobiliary cancer.

Helicobacter pylori in Thai patients with cholangiocarcinoma and its association with biliary inflammation and proliferation

OBJECTIVES

To investigate whether Helicobacter spp. infection and the cagA of H. pylori are associated with hepatobiliary pathology, specifically biliary inflammation, cell proliferation and cholangiocarcinoma (CCA).

METHODS

Helicobacter species including H. pylori, H. bilis and H. hepaticus were detected in the specimens using the polymerase chain reaction (PCR). Biliary inflammation of the liver and gallbladders was semi-quantitatively graded on hematoxylin and eosin (H&E)-stained slides. Biliary proliferation was evaluated by immunohistochemistry using the Ki-67-labelling index.

RESULTS

Helicobacter pylori was found in 66.7%, 41.5% and 25.0% of the patients in the CCA, cholelithiasis and control groups (P < 0.05), respectively. By comparison, H. bilis was found in 14.9% and 9.4% of the patients with CCA and cholelithiasis, respectively (P > 0.05), and was absent in the control group. The cagA gene of H. pylori was detected in 36.2% and 9.1% of the patients with CCA and cholelithiasis, respectively (P < 0.05). Among patients with CCA, cell inflammation and proliferation in the liver and gallbladder were significantly higher among those DNA H. pylori positive than negative.

CONCLUSIONS

The present findings suggest that H. pylori, especially the cagA-positive strains, may be involved in the pathogenesis of hepatobiliary diseases, especially CCA through enhanced biliary cell inflammation and proliferation.

Helicobacter pylori in Thai patients with cholangiocarcinoma and its association with biliary inflammation and proliferation

OBJECTIVES

To investigate whether Helicobacter spp. infection and the cagA of H. pylori are associated with hepatobiliary pathology, specifically biliary inflammation, cell proliferation and cholangiocarcinoma (CCA).

METHODS

Helicobacter species including H. pylori, H. bilis and H. hepaticus were detected in the specimens using the polymerase chain reaction (PCR). Biliary inflammation of the liver and gallbladders was semi-quantitatively graded on hematoxylin and eosin (H&E)-stained slides. Biliary proliferation was evaluated by immunohistochemistry using the Ki-67-labelling index.

RESULTS

Helicobacter pylori was found in 66.7%, 41.5% and 25.0% of the patients in the CCA, cholelithiasis and control groups (P < 0.05), respectively. By comparison, H. bilis was found in 14.9% and 9.4% of the patients with CCA and cholelithiasis, respectively (P > 0.05), and was absent in the control group. The cagA gene of H. pylori was detected in 36.2% and 9.1% of the patients with CCA and cholelithiasis, respectively (P < 0.05). Among patients with CCA, cell inflammation and proliferation in the liver and gallbladder were significantly higher among those DNA H. pylori positive than negative.

CONCLUSIONS

The present findings suggest that H. pylori, especially the cagA-positive strains, may be involved in the pathogenesis of hepatobiliary diseases, especially CCA through enhanced biliary cell inflammation and proliferation.

Helicobacter pylori transiently in the mouth may participate in the transmission of infection

Helicobacter pylori infection is associated with peptic ulcer and gastric carcinoma. The oral cavity may be a reservoir for H. pylori; however, the results of studies on this subject are controversial. We employed single-step and nested polymerase chain reactions (PCR) to detect the presence of the vacA, ureA and 16S rDNA genes of H. pylori in the stomach, saliva and dental plaque of 30 subjects. The results were confirmed by sequencing. Nested 16S rDNA and ureA amplification was achieved in 80% of gastric, 30% of saliva and 20% of dental plaque specimens. Sequencing of 10, seven and four 16S rDNA products from stomach, saliva and dental plaque, respectively, showed > 99% identity with H. pylori. Sequencing of the other four oral cavity PCR products showed similarity with Campylobacter and Wolinella species. Additionally, the vacA genotype identified in the samples of different sites was the same within a given subject.H. pylori may be found in the oral cavity of patients with gastric infection, thus it could be a source of transmission. However, results obtained with detection methods based only on PCR should be interpreted with caution because other microorganisms that are phylogenetically very close to H. pylori are also present in the mouth.

Role of Helicobacter species in Chinese patients with inflammatory bowel disease

Based on 16S rRNA gene PCR, no significant difference was observed in rates of detection of Helicobacter species in intestinal biopsy specimens from 160 Chinese inflammatory bowel disease (IBD) patients (10%) and 80 controls (6.3%). By using a [(13)C]urea breath test, the H. pylori infection rate in 208 Chinese IBD patients (19.7%) was found to be significantly lower than that in 416 controls (48.8%).

Detection of Helicobacteraceae in intestinal biopsies of children with Crohn's disease

BACKGROUND

Given that members of Helicobacteraceae family colonize the intestinal mucus layer, it has been hypothesized that they may play a role in Crohn's disease. This study investigated the presence of Helicobacteraceae DNA in biopsies collected from children with Crohn's disease and controls.

MATERIALS AND METHODS

The presence of Helicobacteraceae DNA was investigated in intestinal biopsies collected from 179 children undergoing colonoscopy (Crohn's disease n = 77, controls n = 102) using a Helicobacteraceae-specific PCR.

RESULTS

Members of the Helicobacteraceae were detected in 32/77 children with Crohn's disease (41.5%) and 23/102 controls (22.5%). Statistical analysis showed the prevalence of Helicobacteraceae detected in patients to be significantly higher than that in controls (p = .0062). Analysis of non-pylori Helicobacteraceae showed that their prevalence was also significantly higher in patients than in controls (p = .04). Helicobacter pylori was detected in 14.0% of the biopsies across all groups. Given that all children tested were negative for gastric H. pylori, this was a surprising finding. Phylogenetic analysis of H. pylori sequences detected in the biopsies showed that the H. pylori strains identified in the patients did not group with gastric H. pylori included in the analysis, but rather with other H. pylori strains detected in the intestine, gall bladder, and liver.

CONCLUSIONS

The higher prevalence of Helicobacteraceae DNA in Crohn's disease patients would suggest that members of this family may be involved in this disease. In addition, phylogenetic analysis of H. pylori strains showed that extragastric sequences clustered together, indicating that different H. pylori strains may adapt to colonize extragastric niches.

Association between Helicobacter pylori infection and inflammatory bowel disease: a meta-analysis and systematic review of the literature

BACKGROUND

Epidemiologic data suggest a protective effect of Helicobacter pylori infection against the development of autoimmune disease. Laboratory data illustrate H. pylori's ability to induce immune tolerance and limit inflammatory responses. Numerous observational studies have investigated the association between H. pylori infection and inflammatory bowel disease (IBD). Our aim was to perform a systematic review and meta-analysis of this association.

METHODS

Medline, EMBASE, bibliographies, and meeting abstracts were searched by 2 independent reviewers. Of 369 abstracts reviewed, 30 promising articles were reviewed in detail. Twenty-three studies met our inclusion criteria (subject N = 5903). Meta-analysis was performed with the metan command in Stata 10.1.

RESULTS

Overall, 27.1% of IBD patients had evidence of infection with H. pylori compared to 40.9% of patients in the control group. The estimated relative risk of H. pylori infection in IBD patients was 0.64 (95% confidence interval [CI]: 0.54-0.75). There was significant heterogeneity in the included studies that could not be accounted for by the method of IBD and H. pylori diagnosis, study location, or study population age.

CONCLUSIONS

These results suggest a protective benefit of H. pylori infection against the development of IBD. Heterogeneity among studies and the possibility of publication bias limit the certainty of this finding. Further studies investigating the effect of eradication of H. pylori on the development of IBD are warranted. Because environmental hygiene and intestinal microbiota may be strong confounders, further mechanistic studies in H. pylori mouse models are also necessary to further define the mechanism of this negative association.

Association between Helicobacter pylori infection and inflammatory bowel disease: a meta-analysis and systematic review of the literature

BACKGROUND

Epidemiologic data suggest a protective effect of Helicobacter pylori infection against the development of autoimmune disease. Laboratory data illustrate H. pylori's ability to induce immune tolerance and limit inflammatory responses. Numerous observational studies have investigated the association between H. pylori infection and inflammatory bowel disease (IBD). Our aim was to perform a systematic review and meta-analysis of this association.

METHODS

Medline, EMBASE, bibliographies, and meeting abstracts were searched by 2 independent reviewers. Of 369 abstracts reviewed, 30 promising articles were reviewed in detail. Twenty-three studies met our inclusion criteria (subject N = 5903). Meta-analysis was performed with the metan command in Stata 10.1.

RESULTS

Overall, 27.1% of IBD patients had evidence of infection with H. pylori compared to 40.9% of patients in the control group. The estimated relative risk of H. pylori infection in IBD patients was 0.64 (95% confidence interval [CI]: 0.54-0.75). There was significant heterogeneity in the included studies that could not be accounted for by the method of IBD and H. pylori diagnosis, study location, or study population age.

CONCLUSIONS

These results suggest a protective benefit of H. pylori infection against the development of IBD. Heterogeneity among studies and the possibility of publication bias limit the certainty of this finding. Further studies investigating the effect of eradication of H. pylori on the development of IBD are warranted. Because environmental hygiene and intestinal microbiota may be strong confounders, further mechanistic studies in H. pylori mouse models are also necessary to further define the mechanism of this negative association.

Helicobacter species in the human colon

OBJECTIVE

To determine the prevalence, frequency and colonization patterns of Helicobacter species throughout the colon.

METHOD

Patients having initial colonoscopy for nonspecific gastrointestinal disturbance had colonic biopsies taken from up to four sites during colonoscopy and examined for evidence of the Helicobacteraceae family using a group-specific PCR. Serum was also collected and examined for IgG reactivity to Helicobacter pylori.

RESULTS

100 patients had colonoscopy of whom 35 were found to have DNA evidence of Helicobacter species throughout the colon, with 22 having H. pylori. Fifteen patients had a demonstrable serum IgG response to H. pylori that was not always associated with molecular evidence of H. pylori DNA in colon biopsies and vice versa. No specific association with colon disease was found in patients with H. pylori infection.

CONCLUSION

We found evidence of Helicobacter infection in a significant number of patients presenting for colonoscopy but no specific association between the presence of these bacteria and colon disease. Our finding of disparity between molecular and serological techniques to detect Helicobacter species suggests that future studies should not rely on serology alone to detect these bacteria in the human colon.

Helicobacter pylori detection and antimicrobial susceptibility testing

The discovery of Helicobacter pylori in 1982 was the starting point of a revolution concerning the concepts and management of gastroduodenal diseases. It is now well accepted that the most common stomach disease, peptic ulcer disease, is an infectious disease, and all consensus conferences agree that the causative agent, H. pylori, must be treated with antibiotics. Furthermore, the concept emerged that this bacterium could be the trigger of various malignant diseases of the stomach, and it is now a model for chronic bacterial infections causing cancer. Most of the many different techniques involved in diagnosis of H. pylori infection are performed in clinical microbiology laboratories. The aim of this article is to review the current status of these methods and their application, highlighting the important progress which has been made in the past decade. Both invasive and noninvasive techniques will be reviewed.

Detection of Helicobacter species in chronic liver disease and chronic inflammatory bowel disease

AIM

To study the association between helicobacters and chronic liver diseases and chronic inflammatory bowel diseases.

PATIENTS AND METHODS

Thirty-two patients with various chronic liver diseases and 137 patients with inflammatory bowel disease were enrolled. Antibodies to H. pylori, H. hepaticus, H. bilis, and H. pullorum were measured by enzyme immunoassay (EIA), and sera positive in a non-pylori helicobacter EIA were further examined by immunoblot assay. Detection of Helicobacter DNA in liver biopsies was done by denaturating gradient gel electrophoresis of PCR products (PCR-DGGE) and DNA sequence analysis.

RESULTS

Six inflammatory bowel disease patients, four with ulcerative colitis and two with Crohn's disease, and one liver disease patient with autoimmune cholangitis had antibodies to non-pylori helicobacters by an immunoblot assay. Four immunoblot assay-negative patients, three with autoimmune and one with non-autoimmune liver disease, had Helicobacter DNA in liver biopsies; three of the polymerase chain reaction (PCR) products were closely related to non-pylori helicobacters.

CONCLUSION

Evidence for non-pylori helicobacters was scant in Finnish patients with inflammatory bowel disease or chronic but not end stage liver disease. We cannot, however, rule out their role in these diseases.

Relationship between the severity of hepatitis C virus-related liver disease and the presence of Helicobacter species in the liver: A prospective study

AIM: To determine the presence of Helicobacter species DNA in the liver of chronic hepatitis C (CHC) patients with and without cirrhosis as compared to controls, and to identify the bacterial species involved.

METHODS: Seventy-nine consecutive patients (HBV and HIV negative) with a liver sample obtained after liver biopsy or hepatic resection were studied: 41 with CHC without cirrhosis, 12 with CHC and cirrhosis, and 26 controls (HCV negative). Polymerase chain reactions (PCRs) targeting Helicobacter 16S rDNA and species-specific were performed on DNA extracted from the liver. A gastric infection with H pylori was determined by serology and confirmed by ¹³C-urea breath test.

RESULTS: Overall, Helicobacter 16S rDNA was found in 16 patients (20.2%). Although positive cases tended to be higher in CHC patients with cirrhosis (41.6%) than in those without cirrhosis (17.0%) or in controls (15.4%), the difference was not statistically significant (P = 0.08). H pylori-like DNA was identified in 12 cases and H. pullorum DNA in 2, while 2 cases remained unidenti-fied. Gastric infection with H pylori was found in only 2 of these patients.

CONCLUSION: Our results do not confirm the associ-ation of Helicobacter species DNA in the liver of CHC patients with advanced liver disease. The lack of correlation between positive H pylori serology and the presence of H pylori-like DNA in the liver may indicate the presence of a variant of this species.

The role of IFN-gamma and IL-4 in gastric mucosa inflammation associated with Helicobacter heilmannii type 1 infection

Although Helicobacter heilmannii infection is less common than H. pylori infection in humans, it is considered to be of medical importance because of its association with gastritis, gastric ulcer, carcinoma, and mucosa-associated lymphoid tissue lymphoma of the stomach. However, there have been no studies evaluating the role of the Th cell response in H. heilmannii gastric infection. We evaluated the participation of pro-inflammatory and anti-inflammatory cytokines, IFN-gamma and IL-4, in H. heilmannii gastric infection in genetically IFN-gamma- or IL-4-deficient mice. The serum IFN-gamma and IL-4 concentrations were determined by ELISA. The gastric polymorphonuclear infiltrate was higher (P = 0.007) in H. heilmannii-positive than in H. heilmannii-negative wild-type (WT) C57BL/6 mice, whereas no significant inflammation was demonstrable in the stomach of H. heilmannii-positive IFN-gamma(-/-) C57BL/6 mice. The degree of gastric inflammatory cells, especially in oxyntic mucosa, was also higher (P = 0.007) in infected IL-4(-/-) than in WT BALB/c mice. Serum IFN-gamma levels were significantly higher in IL-4(-/-) than in WT BALB/c mice, independently of H. heilmannii-positive or -negative status. Although no difference in serum IFN-gamma levels was seen between H. heilmannii-positive (11.3 +/- 3.07 pg/mL, mean +/- SD) and -negative (11.07 +/- 3.5 pg/mL) WT BALB/c mice, in the group of IL-4(-/-) animals, the serum concentration of IFN-gamma was significantly higher in the infected ones (38.16 +/- 10.5 pg/mL, P = 0.04). In contrast, serum IL-4 levels were significantly decreased in H. heilmannii-positive (N = 10) WT BALB/c animals compared to the negative (N = 10) animals. In conclusion, H. heilmannii infection induces a predominantly Th1 immune response, with IFN-gamma playing a central role in gastric inflammation.

Helicobacter pylori: current status and future prospects

Helicobacter pylori is a global pathogen that causes severe gastrointestinal diseases leading to a significant morbidity and mortality. There is an effective treatment for peptic ulcer disease, however, this is being compromised by an increase in the prevalence of antibiotic resistance. Although alternative rescue regimens have been advocated, the best strategy would be to prevent disease, especially in the case of gastric cancer for which there is still no treatment. One approach is to inhibit the first step in the pathogenic process - adhesion of the organism to the host tissue. Another and probably a better approach is vaccination, but clinical trials have so far been unsuccessful. There is still a large uncertainty in relation to how H. pylori causes disease. Knowledge from genomics, proteomics, and the relationship between polymorphism of the bacterium and the host, as well as the continuing investigation of the role played by important virulence factors in the outcome of the disease, will help both in understanding pathogenesis of disease and in the design of the best vaccine.