Detection of Helicobacter species in liver and stomach tissues of patients with chronic liver diseases using polymerase chain reaction-denaturing gradient gel electrophoresis and immunohistochemistry

Helicobacter suis Infection in Mouse Induced not Only Gastric, but Hepatic and Pulmonary MALT Lymphoma: Relation to Substance P

BACKGROUND

The hepatic and pulmonary MALT lymphoma (mucosa-associated lymphoid tissue lymphoma) is clinically occasionally observed but its pathogenesis is unknown and thought to be important to establish the treatment strategy.

OBJECTIVES

The present study was designed to clarify the characteristics of these lymphomas and the effect of the Helicobacter eradication regimen and substance P antagonist.

METHODS

After the long term infection of Helicobacter suis to the C57BL/6 mice stomach, the whole organ was surveyed pathologically. Histochemical characteristics of the lesion and the localization of bacteria were observed. In addition, the effect of the administration of antibiotics and a proton pump inhibitor or the substance P antagonist was investigated.

RESULTS

We have detected the hepatic and pulmonary MALT lymphoma after the long term infection. In situ hybridization study revealed the positive reaction of Helicobacter suis in the hepatic and pulmonary MALT lymphoma. After the administration of antibiotics and a proton pump inhibitor, the bacterial number has significantly decreased and the tumor size in the fundus, liver and lung markedly reduced. Substance P immunoreactivity was clearly shown in the lymphoma cells in the liver and lung, and the spantide II administration induced the marked decrease in the size of tumors.

CONCLUSION

By our experiments using the long term infection of Helicobacter suis to the C57BL/6 mice, we have detected the liver and pulmonary MALT lymphoma. In situ hybridization study suggested the direct interaction of this bacterium to the etiology of these lesions. Substance P within the lymphoma cells was suggested to work on the maintenance of the extragastric MALT lymphoma.

NAFLD, Helicobacter species and the intestinal microbiome

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. It is well-accepted that gut dysbiosis is associated with NAFLD, however, there is some conflicting evidence regarding the nature of these alterations. Infection with Helicobacter species, mainly H. pylori, has also been associated with increased NAFLD risk, however, some studies have failed to reproduce this finding. Further studies including large study samples and standardised procedures for microbiota analyses, H. pylori detection and NAFLD diagnostic criteria, are required. The mechanisms involving Helicobacter species and the intestinal microbiome in NAFLD pathogenesis appear to be part of the multiple-hit theory, in which increased intestinal permeability, inflammatory responses, altered choline, bile acids and carbohydrate metabolism, production of short-chain fatty acids, urea cycle and urea transport systems, altered maintenance of hepatic γδT-17 cells, insulin resistance, hormones secreted by the adipose tissue, metabolic hormones, bacterial metabolites and Helicobacter toxins, are all implicated.

Helicobacter pylori infection among patients with liver cirrhosis

BACKGROUND AND AIM

Inflammatory changes in the stomach caused by Helicobacter pylori indirectly and directly affect liver function. Moreover, the bacteria may worsen the course of the liver cirrhosis. The study aimed at evaluating the incidence of H. pylori infection among patients with liver cirrhosis, depending on the etiology and injury stage, scored according to Child-Pugh classification. Stage of esophageal varices and endoscopic inflammatory lesions in the stomach were evaluated, depending on the presence of H. pylori infection.

PATIENTS AND METHODS

The study included 147 patients with liver cirrhosis: 42 were infected with hepatitis C virus, 31 were infected with hepatitis B virus, 56 had alcoholic liver cirrhosis, and 18 had primary biliary cirrhosis. Diagnosis of H. pylori infection was performed based on the presence of immunoglobulin G antibodies in serum.

RESULTS

H. pylori infection was found in 46.9% of patients. The incidence of H. pylori infection among patients with postinflammatory liver cirrhosis was significantly higher (P=0.001), as compared with patients with alcoholic liver cirrhosis. Ammonia concentration was significantly higher in patients infected with H. pylori, compared with noninfected individuals (129 vs. 112 μmol/l; P=0.002). Incidence of H. pylori infection in patients without esophageal varices was significantly lower compared with patients with esophageal varices (14 vs. 60%; P<0.001).

CONCLUSION

H. pylori infection is significantly more frequent among patients with postinflammatory liver cirrhosis (infected with hepatitis C virus or hepatitis B virus) than in patients with alcoholic liver cirrhosis or primary biliary cirrhosis. H. pylori infection correlates with elevated concentration of blood ammonia and the incidence of esophageal varices.

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.

The effect of helicobacter pylori eradication on liver fat content in subjects with non-alcoholic Fatty liver disease: a randomized open-label clinical trial

BACKGROUND

The role of Helicobacter pylori (HP) in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) is unclear.

OBJECTIVES

The aim of this study was to evaluate the effect of HP eradication on liver fat content (LFC), liver function tests (LFT), lipid profile, and homeostasis model assessment-IR (HOMA-IR) index in NAFLD.

PATIENTS AND METHODS

Dyspeptic patients with increased serum aminotransferase levels were enrolled in the study. The exclusion criteria were factors affecting serum aminotransferase or HP treatment strategy. Participants with persistent elevated serum aminotransferase level and ultrasound criteria for identification of fatty liver were presumed to have NAFLD. "NAFLD liver fat score" was used to classify NAFLD. Those with "NAFLD liver fat score" greater than -0.64 and positive results for urea breath test (UBT), were included. Lifestyle modification was provided to all participants. HP eradication was performed in intervention arm. LFC, fasting serum glucose (FSG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglyceride (TG), cholesterol (CHOL), high and low-density lipoprotein (HDL, LDL), and HOMA-IR were checked at baseline and after that, at intervals of eight weeks and twenty four weeks.

RESULTS

One hundred (49 males) patients with the mean age of 43.46 (± 11.52) were studied. Repeated measure ANOVA showed a significant reduction in LFC, anthropometric measurements, and laboratory parameters (except for HDL) in the both groups during the study; however, no significant difference was observed between the groups.

CONCLUSIONS

It seems that HP eradication per se might not affect LFC, LFT, lipid profile, and insulin resistance in dyspeptic NAFLD patients.

Lactic acid bacterial extracts as anti-Helicobacter pylori: a molecular approach

BACKGROUND

Helicobacter pylori (H. pylori) infection, the main cause of chronic gastritis, increases gastric cancer risk. Antibiotics-based H. pylori eradication treatment is 90% effective. However, it is expensive and causes side effects and antibiotic resistance. Lactic acid bacteria (LAB) could present a low-cost, large-scale alternative solution to prevent or decrease H. pylori colonization.

AIM

This work aimed to study the inhibitory effects of LAB strains on the growth and pathogenic activity of H. pylori stains. To this end, we have selected the most virulent H. pylori strains (out of 20 mucosal antral biopsies) regarding cellular vacuolization and induction of apoptosis/necrosis.

METHOD

The selection of H. pylori pathogenic strains (clinically pre-isolated) were based on their impact of VacA activities on Hep-2 cell line, induction of apoptosis and necrosis in Caco-2 cell line. The Inhibitory effect of LAB strains on the invasion was carried out using the Caco-2 and Hela cell lines, where, they were co-cultured with the pathogenic H. pylori in the presence or absence of LAB extracts. The effect of LAB extracts on TNF-α secretion which induced by H. pylori-LPS was carried out by RT-qPCR.

RESULTS

L. bulgaricus DSMZ 20080, L. acidophilus and L. plantarum (studied previously and reported as high antioxidant candidate strains) showed the highest anti-pylori activities with inhibition ranged from 51.46 to 88.19%, they preventing the adhesion, invasion and DNA fragmentation of cell lines. In addition, they could reduce the TNF-α expression by 62.13%.

CONCLUSION

LAB extracts could inhibit the bacterial adhesion and invasion, gastric inflammation and DNA fragmentation induced by Helicobacter pylori.

Helicobacter Pylori DNA in Liver Tissues From Chronic Hepatitis C Egyptian Patients

Background

Hepatitis C virus (HCV) is considered the most common etiology of chronic liver disease in Egypt, which may progress to cirrhosis and hepatocellular carcinoma (HCC). Previous studies have documented an association between Helicobacter pylori (H. pylori) infection and liver cirrhosis with or without HCC. This study aimed to investigate the presence of H. pylori DNA in the liver tissue of Egyptian patients with chronic hepatitis C (CHC).

Methods

Fifty-two CHC Egyptian patients were enrolled in this study. Plasma anti-H. pylori IgG was assessed with ELISA. Liver biopsies were tested for presence of Helicobacter DNA using genus specific nested polymerase chain reaction (PCR) and species was identified by sequencing.

Results

Anti-H. pylori IgG was detected in 31/52 (59.6%) CHC patients while Helicobacter DNA was detected in 6 (11.5%) patients, all were H. Pylori by sequencing. Helicobacter DNA was more frequent in patients with high stage liver fibrosis (33.3%) than in those with low stage fibrosis (2.7%) (P = 0.006). There was no association between the presence of H. pylori DNA in the liver and age, gender of patients, liver function tests, AFP levels or viral load.

Conclusions

These data confirm the presence of H. pylori DNA in liver of some CHC Egyptian patients and suggest an association of this bacterium with progression of liver fibrosis.

Relationship between common duct stones and Helicobacter pylori infection

AIM: To investigate the rate of Helicobacter pylori (H. pylori) infection in patients with common duct stones and analyze the relationship between common duct stones and H. pylori infection.

METHODS: One hundred and five patients with common duct stones (experiment group) and 132 control subjects (control group) were included in the study. All the patients underwent electronic gastroscopy, rapid urease test and 14C urea breath test (¹⁴C-UBT).

RESULTS: Sixty-eight patients in the experiment group were positive for H. pylori, while 51 subjects in the control group were positive for H. pylori. The rate of H. pylori infection in the experiment group was significantly higher (64.8% vs 38.6%, P < 0.01) than that in the control group.

CONCLUSION: The rate of H. pylori infection is high in patients with common duct stones, and H. pylori infection may be related to the morbidity of common duct stones.

Association between entero-hepatic Helicobacter species and Crohn's disease: a prospective cross-sectional study

BACKGROUND

The pathogenesis of Crohn's disease (CD) involved microbial factors. Some Helicobacter species, the so-called entero-hepatic Helicobacters (EHH), can naturally colonize the intestinal surface and have been detected in humans. Aim To look for an association between CD and the presence of EHH DNA in intestinal biopsies.

METHODS

Two groups of patients were included prospectively in a multicentre cross-sectional study: CD patients with an endoscopic post-operative recurrence within 2 years following a surgical resection and controls screened for colorectal polyps or cancer. Intestinal biopsies were taken for Helicobacter culture and Helicobacter 16S DNA detection. If positive, the EHH species were identified with specific PCRs, sequencing and denaturing gradient gel electrophoresis.

RESULTS

In the 165 included patients (73 CD and 92 controls), Helicobacter cultures were negative. PCR was positive in 44% of CD and 47% of controls. After age-adjustment, CD was significantly associated with EHH in intestinal biopsies (OR = 2.58; 95%CI: 1.04-6.67). All EHH species detected were identified as Helicobacter pullorum and the closely related species Helicobacter canadensis.

CONCLUSION

Crohn's disease is associated with the presence of EHH species DNA in intestinal biopsies after adjustment for age. Whether these species play a role in the pathophysiology of CD remains to be determined.

Detection of Helicobacter pylori in paraffin-embedded specimens from patients with chronic liver diseases, using the amplification method

Helicobacter DNA has been detected in the liver specimens of patients with various hepato-biliary diseases. The aim of this study was to investigate the presence of H. pylori DNA in the liver tissue of Iranian patients with chronic liver diseases (CLD). Genomic DNA was extracted from the paraffin sections of 46 liver biopsies of patients with CLD and 13 from patients with metastatic adenocarcinoma as a control group. Polymerase chain reaction (PCR) analysis was carried out using primers for H. pylori 16S rRNA and cagA genes. On analysis, 17 of the 46 patient samples were positive in H. pylori 16S rRNA PCR and 2 of the 13 were positive from the control group. None of the samples were positive for the cagA gene. This study showed the greater presence of H. pylori-like DNA in the liver samples from patients with CLD than in controls.

Adherence, internalization, and persistence of Helicobacter pylori in hepatocytes

Although Helicobacter pylori have been identified in the liver, the role of Helicobacter sp. in human liver diseases remains unclear. This study explored whether H. pylori were internalized and could persist in hepatocytes. The majority of an inoculum of H. pylori (1 x 10(7) colony forming units) adhered to hepatocytes. Using the gentamicin invasion assay we found that approximately 2% were internalized and persisted following passage for more than 2 months. Electron microscopy confirmed the presence of intracellular Helicobacter. The number of adherent or internalized H. pylori was significantly greater with hepatocytes than with gastric epithelial cells (P < 0.05) and was also dependent on cag pathogenicity island (PAI), VacA, OipA, or BabA status. Transmission electron microscopy was used to confirm adherence and invasion of H. pylori into hepatocytes. Internalization of H. pylori was inhibited by antibodies to beta1-integrin receptors, genistein, and cytochalasin D (P < 0.05) consistent with beta1-integrin acting as a surface receptor with additional requirements for tyrosine kinase phosphorylation and actin polymerization. In summary, H. pylori both adhered to and invaded into hepatocytes in vitro, depending on the virulent factors, and persisted within hepatocytes during subcultures. beta1-integrin is likely a receptor involved in internalization of H. pylori into hepatocytes.

Disturbance of apoptosis and DNA synthesis by Helicobacter pylori infection of hepatocytes

We evaluated the effects of infection of hepatocytes with the well-characterized Helicobacter species, H. pylori. Cell number doubled during each 24 h period in mock cultures or following infection with H. pylori 401C (CagA-, VacA-, BabA-, OipA-) (P < 0.05). In contrast, infection with the more virulent H. pylori NCTC11637 (CagA+, VacA+, BabA+, OipA+) resulted in cell arrest (P < 0.05). Furthermore, NCTC11637 activated caspase-3 and increased DNA fragmentation 6.1 +/- 1.2 fold (P < 0.01) and the number of apoptotic bodies 9.4 +/- 3.5 fold (P < 0.01) compared to controls. The effect was greater than with the less virulent strain 401C (3.8 +/- 0.6 fold and 3.9 +/- 1.7, respectively, P < 0.05). Strain NCTC11637 at low concentrations increased cellular DNA synthesis 139 +/- 6% (P < 0.05) but decreased it to 16 +/- 7% (P < 0.01) at high concentrations. In contrast, strain 401C increased DNA synthesis 155 +/- 14% of controls (P < 0.05) at high concentrations. The presence of intracellular NCTC11637 within hepatocytes increased DNA fragmentation 3.0 +/- 0.4 fold (P < 0.01) greater than in controls. H. pylori infection resulted in strain-species-dependent effects on hepatocytes, and virulent strain caused cell arrest and apoptosis of infected hepatocytes.

DNA of Helicobacter spp. and common gut bacteria in primary liver carcinoma

BACKGROUND AND AIM

Gastric and enteric Helicobacter species have been associated with the pathogenesis of some extragastric diseases.

METHODS

We retrospectively investigated the presence of DNA of Helicobacter species in samples of the cancer and the surrounding tumour-free liver tissues of patients with hepatocellular carcinoma (HCC, n=12) and cholangiocarcinoma (CC, n=13). The patients were from an area with low liver cancer incidence and with low hepatitis B and C prevalence. Patients with a benign liver disease (n=24) were included as controls. Paraffin-embedded liver samples were examined by a Helicobacter genus-specific PCR assay as well as group-specific PCR assays for Enterobacteriaceae, Bacteroides, Lactobacillus and Enterococcus. PCR products of positive samples were characterised by denaturing gradient gel electrophoresis (DGGE) and DNA sequencing.

RESULTS

PCR assay detected Helicobacter DNA in seven of 12 (58%) and eight of 13 (62%) normal liver tissue specimens from HCC and CC patients, respectively. Two cancer samples from HCC patients were Helicobacter-positive but none of the CC cancers. In the control group, three of 24 (12.5%) patients with a benign liver condition were positive for Helicobacter species (p<0.01 compared to results of tumour-free liver tissue from the cancer patients). DGGE and DNA sequence analysis showed that 90% of the detected PCR products were "H. pylori-like". DNA of some other enteric bacteria was detected in the liver of one cancer patient and one control (4% of all patients).

CONCLUSION

The presence of DNA of Helicobacter species in liver specimens, but not of other common gut bacteria, was associated with human hepatic carcinogenesis.

Identification of Helicobacter species by 16S rDNA PCR and sequence analysis in human liver samples from patients with various etiologies of benign liver diseases

BACKGROUND/AIMS

Several reports indicated an increased prevalence of the Helicobacter species in hepatocellular cancer tissue and in liver samples infected with hepatitis viruses. The frequency of Helicobacter spp. in benign liver diseases was, however, not thoroughly investigated.

METHODS

Seventy-five consecutive patients with suspected liver disease were enrolled. The indications were hepatitis B virus (n=30), C virus (n=8), B and C dual infection (n=1), nonalcoholic steatohepatitis (n=27), autoimmune hepatitis (n=3), primary biliary cirrhosis (n=1) and idiopathic elevation of liver enzymes (n=5). PCR detection of 16S recombinant RNA gene of Helicobacter spp. was performed on liver samples. PCR products of positive samples were further identified by DNA sequencing. The patients also had upper gastrointestinal endoscopy and gastric biopsy for the detection of H. pylori using histopathology and PCR.

RESULTS

Helicobacter spp. DNA was detected in two out of 75 liver biopsy samples (2.6%), which were typed as H. pylori by DNA sequencing. One of these patients had chronic hepatitis C infection (man, 51 years old) and the other had nonalcoholic steatohepatitis (woman, 44 years old). Fifty-two out of 75 of the patients (69.3%) had H. pylori infection in their stomachs.

CONCLUSION

We have found that H. pylori infection is much less prevalent in benign liver diseases. The presence of H. pylori in nonalcoholic steatohepatitis (NASH) patients is a novel finding and this finding should be confirmed in a larger series.

Non-pylori Helicobacteraceae in the upper digestive tract of asymptomatic Venezuelan subjects: detection of Helicobacter cetorum-like and Candidatus Wolinella africanus-like DNA

BACKGROUND

The spectrum of human non-pylori Helicobacter infections is expanding, with species such as H. heilmannii and H. felis occasionally being associated with gastritis. However, the existence of non-pylori Helicobacter colonization in asymptomatic subjects has not been evaluated. The aim of this study was to investigate whether Helicobacter species other than pylori are present in the upper digestive tract of asymptomatic human subjects.

MATERIALS AND METHODS

A Helicobacteraceae-specific semi-nested polymerase chain reaction (PCR) assay was used to detect Helicobacter-like organisms in the upper digestive tract of 91 Venezuelan volunteers (aged 18-68 years, 41 females, 50 males). Species were identified by denaturing gradient gel electrophoresis analysis and sequencing of the PCR products.

RESULTS

We detected DNA sharing 99-100% sequence identity in over 300-400 bp with the 16S rRNA genes of H. pylori, H. cetorum, and Candidatus Wolinella africanus in 76%, 16%, and 15% of the subjects, respectively. Multiple colonization was documented in 10% of the subjects: H. cetorum and Candidatus W. africanus (4%), H. pylori and Candidatus W. africanus (4%), and H. pylori and H. cetorum (2%).

CONCLUSIONS

Our results suggest that non-pylori Helicobacteraceae colonization is relatively common in the Venezuelan asymptomatic population. This is the first report documenting the presence of H. cetorum DNA in the human upper digestive tract, and the second report of the recently discovered Candidatus W. africanus.

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.