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

Assessment of the mixed origin of the gastric epithelial extracellular vesicles in acellular transfer of Helicobacter pylori toxins and a systematic review

BACKGROUND

H. pylori are generally considered as extracellular organisms, with exclusive colonization of the gastric milieu. Yet, several extra gastric manifestations are associated with this infection. The aim of the present study was to investigate the feasibility of toxin transfer by extracellular vesicles, from bacterial and epithelial origins.

METHODS

Tox-positive H. pylori and its two cagA and vacA mutant strains were used to produce bacterial vesicles (BVs) and to infect AGS cells. The produced BVs and the infected cell vesicles (ICVs) were collected by ultracentrifugation and evaluated by western blotting, DLS and electron microscopy. These two sets of vesicles were applied to a second set of recipient AGS cells, in which the acellular transfer of toxins, IL-8 production and downstream morphologic changes were assessed, by western blotting, ELISA and light microscopy, respectively.

RESULTS

The BVs were positive for H. pylori membrane markers (BabA and UreB), VacA and CagA toxins, except for from the corresponding mutant strains. The ICVs were larger in size and positive for bacterial markers, as well as epithelial markers of CD9, LGR5, but negative for nuclear (Ki76) or cytoplasmic (β-actin) markers. Bacteria-independent transfer of CagA and VacA into the recipient cells occurred upon treatment of cells with BVs and ICVs, followed by cellular vacuolation and elongation. IL-8 production was induced in recipient AGS cells, treated with BVs (1279.4 ± 19.79 pg/10⁶ cells), early (8 h, 1171.4 ± 11.31 pg/10⁶ cells) and late (48 h, 965.4 ± 36.77 pg/10⁶ cells) ICVs (P < 0.0001).

CONCLUSION

Our data indicates that ICVs, with mixed bacterial and epithelial constituents, similar to BVs, are capable of transferring bacterial toxins into the recipient cells, inducing IL-8 production and subsequent morphologic changes, in an acellular manner.

The gut microbiota: A new perspective for tertiary prevention of hepatobiliary and gallbladder diseases

The gut microbiota is a complex ecosystem that has coevolved with the human body for hundreds of millions of years. In the past 30 years, with the progress of gene sequencing and omics technology, the research related to gut microbiota has developed rapidly especially in the field of digestive system diseases and systemic metabolic diseases. Mechanical, biological, immune, and other factors make the intestinal flora form a close bidirectional connection with the liver and gallbladder, which can be called the "gut-liver-biliary axis." Liver and gallbladder, as internal organs of the peritoneum, suffer from insidious onset, which are not easy to detect. The diagnosis is often made through laboratory chemical tests and imaging methods, and intervention measures are usually taken only when organic lesions have occurred. At this time, some people may have entered the irreversible stage of disease development. We reviewed the literature describing the role of intestinal flora in the pathogenesis and biotherapy of hepatobiliary diseases in the past 3-5 years, including the dynamic changes of intestinal flora at different stages of the disease, as well as the signaling pathways involved in intestinal flora and its metabolites, etc. After summarizing the above contents, we hope to highlight the potential of intestinal flora as a new clinical target for early prevention, early diagnosis, timely treatment and prognosis of hepatobiliary diseases. GRAPHICAL ABSTRACT.

Helicobacter Species and Hepato-Biliary Tract Malignancies: A Systematic Review and Meta-Analysis

Helicobacter species may cause chronic inflammation of the biliary tract, but its relationship with cancer is controversial. We performed a systematic review and meta-analysis to evaluate the association between Helicobacter species and hepatobiliary tract malignancies. Twenty-six studies (4083 patients) were included in qualitative synthesis, and 18 studies (n = 1895 qualified for meta-analysis. All studies were at high-intermediate risk of bias. Most studies combined several direct microbiological methods, mostly PCR (23 studies), culture (8 studies), and/or CLOtest (5 studies). Different specimens alone or in combination were investigated, most frequently bile (16 studies), serum (7 studies), liver/biliary tissue (8 studies), and gastric tissue (3 studies). Patients with Helicobacter species infection had an increased risk of hepatobiliary tract malignancies (OR = 3.61 [95% CI 2.18-6.00]; p < 0.0001), with high heterogeneity in the analysis (I² = 61%; p = 0.0003). This effect was consistent when Helicobacter was assessed in bile (OR = 3.57 [95% CI 1.73-7.39]; p = 0.0006), gastric tissue (OR = 42.63 [95% CI 5.25-346.24]; p = 0.0004), liver/biliary tissue (OR = 4.92 [95% CI 1.90-12.76]; p = 0.001) and serum (OR = 1.38 [95% CI 1.00-1.90]; p = 0.05). Heterogeneity was reduced in these sub-analyses (I² = 0-27%; p = ns), except for liver/biliary tissue (I² = 57%; p = 0.02). In conclusion, based on low-certainty data, Helicobacter species chronic infection is associated with a tripled risk of hepatobiliary tract malignancy. Prospective studies are required to delineate public health interventions.

Concomitant Diseases and Co-contribution on Progression of Liver Stiffness in Patients with Hepatitis B Virus Infection

BACKGROUND

The association between hepatitis B and concomitant diseases, such as fatty liver, T2DM, MetS, and Hp infection, remains unclear.

AIM

The present study was to illustrate the association and explore the co-contribution on abnormal transaminase and progression of liver stiffness.

METHODS

A total of 95,998 participants underwent HBsAg screening in West China Hospital from 2014 to 2017. Multivariable logistic regression was used to determine the adjusted odds ratios.

RESULTS

The prevalence of HBsAg-positive rate was 8.30% of our included study population. HBsAg positive was associated with negative risk of fatty liver (odds ratio [OR] 0.71, 95% confidence interval [CI] 0.65-0.78, p < 0.001) and MetS (OR 0.74, 95% CI 0.67-0.84, p < 0.001), and with positive risk of Hp infection (OR 1.09, 95% CI 1.02-1.17, p = 0.012) and T2DM (OR 1.18, 95% CI 1.01-1.40, p = 0.043). Besides, HBsAg-positive patients with T2DM had higher risk of elevated ALT (OR 2.09, 95% CI 1.69-2.83, p < 0.001 vs OR 1.59, 95% CI 1.51-1.68, p < 0.001), AST (OR 2.69, 95% CI 1.98-3.65, p < 0.001 vs OR 1.89, 95% CI 1.76-2.02, p < 0.001) than HBV alone. In addition to HBV, T2DM also can increase the risk of liver fibrosis (OR 3.23, 95% CI 1.35-7.71, p = 0.008) and cirrhosis (OR 4.31, 95% CI 1.41-13.20, p = 0.010).

CONCLUSION

Hepatitis B patients have a lower risk of fatty liver and MetS, and a higher risk of T2DM and Hp infection. Besides, T2DM might be possibly associated with abnormal liver transaminase and fibrosis progression in HBsAg-positive patients.

Multifunctional Therapeutic Approach of Nanomedicines against Inflammation in Cancer and Aging

Cancer is a fatal disorder that affects people across the globe, yet existing therapeutics are ineffective. The development of submicrometer transport for optimizing the biodistribution of systemically provided medications is the focus of nanomedicine. Nanoparticle- (NP-) based treatments may enable the development of novel therapeutic approaches to combat this deadly disorder. In multifunctional, multimodal imaging, and drug delivery carriers, NPs generally play a major role. They have emerged as potential strategies for the invention of innovative therapeutic procedures in the last decade. The exponential growth of nanotechnologies in recent years has increased public awareness of the application of these innovative therapeutic approaches. Many tumor-targeted nanomedicines have been studied in cancer therapy, and there is clear evidence for a significant improvement in the therapeutic index of antineoplastic drugs. Age-related factors such as metabolic and physiological alterations in old age and inadequate animal models are currently understudied in nanomedicine and pharmacology. This review highlighted the most important targeting approaches, as well as public awareness, therapeutic advancements, and future prospects in age-related metabolic variations, and tumor-targeted nanomedicine studies.

Coinfection of Helicobacter pylori and Hepatitis C Virus in the Development of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

Background

The relationship between Helicobacter pylori (H. pylori) and hepatocellular carcinoma (HCC) was firstly proposed in 1994 after Ward et al demonstrated the role of Helicobacter hepaticus in the development of HCC in mice. Studies also investigated the role of hepatitis B virus (HBV) and hepatitis C virus (HCV) coexisting with H. pylori in causing HCC. A causal relationship was never confirmed, and the relationship remains controversial. This meta-analysis aimed to summarize the research on this topic and investigate if a relationship exists between H. pylori infection and the development of HCC and if the presence of HCV and HBV along with H. pylori plays a role in liver carcinogenesis.

Methods

Following PRISMA guidelines, we performed a systematic review of all relevant studies published in the literature using the keywords “Helicobacter pylori” and “hepatocellular carcinoma” on major literature databases, including PubMed, EMBASE, Web of Science, and Cochrane controlled trials register. A total of 656 research studies were identified between 1994 and 2020. Of those, 26 qualified under our selection criteria. Patients who were positive for HCC were classified as cases and those who did not have HCC were classified as controls. The H. pylori status and HCV status, if available, were identified for both groups. Statistical analysis was carried out by a biostatistician according to the Cochrane reviewer’s handbook.

Results

Out of the 26 studies included in the final analysis, 13 were retrospective case-control studies, 11 were cross-sectional studies, and two were prospective case-control and cohort studies. Overall, the prevalence of H. pylori infection was 64.78% (561 of 866) amongst HCC cases and 47.92% (1,718 of 3,585) in the non-HCC control group. The summary odds ratio (OR) for the association of H. pylori infection with the risk for HCC (using the random-effects model, which accounted for the heterogeneity across the 26 studies) was determined to be 4.75 (95% confidence interval (CI): 3.06 - 7.37, I² = 63%). We also performed a subgroup analysis to determine the odds of developing HCC in the presence of H. pylori and HCV coinfection. The summary OR of it was 12.76 (95% CI: 4.13 - 39.41, I² = 78%). The summary OR for the risk of developing HCC in the presence of HCV infection without H. pylori infection was 2.21 (95% CI: 0.70 - 6.94, I² = 79%). Whereas, the odds of developing HCC in the presence of only H. pylori infection without HCV was found to be 0.54 (95% CI: 0.11 - 2.63, I² = 80%). There was inconsistency in the data presented in some studies regarding HCV infection status. Since data were extracted from different study designs, subgroup analysis by study design was performed which showed no significant difference between the study groups (P = 0.5705).

Conclusion

This meta-analysis demonstrates a positive association between H. pylori infection and the development of HCC. There is a significantly higher risk of developing HCC in the presence of HCV infection along with H. pylori. Further prospective cohort studies are needed to prove the causal relationship, especially in cases of HBV and HCV coinfection, and cirrhotic patients.

Helicobacters and cancer, not only gastric cancer?

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

Role of microbiota-derived short-chain fatty acids in cancer development and prevention

Following cancer, cells in a particular tissue can no longer respond to the factors involved in controlling cell survival, differentiation, proliferation, and death. In recent years, it has been indicated that alterations in the gut microbiota components, intestinal epithelium, and host immune system are associated with cancer incidence. Also, it has been demonstrated that the short-chain fatty acids (SCFAs) generated by gut microbiota are vitally crucial in cell homeostasis as they contribute to the modulation of histone deacetylases (HDACs), resulting effected cell attachment, immune cell immigration, cytokine production, chemotaxis, and the programmed cell death. Therefore, the manipulation of SCFA levels in the intestinal tract by alterations in the microbiota structure can be potentially taken into consideration for cancer treatment/prevention. In the current study, we will explain the most recent findings on the detrimental or protective roles of SFCA (particularly butyrate, propionate, and acetate) in several cancers, including bladder, colon, breast, stomach, liver, lung, pancreas, and prostate cancers.

Implications of the Human Gut-Brain and Gut-Cancer Axes for Future Nanomedicine

Recent clinical and pathological evidence have implicated the gut microbiota as a nexus for modulating the homeostasis of the human body, impacting conditions from cancer and dementia to obesity and social behavior. The connections between microbiota and human diseases offer numerous opportunities in medicine, most of which have limited or no therapeutic solutions available. In light of this paradigm-setting trend in science, this review aims to provide a comprehensive and timely summary of the mechanistic pathways governing the gut microbiota and their implications for nanomedicines targeting cancer and neurodegenerative diseases. Specifically, we discuss in parallel the beneficial and pathogenic relationship of the gut microbiota along the gut-brain and gut-cancer axes, elaborate on the impact of dysbiosis and the gastrointestinal corona on the efficacy of nanomedicines, and highlight a molecular mimicry that manipulates the universal cross-β backbone of bacterial amyloid to accelerate neurological disorders. This review further offers a forward-looking section on the rational design of cancer and dementia nanomedicines exploiting the gut-brain and gut-cancer axes.

Diagnostic reliability of nested PCR depends on the primer design and threshold abundance of Helicobacter pylori in biopsy, stool, and saliva samples

BACKGROUND

The aim of this work was to find a reliable nested PCR for the detection of Helicobacter pylori in biopsy, stool, and saliva specimens.

MATERIALS AND METHODS

Novel nested PCR was elaborated and validated on 81 clinical biopsy, stool, and saliva samples from the same individual and compared to available H pylori assays: histology, rapid urease test (RUT), stool antigen test (SAT), ¹³ C-urea breath test (UBT).

RESULTS

The efficiency and selectivity of 17 published nested polymerase chain reactions (PCR) available for Helicobacter pylori detection were re-evaluated. Most of them had serious limitations and mistakes in primer design. Hence, we elaborated a nested PCR for the unambiguous identification of H pylori in biopsy, stool, and saliva, using primers targeted to variable regions of the 16S ribosomal RNA (rRNA) gene. Moreover, we determined the detection limit by adding a known number of cells. This number was as low as 0.5 cells in a PCR vial, but due to the DNA isolation procedures, it required 1-5 × 10³ cells/g or ml of specimen. The sensitivity for nested PCR from stomach biopsies was on the same scale as ¹³ C-UBT (93.8%), but it was much lower in amplifications from stool (31.3%). Sequencing of all obtained PCR products exclusively confirmed H pylori-specific DNA sequences.

CONCLUSIONS

Elaborated nested PCR assay can serve as an auxiliary method for controversial samples (patients with bleeding or taking proton-pump inhibitor) in laboratories with basic equipment. The sensitivity and specificity for the amplification from gastric biopsies was almost like ¹³ C-UBT. Despite the good sensitivity, the threshold occurrence and the ability to survive in the oral cavity aside from and independent of the stomach is the reason why H pylori DNA cannot be reliably detected in saliva, stool, and some biopsy samples.

Exploring the microbiota to better understand gastrointestinal cancers physiology

Gastrointestinal cancers account for around 40% of cancer-related deaths worldwide, representing a global health burden. There is a growing body of evidence highlighting the link between microbiota and gastrointestinal tumorigenesis and/or resistance to therapy. In the present manuscript, we reviewed the published studies on the relationship between the microbiota and the different gastrointestinal tumors, namely, gastric, colorectal and esophageal, including also the cancer of accessory organs such as liver and pancreas. There is an emergent interest in the manipulation of gastrointestinal microflora in order to understand the gastrointestinal tumorigenesis' processes and the establishment of chemoresistance mechanisms.

Helicobacter pylori Infection as a Risk Factor for Hepatocellular Carcinoma: A Case-Control Study in Ethiopia

Background and Aims. Hepatocellular carcinoma is a major cause of cancer death worldwide, accounting for over half a million deaths per year. Its incidence varies with geographic locations and the type of etiologic factors. In Ethiopia, unidentified causes of liver disease are of sizeable proportion. Recent studies have shown an association of H. pylori infection with different spectrums of chronic liver disease. This study was conducted at St. Paul's Hospital Millennium Medical College in Ethiopia and assesses liver cancer and the association with H. pylori infection. Method. A prospective case-control study conducted on patients with chronic liver disease presenting with a suspicious liver lesion and diagnosed to have HCC in the Gastrointestinal (GI) Clinic of St. Paul's Hospital MMC from Dec 30, 2016, to Nov 1, 2017 G.C. Descriptive surveys on clinical history and physical examination and laboratory profiles were obtained, and the clinical course of the patients including the type of treatment was followed prospectively. Control cases were taken from adult patients without evidence of liver disease in the internal medicine clinic coming for routine evaluation. After collection data were analyzed using SPSS version 23 and associations were assessed using chi-square test. Binary logistic regression was used to assess the association of HCC with different variables and H. pylori infection. All variables with p-value <0.05 were considered as statistically significant. Results. One hundred twenty patients were analyzed with equal representation of cases and controls. The majority of patients with HCC were male with a mean age of 36 years. Older age adjusted Odds Ratio (AOR) (95%CI, p-value) 1.07(1.03-1.09, <0.001), viral hepatitis B (AOR) (95%CI, p-value) 6.19 (1.92-19.93, 0.002), and H. pylori infection (AOR) (95%CI, p-value) 5.22 (2.04-13.31, <0.001) were statistically significantly associated with HCC. Conclusion. H. pylori infection is associated with HCC in this case-control study. This study supports the emerging evidence of H. pylori association with other extra-gastric manifestations.

Opisthorchiasis-Induced Cholangiocarcinoma: How Innate Immunity May Cause Cancer

Innate, inflammatory responses towards persistent Opisthorchis viverrini (OV) infection are likely to contribute to the development of cholangiocarcinoma (CCA), a liver cancer that is rare in the West but prevalent in Greater Mekong Subregion countries in Southeast Asia. Infection results in the infiltration of innate immune cells into the bile ducts and subsequent activation of inflammatory immune responses that fail to clear OV but instead may damage local tissues within the bile ducts. Not all patients infected with OV develop CCA, and so tumourigenesis may be dependent on multiple factors including the magnitude of the inflammatory response that is activated in infected individuals. The purpose of this review is to summarize how innate immune responses may promote tumourigenesis following OV infection and if such responses can be used to predict CCA onset in OV-infected individuals. It also hypothesizes on the role that Helicobacterspp., which are associated with liver fluke infections, may play in activation of the innate the immune system to promote tissue damage and persistent inflammation leading to CCA.

Effects of Medium- and Long-Chain Triacylglycerols on Lipid Metabolism and Gut Microbiota Composition in C57BL/6J Mice

Obesity is related to an increasing risk of chronic diseases. Medium- and long-chain triacylglycerols (MLCT) have been recognized as a promising choice to reduce body weight. In this study, three MLCT with different contents of medium-chain fatty acids (MCFA) (10-30%, w/w) were prepared, and their effects on lipid metabolism and fecal gut microbiota composition of C57BL/6J mice were systematically investigated. MLCT with 30% (w/w) MCFA showed the best performance in decreasing body weight gain as well as optimizing serum lipid parameters and liver triacylglycerol content. The expression levels of genes encoding enzymes for fatty acid degradation increased markedly and expression levels of genes encoding enzymes for de novo fatty acid biosynthesis decreased significantly in the liver of mice treated with MLCT containing 30% (w/w) MCFA. Interestingly, the dietary intake of a high fat diet containing MLCT did significantly decrease the ratio of Firmicutes to Bacteroidetes and down-regulate the relative abundance of Proteobacteria that may attribute to weight loss. Furthermore, we found a notable increase in the total short-chain fatty acid (SCFA) content in feces of mice on a MLCT containing diet. All these results may be concomitantly responsible for the antiobesity effect of MLCT with relatively high contents of MCFA.

Elevated prevalence of Helicobacter species and virulence factors in opisthorchiasis and associated hepatobiliary disease

Recent reports suggest that Opisthorchis viverrini serves as a reservoir of Helicobacter and implicate Helicobacter in pathogenesis of opisthorchiasis-associated cholangiocarcinoma (CCA). Here, 553 age-sex matched cases and controls, 293 and 260 positive and negative for liver fluke O. viverrini eggs, of residents in Northeastern Thailand were investigated for associations among infection with liver fluke, Helicobacter and hepatobiliary fibrosis. The prevalence of H. pylori infection was higher in O. viverrini-infected than uninfected participants. H. pylori bacterial load correlated positively with intensity of O. viverrini infection, and participants with opisthorchiasis exhibited higher frequency of virulent cagA-positive H. pylori than those free of fluke infection. Genotyping of cagA from feces of both infected and uninfected participants revealed that the AB genotype accounted for 78% and Western type 22%. Participants infected with O. viverrini exhibited higher prevalence of typical Western type (EPIYA ABC) and variant AB'C type (EPIYT B) CagA. Multivariate analyses among H. pylori virulence genes and severity of hepatobiliary disease revealed positive correlations between biliary periductal fibrosis during opisthorchiasis and CagA and CagA with CagA multimerization (CM) sequence-positive H. pylori. These findings support the hypothesis that H. pylori contributes to the pathogenesis of chronic opisthorchiasis and specifically to opisthorchiasis-associated CCA.

Helicobacter Species are Possible Risk Factors of Cholangiocarcinoma

Several infectious agents are considered to be causes of cancer in human, mainly hepatitis B and C viruses, high-risk human pailloma viruses, Helicobacter pylori, Clonorchis sinensis, and Opisthorchis viverrini. Here we described the evident research and the association between Helicobacter spp. and biliary tract cancer particularly cholangiocarcinoma (CCA). Global epidemiological studies have suggested that Helicobacter spp. are possible risk factors for biliary tract diseases. Molecular studies support a linkage of Helicobacter spp. with CCA development. H. pylori, H. bilis, and H. hepaticus, are found in CCA, but the most common species are H. pylori and H. bilis. The type of CCA are associated with Helicobacter spp. include extrahepatic CCA, and common bile duct cancer. Up to the present, however, the results from different regions, materials and methods, sub-sites of cancer, and controls have not been consistent, thus introducing heterogeneity. Therefore, a comparison between co-Helicobacter spp.-CCA in the countries with low and high incident of CCA is required to settle the question. Furthermore, clarifying variation in the role of Helicobacter species in this CCA, including pathogenesis of CCA through enhanced biliary cell inflammation and proliferation, is necessary.

Chronic Opisthorchis viverrini Infection Changes the Liver Microbiome and Promotes Helicobacter Growth

Adults of Opisthorchis viverrini reside in the biliary system, inducing inflammation of bile ducts and cholangitis, leading to hepatobiliary disease (HBD) including cholangiocarcinoma. O. viverrini infection also has major implications for the bacterial community in bile ducts and liver. To investigate this in chronic O. viverrini infection (≥ 8 months p.i.), bacterial genomic DNA from livers of hamsters and from worms was investigated using culture techniques, PCR for Helicobacter spp. and high-throughput next-generation sequencing targeting the V3-V4 hypervariable regions of prokaryotic 16S rRNA gene. Of a total of 855,046 DNA sequence reads, 417,953 were useable after filtering. Metagenomic analyses assigned these to 93 operational taxonomic units (OTUs) consisting of 80 OTUs of bacteria, including 6 phyla and 42 genera. In the chronic O. viverrini-infected group, bacterial community composition and diversity were significantly increased compared to controls. Sequences of Fusobacterium spp. were the most common (13.81%), followed by Streptococcus luteciae (10.76%), Escherichia coli (10.18%), and Bifidobacterium spp. (0.58%). In addition, Helicobacter pylori (0.17% of sequences) was also identified in the liver of chronic O. viverrini infections, but not in normal liver. The presence of H. pylori was confirmed by PCR and by use of an antibody against bacterial antigen, supporting the metagenomics data. The identities of bacteria cultured for enrichment suggested that chronic O. viverrini infection changes the liver microbiome and promotes Helicobacter spp. growth. There may be synergy between O. viverrini and the liver microbiome in enhancing immune response-mediated hepatobiliary diseases.

Helicobacter pylori infection may increase the risk of progression of chronic hepatitis B disease among the Chinese population: a meta-analysis

OBJECTIVES

Helicobacter pylori is a bacterium that infects over 50% of the human population worldwide. An increasing number of studies have demonstrated that H. pylori may cause liver diseases, and the underlying relationship between H. pylori infection and chronic hepatitis B has attracted much attention. This study aimed to examine the association between H. pylori infection and the progression of chronic hepatitis B in the Chinese population.

METHODS

A search was performed of the PubMed/MEDLINE, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) databases, as well as the Chinese databases, China National Knowledge Infrastructure and Wanfang Data, for studies published between January 1, 1994 and November 1, 2015.

RESULTS

In total, 2977 patients were included in the chronic hepatitis B group, while 1668 participants were included in the healthy control group. The prevalence of H. pylori among patients with chronic hepatitis B was significantly higher than that among those without chronic hepatitis B. The pooled odds ratio was 3.17. In the subgroup analysis, the odds ratio was 4.28 for hepatitis B virus (HBV)-related cirrhosis and 6.02 for hepatocellular carcinoma.

CONCLUSION

These results indicate a strong relationship between H. pylori and chronic hepatitis B, particularly during HBV progression.

Association between Helicobacter spp. infections and hepatobiliary malignancies: a review

Hepatobiliary cancers are highly lethal cancers that comprise a spectrum of invasive carcinomas originating in the liver hepatocellular carcinoma, the bile ducts intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma, the gallbladder and the ampulla of Vater (collectively known as biliary tract cancers). These tumors account for approximately 13% of all annual cancer-related deaths worldwide and for 10%-20% of deaths from hepatobiliary malignancies. Cholangiocarcinoma (CCA) is a devastating disease that displays a poor survival rate for which few therapeutic options are available. Population genetics, geographical and environmental factors, cholelithiasis, obesity, parity, and endemic infection with liver flukes have been identified as risk factors that influence the development of biliary tract tumors. Other important factors affecting the carcinogenesis of these tumors include chronic inflammation, obstruction of the bile ducts, and impaired bile flow. It has been suggested that CCA is caused by infection with Helicobacter species, such as Helicobacter bilis and Helicobacter hepaticus, in a manner that is similar to the reported role of Helicobacter pylori in distal gastric cancer. Due to the difficulty in culturing these Helicobacter species, molecular methods, such as polymerase chain reaction and sequencing, or immunologic assays have become the methods of choice for diagnosis. However, clinical studies of benign or malignant biliary tract diseases revealed remarkable variability in the methods and the findings, and the use of uniform and validated techniques is needed.

Novel aspects of the liver microenvironment in hepatocellular carcinoma pathogenesis and development

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer that is derived from hepatocytes and is characterised by high mortality rate and poor prognosis. While HCC is driven by cumulative changes in the hepatocyte genome, it is increasingly recognised that the liver microenvironment plays a pivotal role in HCC propensity, progression and treatment response. The microenvironmental stimuli that have been recognised as being involved in HCC pathogenesis are diverse and include intrahepatic cell subpopulations, such as immune and stellate cells, pathogens, such as hepatitis viruses, and non-cellular factors, such as abnormal extracellular matrix (ECM) and tissue hypoxia. Recently, a number of novel environmental influences have been shown to have an equally dramatic, but previously unrecognized, role in HCC progression. Novel aspects, including diet, gastrointestinal tract (GIT) microflora and circulating microvesicles, are now being recognized as increasingly important in HCC pathogenesis. This review will outline aspects of the HCC microenvironment, including the potential role of GIT microflora and microvesicles, in providing new insights into tumourigenesis and identifying potential novel targets in the treatment of HCC.

Relationship between Helicobacter hepaticus infection and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has a high incidence worldwide, with a low diagnostic rate in the early period and therefore a high death rate. Causes for some cases of liver cancer are not completely clear. The finding that the rate of liver cancer in male A/Jr mice is significantly higher makes researchers realize that Helicobacter hepaticus may cause HCC in human beings. To get a new perspective for exploring causes of liver cancer, this paper introduces the biological nature of and detecting methods for Helicobacter hepaticus, as well as the relationship between Helicobacter hepaticus infection and HCC. Helicobacter hepaticus infection may play an important role in some HCC cases.

Helicobacter species infection may be associated with cholangiocarcinoma: a meta-analysis

OBJECTIVE

Since the discovery of Helicobacter species in human biliary system, the association between Helicobacter species infection and cholangiocarcinoma is under debate. This meta-analysis aims to explore this issue.

METHODS

Literature search was carried out to identify all eligible articles. We performed overall meta-analysis of all included studies and subgroup analysis based on regional distribution. Subgroup analysis in the light of detection methods and specimens was also conducted.

RESULTS

Ten case-control studies were included. Overall meta-analysis favoured a significant association between Helicobacter species infection and cholangiocarcinoma (cumulative OR 8.88, 95% CI 3.67-21.49). Subgroup analysis based on geographic distribution indicated that Helicobacter species infection may serve as a risk factor not only in a region with high cholangiocarcinoma incidence (Asia, OR 6.68, 95% CI 2.29-19.49) but also in low incidence region (Europe, OR 14.90, 95% CI 4.79-46.35). The other subgroup analysis showed that PCR was the most effective and efficient method to detect Helicobacter species in surgically resected tissue and bile. There was significant heterogeneity among studies and obvious publication bias.

CONCLUSION

Our meta-analysis supports the possible association between Helicobacter species infection and cholangiocarcinoma. Further investigations are required to clarify the role of Helicobacter species in this malignancy.

Detection of Helicobacter pylori DNA in preliminary stage gastric cancer cells

AIMS

Helicobacter pylori (HP) DNA was assayed using a newly fabricated voltammetric handheld circuit equipped with an interfaced graphite pencil electrode (PE) sensor.

METHODS

Under optimum analytical parameters, the square-wave (SW) stripping detection range attained was 0.1-0.7 mg/L.

RESULTS

A relative standard deviation of 1.68% (RSD, n = 5) was observed at a 3.2 mg/L HP DNA within a 90 s accumulation time. Under these conditions, the analytical detection limit approached 0.07 mg/L.

CONCLUSIONS

The developed methods can be applied to HP assays of preliminary stage gastric cancer patient tissues.

Effects of human and porcine bile on the proteome of Helicobacter hepaticus

BACKGROUND

Helicobacter hepaticus colonizes the intestine and liver of mice causing hepatobiliary disorders such as hepatitis and hepatocellular carcinoma, and has also been associated with inflammatory bowel disease in children. In its habitat, H. hepaticus must encounter bile which has potent antibacterial properties. To elucidate virulence and host-specific adaptation mechanisms of H. hepaticus modulated by human or porcine bile, a proteomic study of its response to the two types of bile was performed employing two-dimensional gel electrophoresis (2-DE) and mass spectrometry.

RESULTS

The 2-DE and mass spectrometry analyses of the proteome revealed that 46 proteins of H. hepaticus were differentially expressed in human bile, 18 up-regulated and 28 down-regulated. In the case of porcine bile, 32 proteins were differentially expressed of which 19 were up-regulated, and 13 were down-regulated. Functional classifications revealed that identified proteins participated in various biological functions including stress response, energy metabolism, membrane stability, motility, virulence and colonization. Selected genes were analyzed by RT-PCR to provide internal validation for the proteomic data as well as provide insight into specific expressions of motility, colonization and virulence genes of H. hepaticus in response to human or porcine bile.

CONCLUSIONS

Overall, the data suggested that bile is an important factor that determines virulence, host adaptation, localization and colonization of specific niches within host environment.

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.

Gut-liver axis plays a role in hepatocarcinogenesis of patients with Crohn’s disease

The development of hepatocellular carcinoma (HCC) is attributed to several factors, including chronic viral infection, alcohol consumption, exposure to aflatoxin B1 and metabolic disorders. Several recent reports have shown that HCC can occur in patients with long-standing Crohn’s disease (CD) in the absence of other underlying high-risk liver diseases. There may be an association between CD and hepatocarcinogenesis, however, the precise mechanism for this requires further investigations.

Role of cagA-positive Helicobacter pylori on cell proliferation, apoptosis, and inflammation in biliary cells

BACKGROUND AND AIMS

The pathogenesis of Helicobacter pylori in the human hepatobiliary system has not been clearly elucidated. We compared the effects of H. pylori cagA(+) and cagA(-) mutant strains on cell proliferation, apoptosis, and inflammation in a cholangiocarcinoma (CCA) cell line (KKU-100).

METHODS

MTT and BrdU were used to determine cell viability and DNA synthesis, respectively. The results were further investigated by RT-PCR and Western-blot analysis. The production of interleukin-8 (IL-8) was measured by ELISA assay.

RESULTS

At low H. pylori inocula (cell-bacteria ratio of 1:1), the H. pylori cagA(+) strain showed a significant stimulation in KKU-100 cell growth (109 ± 1.79%) and DNA synthesis (131 ± 3.39%) than did the H. pylori cagA(-) strain (95 ± 3.06% and 120 ± 2.32%, respectively), through activation of the anti-apoptotic bcl-2 gene, MAP kinase and NF- κB cascade. By contrast, at high H. pylori inocula (cell-bacteria ratio of 1:200), the H. pylori cagA(+) strain showed a significant reduction in KKU-100 cell survival (49 ± 2.47%) and DNA synthesis (49 ± 1.14%) than did the H. pylori cagA(-) strain (60 ± 1.30% and 75 ± 4.00%, respectively), by increased iNOS, p53 and bax, while decreased bcl-2. Additionally, caspase-8 and -3 protein were activated. The H. pylori cagA (+) strain had significantly stronger effect on IL-8 production than did the cagA(-) strain.

CONCLUSIONS

These results suggest that the H. pylori cagA(+) strain may play an important role in the development of biliary cancer by disturbing cell proliferation, apoptosis, and promoting cell inflammation in the CCA cell line.

Helicobacter species and common gut bacterial DNA in gallbladder with cholecystitis

AIM: To analyze the association between Helicobacter spp. and some common gut bacteria in patients with cholecystitis.

METHODS: A nested-polymerase chain reaction (PCR), specific to 16S rRNA of Helicobacter spp. was performed on paraffin-embedded gallbladder samples of 100 cholecystitis and 102 control cases. The samples were also analyzed for some common gut bacteria by PCR. Positive samples were sequenced for species identification.

RESULTS: Helicobacter DNA was found in seven out of 100 cases of acute and chronic cholecystitis. Sequence analysis displayed Helicobacter pullorum (H. pullorum) in six cases and Helicobacter pylori in one; H. pullorum was only found in cases with metaplasia. Control samples were negative for Helicobacter spp. and some common gut bacteria. There was a significant difference (P = 0.007) between cholecystitis and control samples for Helicobacter DNA.

CONCLUSION: A possible relationship was detected between Helicobacter DNA and cholecystitis. Further serological and immunohistochemical studies are needed to support these data.

Contribution of gut bacteria to liver pathobiology

Emerging evidence suggests a strong interaction between the gut microbiota and health and disease. The interactions of the gut microbiota and the liver have only recently been investigated in detail. Receiving approximately 70% of its blood supply from the intestinal venous outflow, the liver represents the first line of defense against gut-derived antigens and is equipped with a broad array of immune cells (i.e., macrophages, lymphocytes, natural killer cells, and dendritic cells) to accomplish this function. In the setting of tissue injury, whereby the liver is otherwise damaged (e.g., viral infection, toxin exposure, ischemic tissue damage, etc.), these same immune cell populations and their interactions with the infiltrating gut bacteria likely contribute to and promote these pathologies. The following paper will highlight recent studies investigating the relationship between the gut microbiota, liver biology, and pathobiology. Defining these connections will likely provide new targets for therapy or prevention of a wide variety of acute and chronic liver pathologies.

Hepatocellular carcinoma: prevalence and molecular pathogenesis of Helicobacter spp

Helicobacter pylori infection is one of the most common chronic bacterial infections in humans. The association of other Helicobacter spp. with extragastric diseases in animals is well established, and a role of these bacteria in human liver disease is becoming clearer. Several case-control studies have reported possible associations of Helicobacter spp. with various liver diseases, including hepatocellular carcinoma, which is the fifth most common type of carcinoma among men worldwide, and the eighth most common among women. Thus, it is important to understand molecular mechanisms that may lead to hepatotoxicity or hepatocellular dysfunction in which Helicobacter spp. may play a role in inducing malignant transformation of liver cells.

Emerging infections of the gastrointestinal tract

Infections account for significant GI morbidity and mortality worldwide. New organisms are being identified, associated with diarrhoeal illness and some with other gastrointestinal illness as well. Among GI viruses, Sapovirus is now recognised to cause diarrhoea, especially in children. A hypervirulent strain of Clostridium difficile has caused epidemics in many countries. Newly identified bacterial species that may cause diarrhoea include Campylobacter concisus, Arcobacteria, Edwardsiella tarda, Aeromonas, Plesiomonas and Laribacter. Helicobacteria are reviewed, as well as the role of gastric acid suppression in predisposing to enteric infections.

Extragastric manifestations of Helicobacter pylori infection: other Helicobacters

The finding that Helicobacter pylori is the main cause of gastritis and peptic ulcer disease has opened a new era in the gastrointestinal world. Today there is evidence that H. pylori may also play a role in different nongastric diseases, opening the new "extragastric manifestations of H. pylori infection" field. Concerning this, several studies have been published in the last year. The most convincing data arise from those investigating idiopathic thrombocytopenic purpura and sideropenic anemia, while there is also an increasing evidence for a possible association with atherosclerotic disease. Furthermore, the discovery of a number of other novel Helicobacter species has stimulated the research in different extragastric diseases, in which an infectious hypothesis is plausible. In particular, several species have been studied for a potential role in different liver and intestinal diseases with interesting findings.