Antibody Responses to Helicobacter pylori and Risk of Developing Colorectal Cancer in a European Cohort

Relationship between Helicobacter pylori infection and colorectal polyp/colorectal cancer

Helicobacter pylori (H. pylori) plays an important role in the development of gastric cancer, although its association to colorectal polyp (CP) or colorectal cancer (CRC) is unknown. In this issue of World Journal of Gastrointestinal Surgery, Zhang et al investigated the risk factors for H. pylori infection after colon polyp resection. Importantly, the researchers used R software to create a prediction model for H. pylori infection based on their findings. This editorial gives an overview of the association between H. pylori and CP/CRC, including the clinical significance of H. pylori as an independent risk factor for CP/CRC, the underlying processes of H. pylori-associated carcinogenesis, and the possible risk factors and identification of H. pylori.

Helicobacter pylori and Gastrointestinal Cancers: Recent Advances and Controversies

Helicobacter pylori (H pylori), a gastric bacterium, has been extensively studied for its association with gastritis, peptic ulcers, and gastric cancer. However, recent evidence suggests its potential implications beyond the stomach, linking it to other gastrointestinal malignancies, such as esophageal cancer, liver cancer, pancreatic cancer, gallbladder cancer, and colorectal cancer. In light of the expanding research landscape and the increasing interest in exploring H pylori broader role in gastrointestinal tumorigenesis, this comprehensive review aims to elucidate the relationship between H pylori and gastrointestinal tumors. This review encompasses recent epidemiological studies, research progress, and emerging perspectives, providing a comprehensive assessment of the relationship between H pylori and gastrointestinal tumors. The findings highlight the captivating world of H pylori and its intricate involvement in gastrointestinal malignancies.

Effects of Helicobacter pylori infection on intestinal microbiota, immunity and colorectal cancer risk

Infecting about half of the world´s population, Helicobacter pylori is one of the most prevalent bacterial infections worldwide and the strongest known risk factor for gastric cancer. Although H. pylori colonizes exclusively the gastric epithelium, the infection has also been associated with various extragastric diseases, including colorectal cancer (CRC). Epidemiological studies reported an almost two-fold increased risk for infected individuals to develop CRC, but only recently, direct causal and functional links between the chronic infection and CRC have been revealed. Besides modulating the host intestinal immune response, H. pylori is thought to increase CRC risk by inducing gut microbiota alterations. It is known that H. pylori infection not only impacts the gastric microbiota at the site of infection but also leads to changes in bacterial colonization in the distal large intestine. Considering that the gut microbiome plays a driving role in CRC, H. pylori infection emerges as a key factor responsible for promoting changes in microbiome signatures that could contribute to tumor development. Within this review, we want to focus on the interplay between H. pylori infection, changes in the intestinal microbiota, and intestinal immunity. In addition, the effects of H. pylori antibiotic eradication therapy will be discussed.

Carcinogenic microbiota and its role in colorectal cancer development

Colorectal cancer (CRC) is one of the most common malignancies worldwide. The main risk factors for CRC are family history of colon or rectal cancer, familial polyposis syndrome or hereditary nonpolyposis, and chronic inflammatory bowel diseases (ulcerative colitis and Crohn's disease). Recent studies show that the gastrointestinal microbiota play a significant role in colorectal carcinogenesis. In this review we present the microorganisms, whose influence on the development of CRC has been proven: Bacteroides fragilis, Clostridioides and Clostridium spp., Enterococcus faecalis, Escherichia coli, Fusobacterium nucleatum, Helicobacter pylori, Peptostreptococcus anaerobius, Streptococcus bovis group, and sulfate-reducing bacteria. Moreover, the carcinogenic mechanisms of action mediated by the above bacteria are laid out.

Impact of microbiota-immunity axis in pancreatic cancer management

The microbiota impact on human diseases is well-known, and a growing body of literature is providing evidence about the complex interplay between microbiota-immune system-human physiology/pathology, including cancers. Together with the defined risk factors (e.g., smoke habits, diet, diabetes, and obesity), the oral, gut, biliary, and intrapancreatic microbiota contribute to pancreatic cancer development through different pathways including the interaction with the immune system. Unfortunately, a great majority of the pancreatic cancer patients received a diagnosis in advanced stages not amenable to be radically treated and potentially cured. Given the poor pancreatic cancer prognosis, complete knowledge of these complicated relationships could help researchers better understand the disease pathogenesis and thus provide early potential non-invasive biomarkers, new therapeutic targets, and tools for risk stratification that might result in greater therapeutic possibilities and eventually in a better and longer patient survival.

Are Inflammatory Bowel Disease and Colorectal Carcinoma Associated with Helicobacter pylori? A Prospective Study and Meta-analysis

Observational studies regarding the correlation between colorectal carcinoma, inflammatory bowel disease and Helicobacter pylori infection are inconsistent. The present study aims to investigate the association between colorectal adenocarcinoma (CRA) and inflammatory bowel disease (IBD) with H. pylori status in 100 patients who have inflammatory bowel disease and colorectal carcinoma was confirmed disease by histological approach. Besides, a meta-analysis was performed of published studies, to evaluate the link between H. pylori infection and an increased risk of CRC and IBD. Among 67 cases with CRA and 33 cases with IBD, 59.7% and 51.5% were H. pylori positive; respectively. In the meta-analysis, thirty-nine articles were included, involving 13 231 cases with CRC and 2477 with IBD. The pooled odds ratio for CRC and IBD was 1.16 (95%CI = 0.73-1.82) and 0.42 (95%CI = 0.32-0.56); respectively. Our meta-analysis indicates that H. pylori is not associated with CRC.

The impact of the human microbiome in tumorigenesis, cancer progression, and biotherapeutic development

Background

Cancer impacts millions of lives globally each year, with approximately 10 million cancer-related deaths recorded worldwide in 2020. Mounting research has recognised the human microbiome as a key area of interest in the pathophysiology of various human diseases including cancer tumorigenesis, progression and in disease outcome. It is suggested that approximately 20% of human cancers may be linked to microbes. Certain residents of the human microbiome have been identified as potentially playing a role, including: Helicobacter pylori, Fusobacterium nucleatum, Escherichia coli, Bacteroides fragilis and Porphyromonas gingivalis.

Main body

In this review, we explore the current evidence that indicate a link between the human microbiome and cancer. Microbiome compositional changes have been well documented in cancer patients. Furthermore, pathogenic microbes harbouring specific virulence factors have been implicated in driving the carcinogenic activity of various malignancies including colorectal, gastric and pancreatic cancer. The associated genetic mechanisms with possible roles in cancer will be outlined. It will be indicated which microbes have a potential direct link with cancer cell proliferation, tumorigenesis and disease progression. Recent studies have also linked certain microbial cytotoxins and probiotic strains to cancer cell death, suggesting their potential to target the tumour microenvironment given that cancer cells are integral to its composition. Studies pertaining to such cytotoxic activity have suggested the benefit of microbial therapies in oncological treatment regimes. It is also apparent that bacterial pathogenic protein products encoded for by certain loci may have potential as oncogenic therapeutic targets given their possible role in tumorigenesis.

Conclusion

Research investigating the impact of the human microbiome in cancer has recently gathered pace. Vast amounts of evidence indicate the human microbiome as a potential player in tumorigenesis and progression. Promise in the development of cancer biomarkers and in targeted oncological therapies has also been demonstrated, although more studies are needed. Despite extensive in vitro and in vivo research, clinical studies involving large cohorts of human patients are lacking. The current literature suggests that further intensive research is necessary to validate both the role of the human microbiome in cancer, and the use of microbiome modification in cancer therapy.

Selective Inhibition of Helicobacter pylori Carbonic Anhydrases by Carvacrol and Thymol Could Impair Biofilm Production and the Release of Outer Membrane Vesicles

Helicobacter pylori, a Gram-negative neutrophilic pathogen, is the cause of chronic gastritis, peptic ulcers, and gastric cancer in humans. Current therapeutic regimens suffer from an emerging bacterial resistance rate and poor patience compliance. To improve the discovery of compounds targeting bacterial alternative enzymes or essential pathways such as carbonic anhydrases (CAs), we assessed the anti-H. pylori activity of thymol and carvacrol in terms of CA inhibition, isoform selectivity, growth impairment, biofilm production, and release of associated outer membrane vesicles-eDNA. The microbiological results were correlated by the evaluation in vitro of H. pylori CA inhibition, in silico analysis of the structural requirements to display such isoform selectivity, and the assessment of their limited toxicity against three probiotic species with respect to amoxicillin. Carvacrol and thymol could thus be considered as new lead compounds as alternative H. pylori CA inhibitors or to be used in association with current drugs for the management of H. pylori infection and limiting the spread of antibiotic resistance.

Relationship between Helicobacter pylori infection and epithelial-mesenchymal transition in colorectal cancer

BACKGROUND

Helicobacter pylori (H. pylori) has been recognized as a class I carcinogen, but its relationship with epithelial-mesenchymal transition (EMT) in colorectal cancer (CRC) T) is rarely reported. We hypothesized that H. pylori infection is related to EMT and may play an important role in the occurrence and development of CRC.

AIM

To investigate the relationship between H. pylori infection and EMT in CRC patients.

METHODS

From January 2016 to October 2017, 97 patients with CRC confirmed by surgical histopathological examination at our hospital were selected, and 118 patients who underwent bowel resection for other reasons during the same period were selected as a control group. Baseline data, H. pylori infection, and the positive rates of EMT-related proteins [E-cadherin (E-cad), vimentin (VIM), and β-catenin (β-CAT)] were compared between the two groups. The expression of EMT-related proteins and clinicopathological parameters in different H. pylori infection states were analyzed to assess the association of H. pylori infection with EMT-related protein expressionn and survival.

RESULTS

The positive rates of H. pylori infection and VIM and β-CAT protein expression were significantly higher in the observation group than in the control group, while the positive rate of E-cad protein expression was significantly lower in the observation group than in the control group (P < 0.05). In the observation group, significantly more H. pylori positive patients had poor differentiation, clinical stage Ⅲ/Ⅳ, deep infiltration (full thickness/extraserous ratio), regional lymph node metastasis, and positive VIM and β-CAT protein erexpression than H. pylori negative ones, while E-cad protein positive rate was significantly lower than that of H. pylori negative patients (P < 0.05). H. pylori infection was negatively correlated with E-cad protein expression, and positively correlated with VIM and β-CAT protein expression (P < 0.05). The 3-year survival rate of H. pylori positive patients was lower than that of H. pylori negative patients (P < 0.05).

CONCLUSION

There is a correlation between H. pylori infection and EMT in patients with CRC. H. pylori infection may cause CRC invasion, metastasis, and poor prognosis by promoting the occurrence of EMT.

Helicobacter pylori and colorectal neoplasms: a concise review

Helicobacter pylori is the main etiological agent of all malignant tumors caused by an infectious disease. It is a major, at times dominant, factor in the pathogenesis of a large spectrum of diseases such as acute and chronic gastritis, gastric and duodenal ulcers, gastric carcinoma, and lymphoma. Epidemiological and experimental studies suggest that H. pylori chronic infection may be related to different extragastric diseases, including colorectal neoplasms. This concise review aims to explore the association of H. pylori infection with colorectal cancer and adenoma, including the recent epidemiological findings, the diagnostic methods employed to detect H. pylori and virulent factors, and the potentially involved mechanisms. Furthermore, is attempted to establish the current data integration for causal inference using the Bradford-Hill causality criteria. The weak, although global, strength of the epidemiological positive association between H. pylori infection and colonic neoplasms associated to new mechanisms postulated to explain this interaction, including intestinal dysbiosis, should stimulate future studies. Prospective confirmatory studies to establish the role of H. pylori eradication in the process of carcinogenic transformation of the colonic epithelium may define its eventual role in the treatment and prevention of colonic neoplasms.

The Role of Gut Barrier Dysfunction and Microbiome Dysbiosis in Colorectal Cancer Development

Accumulating evidence indicates that breakdown of the+ protective mucosal barrier of the gut plays a role in colorectal cancer (CRC) development. Inflammation and oxidative stress in the colonic epithelium are thought to be involved in colorectal carcinogenesis and the breakdown of the integrity of the colonic barrier may increase the exposure of colonocytes to toxins from the colonic milieu, enhancing inflammatory processes and release of Reactive Oxygen Species (ROS). The aetiological importance of the gut microbiome and its composition - influenced by consumption of processed meats, red meats and alcoholic drinks, smoking, physical inactivity, obesity - in CRC development is also increasingly being recognized. The gut microbiome has diverse roles, such as in nutrient metabolism and immune modulation. However, microbial encroachment towards the colonic epithelium may promote inflammation and oxidative stress and even translocation of species across the colonic lumen. Recent research suggests that factors that modify the above mechanisms, e.g., obesity and Western diet, also alter gut microbiota, degrade the integrity of the gut protective barrier, and expose colonocytes to toxins. However, it remains unclear how obesity, lifestyle and metabolic factors contribute to gut-barrier integrity, leading to metabolic disturbance, colonocyte damage, and potentially to CRC development. This review will discuss the interactive roles of gut-barrier dysfunction, microbiome dysbiosis, and exposure to endogenous toxins as another mechanism in CRC development, and how biomarkers of colonic mucosal barrier function may provide avenues for disease, prevention and detection.