Helicobacter pylori and colorectal cancer-A bacterium going abroad?

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.

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.

Gut virome profiling identifies an association between temperate phages and colorectal cancer promoted by Helicobacter pylori infection

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers worldwide. While a close correlation between chronic Helicobacter pylori infection and CRC has been reported, the role of the virome has been overlooked. Here, we infected Apc-mutant mouse models and C57BL/6 mice with H. pylori and conducted a comprehensive metagenomics analysis of H. pylori-induced changes in lower gastrointestinal tract bacterial and viral communities. We observed an expansion of temperate phages in H. pylori infected Apc+/1638N mice at the early stage of carcinogenesis. Some of the temperate phages were predicted to infect bacteria associated with CRC, including Enterococcus faecalis. We also observed a high prevalence of virulent genes, such as flgJ, cwlJ, and sleB, encoded by temperate phages. In addition, we identified phages associated with pre-onset and onset of H. pylori-promoted carcinogenesis. Through co-occurrence network analysis, we found strong associations between the viral and bacterial communities in infected mice before the onset of carcinogenesis. These findings suggest that the expansion of temperate phages, possibly caused by prophage induction triggered by H. pylori infection, may have contributed to the development of CRC in mice by interacting with the bacterial community.

Helicobacter pylori infection: a dynamic process from diagnosis to treatment

Helicobacter pylori, a gram-negative microaerophilic pathogen, causes several upper gastrointestinal diseases, such as chronic gastritis, peptic ulcer disease, and gastric cancer. For the diseases listed above, H. pylori has different pathogenic mechanisms, including colonization and virulence factor expression. It is essential to make accurate diagnoses and provide patients with effective treatment to achieve positive clinical outcomes. Detection of H. pylori can be accomplished invasively and noninvasively, with both having advantages and limitations. To enhance therapeutic outcomes, novel therapeutic regimens, as well as adjunctive therapies with probiotics and traditional Chinese medicine, have been attempted along with traditional empiric treatments, such as triple and bismuth quadruple therapies. An H. pylori infection, however, is difficult to eradicate during treatment owing to bacterial resistance, and there is no commonly available preventive vaccine. The purpose of this review is to provide an overview of our understanding of H. pylori infections and to highlight current treatment and diagnostic options.

Probiotic-Derived Bioactive Compounds in Colorectal Cancer Treatment

Colorectal cancer (CRC) is a multifactorial disease with increased morbidity and mortality rates globally. Despite advanced chemotherapeutic approaches for the treatment of CRC, low survival rates due to the regular occurrence of drug resistance and deleterious side effects render the need for alternative anticancer agents imperative. Accumulating evidence supports that gut microbiota imbalance precedes the establishment of carcinogenesis, subsequently contributing to cancer progression and response to anticancer therapy. Manipulation of the gut microbiota composition via the administration of probiotic-derived bioactive compounds has gradually attained the interest of scientific communities as a novel therapeutic strategy for CRC. These compounds encompass miscellaneous metabolic secreted products of probiotics, including bacteriocins, short-chain fatty acids (SCFAs), lactate, exopolysaccharides (EPSs), biosurfactants, and bacterial peptides, with profound anti-inflammatory and antiproliferative properties. This review provides a classification of postbiotic types and a comprehensive summary of the current state of research on their biological role against CRC. It also describes how their intricate interaction with the gut microbiota regulates the proper function of the intestinal barrier, thus eliminating gut dysbiosis and CRC development. Finally, it discusses the future perspectives in precision-medicine approaches as well as the challenges of their synthesis and optimization of administration in clinical studies.

Gut microbiota mediated the therapeutic efficiency of Simiao decoction in the treatment of gout arthritis mice

BACKGROUND

Gut microbiota plays a significant role in the development and treatment of gouty arthritis. Simiao decoction has been shown to alleviate gouty arthritis by inhibiting inflammation, regulating NLRP3 inflammasome, and altering gut microbiota. However, there is no evidence to prove whether gut microbiota directly mediates the therapeutic efficiency of Simiao decoction in treating gout arthritis.

METHODS

In this study, fecal microbiota transplantation (FMT) was used to transfer the gut microbiota of gout arthritis mice treated with Simiao decoction or allopurinol to blank gout arthritis mice, in order to investigate whether FMT had therapeutic effects on gout arthritis.

RESULTS

Both Simiao decoction and allopurinol effectively reduced the levels of serum uric acid, liver XOD activity, foot thickness, serum IL-1β, and G-CSF in gout arthritis mice. However, Simiao decoction also had additional benefits, including raising the pain threshold, reducing serum TNF-α and IL-6, alleviating gut inflammation, and repairing intestinal pathology, which were not observed with allopurinol treatment. Moreover, Simiao decoction had a greater impact on gut microbiota than allopurinol, as it was able to restore the abundance of phylum Proteobacteria and genus Helicobacter. After transplantation into gout arthritis mice, gut microbiota altered by Simiao decoction exhibited similar therapeutic effects to those of Simiao decoction, but gut microbiota altered by allopurinol showed no therapeutic effect.

CONCLUSIONS

These findings demonstrates that Simiao decoction can alleviate gout arthritis symptoms by regulating gut microbiota.

Role of the gut microbiota in anticancer therapy: from molecular mechanisms to clinical applications

In the past period, due to the rapid development of next-generation sequencing technology, accumulating evidence has clarified the complex role of the human microbiota in the development of cancer and the therapeutic response. More importantly, available evidence seems to indicate that modulating the composition of the gut microbiota to improve the efficacy of anti-cancer drugs may be feasible. However, intricate complexities exist, and a deep and comprehensive understanding of how the human microbiota interacts with cancer is critical to realize its full potential in cancer treatment. The purpose of this review is to summarize the initial clues on molecular mechanisms regarding the mutual effects between the gut microbiota and cancer development, and to highlight the relationship between gut microbes and the efficacy of immunotherapy, chemotherapy, radiation therapy and cancer surgery, which may provide insights into the formulation of individualized therapeutic strategies for cancer management. In addition, the current and emerging microbial interventions for cancer therapy as well as their clinical applications are summarized. Although many challenges remain for now, the great importance and full potential of the gut microbiota cannot be overstated for the development of individualized anti-cancer strategies, and it is necessary to explore a holistic approach that incorporates microbial modulation therapy in cancer.

Long-term effect of Helicobacter pylori eradication on colorectal cancer incidences

Background

There is evidence supporting the association between Helicobacter pylori infection and colorectal cancer (CRC), but whether H. pylori eradication reduces the risk of CRC is still unknown.

Objectives

To compare the incidence of CRC in subjects who had received H. pylori eradication therapy with general population.

Design

A population-based retrospective cohort study.

Methods

This study included all H. pylori-infected subjects who had received their first course of clarithromycin-containing triple therapy in 2003-2015 in Hong Kong. We compared the observed incidences of CRC in this H. pylori eradicated cohort with the expected incidences in the age- and sex-matched general population. The standardized incidence ratio (SIR) with 95% confidence interval (CI) was computed.

Results

Among 96,572 H. pylori-eradicated subjects with a median follow-up of 9.7 years, 1417 (1.5%) developed CRC. Primary analysis showed no significant difference in the observed and expected incidences of CRC (SIR: 1.03, 95% CI: 0.97-1.09). However, when stratified according to the follow-up period, higher incidence of CRC was only observed in the first 5 years after eradication (SIR: 1.47, 95% CI: 1.39-1.55), but it was lower (SIR: 0.85, 95% CI: 0.74-0.99) than general population after 11 years. When stratified by tumor location, the observed incidence was higher for colon (SIR: 1.20, 95% CI: 1.12-1.29) but lower for rectal cancer (SIR: 0.90, 95% CI: 0.81-0.999) among H. pylori-eradicated subjects.

Conclusions

H. pylori-infected subjects appeared to have a higher incidence of CRC initially, which declined progressively to a level lower than general population 10 years after H. pylori eradication, particularly for rectal cancer.

Colorectal cancer risk in East Asian patients with Helicobacter pylori infection: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review and meta-analysis was to assess the relationship between H pylori infection and colorectal cancer risk in East Asian patients.

METHODS

Two researchers independently searched for relevant studies in the PubMed, Cochrane, and Embase databases from inception up to April 2022. A meta-analysis was then performed to calculate pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) using a random effects model.

RESULTS

Nine studies involving 6355 patients were included. Overall, we observed that H pylori infection was associated with an increased risk of colorectal cancer in East Asian patients (OR = 1.48, 95% CI: 1.10-1.99, I2 = 70%), although significant heterogeneity was identified among studies. Subgroup analysis revealed that H pylori infection was associated with an increased risk of colorectal cancer in China (OR = 1.58, 95% CI 1.05-2.37, I2 = 81%) but not in Japan and Korea (OR = 1.26, 95% CI 0.93-1.70, I2 = 0%).

CONCLUSION

This meta-analysis identified a positive association between H pylori infection and colorectal cancer risk in East Asian patients, especially in China.

Epidemiology and risk of colorectal cancer in patients with a history of Helicobacter pylori infection: a population-based study

Background

Numerous modifiable risk factors have been associated with colon cancer. Helicobacter pylori (H. pylori) is the most common bacterial infection worldwide and the strongest known risk factor for gastric cancer. We aim to assess whether the risk of colorectal cancer (CRC) is higher in patients with a history of H. pylori infection.

Methods

A validated multicenter and research platform database of more than 360 hospitals was queried. Patients aged 18-65 years were included in our cohort. We excluded all patients who had previously had a diagnosis of inflammatory bowel disease or celiac disease. Univariate and multivariate regression analyses were used to calculate CRC risk.

Results

A total of 47,714,750 patients were selected after application of the inclusion and exclusion criteria. The 20-year-period prevalence rate of CRC in the United States population from 1999 to September 2022 was 370 of 100,000 individuals (0.37%). According to multivariate analysis, the risk of CRC was higher in smokers (odds ratio [OR] 2.52, 95% confidence interval [CI] 2.47-2.57), obese patients (OR 2.26, 95%CI 2.22-2.30), those with irritable bowel syndrome (OR 2.02, 95%CI 1.94-2.09), or type 2 diabetes mellitus (OR 2.89, 95%CI 2.84-2.95), and patients who had a diagnosis of H. pylori infection (OR 1.89, 95%CI 1.69-2.10).

Conclusion

We provide the first evidence from a large population-based study demonstrating an independent association between a history of H. pylori infection and CRC risk.

Designing multi-epitope vaccine against important colorectal cancer (CRC) associated pathogens based on immunoinformatics approach

BACKGROUND

It seems that several members of intestinal gut microbiota like Streptococcus bovis, Bacteroides fragilis, Helicobacter pylori, Fusobacterium nucleatum, Enterococcus faecalis, Escherichia coli, Peptostreptococcus anaerobius may be considered as the causative agents of Colorectal Cancer (CRC). The present study used bioinformatics and immunoinformatics approaches to design a potential epitope-based multi-epitope vaccine to prevent CRC with optimal population coverage.

METHODS

In this study, ten amino acid sequences of CRC-related pathogens were retrieved from the NCBI database. Three ABCpred, BCPREDS and LBtope online servers were considered for B cells prediction and the IEDB server for T cells (CD4⁺ and CD8⁺) prediction. Then, validation, allergenicity, toxicity and physicochemical analysis of all sequences were performed using web servers. A total of three linkers, AAY, GPGPG, and KK were used to bind CTL, HTL and BCL epitopes, respectively. In addition, the final construct was subjected to disulfide engineering, molecular docking, immune simulation and codon adaptation to design an effective vaccine production strategy.

RESULTS

A total of 19 sequences of different lengths for linear B-cell epitopes, 19 and 18 sequences were considered as epitopes of CD4⁺ T and CD8⁺ cells, respectively. The predicted epitopes were joined by appropriate linkers because they play an important role in producing an extended conformation and protein folding. The final multi-epitope construct and Toll-like receptor 4 (TLR4) were evaluated by molecular docking, which revealed stable and strong binding interactions. Immunity simulation of the vaccine showed significantly high levels of immunoglobulins, helper T cells, cytotoxic T cells and INF-γ.

CONCLUSION

Finally, the results showed that the designed multi-epitope vaccine could serve as an excellent prophylactic candidate against CRC-associated pathogens, but in vitro and animal studies are needed to justify our findings for its use as a possible preventive measure.

Anti-Helicobacter pylori antibody status is associated with cancer mortality: A longitudinal analysis from the Japanese DAIKO prospective cohort study

Paradoxically, patients with advanced stomach cancer who are Helicobacter pylori-positive (HP+) have a higher survival rate than those who are HP-. This finding suggests that HP infection has beneficial effects for cancer treatment. The present study examines whether HP+ individuals have a lower likelihood of death from cancer than those who are HP-. Prospective cohort data (n = 4,982 subjects enrolled in the DAIKO study between 2008-2010) were used to assess whether anti-HP antibody status was associated with cancer incidence. The median age in the primary registry was 53 years-old (range 35-69 years-old). Over the 8-year observation period there were 234 (4.7%) cancer cases in the cohort and 88 (1.8%) all-cause deaths. Urine anti-HP antibody data was available for all but one participant (n = 4,981; 99.98%). The number of HP+ and HP- individuals was 1,825 (37%) and 3,156 (63%), respectively. Anti-HP antibody distribution per birth year revealed that earlier birth year was associated with higher HP+ rates. With a birth year-matched cohort (n = 3,376), all-cancer incidence was significantly higher in HP+ individuals than those who were HP- (p = 0.00328), whereas there was no significant difference in the cancer death rate between HP+ and HP- individuals (p = 0.888). Cox regression analysis for prognostic factors revealed that the hazards ratio of HP+ was 1.59-fold (95%CI 1.17-2.26) higher than HP- in all-cancer incidence. Potential systemic effects of HP+ status may contribute to reduced likelihood of death for patients after an initial diagnosis of cancer.

Nerves in gastrointestinal cancer: from mechanism to modulations

Maintenance of gastrointestinal health is challenging as it requires balancing multifaceted processes within the highly complex and dynamic ecosystem of the gastrointestinal tract. Disturbances within this vibrant environment can have detrimental consequences, including the onset of gastrointestinal cancers. Globally, gastrointestinal cancers account for ~19% of all cancer cases and ~22.5% of all cancer-related deaths. Developing new ways to more readily detect and more efficiently target these malignancies are urgently needed. Whereas members of the tumour microenvironment, such as immune cells and fibroblasts, have already been in the spotlight as key players of cancer initiation and progression, the importance of the nervous system in gastrointestinal cancers has only been highlighted in the past few years. Although extrinsic innervations modulate gastrointestinal cancers, cells and signals from the gut's intrinsic innervation also have the ability to do so. Here, we shed light on this thriving field and discuss neural influences during gastrointestinal carcinogenesis. We focus on the interactions between neurons and components of the gastrointestinal tract and tumour microenvironment, on the neural signalling pathways involved, and how these factors affect the cancer hallmarks, and discuss the neural signatures in gastrointestinal cancers. Finally, we highlight neural-related therapies that have potential for the management of gastrointestinal cancers.

Prevalence and risk of colorectal polyps among the Korean population under 50 years

Colorectal cancer is a common cancer; generally, adults aged ≥ 50 years are screened using stool occult blood tests and colonoscopy. However, colorectal adenoma and cancer have been found in patients under the aged of 50, and studies on characteristics and risk factors in young patients are lacking. We evaluated the prevalence and risk factors of colorectal adenoma and cancer in young adults aged under 50 years. We retrospectively analyzed 570 individuals aged under 50 years who underwent colonoscopy at the Haeundae Paik Hospital, Korea, from January to June 2018. Logistic regression model was used to identify the risk factors for colorectal adenoma and colorectal cancer. The prevalence of colorectal adenoma in group of 19-29 years was 3.2% (1 of 31), 30-39 years was 13.8% (30 of 217) and in the group of 40-49 years was 21.1% (68 of 322) (P = .009). In multivariable analysis, age over 45 years (adjusted odds ratio [OR], 1.941; 95% confidence interval [CI], 1.187-3.172; P = .008) and male sex (adjusted OR, 1.711; 95% CI, 1.044-2.806; P = .033) were independent risk factors for colorectal neoplasia including cancer. The prevalence of colorectal adenoma increases as the age increased in young adults under 50 years of age, especially after the age of 45 years, the risk of colorectal neoplasia increases; hence, early screening should be considered before the age of 50 years.

The impact of oral ciprofloxacin on the structure and functions of rat gastric mucosa

Ciprofloxacin (CPX), is a fluoroquinolone antibiotic used to treat a number of gram-negative and gram-positive bacterial infections. Ciprofloxacin can cause severe side effects, ranging from tendon problems, nerve damage, to serious mood or behavior changes.

The purpose of this study was to investigate how ciprofloxacin affects gastric cell lines in rats with a distinctive emphasis on physiological, histopathological, and bacteriological changes. Male albino rats (n = 21) were distributed into three groups; control, CPX, and CPX-withdrawal groups. The treated rats were given CPX tablets (12.5 mg/kg) dissolved in carboxymethyl cellulose (CMC) 0.5% orally once daily via gavage for sixty consecutive days. Control rats received only the vehicle. The withdrawal group was treated for 60 days and the drug was withdrawn for another sixty days. After completion of the experiment, all rats were sacrificed and gastric tissues were treated for light, immunohistochemical, and scanning electron microscopic examination. Image J software was used to measure immune-labeled gastric epithelial cells. Blood samples were also collected for H. Pylori immunoglobulins IgM, IgA, and IgG. Results showed that treated rats acquired significantly strongly positive tumor necrosis factor (TNFα) and significant reduction of serum level of H. pylori IgM, IgA, and IgG in all the study groups. It could be concluded that prolonged oral CPX administration to albino rats changes the gastric mucosal architecture and bacteriology.

Gut microbiota modulation: a tool for the management of colorectal cancer

Colorectal cancer (CRC) is the second cause of cancer death and the third most frequently diagnosed cancer. Besides the lifestyle, genetic and epigenetic alterations, and environmental factors, gut microbiota also plays a vital role in CRC development. The interruption of the commensal relationship between gut microbiota and the host could lead to an imbalance in the bacteria population, in which the pathogenic bacteria become the predominant population in the gut. Different therapeutic strategies have been developed to modify the gut immune system, prevent pathogen colonization, and alter the activity and composition of gut microbiota, such as prebiotics, probiotics, postbiotics, antibiotics, and fecal microbiota transplantation (FMT). Even though the employed strategies exhibit promising results, their translation into the clinic requires evaluating potential implications and risks, as well as assessment of their long-term effects. This study was set to review the gut microbiota imbalances and their relationship with CRC and their effects on CRC therapy, including chemotherapy and immunotherapy. More importantly, we reviewed the strategies that have been used to modulate gut microbiota, their impact on the treatment of CRC, and the challenges of each strategy.

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.

Effects of Helicobacter pylori infection in gastrointestinal tract malignant diseases: From the oral cavity to rectum

Helicobacter pylori (H. pylori) has infected approximately fifty percent of humans for a long period of time. However, improvements in the public health environment have led to a decreased chance of H. pylori infection. However, a high infection rate is noted in populations with a high incidence rate of gastric cancer (GC). The worldwide fraction of GC attributable to H. pylori is greater than 85%, and a high H. pylori prevalence is noted in gastric mucosa-associated lymphoid tissue lymphoma patients. These results indicate that the majority of GC cases can be prevented if H. pylori infection is eliminated. Because H. pylori exhibits oral-oral or fecal-oral transmission, the relationship between this microorganism and other digestive tract malignant diseases has also attracted attention. This review article provides an overview of H. pylori and the condition of the whole gastrointestinal tract environment to further understand the correlation between the pathogen and the host, thus allowing improved realization of disease presentation.

Periodontitis, Helicobacter pylori infection, and gastrointestinal tract cancer mortality

AIM

Periodontitis has been proposed to lead to Helicobacter pylori infection, which could cause many gastrointestinal tract cancers. This study aimed to determine the association or otherwise between periodontitis and survival outcomes in individuals with respect to H. pylori infection.

MATERIALS AND METHODS

The study population comprised 4955 subjects aged 20-90 who had received both periodontal examination and H. pylori serum test in the Third National Health and Nutrition Examination Survey (NHANES III) database. Logistic regression models were used to analyse the association between periodontitis and H. pylori seropositivity (H. pylori infection). Survival analysis was performed using the NHANES III linked to mortality data. Cox proportional hazard regression was carried out to investigate the association between periodontitis and gastrointestinal tract cancer mortality in individuals with/without H. pylori infection.

RESULTS

Compared to periodontal health, periodontitis was significantly associated with increased odds of H. pylori infection (OR = 1.271, 95% CI = 1.177-1.372). Periodontitis significantly increased the mortality risk from all causes (HR = 1.574, 95% CI = 1.327-1.866) and all cancers (HR = 1.948, 95% CI = 1.701-2.232), including gastrointestinal (GI) tract cancer (HR = 4.140, 95% CI = 3.656-4.687), gastric cancer (HR = 4.288, 95% CI = 3.969-4.632), and colorectal cancer (HR = 4.814, 95% CI = 3.849-6.020) in subjects with H. pylori infection after adjusting for health-related factors. Periodontitis was significantly related to the decreased survival time in subjects with GI tract (p = .001) or colorectal cancer (p = .002) and H. pylori infection.

CONCLUSION

Our study demonstrated that periodontitis was significantly associated with higher mortality risk of GI tract, gastric, and colorectal cancer in subjects with H. pylori infection. Owing to an interactive effect between periodontitis and H. pylori infection on cancer mortality, H. pylori infection has a significant moderating effect in regulating the association between periodontitis and mortality due to all cancers, including GI tract cancer and colorectal cancer.

An Update on the Effects of Probiotics on Gastrointestinal Cancers

Because of their increasing prevalence, gastrointestinal (GI) cancers are regarded as an important global health challenge. Microorganisms residing in the human GI tract, termed gut microbiota, encompass a large number of living organisms. The role of the gut in the regulation of the gut-mediated immune responses, metabolism, absorption of micro- and macro-nutrients and essential vitamins, and short-chain fatty acid production, and resistance to pathogens has been extensively investigated. In the past few decades, it has been shown that microbiota imbalance is associated with the susceptibility to various chronic disorders, such as obesity, irritable bowel syndrome, inflammatory bowel disease, asthma, rheumatoid arthritis, psychiatric disorders, and various types of cancer. Emerging evidence has shown that oral administration of various strains of probiotics can protect against cancer development. Furthermore, clinical investigations suggest that probiotic administration in cancer patients decreases the incidence of postoperative inflammation. The present review addresses the efficacy and underlying mechanisms of action of probiotics against GI cancers. The safety of the most commercial probiotic strains has been confirmed, and therefore these strains can be used as adjuvant or neo-adjuvant treatments for cancer prevention and improving the efficacy of therapeutic strategies. Nevertheless, well-designed clinical studies are still needed for a better understanding of the properties and mechanisms of action of probiotic strains in mitigating GI cancer development.

Inflammatory Bowel Disease-Associated Colorectal Cancer: Translational Risks from Mechanisms to Medicines

The cumulative impact of chronic inflammation in patients with inflammatory bowel diseases predisposes to the development of inflammatory bowel disease-associated colorectal cancer [IBD-CRC]. Inflammation can induce mutagenesis, and the relapsing-remitting nature of this inflammation, together with epithelial regeneration, may exert selective pressure accelerating carcinogenesis. The molecular pathogenesis of IBD-CRC, termed the 'inflammation-dysplasia-carcinoma' sequence, is well described. However, the immunopathogenesis of IBD-CRC is less well understood. The impact of novel immunosuppressive therapies, which aim to achieve deep remission, is mostly unknown. Therefore, this timely review summarizes the clinical context of IBD-CRC, outlines the molecular and immunological basis of disease pathogenesis, and considers the impact of novel biological therapies.

Helicobacter pylori infection and increased diabetes prevalence were the risks of colorectal adenoma for adults: A systematic review and meta-analysis (PRISMA-compliant article)

BACKGROUND

Helicobacter pylori infection and hyperglycemia are associated with an increased risk of colorectal neoplasm, and may have a synergistic effect in combination. However, these 2 factors that affect colorectal neoplasm remain controversial. We aimed to carry out a meta-analysis to evaluate the study population diabetes prevalence rate and H pylori infection rate with colorectal adenoma risk for adults.

METHODS

We conducted systemic research through English databases for medical reports. We also recorded the diabetes prevalence and H pylori infection prevalence in each study. We classified these studies into 4 subgroups as their background population diabetes prevalence <6% (Group 1); between 6% and 8% (Group 2); between 8% and 10% (Group 3), and more than 10% (Group 4). The random-effects model had used to calculate pooled prevalence estimates with 95% confidence interval (CI).

RESULTS

Twenty-seven studies were finally eligible for meta-analysis. The random-effects model of the meta-analysis was chosen, showing pooled odds ratio (OR) equal to 1.51 (95% CI 1.39-1.63). The subgroup meta-analyses showed in Group 1 the H pylori infection associated colorectal adenoma risk OR was 1.24 (95% CI 0.86-1.78). As the diabetes rate exceed 6%, the H pylori infection became the more significant increased risk of colorectal adenoma (Group 2: OR 2.16 (95% CI 1.61-2.91); Group 3: OR 1.40 (95% CI 1.24-1.57); and Group 4: OR 1.52 (95% CI 1.46-1.57)).

CONCLUSIONS

The results of this meta-analysis showed elevated diabetes prevalence combined H pylori infection increasing the risks of colorectal adenoma in the adult population.

Cancer Microbiology

Microbes play important roles in cancer from direct carcinogenic effects to their use in treatment. Cancers caused by microorganisms account for approximately 15% of cancers, mostly in low- and middle-income countries. Unique features of infectious carcinogens include their transmissibility, mutability, and specific immune interactions, which provide challenges and opportunities for cancer prevention and treatment. For these agents, infection control through exposure reduction, antivirals, antibiotics, and vaccines is cancer control. In addition, developing evidence suggests that microorganisms including the human microbiome can indirectly modulate cancer formation and influence the effectiveness and toxicity of cancer treatments. Finally, microorganisms themselves can be used to prevent or treat cancer. The convergence of these factors signals the emergence of a new field, Cancer Microbiology. Recognition of Cancer Microbiology will spur research, stimulate cross-disciplinary training, inform drug development, and improve public health.

Racial Disparities and Sex Differences in Early- and Late-Onset Colorectal Cancer Incidence, 2001-2018

Background

Colorectal cancer (CRC) incidence rates have increased in younger individuals worldwide. We examined the most recent early- and late-onset CRC rates for the US.

Methods

Age-standardized incidence rates (ASIR, per 100,000) of CRC were calculated using the US Cancer Statistics Database’s high-quality population-based cancer registry data from the entire US population. Results were cross-classified by age (20-49 [early-onset] and 50-74 years [late-onset]), race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, American Indian/Alaskan Native, Asian/Pacific Islander), sex, anatomic location (proximal, distal, rectal), and histology (adenocarcinoma, neuroendocrine).

Results

During 2001 through 2018, early-onset CRC rates significantly increased among American Indians/Alaskan Natives, Hispanics, and Whites. Compared to Whites, early-onset CRC rates are now 21% higher in American Indians/Alaskan Natives and 6% higher in Blacks. Rates of early-onset colorectal neuroendocrine tumors have increased in Whites, Blacks, and Hispanics; early-onset colorectal neuroendocrine tumor rates are 2-times higher in Blacks compared to Whites. Late-onset colorectal adenocarcinoma rates are decreasing, while late-onset colorectal neuroendocrine tumor rates are increasing, in all racial/ethnic groups. Late-onset CRC rates remain 29% higher in Blacks and 15% higher in American Indians/Alaskan Natives compared to Whites. Overall, CRC incidence was higher in men than women, but incidence of early-onset distal colon cancer was higher in women.

Conclusions

The early-onset CRC disparity between Blacks and Whites has decreased, due to increasing rates in Whites—rates in Blacks have remained stable. However, rates of colorectal neuroendocrine tumors are increasing in Blacks. Blacks and American Indians/Alaskan Natives have the highest rates of both early- and late-onset CRC.

Impact

Ongoing prevention efforts must ensure access to and uptake of CRC screening for Blacks and American Indians/Alaskan Natives.

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.

Human Gut Microbiota-associated Gastrointestinal Malignancies: A Comprehensive Review

The human gastrointestinal tract houses trillions of microbes. The gut and various types of microorganisms, including bacteria, viruses, fungi, and archaea, form a complex ecosystem known as the gut microbiota, and the whole genome of the gut microbiota is referred to as the gut microbiome. The gut microbiota is essential for homeostasis and the overall well-being of a person and is increasingly considered an adjunct "virtual organ," with a complexity level comparable to that of the other organ systems. The gut microbiota plays an essential role in nutrition, local mucosal homeostasis, inflammation, and the mucosal immune system. An imbalanced state of the gut microbiota, known as dysbiosis, can predispose to development of various gastrointestinal malignancies through three speculated pathogenic mechanisms: (a) direct cytotoxic effects with damage to the host DNA, (b) disproportionate proinflammatory signaling inducing inflammation, and (c) activation of tumorigenic pathways or suppression of tumor-suppressing pathways. Several microorganisms, including Helicobacter pylori, Epstein-Barr virus, human papillomavirus, Mycoplasma species, Escherichia coli, and Streptococcus bovis, are associated with gastrointestinal malignancies such as esophageal adenocarcinoma, gastric adenocarcinoma, gastric mucosa-associated lymphoid tissue lymphoma, colorectal adenocarcinoma, and anal squamous cell carcinoma. Imaging plays a pivotal role in diagnosis and management of microbiota-associated gastrointestinal malignancies. Appropriate use of probiotics, fecal microbiota transplantation, and overall promotion of the healthy gut are ongoing areas of research for prevention and treatment of malignancies. Online supplemental material is available for this article. ^©RSNA, 2021.

Polymorphisms within Autophagy-Related Genes Influence the Risk of Developing Colorectal Cancer: A Meta-Analysis of Four Large Cohorts

Simple Summary

We investigated the influence of autophagy-related variants in modulating colorectal cancer (CRC) risk through a meta-analysis of genome-wide association study (GWAS) data from four large European cohorts. We found that genetic variants within the DAPK2 and ATG5 loci were associated with CRC risk. This study also shed some light onto the functional mechanisms behind the observed associations and demonstrated the impact of DAPK2_rs11631973 and ATG5_rs546456 polymorphisms on the modulation of host immune responses, blood derived-cell counts and serum inflammatory protein levels, which might be involved in promoting cancer development. No effect of the DAPK2 and ATG5 polymorphisms on the autophagy flux was observed.

Abstract

The role of genetic variation in autophagy-related genes in modulating autophagy and cancer is poorly understood. Here, we comprehensively investigated the association of autophagy-related variants with colorectal cancer (CRC) risk and provide new insights about the molecular mechanisms underlying the associations. After meta-analysis of the genome-wide association study (GWAS) data from four independent European cohorts (8006 CRC cases and 7070 controls), two loci, DAPK2 (p = 2.19 × 10⁻⁵) and ATG5 (p = 6.28 × 10⁻⁴) were associated with the risk of CRC. Mechanistically, the DAPK2_rs11631973G allele was associated with IL1 β levels after the stimulation of peripheral blood mononuclear cells (PBMCs) with Staphylococcus aureus (p = 0.002), CD24 + CD38 + CD27 + IgM + B cell levels in blood (p = 0.0038) and serum levels of en-RAGE (p = 0.0068). ATG5_rs546456T allele was associated with TNF α and IL1 β levels after the stimulation of PBMCs with LPS (p = 0.0088 and p = 0.0076, respectively), CD14+CD16− cell levels in blood (p = 0.0068) and serum levels of CCL19 and cortisol (p = 0.0052 and p = 0.0074, respectively). Interestingly, no association with autophagy flux was observed. These results suggested an effect of the DAPK2 and ATG5 loci in the pathogenesis of CRC, likely through the modulation of host immune responses.

Male-Dependent Promotion of Colitis in 129 Rag2-/- Mice Co-Infected with Helicobacter pylori and Helicobacter hepaticus

The prevalence of gastric Helicobacter pylori (Hp) infection is ~50% of the world population. However, how Hp infection influences inflammatory bowel disease in humans is not fully defined. In this study, we examined whether co-infection with Hp influenced Helicobacter hepaticus (Hh)–induced intestinal pathology in Rag2^−/− mice. Rag2^−/− mice of both sexes were infected with Hh, of which a subgroup was followed by infection with Hp two weeks later. Co-infected males, but not females, had significantly higher total colitis index scores in the colon at both 10 and 21 weeks post-Hh infection (WPI) and developed more severe dysplasia at 21 WPI compared with mono-Hh males. There were no significant differences in colonization levels of gastric Hp and colonic Hh between sexes or time-points. In addition, mRNA levels of colonic Il-1β, Ifnγ, Tnfα, Il-17A, Il-17F, Il-18, and Il-23, which play important roles in the development and function of proinflammatory innate lymphoid cell groups 1 and 3, were significantly up-regulated in the dually infected males compared with mono-Hh males at 21 WPI. These data suggest that concomitant Hp infection enhances the inflammatory responses in the colon of-Hh-infected Rag2^−/− males, which results in more severe colitis and dysplasia.

Association of Combined Sero-Positivity to Helicobacter pylori and Streptococcus gallolyticus with Risk of Colorectal Cancer

Previously, we found that risk of colorectal cancer (CRC) is increased in individuals with serum antibody response to both Helicobacter pylori (HP) Vacuolating Cytotoxin (VacA) toxin or Streptococcus gallolyticus (SGG) pilus protein Gallo2178. In the present analysis, we tested the hypothesis that combined seropositivity to both antigens is a better indicator of CRC risk than seropositivity to single antigens. We used multiplex serologic assays to analyze pre-diagnostic serum for antibody responses from 4063 incident CRC cases and 4063 matched controls from 10 US cohorts. To examine whether combined SGG Gallo2178 and HP VacA sero-status was associated with CRC risk, we used conditional logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Compared to dual sero-negative individuals, there was no increased risk for individuals sero-positive to SGG Gallo2178 only (OR: 0.93; 95% CI: 0.66–1.31) or to HP VacA only (OR: 1.08; 95% CI: 0.98–1.19). However, dual sero-positive individuals had a >50% increased odds of developing CRC (OR: 1.54; 95% CI: 1.16–2.04), suggesting an interaction between antibody responses to these two pathogens and CRC risk (p_interaction = 0.06). In conclusion, this study suggests that dual sero-positivity to HP VacA and SGG Gallo2178 is an indicator of increased risk of CRC.

Association between Helicobacter pylori infection and the risk of colorectal cancer: A systematic review and meta-analysis

BACKGROUND

The existing evidence on the relationship between Helicobacter pylori infection and the risk of colorectal cancer is inconsistent. We conducted a systematic review with a meta-analysis to explore this relationship and to determine whether the relationship varies according to the study characteristics.

METHODS

We searched the PubMed, OVID, EMBASE database, and the reference lists of pertinent articles published up to October 2019 by 2 researchers independently. Summary odds ratios (OR) with their 95% confidence intervals (CIs) were estimated using a random-effects model.

RESULTS

Forty seven studies including 17,416 cases of colorectal cancer (CRC) and 55,811 cases of control were included. Overall, H. pylori infection was associated with an increased risk of CRC (OR = 1.70 95% CI 1.64-1.76, I = 97%), although there was significant heterogeneity among the studies. Subgroup analysis revealed that the positive correlation might vary by the design of study conducted.

CONCLUSION

This meta-analysis demonstrates a positive association between H. pylori infection and the risk of colorectal cancer.

Reconsidering the "protective" hypothesis of Helicobacter pylori infection in eosinophilic esophagitis

Since its discovery, Helicobacter pylori (H. pylori) has attracted attention in the biomedical world with its numerous pathophysiologic implications, both gastrointestinal and systemic. Beyond its well-established carcinogenic properties, emerging evidence also supports "harmful" proinflammatory and neurodegenerative roles of H. pylori. On the other hand, H. pylori infection has been proposed to be "protective" against several diseases, such as asthma and gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) is a relatively new, allergen/immune-mediated disease, which has also been linked to these considerations. Main arguments are a postulated shift of immune responses by H. pylori from T helper 2 (T_H 2) to T_H 1 polarization, as well as a potential decline of the H. pylori burden with the dramatic parallel rise of ΕοΕ: a series of observational studies reported an inverse association. In this review, we counter these arguments by providing further epidemiological data, which point out that this generalization might be rather incomplete. We also discuss the limitations of the existing studies evaluating a possible association. Furthermore, we provide current evidence on common pathogenetic components, which share both entities. In summary, the claim that H. pylori is protective against EoE is rather incomplete, and further mechanistic studies are necessary to elucidate a possible association.

Association among helicobacter pylori infection, gastrin level and colorectal cancer in patients aged 50 years and over

Objectives:

To study the correlations among helicobacter pylori infection, gastrin and colorectal cancer in patients aged over 50 years old.

Methods:

In this study, the patients diagnosed with colorectal cancer treated in the department of digestion of our hospital together with the healthy subjects undergoing colonoscopy for health examination without pathologic findings from August 2016 to July 2019 were enrolled in colorectal cancer or control group. The blood sample was taken in fasting state, and anti-H. pylori IgG and anti-CagA antibodies as well as the level of serum gastrin were measured for all the participants. In addition, the information of each participant including age, gender, obesity, smoking history, alcohol consumption, diabetes mellitus was recorded and analyzed.

Results:

Four hundred and twenty-eight patients were enrolled in the colorectal group and 207 healthy subjects were enrolled in the control group. There were not significant differences in the positive rate of Ig G and Cag A and family history between the two groups (p>0.05), but there were significant differences in gastrin level, obesity, smoking history, alcohol consumption and diabetes mellitus between the two groups (p<0.05). In addition, the multivariable analysis showed that obesity, smoking history, alcoholism and diabetes mellitus have the strongest influence on the formation of colorectal cancer, while the level of gastrin didn’t show the influence.

Conclusions:

No significant correlations among H. pylori infection, the level of gastrin, and the occurrence of CRC in patients with a minimum age of 50 years, suggesting elder colorectal cancer patients may have a different carcinogenic mechanism from those younger patients.

Role of Helicobacter pylori infection in the manifestation of old age-related diseases

Helicobacter pylori is one of the most prevalent infection worldwide. It affects individuals of different age groups. Elderly people tend to resist eradication treatment and worsening of infection can lead to several gastric and non-gastric pathologies. Aging-associated cellular and molecular alteration can increase the risk of other pathologies such as osteoporosis, Alzheimer's disease, Parkinson's disease, respiratory and renal dysfunction, and cancer in geriatric patients, more than other age groups. This review article highlights some of the most common old age diseases and the role of H. pylori infection as a risk factor to worsen the conditions, presented by the molecular evidences of these associations. These studies can help clinicians to understand the underlying pathogenesis of the disease and identify high-risk patients, aiding clearer diagnosis and treatment.

Helicobacter pylori prevalence in the Southwest of China: A protocol for systematic review

OBJECTIVES

This epidemiological research will be aimed to evaluate the longitudinal changes of Helicobacter pylori prevalence in Southwest China during recent period through a systematic review and analysis.

METHODS

The database PubMed and China National Knowledge Infrastructure will be searched. The cross-sectional studies or cohort studies on either massive or hospital-based health checkup population will be potentially eligible. The study population was originated from one of the southwestern major cities, Chengdu (Sichuan), Chongqing, Kunming (Yunnan), Guiyang (Guizhou), or Lhasa (Tibet). Two reviewers will independently select studies, extract data, and assess the quality of studies. The prevalence of H pylori infection will be estimated. In the individual city, the longitudinal comparisons will be conducted to evaluate the trends referring to the earliest cross-sectional baseline. The risk ratio and its 95% confidence interval will be estimated. Subgroup analyses will be performed in sex-specific and age-specific subsets. Trend analysis for proportions (p for trend) will be estimated in the longitudinal evaluation. If applicable, the longitudinal clearance rate (%) will be estimated.

ETHICS AND DISSEMINATION

The ethical approval is not required due to the nature of literature-based research. The results will be disseminated through meetings and a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019120764.

Bacterial signatures and their inflammatory potentials associated with prostate cancer

Chronic inflammation can create a microenvironment that can contribute to the formation of prostate pathologies. Far less well understood is the origin of inflammation in the prostate. One potential source is microbial infections of the prostate. This review summarizes recent findings regarding the presence of bacteria in the prostate and the dysbiosis of bacterial populations in the urinary tract and the gastrointestinal tract related to prostate cancer, thereby focusing on next-generation sequencing (NGS)-generated data. The current limitations regarding NGS-based detection methods and other difficulties in the quest for a microbial etiology for prostate cancer are discussed. We then focus on a few bacterial species, including Cutibacterium acnes and Escherichia coli that are often NGS-detected in prostatic tissue specimens, and discuss their possible contribution as initiator or enhancer of prostate inflammation and prostate carcinogenesis.