Helicobacter pylori infection is an independent risk factor for colonic adenomatous neoplasms. Cancer Causes Control. 2017;28:107-115. [PMID: 28025763 DOI: 10.1007/s10552-016-0839-x]

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.

Association between Helicobacter pylori infection and colorectal polyps

It was aimed to investigate whether the Helicobacter pylori infection is related to the frequency, localization, size and number of colorectal polyps. The data of 4561 patients who underwent esophagogastroduodenoscopy and colonoscopy were analyzed retrospectively. Patients with and without polyps at colonoscopy were grouped and the frequency of H pylori infection was compared in these patients. The relationship between the groups was evaluated with statistical methods. It was determined that the rate of H pylori infection was higher in patients with colorectal polyps than in patients without polyps (P < .005). Patients with multiple polyps, polyps larger than 1 cm, and tubulovillous and villous adenoma from polyp types had a higher rate of H pylori infection (P = .095; P .004; P .001). When the polyps were evaluated according to their localization, H pylori infection rates were not different between the groups (P = .341). It has been observed that the rate of H pylori infection is higher in large polyps, multiple polyps, tubulovillous and villous adenomas, which are known to have a higher risk of malignancy.

Predictors for Colorectal Polyps in an Asymptomatic Population Undergoing Medical Check-ups

BACKGROUND

Colorectal cancer primarily arises from colorectal polyps. Early screening and removal is beneficial, especially in asymptomatic populations. This research aimed to reveal the risk factors detected in medical check-ups for colorectal polyps in asymptomatic people.

MATERIALS AND METHODS

Clinical data of 933 asymptomatic people who underwent colonoscopies from May 2014 to December 2021 was analyzed retrospectively. Data included sex, age, colonoscopy findings, polyp pathology, polyp number, and blood test results. The distribution of colorectal lesions was analyzed. Participants were divided into control and polyp groups, adenomatous and non-adenomatous polyp groups, and single and multiple adenoma groups.

RESULTS

Participants' age, proportion of males, carcinoembryonic antigen (CEA), uric acid and glycosylated hemoglobin levels were significantly higher ( P ≤0.05) in the polyp group. Age (>40 y), sex (male), and CEA level (>1.435 ng/mL) were independent risk factors for polyps. CEA, uric acid, carbohydrate antigen 19-9, triglyceride, and total cholesterol levels were significantly higher ( P <0.05) in the adenoma group than in the non-adenomatous group. CEA level (>1.435 ng/mL) was an independent predictor for adenomas ( P <0.05). Participants' age, proportion of males, CEA, glycosylated hemoglobin, and fasting blood glucose levels were significantly higher ( P <0.05) in the multiple adenoma group than in the single group; the high-density lipoprotein cholesterol level was lower ( P <0.05). No independent risk factors were found for the number of adenomas.

CONCLUSIONS

Serum CEA level (>1.435 ng/mL) was independent risk factor for colorectal polyps. It may be conducive to improve discriminative ability of colorectal cancer risk stratification model.

Effects of oxidation-based tea processing on the characteristics of the derived polysaccharide conjugates and their regulation of intestinal homeostasis in DSS-induced colitis mice

Different cultivars and processing technologies involved in producing tea result in the high heterogeneity of derived polysaccharide conjugates, which limits the understanding of their composition and structure, and biological activity. Here, raw tea leaves from the same cultivar were used to produce dried fresh tea leaves, green tea, and black tea, and three polysaccharide conjugates derived from dried fresh tea leaves (FTPS), green tea (GTPS), and black tea (BTPS) were prepared accordingly. Their physiochemical characteristics and bioactivities were investigated. The results showed that the oxidation during tea processing increased the phenolics and proteins while decreasing the GalA in the derived TPS conjugates; meanwhile, it reduced the molecular weight and particle size of BTPS but enhanced their antioxidant activity in vitro. Furthermore, all three TPS conjugates improved intestinal homeostasis by reducing TJ protein loss and inflammation and alleviated DSS-induced colitis symptoms in mice. In addition, the three TPS conjugates showed differential regulation of the intestinal microbiome and altered the produced SCFAs, which contributed to the prevention of colitis. Our findings suggest that TPS conjugates could be applied in colitis prevention in association with the regulation of gut microbiota, and their efficacy could be optimized by employing suitable tea processing technologies.

Label-Free Vibrational and Quantitative Phase Microscopy Reveals Remarkable Pathogen-Induced Morphomolecular Divergence in Tumor-Derived Cells

Delineating the molecular and morphological changes that cancer cells undergo in response to extracellular stimuli is crucial for identifying factors that promote tumor progression. Label-free optical imaging offers a potentially promising route for retrieving such single-cell information by generating detailed visualization of the morphology and determining alterations in biomolecular composition. The potential of such nonperturbative morphomolecular microscopy for analyzing microbiota-cancer cell interactions has been surprisingly underappreciated, despite the growing evidence of the critical role of dysbiosis in malignant transformations. Here, using a model system of breast cancer cells, we show that label-free Raman microspectroscopy and quantitative phase microscopy can detect biomolecular and morphological changes in single cells exposed to Bacteroides fragilis toxin (BFT), a toxin secreted by enterotoxigenicB. fragilis. Remarkably, using machine learning to elucidate subtle, but consistent, cellular differences, we found that the morphomolecular differences between BFT-exposed and control breast cancer cells became more accentuated after in vivo passage, corroborating our findings that a short-term BFT exposure imparts a long-term effect on cancer cells and promotes a more invasive phenotype. Complementing more classical labeling techniques, our label-free platform offers a global detection approach with measurements representative of the overall cellular phenotype, paving the way for further investigations into the multifaceted interactions between the cancer cell and the microbiota.

Association Between H. pylori Infection and Colorectal Polyps: A Meta-Analysis of Observational Studies

Background

It has been suggested that Helicobacter pylori (H. pylori) infection is associated with hypergastrinemia and proliferation of colorectal mucosa via direct stimulation, dysbiosis of the gut microbiome, and changes in the gut microbiome, all of which may lead to the formation of colorectal polyps. However, the consensus remains lacking regarding whether H. pylori infection is independently associated with colorectal polyps and whether the association differs according to histological type of colorectal polyps. To summarize the current evidence regarding the relationship between H. pylori infection and colorectal polyps, we conducted a meta-analysis of related observational studies according to the histological types of colorectal polyps.

Methods

Observational studies investigating the association between H. pylori infection and colorectal polyps using multivariate analyses were included by search of PubMed, Embase, and Web of Science. A random-effects model was adopted to combine the results.

Results

Seventeen studies that include 322,395 participants were analyzed. It was shown that H. pylori infection was independently associated with overall colorectal polyps (odds ratio [OR]: 1.67, 95% CI: 1.24–2.24, p < 0.001; I² = 73%). According to the histological type of colorectal polyps, H. pylori infection was independently associated with adenomatous polyps (APs; OR: 1.71, 95% CI: 1.47–1.99, p < 0.001; I² = 86%), advanced APs (OR: 2.06, 95% CI: 1.56–2.73, p < 0.001; I² = 0%), and hyperplastic polyps (HPs; OR: 1.54, 95% CI: 1.02–2.30, p = 0.04; I² = 78%). Evidence based on only one study showed that H. pylori infection was not associated with sessile serrated polyps (SSPs; OR: 1.00, 95% CI: 0.93–1.07, p = 0.99).

Conclusions

Current evidence from case-control and cross-sectional studies suggested that H. pylori infection was independently associated with colorectal APs, advanced APs, and HPs, but not with SSPs. These findings suggested H. pylori infection may be a possible risk factor of colorectal polyp, which is important for the prevention of colorectal polyp in the adult population.

A Noninvasive Risk Stratification Tool Build Using an Artificial Intelligence Approach for Colorectal Polyps Based on Annual Checkup Data

Colorectal cancer is the leading cause of cancer-related deaths worldwide, and early detection has proven to be an effective method for reducing mortality. The machine learning method can be implemented to build a noninvasive stratifying tool that helps identify patients with potential colorectal precancerous lesions (polyps). This study aimed to develop a noninvasive risk-stratified tool for colorectal polyps in asymptomatic, healthy participants. A total of 20,129 consecutive asymptomatic patients who underwent a health checkup between January 2005 and August 2007 were recruited. Positive relationships between noninvasive risk factors, such as age, Helicobacter pylori infection, hypertension, gallbladder polyps/stone, and BMI and colorectal polyps were observed (p < 0.0001), regardless of sex, whereas significant findings were noted in men with tooth disease (p = 0.0053). A risk stratification tool was developed, for colorectal polyps, that considers annual checkup results from noninvasive examinations. For the noninvasive stratified tool, the area under the receiver operating characteristic curve (AUC) of obese females (males) aged <50 years was 91% (83%). In elderly patients (>50 years old), the AUCs of the stratifying tools were >85%. Our results indicate that the risk stratification tool can be built by using random forest and serve as an efficient noninvasive tool to identify patients requiring colonoscopy.

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.

Association of Helicobacter pylori infection with colorectal adenoma in the Chinese urban population: A cross-sectional study

OBJECTION

Helicobacter pylori (H. pylori) infection is considered to increase the risk of colorectal adenoma (CRA) and remains controversial. In this study, we aimed to evaluate the association between H. pylori infection and CAR in the Chinese urban population.

METHODS

A cross-sectional study of 301 urban adults, who underwent both screening colonoscopy and ¹³C urea breath test (¹³C UBT) from June 2018 to December 2019 at Geriatric Hospital of Nanjing Medical University, was carried out to assess the relationship between H. pylori infection and CRA. All baseline characteristics and laboratory examination of subjects were collected and analyzed by specific personnel. The strength of association between H. pylori infection and the risk of CRA was described by multivariate logistic regression analyses to calculate the odds ratios (ORs) and 95% confidence interval (CIs).

RESULTS

Among the 301 subjects, 82 (27.24%) patients with H. pylori positive and 141 (46.84%) were confirmed to have CRA. Multivariate analysis adjusted for age, gender, uric acid and fatty liver revealed that H. pylori infection increased the risk of CRA significantly (adjusted OR 2.007, 95%CI 1.153-3.492, p = 0.014). In addition, the correlation between H. pylori infection and CRA persisted after further adjusting for metabolic variables (adjusted OR 2.029, 95%CI 1.161-3.544, p = 0.013) or other potential confounding factors related to CRA including smoking status, alcohol intake, cholecystitis and gallstone (adjusted OR 1.996, 95%CI 1.141-3.492, p = 0.015). In a gender-based subgroup analysis, H. pylori infection had an increased risk of CRA in male group (adjusted OR 1.997, 95%CI 1.010-3.945, p = 0.047).

CONCLUSIONS

H. pylori infection had a significant association with the risk of CRA in Chinese urban populations, which will provide new insights into selecting high-risk subjects with CRA.

Gut microbiota-derived metabolites in CRC progression and causation

BACKGROUND

Based on recent research reports, dysbiosis and improper concentrations of microbial metabolites in the gut may result into the carcinogenesis of colorectal cancer. Recent advancement also highlights the involvement of bacteria and their secreted metabolites in the cancer causation. Gut microbial metabolites are functional output of the host-microbiota interactions and produced by anaerobic fermentation of food components in the diet. They contribute to influence variety of biological mechanisms including inflammation, cell signaling, cell-cycle disruption which are majorly disrupted in carcinogenic activities.

PURPOSE

In this review, we intend to discuss recent updates and possible molecular mechanisms to provide the role of bacterial metabolites, gut bacteria and diet in the colorectal carcinogenesis. Recent evidences have proposed the role of bacteria, such as Fusobacterium nucleaturm, Streptococcus bovis, Helicobacter pylori, Bacteroides fragilis and Clostridium septicum, in the carcinogenesis of CRC. Metagenomic study confirmed that these bacteria are in increased abundance in CRC patient as compared to healthy individuals and can cause inflammation and DNA damage which can lead to development of cancer. These bacteria produce metabolites, such as secondary bile salts from primary bile salts, hydrogen sulfide, trimethylamine-N-oxide (TMAO), which are likely to promote inflammation and subsequently cancer development.

CONCLUSION

Recent studies suggest that gut microbiota-derived metabolites have a role in CRC progression and causation and hence, could be implicated in CRC diagnosis, prognosis and therapy.

Age, male sex, smoking and metabolic syndrome as risk factors of advanced colorectal neoplasia for fecal immunochemical test negative patients

BACKGROUND

Fecal immunochemical test (FIT) is worldwide strategy for colorectal cancer screening. The subjects with negative FIT still have the risk of an advanced colorectal neoplasia (AN), including adenoma with villous histology, high grade dysplasia or larger than 1 cm in size, or adenocarcinoma. The study determined the risk factors associated with AN in FIT-negative subjects.

METHODS

The study included asymptomatic subjects who received health checkup colonoscopy and have provided FIT study within 6 months prior to colonoscopy. The risk factors to have AN in cases with negative FIT were analyzed. The numbers of colonoscopies needed to detect one AN were calculated for the subjects with different risk factors.

RESULTS

There were 1411 cases, 85 with positive FIT and 1326 with negative FIT within 6 months before colonoscopy. In FIT positive and FIT negative cases, 45.9% and 34.6% were found to have colorectal adenoma, while 20.2% and 4.6% had AN, respectively. The univariate and multivariate logistic regression analyses showed that age more than 50 years old, male sex, smoking history and metabolic syndrome were the significant risk factors to have AN in the FIT negative cases. For cases with negative FIT to have these risk factors, the number of colonoscopies needed to detect one AN was 3.7, lower than 4.5 of the cases with positive FIT.

CONCLUSION

For the cases with negative FIT, colonoscopy screening should be considered for those male patients over 50 years old, with a history of smoking and metabolic syndrome to detect AN.

The Microbiome and Cancer: Creating Friendly Neighborhoods and Removing the Foes Within

The human body is colonized by the microbial cells that are estimated to be as abundant as human cells, yet their genome is roughly 100 times the human genome, providing significantly more genetic diversity. The past decade has observed an explosion of interest in examining the existence of microbiota in the human body and understanding its role in various diseases including inflammatory bowel disease, neurologic diseases, cardiovascular disorders, and cancer. Many studies have demonstrated differential community composition between normal tissue and cancerous tissue, paving the way for investigations focused on deciphering the cause-and-effect relationships between specific microbes and initiation and progression of various cancers. Also, evolving are the strategies to alter tumor-associated dysbiosis and move it toward eubiosis with holistic approaches to change the entire neighborhood or to neutralize pathogenic strains. In this review, we discuss important pathogenic bacteria and the underlying mechanisms by which they affect cancer progression. We summarize key microbiota alterations observed in multiple tumor niches, their association with clinical stages, and their potential use in cancer diagnosis and management. Finally, we discuss microbiota-based therapeutic approaches.

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.

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.

Diagnosis of Helicobacter pylori infection in the elderly using an immunochromatographic assay-based stool antigen test

The diagnostic value of Helicobacter pylori stool antigen (HpSA) tests in elderly subjects remains unclear. The objective of this study was to assess the diagnostic accuracy of the immunochromatographic assay‐based HpSA test in a male elderly cohort and identify factors affecting the accuracy. Data for asymptomatic elderly male citizens (≥65 years old) who received health checkups at the Chinese PLA General Hospital between July 2007 and November 2018 were collected. The diagnostic accuracy of the HpSA test was determined using the ¹³C‐urea breath test as a reference standard. Associations between baseline comorbidities and the accuracy of the HpSA test were analyzed. In total, 316 participants were enrolled, including 193 in the pre‐treatment group (77.2 ± 7.8 years old) and 123 in the post‐treatment group (78.7 ± 8.3 years old). The accuracy (91.5%, 91.2%, and 91.9%) and specificity (97.6%, 98.7%, and 96.0%) were high in all participants, pre‐ and post‐treatment groups, respectively. However, sensitivities were only 68.7%, 65.1%, and 75.0%, respectively. In the pre‐treatment group, constipation was associated with decreased sensitivity (p = 0.039), while colorectal polyps were associated with increased sensitivity (p = 0.010). Multivariate analysis indicated that constipation and colorectal polyps are independent factors for the sensitivity of HpSA in the pre‐treatment group. The immunochromatographic assay‐based HpSA test achieved high accuracy with high specificity but suboptimal sensitivity in the elderly male cohort. Constipation and colorectal polyps were negatively and positively associated with HpSA sensitivity, respectively, in the pre‐treatment group.

Association of Helicobacter pylori infection with colorectal polyps and malignancy in China

BACKGROUND

Gastric Helicobacter pylori (H. pylori) infection is related to chronic gastritis, gastroduodenal ulcer, and gastric malignancies; whether this infection is related to colorectal polyps and colorectal cancer (CRC), remains debatable.

AIM

To investigate the relationship between gastric H. pylori infection and the risk of colorectal polyps and CRC.

METHODS

We retrospectively analyzed 3872 patients with colorectal polyps who underwent colonoscopy and pathological diagnosis. We also analyzed 304 patients with primary CRC. The characteristics of these patients were compared with those of the control group, which included 2362 patients with the normal intestinal mucosa. All subjects completed a ¹⁴C-urea breath test, bidirectional gastrointestinal endoscopy, and a biopsy on the same day. Data on the number, size, location, and pathology of the polyps, the location, and pathology of the CRC, the detection of H. pylori, and the incidence of H. pylori-associated atrophic gastritis or intestinal metaplasia were obtained. A logistic regression model was used to analyze the relationship between gastric infection due to H. pylori, and the incidence of colorectal polyps and CRC.

RESULTS

The prevalence of H. pylori infection was higher in the multiple polyps group than in the solitary polyp group and the control group [95% confidence interval (CI) = 1.02-1.31, P = 0.03; 95%CI: 2.12-2.74, P < 0.001]. The patients with adenomatous polyps had a higher incidence of H. pylori infection than patients with non-adenomatous polyps [59.95% vs 51.75%, adjusted odds ratio (OR) = 1.41, 95%CI: 1.24-1.60, P < 0.01]. Patients with H. pylori-associated atrophic gastritis or intestinal metaplasia were at high risk of CRC (adjusted OR = 3.46, 95%CI: 2.63-4.55, P < 0.01; adjusted OR = 4.86, 95%CI: 3.22-7.34, P < 0.01, respectively). The size and location of the polyps, the histopathological characteristics and the location of CRC were not related to H. pylori infection.

CONCLUSION

Our study demonstrates that the incidence of gastric H. pylori infection and H. pylori-associated atrophic gastritis or intestinal metaplasia elevates the risk of colorectal polyps and CRC.

The close interrelation between colorectal cancer, infection and microbiota

PURPOSE OF REVIEW

Evaluate the recent literature about the relation of clinical infection and colorectal cancer in terms of diagnosis of an occult infection and possible impact on oncological outcome and review the possible role of the gut microbiota in the role of colorectal cancer oncogenesis.

RECENT FINDINGS

Data published within the 2 last years have been reviewed and the conclusions, mostly supporting previously published information, have been critically discussed.

SUMMARY

Infection (bacteremia, cellulitis) might be a surrogate of occult colorectal cancer and postoperative infection complications might jeopardize long-term survival after potentially curative surgery. The role of the gut microbiota in the genesis of colorectal cancer remains an exciting though unresolved question.

Effect of Gender and Age on the Correlation between Helicobacter pylori and Colorectal Adenomatous Polyps in a Chinese Urban Population: A Single Center Study

Objectives

To investigate whether Helicobacter pylori (H. pylori) infection increases the risk of colorectal adenomatous polyp (CAP) in the context of age and gender.

Methods

A total of 563 study subjects (male/female, 368/195) from Beijing, China, with higher nursing level who underwent colonoscopy were retrospectively collected. H. pylori and CAP were detected by carbon-13 urea breath test and colorectal colonoscopy. The correlations between the number, size, distribution, and pathological grade of CAP and H. pylori infection were analyzed. The population was further stratified by age and gender in order to examine the risk of H. pylori and CAP in the context of these variables. The influence of H. pylori on the risk of CAP was assessed by logistic regression model.

Results

315 participants were diagnosed with CAP, and 207 participants were classified as healthy controls. The prevalence of H. pylori in the CAP group was significantly higher than that in the healthy control group (119/315, 37.8% versus 44/207, 21.3%) (p < 0.001). The proportion of H. pylori positive plus CAP in participants <50 years old was significantly higher than that in participants >50 years old (87/250; 34.8% versus 32/65; 49.2%) (p < 0.001). The proportion of H. pylori positive plus CAP in participants <50 years old was significantly higher than that in participants >50 years old (87/250; 34.8% versus 32/65; 49.2%) (p < 0.001). The proportion of H. pylori positive plus CAP in participants <50 years old was significantly higher than that in participants >50 years old (87/250; 34.8% versus 32/65; 49.2%) (p < 0.001). The proportion of H. pylori positive plus CAP in participants <50 years old was significantly higher than that in participants >50 years old (87/250; 34.8% versus 32/65; 49.2%) (

Conclusions

H. pylori is a major risk factor for CAP. Further studies are needed to assess the effects of H. pylori treatment or persistent infection on the occurrence or recurrence of CAP.

Risk for Colorectal Neoplasia in Patients With Helicobacter pylori Infection: A Systematic Review and Meta-analysis

Helicobacter pylori may reportedly be associated with extragastric malignancy beyond gastric cancer. The present study aimed to evaluate the association between H. pylori infection and colorectal neoplasia through a systematic review and meta-analysis.

Helicobacter pylori infection and the risk of colorectal cancer: a nationwide population-based cohort study

BACKGROUND

The role of Helicobacter pylori (H. pylori) infection in the development of colorectal neoplasia has been a matter of scientific debate with controversial findings.

AIMS

This study examined the association between H. pylori infection and colorectal cancer (CRC) in a nationwide population-based Chinese cohort study.

METHODS

A total of approximately 3936 individuals with newly diagnosed H. pylori infection (the H. pylori-infected cohort) and 15 744 age- and sex-matched patients with diagnoses absence of H. pylori infection (the comparison cohort) from 2000 to 2005 were identified from Taiwan's National Health Insurance Research Database. The Kaplan-Meier method was used for measuring the cumulative incidence of CRC in each cohort. Cox proportional hazards models were used to compute hazard ratios (HRs) and accompanying 95% confidence intervals (CIs) for the estimation of the association between H. pylori infection and CRC.

RESULTS

The cumulative incidence of CRC was higher in H. pylori-infected cohort than that in the comparison cohort (log-rank test, P < 0.001). After adjustment for potential confounders, H. pylori infection was associated with a significantly increased risk of CRC (adjusted HR 1.87; 95% CI 1.37-2.57). In addition, the HR of CRC appeared to increase with increasing frequency of clinical visits for H. pylori infection.

CONCLUSIONS

Our study demonstrated that H. pylori infection was associated with an increased risk of CRC, which warrants confirmation and exploration of the underlying biologic mechanisms by future studies.

Lifestyle and dietary environmental factors in colorectal cancer susceptibility

Colorectal cancer (CRC) incidence changes with time and by variations in diet and lifestyle, as evidenced historically by migrant studies and recently by extensive epidemiologic evidence. The worldwide heterogeneity in CRC incidence is strongly suggestive of etiological involvement of environmental exposures, particularly lifestyle and diet. It is established that physical inactivity, obesity and some dietary factors (red/processed meats, alcohol) are positively associated with CRC, while healthy lifestyle habits show inverse associations. Mechanistic evidence shows that lifestyle and dietary components that contribute to energy excess are linked with increased CRC via metabolic dysfunction, inflammation, oxidative stress, bacterial dysbiosis and breakdown of gut barrier integrity while the reverse is apparent for components associated with decreased risk. This chapter will review the available evidence on lifestyle and dietary factors in CRC etiology and their underlying mechanisms in CRC development. This short review will also touch upon available information on potential gene-environment interactions, molecular sub-types of CRC and anatomical sub-sites within the colorectum.

Endoscopic gastric mucosal atrophy as a predictor of colorectal polyps: a large scale case-control study

Although some studies have indicated a correlation between Helicobacter pylori infection and the risk of colorectal neoplasms, these findings have not been consistent and are controversial. This case-control study aimed to investigate the association between endoscopic gastric mucosal atrophy and colorectal polyp occurrence. Records of 7,394 participants who underwent colonoscopy examinations from August 2008 to July 2018 were reviewed retrospectively. A total of 2,404 subjects were registered; 1,565 (65.1%) were in the gastric mucosal atrophy-positive group and 1,138 (47.3%) had colorectal polyps. The multivariate analysis adjusted by age, sex, smoking habits, alcohol habits, hemoglobin A1c, and systolic blood pressure indicated that patients in the gastric mucosal atrophy-positive group more frequently had colorectal polyps compared with patients in the gastric mucosal atrophy-negative group (odds ratio, 3.27; 95% confidence interval, 2.68-4.01; p<0.001). An analysis of the association between gastric mucosal atrophy degree and colorectal polyp status indicated that, compared with mild gastric mucosal atrophy, severe gastric mucosal atrophy was associated with a higher risk of proximal colon polyps (odds ratio, 1.47; 95% confidence interval, 1.05-2.07; p = 0.024) and two or more colorectal polyps (odds ratio, 1.80; 95% confidence interval, 1.30-2.49; p<0.001). In conclusion, gastric mucosal atrophy found during esophagogastroduodenoscopy may be an indication for complete colon screening.

Impact of the Gastrointestinal Microbiome in Health and Disease: Co-evolution with the Host Immune System

Microbes within the gastrointestinal tract communicate with each other and with the host, which has profound effects on health and disease development. Only now, it is becoming apparent that how and when we acquire our own unique collection of "gut microbes" and also how we choose to maintain them is fundamental to our health. Helicobacter pylori is the most common bacterial infection worldwide, colonizing around half of the world's population, and is the major risk factor for gastric adenocarcinoma. More recently, it has also been shown to have some beneficial effects in terms of protecting against the development of other diseases. Here, we review the current knowledge on how H. pylori has shaped gastrointestinal microbiota colonization and the host immune system with specific focus on the impact of H. pylori on the various microbiome niches of the gastrointestinal tract. We discuss how the presence of H. pylori influences the physiology of three major regions within the gastrointestinal tract-specifically the oesophagus, stomach and colon. We pay particular attention to the role of H. pylori under chronic inflammatory conditions including the development of cancer. With increased incidence of diseases such as eosinophilic oesophagitis, oesophageal adenocarcinoma and squamous cell carcinoma being attributed to the decline in H. pylori, their disease pathogenesis in light of changing H. pylori colonization is also discussed.

Correlation between Colon Polyps and Metabolic Syndrome and HP Infection Status

Background

This study investigated the relationships among the characteristics of colon polyps and potential risk factors, including metabolic condition, CEA level, uric acid level, and Helicobacter pylori (Hp) infection status.

Method

Clinical data from patients who received colonoscopy were collected and analyzed, including patients' gender, age, polyp pathology, metabolic syndrome (MS) status, CEA level, uric acid level, and Hp infection status. Patients were divided into a polyp group and a control group based on whether they presented with colon polyps. Then, clinical data were compared between the two groups to identify any differences between the groups and their relationships to colon polyps.

Result

Compared with the control group, the polyp group had significant differences in patient gender, body mass index (BMI), waistline, blood pressure, fasting blood glucose level, blood lipid level, and uric acid level (p < 0.05), but there were no significant differences in LDL and CEA levels (p > 0.05). Patients with MS or a uric acid level > 340 mg/dl had a greater tendency to develop colon polyps but this was not statistically significant.

Conclusion

The incidence of colon polyps may be associated with MS and uric acid levels, but further studies are warranted to confirm this conclusion.

Mucosal microbiota of intestinal polyps reveals putative biomarkers of colorectal cancer

The human intestine retains a complex microbial ecosystem, which performs crucial functions that impact on host health. Several studies have indicated that intestinal dysbiosis may impact on the establishment of life-threatening intestinal diseases such as colorectal cancer. An adenomatous polyp is the result of abnormal tissue growth, which is benign but is considered to be associated with a high risk of developing colorectal cancer, based on its grade of dysplasia. Development of diagnostic tools that are based on surveying the gut microbiota and are aimed at early detection of colorectal cancer represent highly desirable target. For this purpose, we performed a pilot study in which we applied a metataxonomic analysis based on 16S rRNA gene sequencing approach to unveil the composition of microbial communities of intestinal polyps. Moreover, we performed a meta-analysis involving the reconstructed microbiota composition of adenomatous polyps and publicly available metagenomics datasets of colorectal cancer. These analyses allowed the identification of microbial taxa such as Faecalibacterium, Bacteroides and Romboutsia, which appear to be depleted in cancerogenic mucosa as well as in adenomatous polyps, thus representing novel microbial biomarkers associated with early tumor formation. Furthermore, an absolute quantification of Fusubacterium nucleatum in polyps further compounded the important role of this microorganism as a valuable putative microbial biomarker for early diagnosis of colorectal cancer.

Influence of laboratory-related and endoscopy-related factors on the assessment of serum pepsinogens and gastrin-17

BACKGROUND AND AIM

Serum pepsinogen I (PGI) and pepsinogen II (PGII) are noninvasive parameters in the detection of atrophic gastritis. The diagnostic add-on value of serum gastrin-17 (G-17) remains uncertain. The aim of this study was to assess the stability of these serum parameters over time and to evaluate the influence of clinical factors, such as upper gastrointestinal (GI) endoscopy and bowel cleansing, on serum PGI, PGII, and G-17 assessment.

PATIENTS AND METHODS

A prospective study was carried out in healthy individuals and patients. For the stability analyses, the plasma and serum samples from 23 individuals were processed at different time points with and without the addition of a stabilizer. Ten patients were included to evaluate the influence of upper GI endoscopy and 18 patients to evaluate the effect of bowel cleansing before colonoscopy.

RESULTS

PGI, PGII, and G-17 levels were not statistically different in the serum and plasma. PGI and PGII serum levels were stable over time. G-17 is associated with time-dependent degradation (P=0.0001). The addition of the G-17 stabilizer showed no improvement in stability. Upper GI endoscopy and bowel preparation before colonoscopy were associated with minimal variations in PGI and PGII, whereas G-17 showed patient-specific alterations.

CONCLUSION

PGI and PGII serum levels are stable over time. However, G-17 stability is strongly dependent on the time of processing and storage; therefore, samples for G-17 analysis need to be processed no later than 6 h after blood collection. Upper GI endoscopy and colonoscopy preparation lead to minimal nonsignificant changes in basal PGI, PGII, and G-17 levels.

Helicobacter pylori, gastric cancer and other gastrointestinal malignancies

In a retrospective study performed in California, U.S.A., ca. 3% of patients with gastric intestinal metaplasia (GIM) developed gastric cancer (GC) within a median time period of 4.6 years after diagnosis of GIM. This observation stresses the importance of targeted surveillance even in regions with a low GC prevalence. Patients with alcoholic liver disease as well as survivors of colorectal and lobular breast cancer were found to be at increased risk of secondary GC. A population-based Chinese study confirmed "serologic biopsy" as a useful screening tool for stratifying the individual risk of developing GC. Concerning GC therapy, a post hoc analysis of the MAGIC trial reported that regression of lymph node metastases, but not the tumor regression itself, predicts overall survival. Furthermore, in patients with high microsatellite instable tumors, perioperative chemotherapy leads to an increased risk of mortality. Two studies confirmed that eradication therapy is worthwhile as an initial treatment for gastric mucosa-associated lymphoid tissue (MALT) lymphoma irrespective of the H. pylori infection status and stage. An increased risk of a second primary malignancy including GC was observed in these patients treated with immuno/chemotherapy but not in patients treated solely with an H. pylori eradication treatment. With respect to gastrointestinal malignancies other than GC, discrepant data have been published regarding the association of H. pylori with pancreatic cancer whereas no association has been reported with esophageal squamous cell carcinoma. The majority of published studies still support an association of H. pylori with colon neoplasms.

Microbiota, Inflammation and Colorectal Cancer

Colorectal cancer, the fourth leading cause of cancer-related death worldwide, is a multifactorial disease involving genetic, environmental and lifestyle risk factors. In addition, increased evidence has established a role for the intestinal microbiota in the development of colorectal cancer. Indeed, changes in the intestinal microbiota composition in colorectal cancer patients compared to control subjects have been reported. Several bacterial species have been shown to exhibit the pro-inflammatory and pro-carcinogenic properties, which could consequently have an impact on colorectal carcinogenesis. This review will summarize the current knowledge about the potential links between the intestinal microbiota and colorectal cancer, with a focus on the pro-carcinogenic properties of bacterial microbiota such as induction of inflammation, the biosynthesis of genotoxins that interfere with cell cycle regulation and the production of toxic metabolites. Finally, we will describe the potential therapeutic strategies based on intestinal microbiota manipulation for colorectal cancer treatment.

Keratin 8 reduces colonic permeability and maintains gut microbiota homeostasis, protecting against colitis and colitis-associated tumorigenesis

Keratin 8 (CK8) is the major component of the intermediate filaments of simple or single-layered epithelia. Gene targeting mice model suggest that CK8 is involved in colonic active ion transport, colorectal hyperplasia and inflammation. In the present study, we found that CK8 is downregulated in the colon during DSS-induced colitis and AOM/DSS-induced colitis-associated colorectal cancer (CAC) development. In human patients with colon cancer, CK8 is downregulated. Using CK8 heterozygous knockout mice (CK8^+/-), we found that CK8^+/- mice are highly susceptible to DSS-induced colitis and more prone to AOM/DSS-induced CAC than wild type (WT) mice. The colonic permeability is increased with DSS or AOM/DSS treatment, leading to alteration of gut microbiota in CK8^+/- mice with CAC. Metagenomic analysis of fecal microbiota suggests Firmicutes and Proteobacteria are increased in CK8^+/- mice with CAC, while Bacteroidetes and Verrucomicrobia are decreased. Antibiotic treatment decreases the incidence of colorectal cancer tumorigenesis and TLR4 inhibitor attenuates the susceptibility of CK8^+/- mice to DSS-induced colitis. These data suggest CK8 protects mice from colitis and colitis-associated colorectal cancer by modulating colonic permeability and gut microbiota composition homeostasis.