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

Helicobacter pylori infection is associated with the development of sporadic colorectal carcinoma and colorectal adenomatous polyps

Helicobacter pylori (H. pylori) infection is a well-established carcinogen that has been extensively studied in the context of gastric diseases. Recent studies suggested a potential association between H. pylori and the risk of colorectal carcinoma (CRC). However, available data remains insufficient to definitively establish a causal relationship between H. pylori infection and the development of CRC and its precursor lesions. In our study, we reviewed all patients diagnosed with CRC in 2020 at our institution. H. pylori assessment was performed in all 92 CRC specimens by immunohistochemistry. Notably, two of the three patients detected with H. pylori infection are under the age of 50. Subsequently, we reviewed a total of 52 patients under the age of 50 diagnosed with CRC at our institution from 2015 to 2022. Among these patients, H. pylori infection was detected in 7 CRC specimens (13.46 %). All seven patients had adenocarcinoma on the left side of the colon. In exploring the link between H. pylori infection and the risk of developing CRC precursor lesions, we analyzed 242 patients who underwent colonoscopy guided polypectomy and also had stomach biopsies from 2015 to 2022. Of these patients, 21 were proved to be positive for H. pylori infection in the stomach, while the remaining 221 were negative. Among the H. pylori-positive group, 76.19 % (16 patients) exhibited adenomatous polyps, compared to 33.48 % (74 patients) in the H. pylori-negative patients (p=0.0001). However, no H. pylori was detected in any colonic adenomatous polyps. Our findings contribute additional evidence supporting the association between H. pylori infection and the development of sporadic CRC, probably a particular association with early-onset ones. Furthermore, gastric H. pylori infection appears to be linked to the higher prevalence of colonic adenomatous polyps, suggesting that individuals with gastric H. pylori infection may benefit from closer and earlier monitoring through colonoscopy.

Impact of Helicobacter pylori Infection and Treatment on Colorectal Cancer in a Large, Nationwide Cohort

PURPOSE

Helicobacter pylori is the most common cause of infection-associated cancer worldwide. We aimed to evaluate the impact of H. pylori infection and treatment on colorectal cancer (CRC) incidence and mortality.

PATIENTS

US Veterans who completed H. pylori testing between 1999 and 2018.

METHODS

We conducted a retrospective cohort analysis among adults within the Veterans Health Administration who completed testing for H. pylori. The primary exposures were (1) H. pylori test result (positive/negative) and (2) H. pylori treatment (untreated/treated) among H. pylori-positive individuals. The primary outcomes were CRC incidence and mortality. Follow-up started at the first H. pylori testing and continued until the earliest of incident or fatal CRC, non-CRC death, or December 31, 2019.

RESULTS

Among 812,736 individuals tested for H. pylori, 205,178 (25.2%) tested positive. Being H. pylori-positive versus H. pylori-negative was associated with higher CRC incidence and mortality. H. pylori treatment versus no treatment was associated with lower CRC incidence and mortality (absolute risk reduction 0.23%-0.35%) through 15-year follow-up. Being H. pylori-positive versus H. pylori-negative was associated with an 18% (adjusted hazard ratio [adjusted HR], 1.18 [95% CI, 1.12 to 1.24]) and 12% (adjusted HR, 1.12 [95% CI, 1.03 to 1.21]) higher incident and fatal CRC risk, respectively. Individuals with untreated versus treated H. pylori infection had 23% (adjusted HR, 1.23 [95% CI, 1.13 to 1.34]) and 40% (adjusted HR, 1.40 [95% CI, 1.24 to 1.58]) higher incident and fatal CRC risk, respectively. The results were more pronounced in the analysis restricted to individuals with nonserologic testing.

CONCLUSION

H. pylori positivity may be associated with small but statistically significant higher CRC incidence and mortality; untreated individuals, especially those with confirmed active infection, appear to be most at risk.

Effects of pork sausage on intestinal microecology and metabolism in mice

BACKGROUND

Processed meat, as an important part of the human diet, has been recognized as a carcinogen by the International Agency for Research on Cancer (IARC). Although numerous epidemiological reports supported the IARC's view, the relevant evidence of a direct association between processed meat and carcinogenicity has been insufficient and the mechanism has been unclear. This study aims to investigate the effects of pork sausage (as a representative example of processed meat) intake on gut microbial communities and metabolites of mice. Microbial communities and metabolites from all groups were analyzed using 16S rRNA gene sequencing and Ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometer (UPLC-Q-TOF/MS), respectively.

RESULTS

The levels of Bacteroidetes, Bacteroides, Alloprevotella, Lactobacillus, Prevotella_9, Lachnospiraceae_NK4A136_group, Alistipes, Blautia, Proteobacteria, Firmicutes, Allobaculum, Helicobacter, Desulfovibrio, Clostridium_sensu_stricto_1, Ruminococcaceae_UCG-014, Lachnospiraceae_UCG-006 and Streptococcus (P < 0.05) were obviously altered in the mice fed a pork sausage diet. Twenty-seven metabolites from intestinal content samples and fourteen matabolites from whole blood samples were identified as potential biomarkers from multivariate analysis, including Phosphatidic acid (PA), Sphingomyelin (SM), Lysophosphatidylcholine (LysoPC), Diglyceride (DG), D-maltose, N-acylamides and so forth. The significant changes in these biomarkers demonstrate metabonomic variations in pork sausage treated rats, especially carbohydrate metabolism, lipid metabolism, and amino acid metabolism.

CONCLUSION

The present study provided evidence that a processed meat diet can increase the risk of colorectal cancer and other diseases significantly by altering the microbial community structure and disrupting the body's metabolic pathways. © 2023 Society of Chemical Industry.

Role of Helicobacter pylori virulence factors and alteration of the Tumor Immune Microenvironment: challenges and opportunities for Cancer Immunotherapy

Various forms of malignancies have been linked to Helicobacter pylori. Despite advancements in chemotherapeutic and surgical approaches, the management of cancer, particularly at advanced stages, increasingly relies on the integration of immunotherapy. As a novel, safe therapeutic modality, immunotherapy harnesses the immune system of the patient to treat cancer, thereby broadening treatment options. However, there is evidence that H. pylori infection may influence the effectiveness of immunotherapy in various types of cancer. This association is related to H. pylori virulence factors and the tumor microenvironment. This review discusses the influence of H. pylori infection on immunotherapy in non-gastrointestinal and gastrointestinal tumors, the mechanisms underlying this relationship, and directions for the development of improved immunotherapy strategies.

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.

Cancer statistics for American Indian and Alaska Native individuals, 2022: Including increasing disparities in early onset colorectal cancer

American Indian and Alaska Native (AIAN) individuals are diverse culturally and geographically but share a high prevalence of chronic illness, largely because of obstacles to high-quality health care. The authors comprehensively examined cancer incidence and mortality among non-Hispanic AIAN individuals, compared with non-Hispanic White individuals for context, using population-based data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries. Overall cancer rates among AIAN individuals were 2% higher than among White individuals for incidence (2014 through 2018, confined to Purchased/Referred Care Delivery Area counties to reduce racial misclassification) but 18% higher for mortality (2015 through 2019). However, disparities varied widely by cancer type and geographic region. For example, breast and prostate cancer mortality rates are 8% and 31% higher, respectively, in AIAN individuals than in White individuals despite lower incidence and the availability of early detection tests for these cancers. The burden among AIAN individuals is highest for infection-related cancers (liver, stomach, and cervix), for kidney cancer, and for colorectal cancer among indigenous Alaskans (91.3 vs. 35.5 cases per 100,000 for White Alaskans), who have the highest rates in the world. Steep increases for early onset colorectal cancer, from 18.8 cases per 100,000 Native Alaskans aged 20-49 years during 1998 through 2002 to 34.8 cases per 100,000 during 2014 through 2018, exacerbated this disparity. Death rates for infection-related cancers (liver, stomach, and cervix), as well as kidney cancer, were approximately two-fold higher among AIAN individuals compared with White individuals. These findings highlight the need for more effective strategies to reduce the prevalence of chronic oncogenic infections and improve access to high-quality cancer screening and treatment for AIAN individuals. Mitigating the disparate burden will require expanded financial support of tribal health care as well as increased collaboration and engagement with this marginalized population.

The relationship between colorectal cancer and gastric histopathology: case-control study

Aim: The aim of this study was to investigate the gastric histopathological findings (Helicobacter pylori (H. pylori), intestinal metaplasia (IM), atrophic gastritis (AG), and dysplasia) in the patients with and without colorectal cancer (CRC). Material and Method: Two hundred ninety five patients (160 CRC patients and 135 control individuals) were included in the study. Gastric histopathological findings of the patients who underwent upper gastrointestinal (GI) endoscopy were analyzed retrospectively. Results: H. pylori positivity and IM rates in the CRC patient group were significantly higher than the control group (58.8%&amp;27.8% and 33.1%&amp;19.5%, p&lt;0.001 and p&lt;0.012, respectively). In addition, AG, lymphoplasmocytic infiltration, and dysplasia rates were also higher in the CRC patients compared to the control group. But, they were not statistically significant (p=0.462, p=0.103, and p=0.195, respectively). Conclusion: In our study, the frequency of H. pylori and IM in patients with CRC was higher than in the control group. Since the prevalence of H. pylori infection is high in Turkey and H. pylori-related gastric diseases may be potential risk factors for colorectal neoplasia, it is recommended that individuals in the high-risk group to be screened for colonoscopy. Also, upper GI endoscopic examination should be performed to screen for gastric premaling lesions in patients with CRC.

Association of Helicobacter pylori enrichment in colorectal adenoma tissue on clinical and pathological features of adenoma

OBJECTIVE

To investigate the enrichment of Helicobacter pylori (Hp) in adenoma tissue of patients with colorectal adenoma, and analyze the correlation between the enrichment and the clinical and pathological characteristics of colorectal adenoma.

METHODS

The data of 1,622 patients undergoing gastrointestinal endoscopy in the Endoscopy Center of Wenzhou Integrated Traditional Chinese and Western Medicine Hospital affiliated to Zhejiang University of Traditional Chinese Medicine from January 2019 to June 2021 were retrospectively collected. The general data, gastric Hp infection, clinical and pathological features of colorectal adenoma, methylene blue staining of adenoma Hp, immunohistochemistry of adenoma Hp and immunofluorescence staining of adenoma TLR5 protein. were compared between the colorectal adenoma group (743 cases) and the control group (879 cases).

RESULTS

There were 361 gastric Hp positive cases in the colorectal adenoma group, with a positive rate of 48.59%, and 331 gastric Hp positive cases in the control group, with a positive rate of 37.66%, and the difference was statistically significant (P < 0.001). Gastric Hp infection significantly correlates with the Hp enrichment in colorectal adenomas (OR: 28.449; 95%CI: 18.188-44.500; P < 0.001). Moreover, we found that Hp enrichment in colorectal adenomas was correlated with the diameter, pathological type, and malignancy of adenoma (OR: 3.536; 3.652; 2.833; all P < 0.001). Expression TLR5 protein was also increased in Hp-enriched adenoma tissue.

CONCLUSION

There is a correlation between gastric Hp infection and intestinal Hp enrichment. The intestinal Hp enrichment significantly correlates with the clinical and pathological characteristics of colorectal adenomas, and its tumor-promoting effect may be related to the up-regulation of mucosal TLR5 expression.

The role of microbiota in colorectal cancer

Cancer is one of the most important causes of death throughout the world, and the mortality rate is increasing significantly due to the aging of the population. One of the most common types of cancer is colorectal cancer (CRC). Human microbial ecosystems use metabolism to make important impacts on the body physiology. An intensive literature review was made to investigate the correlations between human gut microbiota and the incidence of CRC. The results of these studies show that there are differences in the composition of microbiota between CRC patients and normal people and the microorganisms in CRC patients are very different from healthy individuals. Therefore, changes in the microbiome can be used as a biomarker for the early detection of CRC. On the other hand, the intestinal flora is may be act as a powerful weapon against CRC in the future.

Fabrication and In Vitro/In Vivo Appraisal of Metronidazole Intra-Gastric Buoyant Sustained-Release Tablets in Healthy Volunteers

Helicobacter pylori is thought to be the most common cause of peptic and duodenal ulcers. Eradication of this organism is now considered one of the lines of treatment of gastric and duodenal ulcers. This can be achieved via local delivery of antibacterial agents in high concentrations. Accordingly, our objective was to fabricate and evaluate sustained release floating tablets for metronidazole to extend the gastric residence period and control the release rate of metronidazole. Floating tablets containing cellulose derivatives and Avicel were prepared using direct compression. The rate of metronidazole release from the floating tablets (K = 6.278 mg min^−1/2) was significantly lower than that from conventional tablets (K = 10.666 mg min^−1/2), indicating sustained drug release, according to the Higuchi model, for more than 6 h in an acidic medium of 0.1 N HCl. In vivo study in healthy volunteers revealed significantly improved bioavailability; increased Tmax, AUC, and MRT; and significantly lower absorption rate constant after a single oral dose of 150 mg metronidazole as floating tablets. In addition, the significant increase in MRT indicated an in vivo sustained drug release. The floating tablets provided several benefits, including ease of preparation, absence of effervescent ingredients, and reliance on a pH-independent gel-forming agent to deliver metronidazole in a sustained manner. In conclusion, the prepared tablets could be promising for enhancing both local and systemic metronidazole efficacy.

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.

Progress in elucidating the relationship between Helicobacter pylori infection and intestinal diseases

Helicobacter pylori (H. pylori) infection causes changes to the intestinal flora, such as small intestinal bacterial overgrowth, and increases gastric acid secretion-stimulating gastrointestinal hormones, mainly gastrin, due to a decrease in gastric acid caused by atrophic gastritis. In addition, the cellular components of H. pylori travel through the intestinal tract, so the bacterial infection affects the immune system. Therefore, the effects of H. pylori infection are observed not only in the stomach and the proximal duodenum but also in the small and large intestines. In particular, meta-analyses reported that H. pylori-infected individuals had an increased risk of colorectal adenoma and colorectal cancer. Moreover, a recent study reported that the risk of developing colorectal cancer was increased in subjects carrying H. pylori vacuolating cytotoxin A antibody. In addition, it has been reported that H. pylori infection exacerbates the symptoms of Fabry’s disease and familial Mediterranean fever attack and is involved in irritable bowel syndrome and small intestinal ulcers. On the other hand, some studies have reported that the frequency of ulcerative colitis, Crohn’s disease, and celiac disease is low in H. pylori-infected individuals. Thus, H. pylori infection is considered to have various effects on the small and large intestines. However, few studies have reported on these issues, and the details of their effects have not been well elucidated. Therefore, additional studies are needed.

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.

Microbiota's role in health and diseases

The microbiome is a term that usually refers to the community of various microorganisms that inhabit/live inside human/animal bodies or on their skin. It forms a complex ecosystem that includes trillions of commensals, symbiotics, and even pathogenic microorganisms. The external environment, diet, and lifestyle are the major determinants influencing the microbiome's composition and vitality. Recent studies have indicated the tremendous influence of the microbiome on health and disease. Their number, constitution, variation, and viability are dynamic. All these elements are responsible for the induction, development, and treatment of many health disorders. Serious diseases such as cancer, metabolic disorders, cardiovascular diseases, and even psychological disorders such as schizophrenia are influenced directly or indirectly by microbiota. In addition, in the last few weeks, accumulating data about the link between COVID-19 and the microbiota were published. In the present work, the role of the microbiome in health and disease is discussed. A deep understanding of the exact role of microbiota in disease induction enables the prevention of diseases and the development of new therapeutic concepts for most diseases through the correction of diet and lifestyle. The present review brings together evidence from the most recent works and discusses suggested nutraceutical approaches for the management of COVID-19 pandemic.

Multidimensional role of bacteria in cancer: Mechanisms insight, diagnostic, preventive and therapeutic potential

The active role of bacteria in oncogenesis has long been a topic of debate. Although, it was speculated to be a transmissible cause of cancer as early as the 16th-century, yet the idea about the direct involvement of bacteria in cancer development has only been explored in recent decades. More recently, several studies have uncovered the mechanisms behind the carcinogenic potential of bacteria which are inflammation, immune evasion, pro-carcinogenic metabolite production, DNA damage and genomic instability. On the other side, the recent development on the understanding of tumor microenvironment and technological advancements has turned this enemy into an ally. Studies using bacteria for cancer treatment and detection have shown noticeable effects. Therapeutic abilities of bioengineered live bacteria such as high specificity, selective cytotoxicity to cancer cells, responsiveness to external signals and control after ingestion have helped to overcome the challenges faced by conventional cancer therapies and highlighted the bacterial based therapy as an ideal approach for cancer treatment. In this review, we have made an effort to compile substantial evidence to support the multidimensional role of bacteria in cancer. We have discussed the multifaceted role of bacteria in cancer by highlighting the wide impact of bacteria on different cancer types, their mechanisms of actions in inducing carcinogenicity, followed by the diagnostic and therapeutic potential of bacteria in cancers. Moreover, we have also highlighted the existing gaps in the knowledge of the association between bacteria and cancer as well as the limitation and advantage of bacteria-based therapies in cancer. A better understanding of these multidimensional roles of bacteria in cancer can open up the new doorways to develop early detection strategies, prevent cancer, and develop therapeutic tactics to cure this devastating disease.

Helicobacter pylori infection with atrophic gastritis: An independent risk factor for colorectal adenomas

BACKGROUND

The significance of Helicobacter pylori (H. pylori) infection and atrophic gastritis (AG) in the prevalence of colorectal adenomas has been examined in a limited number of studies. However, these studies reported disputed conclusions.

AIM

To investigate whether H. pylori infection, AG, and H. pylori-related AG increase the risk of colorectal adenomas.

METHODS

This retrospective cross-sectional study included 6018 health-check individuals. The relevant data for physical examination, laboratory testing, ¹³C-urea breath testing, gastroscopy, colonoscopy and histopathological examination of gastric and colorectal biopsies were recorded. Univariate and multivariate logistic regression analyses were performed to determine the association between H. pylori-related AG and colorectal adenomas.

RESULTS

Overall, 1012 subjects (16.8%) were diagnosed with colorectal adenomas, of whom 143 (2.4%) had advanced adenomas. Among the enrolled patients, the prevalence of H. pylori infection and AG was observed as 49.5% (2981/6018) and 10.0% (602/6018), respectively. Subjects with H. pylori infection had an elevated risk of colorectal adenomas (adjusted odds ratio [OR] of 1.220, 95% confidence interval (CI): 1.053-1.413, P = 0.008) but no increased risk of advance adenomas (adjusted OR = 1.303, 95%CI: 0.922-1.842, P = 0.134). AG was significantly correlated to an increased risk of colorectal adenomas (unadjusted OR = 1.668, 95%CI: 1.352-2.059, P < 0.001; adjusted OR = 1.237, 95%CI: 0.988-1.549, P = 0.064). H. pylori infection accompanied by AG was significantly associated with an increased risk of adenomas (adjusted OR = 1.491, 95%CI: 1.103-2.015, P = 0.009) and advanced adenomas (adjusted OR = 1.910, 95%CI: 1.022-3.572, P = 0.043).

CONCLUSION

H. pylori-related AG was associated with a high risk of colorectal adenomas and advanced adenomas in Chinese individuals.

H. pylori Infection and Colorectal Cancers by Anatomical Locations

Background:

H. pylori infection may play a role in the development of colorectal cancers (CRC). We aimed to examine the association between H. pylori infection and the risk of CRC by anatomical locations.

Methods:

We conducted a case-control study on 91 incidence cases of CRC and 224 hospital controls. CRC was determined by histopathological examinations. H. pylori IgG antibody in serum was tested. We collected data on the diet, nutrition, and lifestyle by the validated semi-quantitative food frequency and demographic lifestyle questionnaire. The odds ratio and 95% confidence interval (OR (95%CI) were estimated for CRC and its subgroups.

Results:

Overall 54.95% of CRC cases and 42.41% of the controls were H. pylori-seropositive, OR (95%CI): 1.56 (0.88, 2.74), p for trend=0.115. Positive dose-response association in quartiles, highest vs lowest, was observed for total CRC, OR (95%CI): 2.14 (1.00, 4.58), p for trend=0.049, for proximal colon, OR (95%CI): 1.52 (0.37, 6.25), p for trend=0.571), and for distal colon and rectum cancers combined, OR (95%CI): 2.38 (1.03, 5.50), p for trend=0.039.

Conclusions:

There is a positive association between H. pylori and colorectal cancers, especially distal colon and rectum cancers combined, but additional research is needed to determine the underlying mechanism of chronic H. pylori infection-induced CRC in humans.

Adaptogenic flower buds exert cancer preventive effects by enhancing the SCFA-producers, strengthening the epithelial tight junction complex and immune responses

Microbiome therapy has attracted a keen interest from both research and business sectors. Our lab has been applying this "second genome" platform to assess the functionality of herbal medicines with fulfilling results. In this study, we applied this platform to assess the potential cancer-preventive effects of three selected adaptogenic plants. The flower buds from these plants were used to constitute Preparations SL and FSP according to the receipts of two commonly consumed Chinese medicinal decoctions for gastrointestinal discomfort. Preparation SL contains Sophorae japonica and Lonicerae Japonicae, and Preparation FSP contains Sophorae japonica and Gardenia Jasminoides. SL and FSP extracts significantly (p < 0.001) lowered the polyp burden, as well as the expressions of oncogenic signaling molecules, such as MAPK/ERK, PI3K/AKT, and STAT3 in Apc^Min/+ mice. The inflamed gut was alleviated by shifting M1 to M2 macrophage phenotypes and the associated immune cytokines. The other remarkable change was on the extracellular tight junction protein complex, where the occludin, ZO-1, ICAM-1, E-cadherin were significantly (p < 0.05) upregulated while the N-cadherin and β-catenin were downregulated in the treated mice. The above physiological changes in the gut epithelial barrier were companied with the changes in gut microbiome. The 16S Sequencing data revealed a marked decrease in the potential pathogens (especially Helicobacter species and hydrogen sulfide producing-bacteria) and the increase in beneficial bacteria (especially for species from the genera of Akkermansia, Barnesiella, Coprococcus, Lachnoclostridium, and Ruminococcus). The majority of which were the short-chain fatty acids (SCFAs) producers. Meanwhile SCFAs-sensing G protein-coupled receptors (GPCRs), including GPR41, GPR43, and GPR109a were also significantly upregulated. In a recent report, we proved that the bacteria-derived SCFAs plays an essential role to the anti-cancer effects of the mushroom polysaccharides and saponins in Apc^Min/+ mice. In this study, we further demonstrated that butyrate treatment could enhance the extracellular tight junction protein complex as effective as the treatments with SL and FSP to the Apc^Min/+ mice. Our findings provide strong evidence of the vital role of the SCFA-producers and their metabolites to the cancer-preventive properties of the SL and FSP preparations.

The Bacterial Microbiota of Gastrointestinal Cancers: Role in Cancer Pathogenesis and Therapeutic Perspectives

The microbiota has an essential role in the pathogenesis of many gastrointestinal diseases including cancer. This effect is mediated through different mechanisms such as damaging DNA, activation of oncogenic pathways, production of carcinogenic metabolites, stimulation of chronic inflammation, and inhibition of antitumor immunity. Recently, the concept of "pharmacomicrobiomics" has emerged as a new field concerned with exploring the interplay between drugs and microbes. Mounting evidence indicates that the microbiota and their metabolites have a major impact on the pharmacodynamics and therapeutic responses toward anticancer drugs including conventional chemotherapy and molecular-targeted therapeutics. In addition, microbiota appears as an attractive target for cancer prevention and treatment. In this review, we discuss the role of bacterial microbiota in the pathogenesis of different cancer types affecting the gastrointestinal tract system. We also scrutinize the evidence regarding the role of microbiota in anticancer drug responses. Further, we discuss the use of probiotics, fecal microbiota transplantation, and antibiotics, either alone or in combination with anticancer drugs for prevention and treatment of gastrointestinal tract cancers.

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 carcinoma: a systematic review and meta-analysis

INTRODUCTION

Helicobacter pylori is a gram-negative bacterium that is colonized in the stomach. H. pylori infection can lead to a series of stomach diseases. However, the relationship between H. pylori infection and colorectal cancer is currently controversial. Therefore, we performed this meta-analysis to further understand the relationship between H. pylori infection and colorectal cancer.

EVIDENCE ACQUISITION

We conducted a comprehensive retrieval from electronic databases, included the PubMed, Medline, China National Knowledge Infrastructure (CNKI), and China Wanfang Data Knowledge Service Platform databases (Wanfang Databases) through May 1st, 2018. We used the search terms H. pylori and colorectal cancer or colorectal carcinoma and collected all relevant studies to explore the association between H. pylori infection and colorectal cancer.

EVIDENCE SYNTHESIS

Twenty-seven studies including 14357 cases were included. H. pylori infection was associated with an increased risk of colorectal cancer. A pooled odds ratio (OR) of 1.27 with a 95% CI of 1.17-1.37 (P<0.001) was calculated by using a fixed-effects model (I2=45.5%, P=0.006). The subgroup analysis revealed that H. pylori infection was associated with an increased risk of colorectal cancer in the subgroups of Western countries (OR=1.34, 95% CI: 1.14-1.57) (P<0.001), serological testing (OR=1.20, 95% CI: 1.08-1.34) (P=0.001), multiple methods of testing (OR=2.63, 95% CI: 1.09-6.31) (P=0.031), cross-sectional studies (OR=1.92, 95% CI: 1.17-3.16) (P=0.010) and case-control studies (OR 1.26, 95% CI: 1.16-1.36) (P<0.001).

CONCLUSIONS

The present meta-analysis provides evidence suggests that a positive association between H. pylori infection and the risk of colorectal cancer.

H. pylori infection and extra-gastroduodenal diseases

Helicobacter pylori infection is the principal cause of peptic ulcer disease, gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue lymphoma. Recent studies have shown that it may interfere with many biological processes and determine or influence the occurrence of many diseases outside the stomach. Currently, the role of H. pylori in idiopathic thrombocytopenic purpura and iron deficiency anemia is well documented. Emerging evidence suggests that it may also contribute to vitamin B12 deficiency, insulin resistance, metabolic syndrome, diabetes mellitus and non-alcoholic liver disease. Additionally, it may increase the risk of acute coronary syndrome, cerebrovascular disease, neurodegenerative disease and other miscellaneous disorders. Different pathogenic mechanisms have been hypothesized, including the occurrence of molecular mimicry and the induction of a low-grade inflammation. This review summarizes the results of the most relevant studies on the extra-gastroduodenal manifestations of H. pylori infection.

The association between Helicobacter pylori infection and the risk of advanced colorectal neoplasia may differ according to age and cigarette smoking

BACKGROUND

The association between Helicobacter pylori infection and advanced colorectal neoplasia (ACN) remains controversial. This study aimed to clarify the association between H. pylori infection and ACN according to age groups.

METHODS

We retrospectively analyzed the association between H. pylori infection and ACN in patients aged <50 and ≥50 years receiving a health checkup that included colonoscopy. Helicobacter pylori positivity was determined by the results of serum anti-H. pylori immunoglobulin G or rapid urease test, if the anti-H. pylori immunoglobulin G was in the borderline range.

RESULTS

Among the 19 337 patients who were included, 56.2% and 3.4% were positive for H. pylori and ACN, respectively. Helicobacter pylori infection independently increased the risk of ACN in patients aged <50 years (odds ratio [OR], 1.602; 95% confidence intervals [CI], 1.194-2.150) but not in patients aged ≥50 years (OR, 1.046; 95% CI, 0.863-1.268). The positive association between H. pylori infection and ACN was affected by smoking history. When stratified by age and smoking history, H. pylori infection conferred an increased risk of ACN in patients aged <50 years with a history of smoking (OR, 1.926; 95% CI, 1.336-2.775) but not in the other 3 groups (3-way interaction test P = .023). Among patients aged <50 years with ACN, ACN in the left colon was found more frequently in patients with H. pylori infection and a history of smoking than in those without (69.3% vs 54.4%, respectively; P = .031).

CONCLUSIONS

Helicobacter pylori infection confers an increased risk of ACN, but the association may differ according to age and smoking history.

Helicobacter pylori is associated with increased risk of serrated colonic polyps: Analysis of serrated polyp risk factors

BACKGROUND

Sessile serrated adenomas (SSA) and traditional serrated adenomas (TSA) are recognized precursors of colorectal cancer, but their risk factors are not well established. We investigated the association between Helicobacter pylori infection (HPI) and the development of SSA and TSA.

METHODS

Retrospective data were collected on patients aged ≥ 18 years that underwent colonoscopy with biopsy between 2006 and 2016. Based on histology, patients were classified into three groups: those with SSA and/or TSA, (serrated neoplasia group, SN); conventional adenomas only (CA); and with no polyps (NP). Gastric HPI status, demographic, and clinical risk factors were compared between groups using bivariate and multivariable analysis.

RESULTS

HPI was significantly associated with increased risk of SN (SN vs. NP: OR 1.71 [95% CI 1.29-2.27]; SN vs. CA: 1.49 [1.14-1.96]). Additional factors associated with increased risk of SN included the following: age 50-75 years, compared to younger age (SN vs. NP: 2.83 [1.69-4.74]), female gender (SN vs. CA: 1.28 [0.99-1.64]), White race, compared to Blacks (SN vs. CA: 1.52 [1.07-2.15)], overweight and obese body mass index [SN vs. NP: p < 0.001) and current smoking status (SN vs. CA: 2.09 [1.55-2.82)]. Among SN, higher HPI prevalence was associated with dysplasia (p = 0.05) and proximal location (p = 0.01).

CONCLUSIONS

Our data suggest that gastric HPI is associated with increased risk of SN and CA, with a stronger association with SN as compared to CA. Age 50-75 years, female gender, White race, obesity, and smoking were also predictors of SN. A positive correlation of HPI with proximal and dysplastic SN suggests a possible role in serrated pathway carcinogenesis. Prospective studies with large patient population are needed to further investigate this association.

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

Repurposing the anthelmintic drug niclosamide to combat Helicobacter pylori

There is an urgent need to discover novel antimicrobial therapies. Drug repurposing can reduce the time and cost risk associated with drug development. We report the inhibitory effects of anthelmintic drugs (niclosamide, oxyclozanide, closantel, rafoxanide) against Helicobacter pylori strain 60190 and pursued further characterization of niclosamide against H. pylori. The MIC of niclosamide against H. pylori was 0.25 μg/mL. Niclosamide was stable in acidic pH and demonstrated partial synergy with metronidazole and proton pump inhibitors, such as omeprazole and pantoprazole. Niclosamide administration at 1 × MIC concentration, eliminated 3-log₁₀ CFU of H. pylori adhesion/invasion to AGS cells. Interestingly, no resistance developed even after exposure of H. pylori bacteria to niclosamide for 30 days. The cytotoxic assay demonstrated that niclosamide is not hemolytic and has an IC₅₀ of 4 μg/mL in hepatic and gastric cell lines. Niclosamide administration decreased transmembrane pH as determined by DiSC₃(5) assay indicating that the mechanism of action of the anti-H. pylori activity of niclosamide was the disruption of H. pylori proton motive force. Niclosamide was effective in the Galleria mellonella-H. pylori infection model (p = 0.0001) and it can be develop further to combat H. pylori infection. However, results need to be confirmed with other H. pylori and clinical strains.

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.

The ethnic distribution of sessile serrated polyps in the United States is inversely associated with Helicobacter pylori prevalence

AIM

Little is known about the epidemiology of sessile serrated polyps (SSP). Our study aimed to investigate the influence of Helicobacter pylori gastritis and patient demographic characteristics (age, gender, ethnicity) on the prevalence of SSP using a large national database of patients undergoing bi-directional endoscopy.

METHOD

De-identified patient data were extracted from the Miraca Life Sciences electronic database of histopathological reports. Using multivariate logistic regression analysis, the influence of H. pylori gastritis and demographic characteristics on the occurrence of SSP were expressed as odds ratios (OR) with their 95% confidence intervals (CI).

RESULTS

The total study population comprised 228 506 subjects, of whom 28 890 carried a diagnosis of H. pylori gastritis and 11 285 SSP. Age (OR 4.35, 95% CI: 3.82-4.96), female gender (0.92, 0.88-0.95) and H. pylori gastritis (0.94, 0.88-0.99) exerted the strongest influence on the occurrence of SSP. In comparison with the population comprising Caucasians and African Americans, SSP were less common among subjects of Hispanic (0.67, 0.62-0.73), East Asian (0.59, 0.50-0.69), Indian (0.43, 0.27-0.64) or Middle Eastern descent (0.61, 0.41-0.87). All these ethnic subgroups were also characterized by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of SSP (R²  = 0.82, P < 0.001).

CONCLUSION

The prevalence of SSP within the United States is characterized by a marked ethnic variation. The inverse correlation between the prevalence of H. pylori and SSP suggests that gastric infection with H. pylori may be partly responsible for the observed ethnic distribution of SSP.

Family history of gastric cancer is associated with the risk of colorectal neoplasia in Korean population

BACKGROUND

Family history of cancers at different sites except for colorectum has not been evaluated as a risk factor for colorectal neoplasia (CRN).

AIMS

To investigate CRN risk according to family history of cancers at 12 different sites, including stomach and colorectum.

METHODS

A cross-sectional study was performed on 139,497 asymptomatic Koreans who underwent colonoscopy as part of a health check-up.

RESULTS

The mean age of the study population was 41.6 and the prevalence of CRN was 16.3%. Multivariate analyses revealed that family histories of CRC (adjusted odds ratio; confidence interval, 1.26; 1.17-1.35) and gastric cancer (1.07; 1.01-1.13) were independent risk factors for CRN. Notably, the risk of CRN increased even more for participants with family histories of both CRC and gastric cancer (1.38; 1.12-1.70). Family history of CRC was associated with risk of CRN in participants aged both <50 and ≥50 years, whereas family history of gastric cancer was associated with risk of CRN in participants aged <50 years (1.22; 1.14-1.30), but not in participants aged ≥50 years (1.08; 0.99-1.18).

CONCLUSIONS

Family history of gastric cancer was an independent risk factor for CRN, especially in those aged <50years. Persons with family histories of gastric cancer and CRC, especially those with family histories of both, may need to begin colonoscopy earlier.

Significance of histone methyltransferase SETDB1 expression in colon adenocarcinoma

This study investigated the clinical implications of SETDB1 (also known as KMT1E) in human colon adenocarcinoma. Expression levels of SETDB1 proteins were analyzed by immunohistochemistry staining, and tissue microarrays were used to examine expression profiles in human patients. Our results revealed that SETDB1 protein expression was significantly higher in tumor tissue than in normal tissue for the breast, colon, liver, and lung (p < 0.05). Moreover, an analysis with SurvExpress software suggested that elevated expression of SETDB1 mRNA was significantly associated with the overall survival of colon adenocarcinoma patients (p < 0.05); and additional analysis involving 90 paired samples of colon adenocarcinoma tissue and normal tissue revealed that SETDB1 protein expression was 82% higher in cancerous cells (p < 0.001). High SETDB1 expression was also found to be significantly correlated with histological grade (p = 0.005), TNM stage (p = 0.003), T-class/primary tumor (p = 0.001), and N-class/regional lymph nodes (p = 0.017); and Kaplan-Meier survival curves indicated that SETDB1 protein expression was significantly associated with poor survival. Finally, univariate analysis demonstrated that SETDB1 protein expression was related to TNM stage (p = 0.004) and SETDB1 score (p = 0.001), whereas multivariate analysis showed that the influence of SETDB1 on overall colon adenocarcinoma survival was independent from other risk factors. Taken together, our results suggest that the SETDB1 protein could serve as a clinical prognostic indicator for colon adenocarcinoma.

Helicobacter pylori Infection with Atrophic Gastritis Is an Independent Risk Factor for Advanced Colonic Neoplasm

Background/Aims

Helicobacter pylori is a major risk factor for atrophic gastritis (AG) and gastric cancer. The correlation between H. pylori, AG and colorectal neoplasm (CRN) has only been examined in a limited number of studies, and findings have been inconclusive. We aimed to investigate the association between H. pylori infection status, AG and advanced CRN.

Methods

This cross-sectional study investigated the relationship between the presence of serum anti-H. pylori IgG antibodies, AG, and advanced CRN in 6,351 consecutive asymptomatic subjects who underwent a screening colonoscopy.

Results

A total of 316 participants (5.0%) had advanced CRN. H. pylori seropositivity was 61.3%. In a univariate analysis, the presence of H. pylori infection was associated with advanced CRN (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.17 to 1.91; p=0.001). H. pylori infection was associated with an increased risk of advanced CRN after adjusting for clinically relevant confounders (OR, 1.34; 95% CI, 1.04 to 1.72; p=0.023). H. pylori-related AG was significantly associated with the risk of advanced CRN (OR, 1.40; 95% CI, 1.03 to 1.91; p=0.030), whereas H. pylori infection without AG was not.

Conclusions

H. pylori infection increased the risk of advanced CRN, especially when it was combined with AG. Strict colonoscopy screening and surveillance may be warranted in those with H. pylori-positive AG.

Does colorectal cancer significantly influence the assembly of gut microbial communities?

Colorectal cancer (CRC) is the third commonest malignant tumor. Previous studies have revealed that the composition change of the human gut microbiome, measured by community diversity, is associated with the progression of CRC. However, a further question, whether or not the mechanism of community assembly and diversity maintenance of the gut microbiome is influenced by CRC has not been addressed. To address this question, we applied Hubbell's neutral theory for biodiversity to reanalyze the dataset from Wang et al.'s (2012) study of the gut microbiome sampled from 46 CRC patients and 56 healthy individuals. Our reanalysis presents two important findings. Firstly, our analysis demonstrated that only around 4% (4/102) samples (in total of both the CRC and control groups) have their species abundance distribution (SAD) satisfied the prediction of the neutral theory null model. No significant difference in the number of the samples satisfying the neutral null model was detected between the healthy individuals and CRC patients, suggesting that the nature or mechanism of community assembly and diversity maintenance of the gut microbiome is not significantly influenced by CRC. That is, the stochasticity of survival, reproduction and migration of gut microbes, as implied by the neutral theory model, does not play a significant role in shaping the community assembly and diversity maintenance. We further infer that the alternative hypothesis to the neutral null model, i.e., the deterministic niche differentiations should be the driving forces that shape the assembly and diversity maintenance of the gut microbiome in both the healthy individuals and CRC patients. Secondly, although CRC does not seem to influence the nature of community assembly, we postulate that it may indirectly influence the outcome (i.e., the community composition as measured by community diversity) of the community assembly, possibly by influencing niche differentiations. This postulation is supported by our second finding: the diversity of the gut microbiome in CRC patients is significantly lower than that in the healthy individuals as demonstrated by the fundamental diversity parameter (θ) of the neutral theory model. This second finding offers an independent confirmation of the relationship between the CRC disease and diversity of the gut microbiome, about which existing studies have presented conflicting evidences. Finally, we suggest that hybrid modeling which integrates both the neutral and niche theories should be explored in future studies to further understanding of the CRC influence on the human gut microbiome.

Helicobacter pylori Antibody Reactivities and Colorectal Cancer Risk in a Case-control Study in Spain

Background: Several studies have suggested that Helicobacter pylori (H. pylori) infection is a risk factor for colorectal cancer (CRC), while others have not confirmed this hypothesis. This work aimed to assess the relation of CRC with H. pylori seropositivity and with seropositivity to 16 H. pylori proteins, in the MultiCase-Control study, MCC-Spain.

Methods: MCC-Spain is a multicase-control study carried out in Spain from 2008 to 2013. In total, 2,140 histologically-confirmed incident CRC cases and 4,098 population-based controls were recruited. Controls were frequency-matched by sex, age, and province. Epidemiological data were collected through a questionnaire fulfilled by face-to-face interviews and a self-administered food-frequency questionnaire. Seroreactivities against 16 H. pylori proteins were determined in 1,488 cases and 2,495 controls using H. pylori multiplex serology. H. pylori seropositivity was defined as positivity to ≥4 proteins. Multivariable logistic regression mixed models were used to estimate odds ratios (OR) and 95% confidence intervals (CI).

Results:H. pylori seropositivity was not associated with increased CRC risk (OR = 0.91; 95% CI: 0.71–1.16). Among H. pylori seropositive subjects, seropositivity to Cagδ showed a lower CRC risk, and risk decreased with increasing number of proteins seropositive. Seropositivity to the most recognized virulence factors, CagA and VacA, was not associated with a higher CRC risk. No statistically significant heterogeneity was identified among tumor sites, although inverse relations were stronger for left colon cancer. An interaction with age and sex was found: H. pylori seropositivity was associated with a lower CRC risk in men younger than 65 and with a higher risk in older women.

Conclusions: Our results suggest that neither H. pylori seropositivity, nor seropositivity to the virulence factor CagA are associated with a higher CRC risk. A possible effect modification by age and sex was identified.

Helicobacter Pylori Infection in Texas Hispanic and Non-Hispanic White Men: Implications for Gastric Cancer Risk Disparities

Chronic Helicobacter pylori ( H. pylori) infection is a major gastric adenocarcinoma (GA) risk factor. GA disproportionately affects U.S. Hispanics compared with non-Hispanic Whites (NHWs). Since H. pylori infection studies in Hispanics are few, infection rates in Hispanic and NHW men in Bexar County were compared, and relationships with ethnicity and obesity examined. Age- and zip code-matched participants from a community-dwelling cohort were randomly selected. Sera from 284 men were analyzed by enzyme immunoassay for H. pylori antibodies. Adjusted risk ratio estimation for matched data was conducted to identify differences. Hispanics had a markedly higher prevalence of infection (30.3%) than NHWs (9.2%). Matched risk ratio (mRR) analyses revealed a strong association between H. pylori seropositivity and Hispanic ethnicity (mRR = 3.31; 95% CI [1.91, 5.73], adjusted by BMI, smoking status, and family history of cancer (mRR range = 3.28-3.89). BMI mRRs (range = 1.19-1.22) were significant in all models. In this cohort, Hispanic men had higher H. pylori infection rates than NHWs, and parallel the disproportionately higher rates of GA; obesity contributes to this higher prevalence. Future studies should address country of origin, acculturation, and other factors influencing obesity to further elucidate risk of GA in Hispanic populations.

Interaction of Ethnicity and H. pylori Infection in the Occurrence of Microscopic Colitis

BACKGROUND

Previous studies found that microscopic colitis is inversely associated with Helicobacter pylori infection and that microscopic colitis is characterized by a marked ethnic variation.

AIM

The aim of the present study was to test whether an underlying ethnic variation of H. pylori infection is responsible for the ethnic variation of microscopic colitis.

METHODS

The Miraca Life Sciences Database is a large national electronic repository of histopathologic records of patients distributed throughout the entire USA. A cross-sectional study evaluated the influence of age, gender, ethnicity, and histologic diagnosis of H. pylori on the occurrence of microscopic colitis among subjects who underwent esophago-gastro-duodenoscopies plus colonoscopy.

RESULTS

The total study population comprised 228,506 subjects, of whom 28,890 carried a diagnosis of H. pylori gastritis and 3460 microscopic colitis. Female sex, old age, and H. pylori infection exerted the strongest influence on the occurrence of microscopic colitis. In comparison with the population comprising Caucasians and African-Americans, microscopic colitis was less common among subjects of Hispanic (0.34, 0.27-0.47), East Asian (0.13, 0.06-0.22), Indian (0.31, 0.10-0.73), or Middle Eastern descent (0.28, 0.07-0.74). All these ethnic subgroups were also characterized by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of microscopic colitis (R ² = 0.91, p < 0.001).

CONCLUSION

Ethnic variations in the gastric infection with H. pylori may be partly responsible for the observed ethnic distribution of microscopic colitis.

Host pathogen interactions in Helicobacter pylori related gastric cancer

Helicobacter pylori (H. pylori), discovered in 1982, is a microaerophilic, spiral-shaped gram-negative bacterium that is able to colonize the human stomach. Nearly half of the world's population is infected by this pathogen. Its ability to induce gastritis, peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma has been confirmed. The susceptibility of an individual to these clinical outcomes is multifactorial and depends on H. pylori virulence, environmental factors, the genetic susceptibility of the host and the reactivity of the host immune system. Despite the host immune response, H. pylori infection can be difficult to eradicate. H. pylori is categorized as a group I carcinogen since this bacterium is responsible for the highest rate of cancer-related deaths worldwide. Early detection of cancer can be lifesaving. The 5-year survival rate for gastric cancer patients diagnosed in the early stages is nearly 90%. Gastric cancer is asymptomatic in the early stages but always progresses over time and begins to cause symptoms when untreated. In 97% of stomach cancer cases, cancer cells metastasize to other organs. H. pylori infection is responsible for nearly 60% of the intestinal-type gastric cancer cases but also influences the development of diffuse gastric cancer. The host genetic susceptibility depends on polymorphisms of genes involved in H. pylori-related inflammation and the cytokine response of gastric epithelial and immune cells. H. pylori strains differ in their ability to induce a deleterious inflammatory response. H. pylori-driven cytokines accelerate the inflammatory response and promote malignancy. Chronic H. pylori infection induces genetic instability in gastric epithelial cells and affects the DNA damage repair systems. Therefore, H. pylori infection should always be considered a pro-cancerous factor.

Helicobacter pylori infection is an independent risk factor for colonic adenomatous neoplasms

PURPOSE

Helicobacter pylori infection is considered to have a positive association with colorectal neoplasms. In this study, we evaluated the association between H. pylori infection and colorectal adenomas, based on the characteristics of these adenomas in Korea, where the prevalence of H. pylori infection is high and the incidence of colorectal cancer continues to increase.

METHODS

The study cohort consisted of 4,466 subjects who underwent colonoscopy and esophagogastroduodenoscopy during screening (1,245 colorectal adenomas vs. 3,221 polyp-free controls). We compared the rate of H. pylori infection between patients with adenoma and polyp-free control cases, using multivariable logistic regression analysis.

RESULTS

The overall rate of positive H. pylori infection was higher in adenoma cases than in polyp-free control cases (55.0 vs. 48.5%, p < 0.001). The odds ratio (OR) of positive H. pylori infection in patients with adenoma compared to polyp-free controls was 1.28 (95% CI 1.11-1.47). The positive association of H. pylori infection with colorectal adenomas was more prominent in advanced adenomas (OR 1.84, 95% CI 1.25-2.70) and multiple adenomas (OR 1.72, 95% CI 1.26-2.35). Based on the location of these adenomas, the OR was significant only in patients with colonic adenomas (OR 1.31, 95% CI 1.13-1.52) and not in those with rectal adenoma (OR 0.85, 95% CI 0.58-1.24).

CONCLUSION

Helicobacter pylori infection is an independent risk factor for colonic adenomas, especially in cases of advanced or multiple adenomas, but not for rectal adenomas.

Gut microbiota, inflammation and colorectal cancer

Although genes contribute to colorectal cancer, the gut microbiota are an important player. Accumulating evidence suggests that chronic infection and the ensuing inflammation contributes to tumor initiation and tumor progression. A variety of bacterial species and tumor-promoting virulence mechanisms have been investigated. Significant advances have been made in understanding the composition and functional capabilities of the gut microbiota and its roles in cancer. In the current review, we discuss the novel roles of microbiota in the progression of colon cancer. Although microbiota technically include organisms other than bacteria e.g., viruses and fungi, this review will primarily focus on bacteria. We summarize epidemiological studies of human microbiome and colon cancer. We discuss the progress in the scientific understanding of the interplay between the gut microbiota, barrier function, and host responses in experimental models. Further, we discuss the potential application in prevention, diagnosis, and therapy of colon cancer by targeting microbiota. We discuss the challenges lie ahead and the future direction in studying gut microbiome in colon cancer to close the gap between the basic sciences and clinical application.

Correlation between Helicobacter pylori-associated gastric diseases and colorectal neoplasia

AIM: To explore the correlation between Helicobacter pylori (H. pylori)-associated gastric diseases and colorectal neoplasia.

METHODS: Patients included in this study underwent a colonoscopy and esophago-gastro-duodenoscopy (EGD) along with histopathological measurement between March 2012 and March 2015 at Qi-Lu Hospital of Shandong University, who also had results of H. pylori detection. A total of 233 cases were selected. Demographic data, H. pylori infection status (including results of rapid urease tests and gastric mucosa pathological examinations) and histopathological examination results of gastric and colorectal mucosa were gathered and analyzed. The statistical analysis focused on the prevalence of colorectal neoplasms among patients with various histopathological categories of the stomach. ORs and their 95%CI were calculated to describe the strengths of the associations.

RESULTS: The incidence rates of colorectal adenoma without high-grade intraepithelial neoplasia (HGIEN) (OR = 2.400, 95%CI: 0.969-5.941), adenoma with HGIEN (5.333, 1.025-27.758) and adenocarcinoma (1.455, 0.382-5.543) were all higher for patients with H. pylori-associated gastritis than for those in the control group. The incidence rate of colorectal adenoma with HGIEN (3.218, 0.767-13.509) was higher in patients with intestinal metaplasia than in the control group, while the incidence rates of adenoma without HGIEN (0.874, 0.414-1.845) and adenocarcinoma (0.376, 0.096-1.470) were lower in the intestinal metaplasia group than in the control group. The incidence rate of colorectal adenoma without HGIEN (3.111, 1.248-7.753) was significantly higher in the gastric intraepithelial neoplasia group than in the control group, while the rates of adenoma with HGIEN (1.481, 0.138-15.941) and adenocarcinoma (2.020, 0.561-7.272) were higher in the gastric intraepithelial neoplasia group. Incidence rates of colorectal adenoma without HGIEN (1.067, 0.264-4.314), adenoma with HGIEN (2.667, 0.231-30.800) and adenocarcinoma (2.182, 0.450-10.585) were all higher in the gastric adenocarcinoma group than in the control group.

CONCLUSION: H. pylori infection as well as H. pylori-associated gastric diseases are risk factors for colorectal neoplasia.

Long-term risk of gastrointestinal cancers in persons with gastric or duodenal ulcers

Peptic ulcer predicts gastric cancer. It is controversial if peptic ulcers predict other gastrointestinal cancers, potentially related to Helicobacter pylori or shared lifestyle factors. We hypothesized that gastric and duodenal ulcers may have different impact on the risk of gastrointestinal cancers. In a nationwide cohort study using Danish medical databases 1994-2013, we quantified the risk of gastric and other gastrointestinal cancers among patients with duodenal ulcers (dominantly H. pylori-related) and gastric ulcers (dominantly lifestyle-related) compared with the general population. We started follow-up 1-year after ulcer diagnosis to avoid detection bias and calculated absolute risks of cancer and standardized incidence ratios (SIRs). We identified 54,565 patients with gastric ulcers and 38,576 patients with duodenal ulcers. Patient characteristics were similar in the two cohorts. The 1-5-year risk of any gastrointestinal cancer was slightly higher for gastric ulcers patients (2.1%) than for duodenal ulcers patients (2.0%), and SIRs were 1.38 (95% CI: 1.31-1.44) and 1.30 (95% CI: 1.23-1.37), respectively. The SIR of gastric cancer was higher among patients with gastric ulcer than duodenal ulcer (1.92 vs. 1.38), while the SIRs for other gastrointestinal cancers were similar (1.33 vs. 1.29). Compared with gastric ulcer patients, duodenal ulcer patients were at lower risk of smoking- and alcohol-related gastrointestinal cancers. The risk of nongastric gastrointestinal cancers is increased both for patients with gastric ulcers and with duodenal ulcers, but absolute risks are low. H. pylori may be less important for the development of nongastric gastrointestinal cancer than hypothesized.

Recent Decrease in Colorectal Cancer Mortality Rate is Affected by Birth Cohort in Korea

BACKGROUND

Colorectal cancer mortality has started to decrease in several developed countries in Asia. The current study aimed to present the long-term trends in colorectal cancer mortality in Korea using joinpoint analysis and age-period-cohort modeling.

MATERIALS AND METHODS

The number of colorectal cancer deaths and the population for each 5-year age group were obtained from Statistics Korea for the period 1984-2013 for adults 30 years and older. Joinpoint regression analysis was conducted to determine changes in trends in age-standardized mortality rates, and age-period-cohort analysis was performed to describe trends in colorectal cancer mortality using the intrinsic estimator method.

RESULTS

In men, the age-standardized mortality rate for colorectal cancer increased from 1984 to 2003, and the mortality rates stabilized thereafter, whereas the mortality rate of colorectal cancer in women has decreased since 2004. The age-specific mortality rate of colorectal cancer increased in both men and women over time, whereas decreases in the age-specific mortality rate in younger cohorts were observed. In the age-period-cohort analysis, old age and recent period were associated with higher mortality for both men and women. The birth cohort born after 1919 showed reduced colorectal cancer mortality in both men and women.

CONCLUSIONS

Our study showed a recent decreasing trend in colorectal cancer mortality in women and a stable trend in men after 2003-2004. These changes in colorectal cancer mortality may be attributed to birth cohort effects.

Effect of Perioperative Probiotics and Synbiotics on Postoperative Infections After Gastrointestinal Surgery: A Systematic Review With Meta-Analysis

BACKGROUND

Bacterial infection following gastrointestinal surgery remains a common morbidity. The aim of this study was to estimate the effect of the perioperative use of probiotics and synbiotics on postoperative infections.

MATERIALS AND METHODS

We searched PubMed, Embase, and the Cochrane Library to identify pertinent randomized controlled trials (RCTs). The primary outcome was postoperative infection rate. The secondary outcomes were length of hospital and intensive care unit (ICU) stay, length of antibiotic therapy, and mortality. The pooled outcomes were calculated using random effects models.

RESULTS

Twenty-eight RCTs involving 2511 patients were included in this systematic review. The incidence of infectious complications was lower among patients who received probiotics/synbiotics than among the controls (odds ratio [OR] = 0.35; 95% confidence interval [CI], 0.24-0.50), particularly regarding respiratory (OR = 0.44; 95% CI, 0.28-0.68), urinary tract (OR = 0.30; 95% CI, 0.16-0.55), and wound infections (OR = 0.58; 95% CI, 0.42-0.80). The lengths of hospital stay (mean difference [MD] = -3.20; 95% CI, -4.87 to -1.54) and duration of antibiotic therapy (MD = -3.40; 95% CI, -4.67 to -2.13) were shorter for patients who received probiotics/synbiotics than for controls. There were no significant differences in mortality (OR = 1.19; 95% CI, 0.52-2.74) or length of ICU stay (MD = -0.46; 95% CI, -1.07 to 0.14) between the compared groups.

CONCLUSION

Probiotics and synbiotics may prevent postoperative infections in patients undergoing gastrointestinal surgery. However, the results need to be interpreted with caution due to the risk of bias in the included studies and the potential publication bias.

Helicobacter pylori and colorectal neoplasia: Is there a causal link?

Ever since Helicobacter pylori (H. pylori) was recognized as an infectious cause of gastric cancer, there has been increasing interest in examining its potential role in colorectal carcinogenesis. Data from case-control and cross-sectional studies, mostly relying on hospital-based samples, and several meta-analyses have shown a positive statistical relationship between H. pylori infection and colorectal neoplasia. However, the possibility exists that the results have been influenced by bias, including the improper selection of patients and disparities with respect to potential confounders. While the evidence falls short of a definitive causal link, it appears that infection with H. pylori/H. pylori-related gastritis is associated with an increased, although modest, risk of colorectal adenoma and cancer. The pathogenic mechanisms responsible for this association remain uncertain. H. pylori has been detected in colorectal malignant tissues; however, the possibility that H. pylori is a direct activator of colonic carcinogenesis remains purely hypothetical. On the other hand, experimental data have indicated a series of potential oncogenic interactions between these bacteria and colorectal mucosa, including induction and perpetuation of inflammatory responses, alteration of gut microflora and release of toxins and/or hormonal mediators, such as gastrin, which may contribute to tumor formation.

[Helicobacter pylori -- 2014]

The author reviews the main achievements in Helicobacter pylori research in the past 2 years. Of the more than 1000 microRNAs described thus far, sets of over- and underexpressed samples were identified that are associated with either gastric cancer or precancerous lesions, and some of them could be either markers or therapeutic targets in the near future. Meta-analyses involved 95 new publications: the association between infection and oesophageal, colorectal, pancreatic and liver carcinomas is supported by the increased odds ratios, but the results do not reach the strength seen in gastric carcinoma. Epstein-Barr virus is an emerging pathogen: 10% of gastric cancers are virus-associated; the prevalence of the virus in normal mucosa, chronic gastritis and peptic ulcer are currently being studied. Current Helicobacter pylori eradication regimens frequently achieve suboptimal results: a few optimisation methods are presented, although not all are supported by the meta-analyses. In 2013, the European Helicobacter Study Group proposed the development of a pan-European registry; data from 5792 patients registered so far indicated that many therapeutic regimens resulted in a low eradication rate. In 2013, the Healthy Stomach Initiative was started with the aim of supporting and disseminating research performed in the field of healthy and diseased stomachs.