Helicobacter pylori Infection and the Development of Advanced Colorectal Neoplasia

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.

Helicobacter Pylori Infection Is Associated with Neurodegeneration in Cognitively Normal Men

BACKGROUND

An association between Helicobacter pylori (H. pylori) infection and dementia was reported in previous studies; however, the evidence is inconsistent.

OBJECTIVE

In the present study, the association between H. pylori infection and brain cortical thickness as a biomarker of neurodegeneration was investigated.

METHODS

A cross-sectional study of 822 men who underwent a medical health check-up, including an esophagogastroduodenoscopy and 3.0 T magnetic resonance imaging, was performed. H. pylori infection status was assessed based on histology. Multiple linear regression analyses were conducted to evaluate the relationship between H. pylori infection and brain cortical thickness.

RESULTS

Men with H. pylori infection exhibited overall brain cortical thinning (p = 0.022), especially in the parietal (p = 0.008) and occipital lobes (p = 0.050) compared with non-infected men after adjusting for age, educational level, alcohol intake, smoking status, and intracranial volume. 3-dimentional topographical analysis showed that H. pylori infected men had cortical thinning in the bilateral lateral temporal, lateral frontal, and right occipital areas compared with non-infected men with the same adjustments (false discovery rate corrected, Q < 0.050). The association remained significant after further adjusting for inflammatory marker (C-reactive protein) and metabolic factors (obesity, dyslipidemia, fasting glucose, and blood pressure).

CONCLUSION

Our results indicate H. pylori infection is associated with neurodegenerative changes in cognitive normal men. H. pylori infection may play a pathophysiologic role in the neurodegeneration and further studies are needed to validate this association.

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.