Impact of Helicobacter pylori on the gastric microbiome in patients with chronic gastritis: a systematic review and meta-analysis protocol

Introduction
Chronic gastritis is a common disease worldwide. Studies have consistently shown that chronic gastritis is usually associated with gastric microbial dysbiosis, especially the infection of Helicobacter pylori. However, the interaction between H. pylori and non-H. pylori bacteria in patients with chronic gastritis has not been clearly identified yet. Consequently, we designed a protocol for a systematic review and meta-analysis, which focused on identifying the changes in gastrointestinal microbiota composition between patients with H. pylori-infective and non-infective chronic gastritis.

Method and analysis
We will search PubMed, EMBASE and Cochrane Library databases to retrieve observational studies on humans. The eligible studies must include data about the relative abundance of the gastrointestinal microbiome in patients with H. pylori-infective or non-infective chronic gastritis. Only the data of adults aged over 18 years will be analysed. Two researchers will extract the data independently, and Newcastle–Ottawa Scale will be used to assess the risk of bias. Random-effects model will be performed in quantitative analyses. Correlation analysis, bioinformatics analysis and function analysis will be performed.

Discussion
Currently, numerous studies have revealed the role of H. pylori in chronic gastritis. However, the alterations of non-H. pylori bacteria in patients with chronic gastritis remain an open question. The results of our study might provide new insights into future diagnosis and treatments.

Ethics and dissemination
This study is based on published documents, unrelated to personal data, so ethical approval is not in need. The results of this study are expected to be published in journals or conference proceedings.

PROSPERO registration number
CRD42020205260; Pre-results.

Leggi
Marzo 2023

Effect of polyphenol compounds on Helicobacter pylori eradication: a systematic review with meta-analysis

Objectives
Polyphenol compounds are classified as organic compounds with phenolic units exhibiting a variety of biological functions. This meta-analysis aims to assess the efficacy and safety of polyphenol compounds (curcumin, cranberry, garlic, liquorice and broccoli) in eradicating Helicobacter pylori.

Design
Systematic review and meta-analysis.

Methods
Literature searches were conducted on PubMed, Embase, The Cochrane Library, Web of Science, Medline, Chinese National Knowledge Infrastructure database, Chinese Scientific Journal Database and Wan Fang database from inception to January 2022. All randomised controlled trials comparing polyphenol compounds with the placebo or used as an adjunct treatment are included in this meta-analysis.The treatment effect for dichotomous outcomes was assessed using risk ratio (RR), while for continuous outcomes, mean differences both with 95% CIs, were used. Subgroup analyses were carried out for different treatment schemes and polyphenol compound species.

Results
12 trials were included in the meta-analysis. The total eradication rate of H.pylori in the polyphenol compounds group was higher than in the group without polyphenol compounds. Statistical significance was also observed (RR 1.19, 95% CI 1.03 to 1.38, p=0.02). The most frequent adverse effects of polyphenol compounds included diarrhoea, headache and vomiting. However, there were no differences regarding side effects between the two groups (RR 1.47, 95% CI 0.83 to 2.58, p=0.18). In subgroup analyses, the H.pylori eradication rate regimens with polyphenols therapy was superior to that of regimens without polyphenols therapy in the polyphenols versus placebo subgroup (RR 4.23, 95% CI 1.38 to 12.95, p=0.01), polyphenols plus triple therapy versus triple therapy subgroup (RR 1.11, 95% CI 1.01 to 1.22, p=0.03).

Conclusion
Polyphenol compounds can improve H.pylori eradication rates. Polyphenol compounds plus standard triple therapy can significantly improve the eradication. However, no evidence of a higher incidence of side effects could be found.

PROSPERO registration number
CRD42022307477.

Leggi
Gennaio 2023