Association between H. pylori infection and health Outcomes: an umbrella review of systematic reviews and meta-analyses

Causal associations between Helicobacter pylori infection and pregnancy and neonatal outcomes: a two-sample Mendelian randomization study

Background

Observational studies have reported that Helicobacter pylori (H. pylori) infection is associated with a series of pregnancy and neonatal outcomes. However, the results have been inconsistent, and the causal effect is unknown.

Methods

A two-sample Mendelian randomization (MR) study was performed using summary-level statistics for anti-H. pylori IgG levels from the Avon Longitudinal Study of Parents and Children Cohort. Outcome data for pregnancy (miscarriage, preeclampsia-eclampsia, gestational diabetes mellitus, placental abruption, premature rupture of membranes, postpartum hemorrhage) and neonates (birthweight, gestational age, and preterm birth) were sourced from genome-wide association meta-analysis as well as the FinnGen and Early Growth Genetics Consortium. Causal estimates were calculated by five methods including inverse variance weighted (IVW). The heterogeneity of instrumental variables was quantified by Cochran's Q test, while sensitivity analyses were performed via MR-Egger, MR-PRESSO, and leave-one-out tests.

Results

IVW estimates suggested that genetically predicted anti-H. pylori IgG levels were significantly associated with increased risks of preeclampsia-eclampsia (odds ratio [OR] = 1.12, 95% confidence interval [CI] 1.01-1.24, P = 0.026) and premature rupture of membranes (OR = 1.17, 95% CI 1.05-1.30, P = 0.004). Similar results were obtained for preeclampsia-eclampsia from the MR-Egger method (OR = 1.32, 95% CI 1.06-1.64, P = 0.027) and for premature rupture of membranes from the weighted median method (OR = 1.22, 95% CI 1.06-1.41, P = 0.006). No significant causal effects were found for other outcomes. There was no obvious heterogeneity and horizontal pleiotropy across the MR analysis.

Conclusion

Our two-sample MR study demonstrated a causal relationship of H. pylori infection with preeclampsia-eclampsia and premature rupture of membranes. The findings confirm the epidemiological evidence on the adverse impact of H. pylori in pregnancy. Further studies are needed to elucidate the pathophysiological mechanisms and assess the effectiveness of pre-pregnancy screening and preventive eradication.

Diagnostic and therapeutic recommendations on Helicobacter pylori infection. Recommendations of the Working Group of the Polish Society of Gastroenterology

Helicobacter pylori remains a major health problem worldwide, causing considerable morbidity and mortality due to peptic ulcer disease and gastric cancer. These guidelines constitute an update of the previous "Recommendations on the diagnosis and management of Helicobacter pylori infection" issued in 2014. They have been developed by a Task Force organized by the Governing Board of the Polish Society of Gastroenterology. They discuss, with particular emphasis on new scientific data covering papers published since 2014: the epidemiology, clinical presentation, diagnostic principles and criteria for the diagnosis, and recommendations for the treatment of H. pylori infection. The guidelines in particular determine which patients need to be tested and treated for infection. The Task Force also discussed recommended treatment algorithms. Accordingly, a combination of available evidence and consensus-based expert opinion were used to develop these best practice advice statements. It is worth noting that guidelines are not mandatory to implement but they offer advice for pragmatic, relevant and achievable diagnostic and treatment pathways based on established key treatment principles and using local knowledge and available resources to guide regional practice.

Periodontal and Other Oral Bacteria and Risk of Lung Cancer in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Evidence suggests that periodontal disease is associated with increased lung cancer risk, but whether periodontal pathogens are explanatory is unknown. We prospectively studied associations of prediagnostic circulating antibodies with oral bacteria and of periodontal bacteria in subgingival plaque with lung cancer.

METHODS

We included 4,263 cancer-free participants in the Atherosclerosis Risk in Communities study with previously measured serum IgG antibodies to 18 oral bacteria. In 1,287 participants for whom subgingival plaque was collected, counts for 8 periodontal bacteria were previously measured. Incident lung cancers (N = 118) were ascertained through 2015 (median follow-up = 17.5 years). We used Cox regression to estimate multivariable-adjusted associations, including for sums of antibodies to orange (C. rectus, F. nucleatum, P. intermedia, P. micra, and P. nigrescens) and red (P. gingivalis, T. forsythensis, and T. denticola) complex bacteria.

RESULTS

Orange complex bacteria antibodies were positively associated with lung cancer [per IQR hazard ratios (HR) = 1.15; 95% confidence intervals (CI), 1.02-1.29], which was stronger in men (HR = 1.27, 95% CI 1.08-1.49), and explained by P. intermedia and P. nigrescens (HR = 1.15; 95% CI, 1.04-1.26). Suggestive positive associations with lung cancer (N = 40) were observed for F. nucleatum, A. actinomycetemcomitans, and P. gingivalis counts. Significant positive associations were found for the count to antibody ratio for P. intermedia and P. gingivalis.

CONCLUSIONS

We identified positive associations with lung cancer for oral bacteria, especially orange complex that are moderately pathogenic for periodontal disease.

IMPACT

This prospective study supports the need for more research on periodontal bacteria in lung cancer etiology. If associations are supported, this may inform novel lung cancer prevention strategies.

[Prospects for personalized Helicobacter pylori eradication therapy. Pro et contra]

The article is devoted to debatable aspects of Helicobacter pylori eradication therapy. The eradication cancer-preventive effects are considered. A negative comorbidity between H. pylori infection and such diseases as gastroesophageal reflux disease, inflammatory bowel disease and bronchial asthma has been described. The perspectives of populational, individualized and personalized strategies for H. pylori eradication therapy assessment are given. Recommendations for individualized H. pylori eradication strategy implementation in practical healthcare are proposed.

Helicobacter pylori-Related Extraintestinal Manifestations—Myth or Reality

It is well documented that Helicobacter pylori (H. pylori) can cause both gastrointestinal and extraintestinal manifestations. The latter one represents a major burden in terms of diagnosis and treatment. H. pylori-associated systemic subclinical inflammation is mostly responsible for the development of extraintestinal manifestations, and its early eradication might result in preventing all adverse events related to their occurrence. Thus, it was suggested that H. pylori might be associated with iron deficiency anemia, thrombocytopenia (immune thrombocytopenic purpura), Schonlein Henoch purpura, failure to thrive, vitamin B12 deficiency, diabetes mellitus, body mass index, cardiovascular diseases, as well as certain neurological conditions. Nevertheless, studies showed both pros and cons in terms of the role of H. pylori in the development of previously mentioned clinical entity underlining the crucial need for further studies on these topics. Although most of these extraintestinal manifestations occur during adulthood, we must not forget that H. pylori infection is acquired mainly during childhood, and thus its early diagnosis and eradication might represent the cornerstone in the prevention of H. pylori-induced inflammatory status and consequently of all related extraintestinal conditions.

Methodological approaches for assessing certainty of the evidence in umbrella reviews: A scoping review

Introduction

The number of umbrella reviews (URs) that compiled systematic reviews and meta-analysis (SR-MAs) has increased dramatically over recent years. No formal guidance for assessing the certainty of evidence in URs of meta-analyses exists nowadays. URs of non-interventional studies help establish evidence linking exposure to certain health outcomes in a population. This study aims to identify and describe the methodological approaches for assessing the certainty of the evidence in published URs of non-interventions.

Methods

We searched from 3 databases including PubMed, Embase, and The Cochrane Library from May 2010 to September 2021. We included URs that included SR-MAs of studies with non-interventions. Two independent reviewers screened and extracted data. We compared URs characteristics stratified by publication year, journal ranking, journal impact factor using Chi-square test.

Results

Ninety-nine URs have been included. Most were SR-MAs of observational studies evaluating association of non-modifiable risk factors with some outcomes. Only half (56.6%) of the included URs assessed the certainty of the evidence. The most frequently used criteria is credibility assessment (80.4%), followed by GRADE approach (14.3%). URs published in journals with higher journal impact factor assessed certainty of evidence than URs published in lower impact group (77.1 versus 37.2% respectively, p < 0.05). However, criteria for credibility assessment used in four of the seven URs that were published in top ranking journals were slightly varied.

Conclusions

Half of URs of MAs of non-interventional studies have assessed the certainty of the evidence, in which criteria for credibility assessment was the commonly used method. Guidance and standards are required to ensure the methodological rigor and consistency of certainty of evidence assessment for URs.

Modifiable predictive factors and all-cause mortality in the non-hospitalized elderly population: An umbrella review of meta-analyses

OBJECTIVE

This umbrella review aimed to summarize the association between modifiable predictive factors and all-cause mortality in the non-hospitalized elderly population, and estimated the credibility and strength of the current evidence.

METHODS

PubMed, Embase, Web of science, and EBSCOhost were searched up to February 28, 2022. Random-effect summary effect sizes and 95% confidence intervals (CIs), heterogeneity, small-study effect, excess significance bias, as well as 95% prediction intervals (PIs) were calculated. Methodological quality was assessed with the Assessment of Multiple Systematic Reviews 2 (AMSTAR-2) tool. The credibility of the included meta-analyses was graded from convincing to weak using established criteria. This umbrella review was registered with PROSPERO, CRD 42021282183.

RESULTS

In total, 32 predictive factors involving 49 associations extracted from 35 meta-analyses were analyzed. Forty-three of the 49 (87.8%) associations presented nominal significant effects by the random-effect model (P < 0.05), of which 34 had harmful associations and nine had beneficial associations with all-cause mortality. Frailty (FRAIL scale), low short physical performance battery (SPPB) score, and fewer daily steps carried a more than three-fold risk for all-cause mortality. Convincing evidence showed that weight fluctuation, prefrailty and frailty status, sarcopenia, low SPPB score, fewer daily steps, and fatigue increased the risk of all-cause mortality, while daily moderate-to-vigorous physical activity (MVPA) duration and total physical activity participation reduced the risk of death. There were twenty, nine, five, and six associations that yielded highly suggestive, suggestive, weak, and non-significant grades of evidence. Thirty-four (69.4%) of the associations exhibited significant heterogeneity. Twenty-two associations presented 95% PIs excluding the null value, two indicated small-study effects, and three had evidence for excess significance bias, respectively. The methodological quality of most meta-analyses was rated as low (37.1%) or critically low (42.9%).

CONCLUSIONS

A summary of the currently available meta-analyses suggests that a broad range of modifiable predictive factors are significantly associated with all-cause mortality risk in the non-hospitalized elderly population. The most credible evidence indicates that physical function represented by frailty and sarcopenia, as well as physical activity, are significant predictors for all-cause mortality. This umbrella review may provide prognostic information to direct appropriate diagnostic evaluation and treatment goals in the future. More solid evidence is still needed coming from moderate-to-high quality meta-analyses.

Did an introduction of CONSORT for abstracts guidelines improve reporting quality of randomised controlled trials' abstracts on Helicobacter pylori infection? Observational study

OBJECTIVE

To determine abstracts' adherence to the Consolidated Standards of Reporting Trials for Abstracts (CONSORT-A) statement and to explore the factors associated with reporting quality.

DESIGN

An observational study.

SETTING

Abstracts of randomised controlled trials published between 2010 and 2019, found searching the MEDLINE database.

PARTICIPANTS

A total of 451 abstracts of the clinical trials on Helicobacter pylori infections were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Abstracts' reporting quality was determined by assessing their adherence to 17-item CONSORT-A checklist, with overall score being calculated as the sum of items that were adequately reported for each abstract. Additional factors that might influence the reporting quality of the abstracts were analysed, with univariate and multivariate linear regression used to determine how those factors influenced the overall reporting quality.

RESULTS

Included abstracts had an overall median quality score of 8/17 (IQR 7-9). Large proportions of abstracts adequately reported interventions, participants, objectives, numbers randomised and conclusions (97.1, 99.3, 89.1. 94.7 and 98.4% of abstracts, respectively). Trial design, randomisation, blinding and funding were severely under-reported with only 8.0, 2.7, 11.0 and 2.0% of abstracts reporting each item. Overall quality scores for H. pylori abstracts were higher in association with CONSORT-A endorsement (B=5.698; 95% CI 1.781 to 9.615), pharmacological interventions (B=4.063; 95% CI 0.224 to 7.902), multicentre settings (B=5.057; 95% CI 2.370 to 7.743), higher numbers of participants (B=3.607; 95% CI 1.272 to 5.942), hospital settings (B=4.827; 95% CI 1.753 to 7.901) and longer abstracts (B=3.878; 95% CI 0.787 to 6.969 for abstracts with 251-300 words and B=7.404; 95% CI 3.930 to 10.878 for abstracts with more than 300 words).

CONCLUSIONS

The overall reporting quality of abstracts was inadequate. The endorsement of CONSORT-A guidelines by more journals might improve the standards of reporting.

Prevalence and associated risk factors of Helicobacter pylori infection in the Wuwei cohort of north-western China

OBJECTIVES

To evaluate the prevalence of Helicobacter pylori infection and risk factors and to serotype the strains in Wuwei, located in north-western China, which has a high incidence of gastric cancer.

METHODS

Helicobacter pylori infection was analysed in 21 291 adults by ¹⁴ C-urea breath test, and H. pylori antibody were detected in 9183 serum samples by latex immunoturbidimetric method. The correlation of H. pylori infection with demographic-economic, lifestyle factors and medical history among the participants was determined by questionnaire. The antibodies against H. pylori urease, VacA and CagA in serum were determined by dot immunobinding assay.

RESULTS

The infection rate of H. pylori was 53.0%, and 90.1% of strains were type I strains. The H. pylori infection rate was higher among farmers (OR = 1.34, 95% CI: 1.19-1.50) and individuals who had a junior high school or higher education level (OR = 1.10, 95% CI: 1.06-1.15), and was lower in older individuals (OR = 0.86, 95% CI: 0.83-0.90), individuals with high income (OR = 0.93, 95% CI: 0.90-0.95), individuals with a habit of eating quickly (OR = 0.93, 95% CI: 0.87-0.99) and individuals who consumed more fruit and vegetables (OR = 0.90, 95% CI: 0.85-0.95). Individuals with history of cholecystitis/cholecystolithiasis, hypertension and asthma were negatively correlated with H. pylori infection (P < 0.05).

CONCLUSION

The prevalence of H. pylori infection is high in Wuwei. The major prevalent strain is type I strain. Age, education, occupation, household income, consumption of fruit and vegetables, and habit of eating quickly are independent risk factors for H. pylori infection, which is also associated with individuals with a history of extragastric diseases.

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

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