Role of childhood infection in the sequelae of H. pylori disease

Helicobacter pylori Infections in Children

In the context of epidemiology, host response, disease presentation, diagnosis, and treatment management, the manifestation of Helicobacter pylori (H. pylori) infection diverges between children and adults. H. pylori infection stands out as one of the most prevalent bacterial infections globally, and its prevalence in both children and adults is decreasing in many developing countries but some still struggle with a high prevalence of pediatric H. pylori infection and its consequences. The majority of infected children are asymptomatic and pediatric studies do not support the involvement of H. pylori in functional disorders such as recurrent abdominal pain. The pathophysiology of H. pylori infection relies on complex bacterial virulence mechanisms and their interaction with the host immune system and environmental factors. This interaction gives rise to diverse gastritis phenotypes, which subsequently influence the potential development of various gastroduodenal pathologies. In clinical settings, the diagnosis of this infection in childhood requires an upper gastrointestinal endoscopic exam with mucosal biopsy samples for histology and culture, or Polymerase Chain Reaction (PCR) at the very least. When warranted, eradication treatment should be given when good compliance is expected, and there should be systematic use of a treatment adapted to the antimicrobial susceptibility profile. To combat the burgeoning threat of multidrug resistance, vigilant surveillance of resistance patterns and strategic antibiotic management are paramount.

Helicobacter pylori Chronic-Stage Inflammation Undergoes Fluctuations That Are Altered in tlpA Mutants

Helicobacter pylori colonizes half of the world's population and is responsible for a significant disease burden by causing gastritis, peptic ulcers, and gastric cancer. The development of host inflammation drives these diseases, but there are still open questions in the field about how H. pylori controls this process. We characterized H. pylori inflammation using an 8-month mouse infection time course and comparison of the wild type (WT) and a previously identified mutant lacking the TlpA chemoreceptor that causes elevated inflammation. Our work shows that H. pylori chronic-stage corpus inflammation undergoes surprising fluctuations, with changes in Th17 and eosinophil numbers. The H. pylori tlpA mutant changed the inflammation temporal characteristics, resulting in different inflammation from the wild type at some time points. tlpA mutants have equivalent total and gland colonization in late-stage infections. During early infection, in contrast, they show elevated gland and total colonization compared to those by WT. Our results suggest the chronic inflammation setting is dynamic and may be influenced by colonization properties of early infection.

School-based Hygiene Intervention to Prevent HelicObacter Pylori infection among childrEn (SHIP HOPE): protocol for a cluster-randomised controlled trial

INTRODUCTION

Helicobacter pylori infection rates are high in China and worldwide, and maintaining good hygiene is effective in preventing H. pylori infection. Childhood is a critical stage for developing good hygiene practices. Therefore, in this study, we aimed to explore whether a comprehensive hygiene intervention can prevent H. pylori infection in primary schools in China.

METHODS AND ANALYSIS

The School-based Hygiene Intervention to Prevent HelicObacter Pylori infection among childrEn study is a cluster-randomised controlled trial, which will include approximately 2400 children in grades 2-4 from 60 classes in 10 primary schools of Linqu County, Shandong Province. Schools will be randomly assigned (1:1) via a computer-generated list, to receive either comprehensive hygiene intervention (intervention) or the usual health education lessons (control), with stratification by area (urban or rural). The interventions will include the following: (1) Children's education: lessons and cartoon books designed to provide basic knowledge about hygiene, H. pylori, hand hygiene, diet and oral hygiene will be provided to children; (2) Caregiver's education: children will be empowered to share hygiene-related knowledge with their caregivers as homework; caregivers will be also invited to the school for hygiene lessons; (3) School hygiene promotion: suggestions will be provided for improving the hygienic environment. Children in control schools will receive usual health education lessons according to the arrangements of each school. The primary outcome is the prevalence and incidence of H. pylori infection among children at 1-year follow-up. The secondary outcomes are H. pylori and hygiene knowledge, family eating customs and hygiene practices among children and their caregivers, as well as school absences owing to diarrhoea. Additionally, growth in children is set as an exploratory outcome. General linear mixed models will be used to analyse differences between the intervention and control schools.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Institution Review Board of Tsinghua University (No: 20220020). Written informed consent will be obtained from each child and one of their caregivers. The findings of this study will be actively disseminated through scientific publications and conference presentations.

TRIAL REGISTRATION NUMBER

ChiCTR2200056191.

Helicobacter pylori, gastric microbiota and gastric cancer relationship: Unrolling the tangle

Helicobacter pylori infection (Hp-I) represents a typical microbial agent intervening in the complex mechanisms of gastric homeostasis by disturbing the balance between the host gastric microbiota and mucosa-related factors, leading to inflammatory changes, dysbiosis and eventually gastric cancer. The normal gastric microbiota shows diversity, with Proteobacteria [Helicobacter pylori (H. pylori) belongs to this family], Firmicutes, Actinobacteria, Bacteroides and Fusobacteria being the most abundant phyla. Most studies indicate that H. pylori has inhibitory effects on the colonization of other bacteria, harboring a lower diversity of them in the stomach. When comparing the healthy with the diseased stomach, there is a change in the composition of the gastric microbiome with increasing abundance of H. pylori (where present) in the gastritis stage, while as the gastric carcinogenesis cascade progresses to gastric cancer, the oral and intestinal-type pathogenic microbial strains predominate. Hp-I creates a premalignant environment of atrophy and intestinal metaplasia and the subsequent alteration in gastric microbiota seems to play a crucial role in gastric tumorigenesis itself. Successful H. pylori eradication is suggested to restore gastric microbiota, at least in primary stages. It is more than clear that Hp-I, gastric microbiota and gastric cancer constitute a challenging tangle and the strong interaction between them makes it difficult to unroll. Future studies are considered of crucial importance to test the complex interaction on the modulation of the gastric microbiota by H. pylori as well as on the relationships between the gastric microbiota and gastric carcinogenesis.

Helicobacter pylori infection treatment in the United States: clinical consequences and costs of eradication treatment failure

INTRODUCTION

Helicobacter pylori (Hp) is causal in benign and malignant gastrointestinal diseases. Accordingly, current guidelines recommend Hp eradication in patients with active infection. Unfortunately, treatment failure is common, exposing patients to complications associated with persistent Hp infection and consequences of repeated treatment, including promotion of antibiotic resistance. In the United States (US), data regarding eradication rates with available therapies are limited. Moreover, the clinical and economic burden of eradication treatment failure have not been thoroughly described.

AREAS COVERED

We aimed to characterize Hp eradication rates and the clinical consequences and associated costs of persistent Hp infection among US adults. We conducted focused literature reviews using initial searches in Embase, MEDLINE, and Cochrane Database of Systematic Reviews via Ovid followed by manual searches to identify relevant publications.

EXPERT OPINION

Hp eradication rates were suboptimal, with most studies reporting rates ≤80% with clarithromycin-based triple therapy and bismuth quadruple therapy. There was direct evidence supporting numerous benefits of successful Hp eradication, including decreased risk of recurrent or complicated peptic disease and non-cardia gastric cancer. Cost benefits of eradication were related to mitigation of conditions associated with persistent Hp infection, (e.g. complicated peptic ulcer disease, and gastric cancer) which altogether exceed US$5.3 billion.

Helicobacter pylori Infection and the Patterns of Gastric Mucin Expression in Children

Background: The updated model for the mechanism of gastric carcinogenesis demonstrates that Helicobacter pylori (H. pylori) is a risk factor in every step of the process. The expression of certain gastric mucins is altered by H. pylori infection in adult patients. The aim of our research was to assess the impact of H. pylori infection on the expression of secretory mucins in the pediatric antral mucosa. Methods: Slides were stained with monoclonal antibodies for MUC5AC, MUC6 and MUC2, digitalized and scored using both a semiquantitative and a quantitative approach. Results: The expression of MUC5AC was significantly lower in infected children. Also, MUC2 expression was more pronounced in infected children. MUC6 expression did not differentiate between infected and noninfected children. Additionally, the presence of chronic inflammation significantly altered the expression of MUC6 and MUC2. The expression of MUC6 was significantly higher in patients with gastric atrophy. Conclusion: The minor differences in mucin expression at distinct ages might stem from different H. pylori exposure periods. Further research is needed to determine the particular patterns of expression according to age and to evaluate the effects of the interaction between H. pylori and mucins in the progression of the gastric carcinogenesis cascade.

Particular Morphological Features in the Diagnosis of Pediatric Helicobacter pylori Gastritis: A Morphometry-Based Study

Background: Current pediatric guidelines recommend the use of the Updated Sydney Classification for gastritis to assess histological changes caused by Helicobacter pylori (H. pylori) infection. The purpose of this study was to investigate the morphometric alterations of the antral mucosa in relation to pediatric H. pylori infection. Methods: A total of 65 cases were considered eligible. Apart from scoring the biopsies according to the recommendations, foveolar hyperplasia (FH) was assessed. The following measurements were performed on digital slides: total mucosal thickness, foveolar and glandular length, number of glandular cross sections per 40X field, glandular diameter, and distance between glands. Results: The thickness of the antral mucosa increased along with the bacterial density and the intensity of inflammation in H. pylori-infected children (p < 0.05). FH was significantly associated with the presence of H. pylori (p < 0.001) and also exhibited a greater length of the foveolar and glandular structures and an increased glandular diameter (p < 0.05), but without influencing the thickness of the mucosa. Conclusions: Our results reinforce the fact that FH is not only an important histologic characteristic of gastropathy, but is also a significant change observed in H. pylori infection in children and may be considered for reporting when evaluating pediatric gastric biopsies.

Association of Helicobacter pylori Infection with Vitamin D Deficiency in Infants and Toddlers

Helicobacter pylori (H. pylori), a gram-negative pathogen, has been shown to colonize multiple organs and cause various forms of extra-gastrointestinal diseases. The association of H. pylori infection with vitamin D status in apparently healthy children remained unclear; therefore, we investigated the relationship between vitamin D and H. pylori infection among apparently healthy infants and toddlers. In this large cross-sectional study, the examination data of children were collected from January 2013 to September 2017 in the Center for Children's Health Care. Among these children, 6,896 infants and toddlers were screened for our study. Helicobacter pylori infection and vitamin D status were the main indicators, and micronutrients (zinc, iron, copper, magnesium), and growth parameters (height, weight, and weight for age Z score [WAZ], height for age Z score [HAZ]) were also analyzed in this study. Among the 6,896 infants and toddlers, the detection rate of H. pylori seropositivity was 30.6%. The prevalence of vitamin D deficiency in H. pylori seropositive and seronegative groups was 20.7% and 12.1%, respectively (P < 0.001). The logistic regression analysis suggested children with H. pylori-positive antibody were 2.06 times more likely to be vitamin D deficient compared with children who had negative H. pylori antibody (odds ratio: 2.06; 95% CI: 1.77, 2.38) after controlling for confounding factors. These data suggested that there was a significant association between H. pylori seropositivity and vitamin D deficiency in children aged 6-36 months, which would make a contribution to the treatment and monitoring of vitamin D deficiency and H. pylori infection.

Helicobacter pylori Gastritis in Children-The Link between Endoscopy and Histology

Background: The management of Helicobacter pylori (H. pylori) infection raises important challenges, still being the most common chronic infection worldwide in all age groups. In high-prevalence regions, paediatric patients need a specific focus, as the acquisition of the infection takes place in childhood. The objective of this study was to analyze the endoscopic and histopathologic changes of the gastric mucosa in H. pylori infected children. Material and Methods: A retrospective study was performed on consecutive paediatric patients, ranging from 0 to 18 years of age, who underwent an upper gastrointestinal endoscopy (UGE) for a period of 5 years, regardless of their symptomatology. Endoscopy reports and histological slides were reviewed and clinical, endoscopic, and histologic data were recorded. Results: A total of 248 patients were included in the study, 82 (33.06%) of them being H. pylori infected. There was no difference in age and symptoms between the infected and noninfected group. A significant association was found between the H. pylori infection and histopathological parameters such as acute and chronic inflammatory infiltrate. The bacterial load influences the intensity of inflammation (p < 0.001). The chronic inflammation was predominant, only 23.2% of the patients displayed acute inflammation (p < 0.0001). The topographic distribution of inflammation was dominated by pangastritis (p = 0.04) with 58.6% of the patients presenting similar degrees of inflammation both in the antrum and corpus. Conclusion: Endoscopic features such as nodularity of the antral mucosa (p < 0.05) along with histological findings as lymphoid follicles (p < 0.05) are suggestive of H. pylori infection. However, the concordance between the endoscopic and histological diagnosis is still far from perfect (Cohen’s k coefficient = 0.42), maintaining the need for an invasive approach in children.

The relationship of gastric microbiota and Helicobacter pylori infection in pediatrics population

BACKGROUND

In recent years, the impact of Helicobacter pylori (H pylori) on the gut microbiota has attracted more attention; however, the relationship in pediatric population rarely was reported.

METHODS

Endoscopic gastric mucosal biopsy specimens from 55 children with gastrointestinal symptoms were collected, 37 of them were H pylori-positive (23 nonpeptic ulcer and 14 peptic ulcer) and 18 were H pylori-negative. In addition, 11 specimens were collected from H pylori-positive children who performed second endoscopy in 4 weeks after therapy. Microbial abundance and compositions were analyzed by 16S ribosomal RNA amplification and microbial functions were predicted using the software PICRUSt.

RESULTS

The gastric microbiota of H pylori-positive children were mainly dominated by Helicobacter in genus (95.43%). The microbiota richness and diversity of H pylori-positive children were lower than that of H pylori-negative children. No difference was found in microbiota structure between H pylori-positive children with or without peptic ulcer. The richness and compositions after therapy were closer to the characteristics of H pylori-negative children. For predicted functions, higher abundance in pathways of infection diseases, cancer and lower abundance in the pathways of amino acid, lipid, and carbohydrate metabolism were found in H pylori-positive group than H pylori-negative group.

CONCLUSION

The characteristics of gastric microbiota were affected by H pylori infection rather than disease states, and the richness and diversity of gastric species were inverse correlation with H pylori infection in children. Eradication therapy was helpful to restore shifted gastric microbiota.

Effect of trimethylamine N-oxide on inflammation and the gut microbiota in Helicobacter pylori-infected mice

Diet is one of the factors contributing to symptom of Helicobacter pylori (H. pylori) infection. Trimethylamine N-oxide (TMAO), a diet-related microbial metabolite, is associated with inflammatory and metabolic diseases. The aim of this study is to investigate the effects of TMAO intake on inflammation and gut microbiota composition in H. pylori-infected mice via 16S rRNA sequencing and biochemical analyses. The in vitro experiments showed that TMAO not only increased the expression of growth- and metabolism-associated genes and the urease activity of H. pylori, but increased the production of virulence factors. Moreover, TMAO intake increased the production of inflammatory markers and reduced the richness and diversity of the gut microbiota in H. pylori-infected mice. Further analysis showed that TMAO increased the relative abundance of Escherichia_Shigella in H. pylori-infected mice, which had positive correlation with the levels of LPS, CRP, and CXCL1. Collectively, our results suggest that TMAO may aggravate H. pylori-induced inflammation by increasing the viability and virulence of H. pylori and may aggravate inflammation in association with the gut microbiota in H. pylori-infected mice. This study may provide a novel insight into the mechanism for the effect of diet-derived metabolites such as TMAO on H. pylori-induced disease development.

Relationship between Helicobacter pylori Infection and Plasmacytoid and Myeloid Dendritic Cells in Peripheral Blood and Gastric Mucosa of Children

PURPOSE

To investigate the frequency and activation status of peripheral plasmacytoid DCs (pDCs) and myeloid DCs (mDCs) as well as gastric mucosa DC subset distribution in Helicobacter pylori- (H. pylori-) infected and noninfected children.

MATERIALS AND METHODS

Thirty-six children were studied; twenty-one had H. pylori. The frequencies of circulating pDCs (lineage-HLA-DR+CD123+) and mDCs (lineage-HLA-DR+CD11c+) and their activation status (CD83, CD86, and HLA-DR expression) were assessed by flow cytometry. Additionally, the densities of CD11c+, CD123+, CD83+, CD86+, and LAMP3+ cells in the gastric mucosa were determined by immunohistochemistry.

RESULTS

The frequency of circulating CD83+ mDCs was higher in H. pylori-infected children than in the noninfected controls. The pDCs demonstrated upregulated HLA-DR surface expression, but no change in CD86 expression. Additionally, the densities of gastric lamina propria CD11c+ cells and epithelial pDCs were increased. There was a significant association between frequency of circulating CD83+ mDCs and gastric lamina propria mDC infiltration.

CONCLUSION

This study shows that although H. pylori-infected children had an increased population of mature mDCs bearing CD83 in the peripheral blood, they lack mature CD83+ mDCs in the gastric mucosa, which may promote tolerance to local antigens rather than immunity. In addition, this may reduce excessive inflammatory activity as reported for children compared to adults.

Helicobacter pylori Infection in Pediatric Patients: Update on Diagnosis and Eradication Strategies

Helicobacter pylori infection is acquired mainly in childhood and remains an essential cause of peptic ulcer disease and gastric cancer. This article provides commentary on the last ESPGHAN/NASPGHAN guidelines and on publications made after the consensus conference of 2015. The majority of infected children are asymptomatic and pediatric studies do not support a role for H. pylori in functional disorders such as recurrent abdominal pain. The role of H. pylori infection in failure to thrive, children's growth, type I diabetes mellitus (T1DM), and celiac disease remains controversial. The diagnosis of infection should be based on upper-digestive endoscopy with biopsy-based methods. Eradication control after treatment should be based on validated non-invasive tests. Nodular gastritis is the main endoscopic finding of childhood H. pylori infection, but gastroduodenal erosions/ulcers are seen in some children, especially after 10 years of age. When indicated, eradication treatment should be given when good compliance is expected and based on the antimicrobial susceptibility profile.

Correlation between Helicobacter pylori Infection and Metabolic Abnormality in General Population: A Cross-Sectional Study

Background

Previous studies have suggested a link between Helicobacter pylori (H. pylori) and metabolic abnormality. This study aimed at investigating the correlation between H. pylori infection and metabolic abnormality in a general population.

Methods

All enrolled participants underwent a carbon-13 urea breath test (¹³C-UBT). For each individual, the following data were collected: age, gender, alanine transaminase (ALT), total protein, albumin, cholesterol, triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), urea nitrogen, creatinine, uric acid, fasting plasma glucose, postprandial blood sugar, nonalcoholic fatty liver disease (NAFLD), and bone mineral density (BMD).

Results

The study included 1867 (393 females and 1474 males, aged 54.0 ± 9.6 years) people that took a physical examination. There was no significant difference in gender and age between the study participants with and without H. pylori infection. The statistical data are as follows: albumin: P = 0.045, uric acid: P = 0.025, fasting glucose: P = 0.043, and postprandial blood glucose: P = 0.035. In terms of the patients with NAFLD, there were significant differences in ALT and HDL-C between the study participants with and without H. pylori infection. TG (P = 0.048), HDL-C (P = 0.011), and fasting blood glucose (P = 0.018) were significantly different in both groups among individuals who got osteopenia.

Conclusion

H. pylori infection may be an important factor affecting metabolic abnormality and osteoporosis.

Review: Prevalence and dynamics of Helicobacter pylori infection during childhood

INTRODUCTION

Long-term persistent Helicobacter pylori infection has been associated with ulceropeptic disease and gastric cancer. Although H. pylori is predominantly acquired early in life, a clear understanding of infection dynamics during childhood has been obfuscated by the diversity of populations evaluated, study designs, and methods used.

AIM

Update understanding of true prevalence of H. pylori infection during childhood, based on a critical analysis of the literature published in the past 5 years.

METHODS

Comprehensive review and meta-analysis of original studies published from 2011 to 2016.

RESULTS

A MEDLINE^® /PubMed^® search on May 1, 2016, using the terms pylori and children, and subsequent exclusion, based on abstract review using predefined criteria, resulted in 261 citations. An Embase^® search with the same criteria added an additional 8 citations. In healthy children, meta-analysis estimated an overall seroprevalence rate of 33% (95% CI: 27%-38%). Seven healthy cohort studies using noninvasive direct detection methods showed infection prevalence estimates ranging from 20% to 50% in children ≤5 and 38% to 79% in children >5 years. The probability of infection persistence after a first positive sample ranged from 49% to 95%. Model estimates of cross-sectional direct detection studies in asymptomatic children indicated a prevalence of 37% (95% CI: 30%-44%). Seroprevalence, but not direct detection rates increased with age; both decreased with increasing income. The model estimate based on cross-sectional studies in symptomatic children was 39% (95% CI: 35%-43%).

CONCLUSIONS

The prevalence of H. pylori infection varied widely in the studies included here; nevertheless, model estimates by detection type were similar, suggesting that overall, one-third of children worldwide are or have been infected. The few cohort and longitudinal studies available show variability, but most studies, show infection rates over 30%. Rather surprisingly, overall infection prevalence in symptomatic children was only slightly higher, around 40%. Studies including only one positive stool sample should be interpreted with caution as spontaneous clearance can occur.

Treatment of synchronous adenocarcinoma and lymphoma of the stomach: A case report

Gastric cancer is one of the leading causes of cancer-related mortality worldwide. The majority of gastric cancers are diagnosed at an advanced or metastatic stage, with a 5-year survival rate of ~5-20% and a median overall survival of <1 year. Synchronous occurrence of gastric adenocarcinoma and lymphoma is rare, and thus far there is no consensus regarding their management. We herein describe a case of synchronous gastric adenocarcinoma and diffuse large B-cell lymphoma in a patient with chronic hepatitis B and the treatment strategy. A literature review with the most up-to-date treatment options and their application in similar situations was also performed.

Imbalance of Gastrointestinal Microbiota in the Pathogenesis of Helicobacter pylori-Associated Diseases

The development of new nucleotide sequencing techniques and advanced bioinformatics tools has opened the field for studying the diversity and complexity of the gastrointestinal microbiome independent of traditional cultural methods. Owing largely to the gastric acid barrier, the human stomach was long thought to be sterile. The discovery of Helicobacter pylori, the gram-negative bacterium that infects upwards of 50% of the global population, has started a major paradigm shift in our understanding of the stomach as an ecologic niche for bacteria. Recent sequencing analysis of gastric microbiota showed that H. pylori was not alone and the interaction of H. pylori with those microorganisms might play a part in H. pylori-associated diseases such as gastric cancer. In this review, we summarize the available literature about the changes of gastrointestinal microbiota after H. pylori infection in humans and animal models, and discuss the possible underlying mechanisms including the alterations of the gastric environment, the secretion of hormones and the degree of inflammatory response. In general, information regarding the composition and function of gastrointestinal microbiome is still in its infancy, future studies are needed to elucidate whether and to what extent H. pylori infection perturbs the established microbiota. It is assumed that clarifying the role of gastrointestinal communities in H. pylori-associated diseases will provide an opportunity for translational application as a biomarker for the risk of serious H. pylori diseases and perhaps identify specific organisms for therapeutic eradication.

Helicobacter pylori and allergy: Update of research

Recently a lot of literature has been published about the possible preventive action of Helicobacter pylori (H. pylori) against allergy. The present review summarizes research data about the association between H. pylori and allergic diseases, as well as discusses possible hypotheses about the preventive action of H. pylori against atopy. There is evidence from observational studies to support a weak inverse association between prevalence of H. pylori infection and allergy. However, confounders like some unidentified socioeconomic factors, antibiotic use and others could bias the association. Although data from cohort studies point to a possible association of H. pylori with some of the allergic diseases, no definite proof for causal relationship has been clearly demonstrated yet. A biological mechanism proposed to explain the preventive action of H. pylori to allergy is reduced exposure to a major stimulus for the generation of Treg cells in individuals without H. pylori infection. In addition, H. pylori could be an indicator for changes in gut microbiome, reflecting the complex interaction between microbes and immune system.

Gastric microbiome and gastric cancer

Cancer of the stomach is the fourth most common cancer worldwide. The single strongest risk factor for gastric cancer is Helicobacter pylori-associated chronic gastric inflammation. Among persons with H. pylori infection, strain-specific components, host immune responses, and environmental factors influence the risk for gastric disease, including adenocarcinoma of the stomach, although only a small proportion of infected persons develop the malignancy. Recent advances in DNA sequencing technology have uncovered a complex community of noncultivatable inhabitants of the human stomach. The interaction between these inhabitants, collectively referred to as the gastric microbiota, and H. pylori likely affects gastric immunobiology and possibly the sequelae of H. pylori infection. Thus, characterization of the gastric microbiota in subjects with and without H. pylori infection could provide new insight into gastric homeostasis and the pathogenesis of H. pylori-associated disease, including gastric cancer.