Helicobacter pylori in pediatrics

Pathogenesis and potential reversibility of intestinal metaplasia - a milestone in gastric carcinogenesis

BACKGROUND

Non-cardia gastric cancer remains a major cause of cancer-related mortality worldwide, despite declining incidence rates in many industrialized countries. The development of intestinal-type gastric cancer occurs through a multistep process in which normal mucosa is sequentially transformed into hyperproliferative epithelium, followed by metaplastic processes leading to carcinogenesis. Chronic infection with Helicobacter pylori is the primary etiological agent that causes chronic inflammation of the gastric mucosa, induces atrophic gastritis, and can lead to intestinal metaplasia and dysplasia. Both intestinal metaplasia and dysplasia are precancerous lesions, in which gastric cancer is more likely to occur. Atrophic gastritis often improves after eradication of Helicobacter pylori; however, the occurrence of intestinal metaplasia has been traditionally regarded as "the point of no return" in the carcinogenesis sequence. Helicobacter pylori eradication heals non-atrophic chronic gastritis, may lead to regression of atrophic gastritis, and reduces the risk of gastric cancer in patients with these conditions. In this article, we discuss the pathogenesis, epigenomics, and reversibility of intestinal metaplasia and briefly touch upon potential treatment strategy.

CONCLUSIONS

Gastric intestinal metaplasia no longer appears to be an irreversible precancerous lesion. However, there are still many controversies regarding the improvement of intestinal metaplasia after Helicobacter pylori eradication.

Helicobacter pylori Infection and Peptic Ulcer Disease in Symptomatic Children in Southern Vietnam: A Prospective Multicenter Study

BACKGROUND

Helicobacter pylori (H. pylori) remains a major cause of gastroduodenal diseases. We aimed to evaluate the burden of this infection, particularly peptic ulcer disease in Vietnamese children.

METHODS

We enrolled consecutive children referred for esophagogastroduodenoscopy at two tertiary children's hospitals in Ho Chi Minh City, from October 2019 to May 2021. Children treated with proton pump inhibitors during the last two weeks or antibiotics for four weeks, and those having a previous or interventional endoscopy were excluded. H. pylori infection was diagnosed with either a positive culture or positive histopathology combined with a rapid urease test, or with a polymerase chain reaction of the urease gene. The study was approved by the Ethics Committee and written informed consent/assent was obtained.

RESULTS

Among 336 enrolled children aged 4-16 (mean: 9.1 ± 2.4 years; 55.4% girls), H. pylori infection was positive in 80%. Peptic ulcers were detected in 65 (19%), increasing with age, and 25% with anemia. cagA+ strains were detected at a higher rate in children with ulcers.

CONCLUSIONS

Prevalence of H. pylori and peptic ulcers is high among symptomatic Vietnamese children. It is crucial to have a program for early detection of H. pylori to reduce ulcer risk and gastric cancer later.

Helicobacter pylori infection in children: an overview of diagnostic methods

Children differ from adults regarding Helicobacter pylori (H. pylori) infection in many terms. H. pylori infection represents a key factor in the pathogenesis of duodenal ulcer and chronic gastritis in children. H. pylori infection causes some extraintestinal diseases as well as gastrointestinal diseases. Although, among these illnesses in children, symptoms like recurrent abdominal pain are not specific. Moreover, the role of the pathogen in the growth faltering, iron deficiency anemia, and asthma still remains controversial. A reliable method to detect H. pylori infection is a crucial issue, sand is still a matter of active debate. The tests applied for H. pylori diagnosis are grouped as either invasive or non-invasive methods. Invasive methods consist of endoscopic evaluation, the rapid urease test (RUT), histology, and bacterial culture. Non-invasive tests include the urea breath test (UBT), stool antigen test (SAT), serology, and molecular diagnostic approaches. Use of endoscopy is a pre-requisite for all invasive methods and poses difficulties in children as it is a difficult procedure and requires patient's cooperation. For this reason, the non-invasive tests have been commonly used in children, although their accuracy is not very reliable in some cases. Invasive tests may be opted to confirm the diagnosis as and when needed. This review presents the diagnostic tests used to detect H. pylori infection in children.

Helicobacter pylori infections in Ethiopia; prevalence and associated factors: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H.pylori) infections are prevalent and recognized as major cause of gastrointestinal diseases in Ethiopia. However, Studies conducted on the prevalence, risk factors and other clinical forms of H.pylori on different population and geographical areas are reporting conflicting results. Therefore, this review was conducted to estimate the pooled prevalence of H.pylori infections and associated factors in Ethiopia.

METHODS

PubMed, Embase, Google scholar, and Ethiopian Universities' repositories were searched following the Preferred Items for Systematic review and Meta-analysis (PRISMA) guideline. The quality of included studies was assessed using the Newcastle-Ottawa Scale in meta-analysis. Heterogeneity between studies was assessed using Cochrane Q test and I2 test statistics based on the random effects model. Comprehensive meta-analysis (CMA 2.0) and Review Manager (RevMan 5.3) were employed to compute the pooled prevalence and summary odds ratios of factors associated with of H.pylori infection.

RESULTS

Thirty seven studies with a total of 18,890 participants were eligible and included in the analysis. The overall pooled prevalence of H.pylori infection was 52.2% (95% CI: 45.8-58.6). In the subgroup analysis by region, the highest prevalence was found in Somalia (71%; 95% CI: 32.5-92.6) and the lowest prevalence was reported in Oromia (39.9%; 95% CI: 17.3-67.7). Absence of hand washing after toilet (OR = 1.8, 95% CI; 1.19-2.72), alcohol consumption (OR = 1.34, 95% CI; 1.03-1.74) and gastrointestinal (GI) symptoms (OR = 2.23, 95% CI; 1.59-3.14) were associated with H.pylori infection. The trend of H.pylori infection showed a decreasing pattern overtime from 1990 to 2017 in the meta-regression analysis.

CONCLUSION

The prevalence of H.pylori infection remains high; more than half of Ethiopians were infected. Although the trend of infection showed a decreasing pattern; appropriate use of eradication therapy, health education primarily to improve knowledge and awareness on the transmission dynamics of the bacteria, behavioral changes, adequate sanitation, population screening and diagnosis using multiple tests are required to reduce H.pylori infections. Recognizing the bacteria as a priority issue and designing gastric cancer screening policies are also recommended.

Characterization of Gastric Microbiota in Twins

Contribution of host genetic backgrounds in the development of gastric microbiota has not been clearly defined. This study was aimed to characterize the biodiversity, structure and composition of gastric microbiota among twins. A total of four pairs of twins and eight unrelated individuals were enrolled in the study. Antral biopsies were obtained during endoscopy. The bacterial 16S rRNA gene was amplified and pyrosequenced. Sequences were analyzed for the composition, structure, and α and β diversities of gastric microbiota. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, and Fusobacteria were the most predominant phyla of gastric microbiota. Each individual, twins as well as unrelated individuals, harbored a microbiota of distinct composition. There was no evidence of additional similarity in the richness and evenness of gastric microbiota among co-twins as compared to unrelated individuals. Calculations of θ_YC and PCoA demonstrated that the structure similarity of gastric microbial community between co-twins did not increase compared to unrelated individuals. In contrast, the structure of microbiota was altered enormously by Helicobacter pylori infection. These results suggest that host genetic backgrounds had little effect in shaping the gastric microbiota. This property of gastric microbiota could facilitate the studies discerning the role of microbiota from genetic grounds in the pathogenesis.

Prevalence of Helicobacter pylori infection among preschool children in Latvia: no significant decrease in prevalence during a ten year period

Aims: Published data show a trend of decreasing prevalence of Helicobacter pylori in Eastern European countries due to socioeconomic changes. The aim of this study was to determine the prevalence of H. pylori infection among children in Latvia and to compare these results with previous studies in the same population. The risk factors associated with infection were also analysed. Methods: Preschool children in kindergartens and primary health care centres were investigated using a stool antigen test. Their parents were asked to fill out a questionnaire about possible risk factors. Statistical analysis included Pearson’s χ2 test and linear regression analysis. Results: The prevalence of H. pylori infection determined by the monoclonal stool antigen test in children aged 1–6 years (median 5 years) was 15.5% (15/101) (95% confidence interval 8.67–23.48%). In the regression analysis, H. pylori positivity was significantly negatively associated with the consumption of imported fruit at least once per week ( p=0.02). Conclusions: The prevalence of H. pylori in the studied population has not decreased significantly during the last decade and is still associated with socioeconomic factors. The role of some dietary factors (e.g. the consumption of fruit) in the spread of infection should be studied further.

Association between Helicobacter pylori infection and migraine: A meta-analysis

AIM: To quantify the association between Helicobacter pylori (H. pylori) infection and migraine.

METHODS: A systematic literature search of PubMed and EMBASE was conducted from inception to December 2013. Studies that provided data dealing with H. pylori infection in patients with migraine, as well as healthy controls, were selected. Meta-analysis was carried out using the odds ratio (OR) with a fixed or random effects model, and a 95%CI for the OR was calculated. An unconditional logistic regression model was used to analyze potential parameters related to H. pylori prevalence. Subgroup analyses were conducted as methods of detection and evidence grade.

RESULTS: Five case-control studies published between 2000 and 2013 were finally identified, involving 903 patients, with a total H. pylori infection rate of 39.31%. The prevalence of H. pylori infection was significantly greater in migraineurs than in controls (44.97% vs 33.26%, OR = 1.92, 95%CI: 1.05-3.51, P = 0.001). A sensitivity test indicated that no single study dominated the combined results. Univariate regression analysis found that publication year, geographical distribution and evidence grade were relevant to the results and were the main reason for the heterogeneity. Subgroup analysis found a significantly greater infection rate of H. pylori in Asian patients with migraine, but no statistically significant infection rate in European patients. The ORs were 3.48 (95%CI: 2.09-5.81, P = 0.000) and 1.19 (95%CI: 0.86-1.65, P = 0.288), respectively.

CONCLUSION: The pooled data suggest a trend of more frequent H. pylori infections in patients with migraine.

An association between Helicobacter pylori and upper respiratory tract disease: Fact or fiction?

Helicobacter pylori (H. pylori) is a major cause of chronic gastritis and gastric ulcers and considerable evidence supports the notion that infection with this bacterium is also associated with gastric malignancy in addition to various other conditions including pulmonary, vascular and autoimmune disorders. Gastric juice infected with H. pylori might play an important role in upper respiratory tract infection. Although direct and/or indirect mechanisms might be involved in the association between H. pylori and upper respiratory tract diseases, the etiological role of H. pylori in upper respiratory tract disorders has not yet been fully elucidated. Although various studies over the past two decades have suggested a relationship between H. pylori and upper respiratory tract diseases, the findings are inconsistent. The present overview describes the outcomes of recent investigations into the impact of H. pylori on upper respiratory tract and adjacent lesions.