Rapidly decreasing prevalence of Helicobacter pylori among Japanese children and adolescents

Impact of Probiotics on the Prevention and Treatment of Gastrointestinal Diseases in the Pediatric Population

Despite the high prevalence of gastrointestinal disorders (GIDs) in infants and children, especially those categorized as functional GIDs (FGIDs), insufficient knowledge about their pathophysiology has limited both symptomatic diagnosis and the development of optimal therapies. Recent advances in the field of probiotics have made their potential use as an interesting therapeutic and preventive strategy against these disorders possible, but further efforts are still needed. In fact, there is great controversy surrounding this topic, generated by the high variety of potential probiotics strains with plausible therapeutic utility, the lack of consensus in their use as well as the few comparative studies available on probiotics that record their efficacy. Taking into account these limitations, and in the absence of clear guidelines about the dose and timeframe for successful probiotic therapy, our review aimed to evaluate current studies on potential use of probiotics for the prevention and treatment of the most common FGIDs and GIDs in the pediatric population. Furthermore, matters referring to know major action pathways and key safety recommendations for probiotic administration proposed by major pediatric health agencies shall also be discussed.

Patients with Whipple's disease have a high prevalence of Helicobacter pylori infection

INTRODUCTION

Whipple's disease is a rare systemic infection due to an impaired immunological response against T. whipplei in genetically predisposed individuals. Since we previously noted development of H. pylori related complications in some patients with Whipple's disease, our aim was to study the prevalence of H. pylori infection and H. pylori related disorders in Whipple's disease.

METHODS

Whipple's disease patients diagnosed from Jan-2002 to Dec-2021 and two controls per patient, matched for age, gender, ethnicity and year of H. pylori testing were enrolled.

RESULTS

34 patients with Whipple's disease and 68 controls were enrolled. H. pylori infection (13/34 vs 8/68, p<0.01), H. pylori-related gastritis (p<0.01) and gastric atrophy (p = 0.01) were significantly more common in patients with Whipple's disease than controls. H. pylori infection and Whipple's disease were diagnosed synchronously in 6/13 patients, and during follow-up in the remaining 7. Interestingly, these last 7 patients were all on trimethoprim-sulfamethoxazole long-term therapy. Two patients developed H. pylori-related gastric malignancies during follow-up. No patients on doxycycline developed H. pylori infection.

CONCLUSIONS

H. pylori infection and related disorders are common in patients with Whipple's disease and should always be excluded both at time of diagnosis and during follow-up. These findings should be taken into account when selecting antibiotics for Whipple's disease long-term prophylaxis.

Analysis of Genetic Relatedness between Gastric and Oral Helicobacter pylori in Patients with Early Gastric Cancer Using Multilocus Sequence Typing

The oral cavity is the second most colonized site of Helicobacter pylori after the stomach. This study aimed to compare the genetic relatedness between gastric and oral H. pylori in Japanese patients with early gastric cancer through multilocus sequence typing (MLST) analysis using eight housekeeping genes. Gastric biopsy specimens and oral samples were collected from 21 patients with a fecal antigen test positive for H. pylori. The number of H. pylori allelic profiles ranged from zero to eight since the yield of DNA was small even when the nested PCR was performed. MLST analysis revealed that only one patient had a matching oral and gastric H. pylori genotype, suggesting that different genotypes of H. pylori inhabit the oral cavity and gastric mucosa. The phylogenetic analysis showed that oral H. pylori in six patients was similar to gastric H. pylori, implying that the two strains are related but not of the same origin, and those strains may be infected on separate occasions. It is necessary to establish a culture method for oral H. pylori to elucidate whether the oral cavity acts as the source of gastric infection, as our analysis was based on a limited number of allele sequences.

Worldwide Prevalence and Risk Factors of Helicobacter pylori Infection in Children

Helicobacter pylori is usually acquired during childhood. The reports from the last two decades pointed out a decrease in H. pylori prevalence across geographical areas worldwide compared to previously reported data. Most of the studies performed in America found an overall H. pylori infection prevalence of approximately 50%. The most important risk factors in America include being male, poor adherence or difficult access to treatment, and the lack of in-home water service. Despite the descending trend in prevalence worldwide, the overall prevalence in Africa remains very high (70%). Nevertheless, the prevalence of H. pylori in children without gastrointestinal who underwent screening was reported to be only 14.2%. The main risk factors in Africa are having a traditional pit or no toilet, poverty, birth order, source of drinking water, or being a farmer. Asia seems to have the widest variations in terms of H. pylori prevalence. Several risk factors were reported in Asia to be associated with this infection, such as lower income and educational level, house crowding, rural residence, ethnicity, the use of tanks as water supplies, alcohol drinking, active smoking, eating spicy food or raw uncooked vegetables, poor living conditions and sanitation. The overall prevalence of H. pylori infection in European children is almost 25%. Portugal has the highest prevalence of all European countries at 66.2% in children 13 years of age. The risk factors in European individuals consist of living in rural areas, eating unwashed fruits and vegetables, not washing hands after school, low parental education and unemployment, and short education duration. Further studies are required to identify the precise mechanisms involved in the discrepancies of H. pylori prevalence worldwide.

Recent Changes in the Treatment of Helicobacter pylori Infection in Children and Adolescents

Treatments aimed at eradicating Helicobacter pylori (H. pylori) infections in children and adolescents should be clearly beneficial. According to the updated guidelines, a 14-day triple therapy or bismuth-based triple therapy is the first choice for treatment of children based on the results of antimicrobial sensitivity testing. Though culturing H. pylori using biopsy specimens is not always feasible, it should be performed for establishing empirical rescue therapy for patients not responding to first-line eradication therapy. The European and North American therapeutic strategies for children and adolescents with H. pylori infections may not be appropriate for treating children and adolescents in other countries owing to regional differences in epidemiological characteristics of H. pylori. The existence of clarithromycin-resistant H. pylori is an important factor involved in eradication failure. The development of new treatment-related allergies, treatment failure, side effects, and alteration of the gut microbiome have been highlighted as factors potentially outweighing the possible benefit of preventing future peptic ulcers or gastric cancer. Drug compliance can be improved by providing a detailed explanation of the reason for therapy, duration, and routes of drug administration. Physicians should understand the mechanisms underlying eradication treatment and explain drug prescriptions in detail to both parents and children to increase compliance. Herein, we reviewed the indications for and various modalities of eradication treatment in children with H. pylori infections in accordance with a review of recently published articles.

Prevalence and clinicopathological/molecular characteristics of mismatch repair protein-deficient tumours among surgically treated patients with prostate cancer in a Japanese hospital-based population

BACKGROUND

The prevalence and molecular characteristics of deficient mismatch repair prostate cancer in the Japanese population have scarcely been investigated.

METHODS

Immunohistochemistry for mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) was performed in formalin-fixed paraffin-embedded sections prepared from resected primary prostate cancers in patients who underwent prostatectomy at our institution between January 2001 and May 2016. Genetic and/or epigenetic alterations of mismatch repair genes were investigated in patients with any loss of mismatch repair protein expression in the tumour.

RESULTS

Of the 337 patients, four (1.2%) showed loss of mismatch repair protein expression on immunohistochemistry. All four patients showed loss of both MSH2 and MSH6 protein expression. Genetic testing was performed in two of the four patients, demonstrating no pathogenic germline alterations were present. In each of these two patients, at least one somatic alteration inactivating MSH2 without MSH2 hypermethylation was identified, leading to the diagnosis of supposed 'Lynch-like syndrome'. Patients with deficient mismatch repair prostate cancer were at a significantly higher stage (pT2pN0 vs. pT3-4pN0/pTanypN1, P = 0.02) and had a greater Gleason score (<8 vs. ≥8, P < 0.01) than those with proficient mismatch repair prostate cancer.

CONCLUSIONS

The prevalence of deficient mismatch repair prostate cancer in the Japanese hospital-based prostatectomized population was extremely low. To improve screening efficacy for deficient mismatch repair prostate cancer, screening candidates can be limited to patients with locally advanced, node-positive and/or Gleason score of 8 or greater prostate cancer. Universal tumour screening for Lynch syndrome seems ineffective in patients with prostate cancer.

Changes in the Seroprevalence of Helicobacter pylori among the Lithuanian Medical Students over the Last 25 Years and Its Relation to Dyspeptic Symptoms

Background and Objectives: The prevalence of Helicobacter pylori infection is decreasing in the Western world, while remaining high in developing countries. There is limited up-to-date information about the prevalence of H. pylori in Central and Eastern Europe. The aim of our study was to assess the seroprevalence of H. pylori and its trend over the past 25 years among students of the Lithuanian University of Health Sciences (LUHS) and to assess its relation to dyspeptic symptoms. Materials and Methods: In the years 1995, 2012, 2016 and 2020, students from Medical and Nursing Faculties of LUHS were tested for the presence of antibodies against H. pylori by performing serological tests from finger capillary blood. In addition, in the years 2012, 2016 and 2020, the students completed a gastrointestinal symptom rating scale (GSRS) questionnaire in order to assess dyspeptic symptoms. The study population consisted of 120 students in the year 1995 (mean age—21.3 ± 1.0 years), 187 students in the year 2012 (mean age—22.4 ± 0.7 years), 262 students in the year 2016 (mean age—20.4 ± 1.0 years) and 148 students in the year 2020 (mean age—20.4 ± 1.7 years). Results: The seroprevalence for H. pylori was positive in 62 (51.7%) students in 1995, in 57 (30.4%) students in 2012, in 69 (26.3%) students in 2016 and in 21 (14.2%) students in 2020. The statistically significant difference was found between all study years, except between 2012 and 2016. There were no significant differences in frequency and intensity of upper dyspeptic symptoms between H. pylori positive and negative students. Conclusions: Over the last 25 years the seroprevalence of H. pylori among students of LUHS has decreased significantly. No consistent differences in dyspeptic symptoms among H. pylori positive and negative subgroups were found.

Prevalence and molecular characteristics of DNA mismatch repair deficient endometrial cancer in a Japanese hospital-based population

BACKGROUND

The prevalence and molecular characteristics of defective DNA mismatch repair endometrial cancers in the Japanese population have been underexplored. Data supporting clinical management of patients with Lynch-like syndrome and germline variant of uncertain significance of mismatch repair genes are still lacking.

METHODS

Immunohistochemistry of mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) was performed on formalin-fixed paraffin-embedded sections prepared from resected primary endometrial cancers in 395 women with a median age of 59 years. Genetic and/or epigenetic alterations of the mismatch repair genes were also investigated.

RESULTS

Loss of expression of one or more mismatch repair proteins was observed in 68 patients (17.2%). A total of 17 out of 68 patients (25%, 4.3% of all cases) were identified as candidates for genetic testing for Lynch syndrome after excluding 51 patients with MLH1 hypermethylated cancer. Fourteen of these 17 patients subjected to genetic testing were found to have Lynch syndrome (n = 5), germline variant of uncertain significance (n = 2) or Lynch-like syndrome (n = 7). Compared with patients with Lynch syndrome, those with germline variant of uncertain significance and Lynch-like syndrome tended to demonstrate an older age at the time of endometrial cancer diagnosis (P = 0.07), less fulfillment of the revised Bethesda guidelines (P = 0.09) and lower prevalence of Lynch syndrome-associated tumors in their first-degree relatives (P = 0.01).

CONCLUSIONS

This study provides useful information for management in patients with DNA mismatch repair endometrial cancer. Specifically, cancer surveillance as recommended in patients with Lynch syndrome might not be necessary in patients with germline variant of uncertain significance and Lynch-like syndrome and their relatives.

High Prevalence of Helicobacter pylori Infection in Special Needs Schools in Japan

Background: Developmental disorders and high Helicobacter pylori (H. pylori) infection rates have been reported. This study aimed to examine the prevalence of H. pylori in a special needs school where all students had developmental disorders in Japan. Methods: In 2017, third-grade junior high school and second- and third-grade high school students attending a special needs school with developmental disorders were enrolled. Participants of Saga Prefecture's H. pylori test and treat project, which comprised third-grade junior high school students not from special needs school, were assigned to the control group. Results: In the control group, H. pylori positive results were 3.18% (228/7,164) students. Similarly, in developmental disorder group, H. pylori positive results were 6.80% (13/191) students. For the developmental disorder and control groups, this present examination sensitivity was 7.03% (13/185), specificity was 96.76% (6,815/7,043), positive predictive value was 5.39% (13/241), negative predictive value was 97.54% (6,815/6,987), Likelihood ratio of a positive result 2.17 and Odds ratio was 2.26 (95% confidence interval: 1.27-4.03, p = 0.005). Conclusion: The prevalence of H. pylori infection was significantly higher in adolescents with developmental disorders than in typically developing adolescents.

Current Prevalence of Oral Helicobacter pylori among Japanese Adults Determined Using a Nested Polymerase Chain Reaction Assay

In Japan, gastric Helicobacter pylori infection prevalence has markedly decreased with socioeconomic development. We aimed to investigate the prevalence of oral H. pylori in Japanese adults in 2020 by sex, age, sampling site, and medical history. Unstimulated saliva, supragingival biofilm, and tongue coating were obtained from 88 subjects-with no complaints of upper digestive symptoms-attending a dentist's office for dental check-up or disorders. Supragingival biofilm was collected from the upper incisors, lower incisors, upper right molars and lower left molars to analyze the characteristic distribution. Oral H. pylori was detected using nested polymerase chain reaction. Oral H. pylori prevalence did not statistically differ by sex or age. Supragingival biofilm (30.7%) was the most common oral H. pylori niche; it was also detected in 4.5% of saliva and 2.3% of tongue samples. The lower incisor was the most common site among the supragingival biofilm samples, followed by the upper incisors, lower left molars, and upper right molars. Oral H. pylori DNA was frequently detected in patients with a history of gastric H. pylori infection. Oral H. pylori has a characteristic distribution independent of sex and age, suggesting that it is part of the normal microflora in the adult oral cavity.

Review: Helicobacter pylori infection in children

Helicobacter pylori infection in children and adolescents differs in comparison to adults with respect to epidemiology, host responses, and disease manifestations. Furthermore, treatment options are limited in this population and antibiotic resistance rates continue to increase. Therefore, ongoing research is vital to understand disease pathogenesis and provide optimal management of children with infection. This review summarizes relevant publications from April 2019 to March 2020. Similar to adults, recent studies show a decreasing prevalence of infection in the pediatric population. Studies of pathogenesis investigated serum immune responses and the potential inverse association of infection and allergy. Several studies investigated the effect of H pylori and related inflammation on the gut microbiome. The recommendation of endoscopy-based testing to identify the cause of symptoms and not just H pylori, reserving noninvasive UBT or stool antigen tests for post-eradication follow-up, was supported by the current literature.

Diagnosis and treatment of Helicobacter pylori infections in children and elderly populations

Helicobacter pylori (H. pylori) infection is associated with various gastric and extra-gastric diseases. Importantly, this infection is the strongest known risk factor for gastric cancer (GC). H. pylori eradication can effectively prevent H. pylori infection-associated diseases in H. pylori-positive patients, including children and elderly subjects. However, a limited selection of antibiotics, a higher reinfection rate, and certain spontaneous clearance rates, to some extent, restrict the choice of H. pylori treatments in pediatrics. In addition, it is imperative to perform an accurate diagnosis of H. pylori infection in children by determining the presence of the H. pylori infection and the underlying cause of symptoms. In elderly patients, poor tolerance to drugs and higher sensitivity to adverse effects are major concerns during H. pylori therapy. Recent studies have demonstrated that H. pylori eradication could significantly lower the GC risk in the elderly population. The benefit and risk of H. pylori eradication in elderly patients should be comprehensively considered and balanced. If available, susceptibility-based tailored therapies may be preferable in eradicating H. pylori. In addition, to increase the eradication rate and reduce adverse effects, new therapeutic strategies (e.g., probiotic supplementation, berberine supplementation, dual therapy) for H. pylori infection are being extensively investigated. The impact of H. pylori eradication with antibiotics on the microbiota in children has been explored, but further high-quality studies are crucial to delineate the extent of H. pylori eradication affecting the microbial community in children. In this review, we summarize the current understanding of H. pylori diagnosis and treatment in children and the elderly population and aim to provide insights into the efficient management and treatment implementation in these populations.