Helicobacter pylori infection: How does age influence the inflammatory pattern?

Assessment of Helicobacter pylori infection in Lebanon: Endoscopic and histopathological findings

Helicobacter pylori (H. pylori), a pervasive pathobiont, colonizes the gastric mucosa and plays a crucial role in the pathogenesis of several gastroduodenal pathologies ranging from chronic gastritis to more severe disorders including peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric adenocarcinoma. In symptomatic patients, endoscopy and histological examination of the gastric mucosa are the preferred tests for diagnosing H. pylori. Our study aimed to identify the frequency of H. pylori and its association with endoscopic and histopathological findings in adult Lebanese patients. Thus, 332 symptomatic adult patients, attending the Endoscopy unit of Makassed General Hospital in Beirut, were enrolled in this cross-sectional study. Overall, 14.16 % of the patients were infected with H. pylori, with male predominance. The most common endoscopic findings were gastritis and gastropathy. Moreover, H. pylori infection was significantly associated with gastric ulcers and duodenitis. On the other hand, active gastritis and chronic gastritis were the most common histopathological findings. Chronic gastritis was more frequent in H. pylori-positive patients. The association between endoscopic diagnosis and histopathological findings was then assessed. It was shown that gastropathy was significantly associated with chronic gastritis. In addition, gastric ulcer was significantly related to active gastritis and chronic gastritis. In conclusion, this study reported various endoscopic findings in H. pylori-positive patients based on the Kyoto classification. This highlights the importance of invasive diagnosis in symptomatic patients. Therefore, a combination-based approach including endoscopic and histopathological findings remains crucial in clinical practice for a definitive and accurate diagnosis of H. pylori infection and related disorders, especially in resource-limited settings.

Comparative efficacy of Helicobacter pylori eradication therapy between tegoprazan-based concomitant and bismuth quadruple therapies: A real-world evidence

BACKGROUND AND AIM

Tegoprazan, a potassium-competitive acid blocker, can be used as a substitute for proton pump inhibitors in Helicobacter pylori eradication therapy; some studies have reported improved efficacy. In Korea, where clarithromycin resistance rates are high, we aimed to compare the efficacies of tegoprazan-based concomitant and bismuth quadruple therapies.

METHODS

We retrospectively analyzed data from patients with H. pylori infection who received either 10-day tegoprazan-based concomitant therapy or 14-day tegoprazan-based bismuth quadruple therapy as first-line treatment. The primary outcome was H. pylori eradication rate, with secondary outcomes including adverse events and insufficient medication rates.

RESULTS

Among the 1082 patients included in the study, 620 and 462 were treated with tegoprazan-based concomitant and bismuth quadruple therapies, respectively. Intention-to-treat analysis demonstrated no difference in eradication rates between the tegoprazan-based concomitant and bismuth quadruple therapy groups (74.7% [95% confidence interval-CI, 71.1-78.0%] vs 74.7% [95% CI, 70.6-78.5%], P = 0.999). Per-protocol analysis also showed similar eradication rates between the two groups (88.0% [95% CI, 85.0-90.6%] vs 89.7% [95% CI, 86.3-92.5%], P = 0.424). The overall adverse event rates (49.6% vs 39.2%, P = 0.001) and insufficient medication rates (4.8% vs 2.4%, P = 0.036) were higher in the bismuth quadruple therapy group than in the concomitant therapy group.

CONCLUSIONS

The eradication rates of tegoprazan-based 10-day concomitant therapy and 14-day bismuth quadruple therapy were comparable. However, because of its shorter treatment duration, better medical adherence, and lower incidence of adverse events, tegoprazan-based concomitant therapy may be preferable in regions with high rates of clarithromycin and metronidazole resistance.

Prevalence and associated risk factors of Helicobacter pylori infection in community households in Lanzhou city

BACKGROUND

Helicobacter pylori (H. pylori) infection exhibits a familial clustering phenomenon.

AIM

To investigate the prevalence of H. pylori infection, identify associated factors, and analyze patterns of transmission within families residing in the community.

METHODS

From July 2021 to September 2021, a total of 191 families (519 people) in two randomly chosen community health service centers in the Chengguan District of Lanzhou in Gansu Province, were recruited to fill out questionnaires and tested for H. pylori infection. Individuals were followed up again from April 2023 and June 2023 to test for H. pylori infection. The relationship between variables and H. pylori infection was analyzed using logistic regression and generalized linear mixed models.

RESULTS

In 2021, the individual-based H. pylori infection rate was found to be 47.0% (244/519), which decreased to 38.1% (177/464) in 2023. Additionally, the rate of individual-based H. pylori new infection was 22.8% (55/241). The family-based H. pylori infection rate in 2021 was 76.9% (147/191), which decreased to 67.1% (116/173) in 2023, and the rate of family-based H. pylori new infection was 38.6% (17/44). Individual H. pylori infection was positively correlated with age, body mass index (BMI), eating food that was excessively hot, frequent acid reflux, bloating, and halitosis symptoms, and negatively correlated with family size and nut consumption. New individual H. pylori infection was positively correlated with BMI, other types of family structures, drinking purified water, and frequent heartburn symptoms, while negatively correlated with the use of refrigerators and following a regular eating schedule. A larger living area was an independent protective factor for H. pylori infection in households. Frequently consuming excessively hot food and symptoms of halitosis were independent risk factors for H. pylori infection in individuals; frequent consumption of nuts was an independent protective factor for H. pylori infection. Other types of family structure, drinking purified water, and frequent heartburn symptoms were independent risk factors for new individual H. pylori infection; the use of a refrigerator was an independent protective factor for new H. pylori infections.

CONCLUSION

The household H. pylori infection rate in Lanzhou is relatively high and linked to socio-demographic factors and lifestyles. Eradication efforts and control of related risk factors are recommended in the general population.

Nationwide Trends in Helicobacter pylori Eradication Therapies in Korea: Impact of Guideline Updates on Treatment Practices

INTRODUCTION

Helicobacter pylori infects over 50% of the global population, prompting the issuance of guidelines for effective diagnosis and treatment. However, research on guideline dissemination and adherence is limited. Therefore, we assessed the nationwide status of H. pylori eradication therapies in Korea before and after guideline updates.

METHODS

Using data from the Korean National Health Insurance Service, this retrospective cohort study analyzed changes in H. pylori eradication therapies across three periods: Phase I (2006-2007), Phase II (2014-2015), and Phase III (2021-2022). It examined therapy regimens, confirmation tests, and retreatment rates.

RESULTS

Among 1,657,746 patients included, the number undergoing eradication therapy increased across the phases (Phase I: 234,365; Phase II: 493,889; Phase III: 929,492). The use of conventional triple therapy declined from 96.1% in Phase I to 88.3% in Phase III, while non-bismuth and bismuth quadruple therapies increased to 6.8% and 3.3%, respectively, in Phase III. The proportion of patients following a 1-week regimen of conventional triple therapy decreased from 90.3% in Phase I to 54.2% in Phase III, while a 2-week regimen increased to 36.1% in Phase III. Confirmation testing within 1 year of therapy increased from 21.3% in Phase I to 43.0% in Phase III, whereas retreatment rates increased from 3.8% in Phase I to 8.8% in Phase III.

CONCLUSIONS

Guideline updates have influenced H. pylori eradication practices in Korea, leading to increased use of quadruple therapies with longer treatment durations. However, further improvements in confirmatory tests and retreatment following failed initial therapy are required.

Mixed Th1/Th2/Th17 Responses Induced by Plant Oil Adjuvant-Based B. bronchiseptica Vaccine in Mice, with Mechanisms Unraveled by RNA-Seq, 16S rRNA and Metabolomics

BACKGROUND/OBJECTIVES

The current Bordetella bronchiseptica (Bb) vaccine, when adjuvanted with alum, does not elicit adequate robust cellular immunity or effective antibody defense against Bb attacks. Unfortunately, antibiotic treatment generally represents an ineffective strategy due to the development of resistance against a broad range of antibiotics.

METHODS

The present study was designed to investigate the immune response, protective capabilities and underlying mechanisms of a plant oil-based adjuvant E515 formulated with inactivated Bb antigen as a potential vaccine candidate against Bordetella bronchiseptica.

RESULTS

Immunization studies revealed that a combination of SO, VE and GS (E515) exhibited a good synergistic adjuvant effect. The E515 adjuvanted Bb vaccine was proven to be highly efficacious and induced a mixed Th1/Th2/Th17 immune response in mice, leading to a significant increase in Bb-specific IgG, IgG1 and IgG2a antibodies, proliferative lymphocyte responses and cytokine levels (by lymphocytes and serum) and effectively induced responses by CD4+ TE, TM cells and B cells. The E515 adjuvant significantly enhanced the immune protection provided by the Bb vaccine in a mice model, as indicated by a reduced bacterial burden in the lungs. Multi-omics sequencing analysis revealed that E515 functions as an adjuvant by modulating critical pathways, including cytokine-cytokine receptor interaction, the IL-17 signaling pathway and the chemokine signaling pathway. This modulation also included interactions with beneficial species of bacteria including Alistipes, Odoribacter and Colidextribacter, as well as energy and lipid-related metabolites, thus highlighting its role as an immunomodulatory agent.

CONCLUSION

Collectively, our results demonstrate the huge potential of E515-Bb vaccine candidates, thus highlighting the vegetable oil original adjuvant E515 as a promising agent for the development of new veterinary vaccines.

Helicobacter pylori seropositivity associates with hyperglycemia, but not obesity, in Danish children and adolescents

BACKGROUND

Helicobacter pylori colonizes the human stomach and may affect the inflammatory response, hormone production related to energy regulation, and gastrointestinal microbiota composition. Previous studies have explored a potential association between H. pylori infection and pediatric obesity with varying results. Considering the immunomodulatory effects of early-life infection with H. pylori that can confer beneficial effects, we hypothesized that we would find an inverse relationship between H. pylori seropositivity and obesity among Danish children and adolescents.

METHODS

We assessed H. pylori seroprevalence in 713 subjects from an obesity clinic cohort and 990 subjects from a population-based cohort, aged 6 to 19 years, and examined its association with obesity and other cardiometabolic risk factors.

RESULTS

No association was found between H. pylori and body mass index standard deviation score (BMI SDS). H. pylori seropositivity was, however, significantly associated with higher fasting plasma glucose levels and the prevalence of hyperglycemia.

CONCLUSION

While we did not find an association between H. pylori seropositivity and BMI SDS, we observed a significant association with higher fasting plasma glucose levels and increased prevalence of hyperglycemia, suggesting that H. pylori infection may contribute to impaired glucose regulation in Danish children and adolescents.

High galectin expression in Helicobacter pylori-infected gastric mucosa in childhood

BACKGROUND

Mild Th1 and Th17 immune responses in childhood against Helicobacter pylori are presumed to be responsible for H. pylori colonization and mucosal atrophy reduction. However, the mechanism remains unclear. In this study, we aimed to investigate the childhood-specific immune responses observed after H. pylori infection by analyzing galectin expression in the gastric mucosa. We focused on galectin-1 (Gal-1) and galectin-9 (Gal-9), which function to suppress Th1 and Th17 immune responses.

METHODS

We analyzed changes in the expression of Gal-1 and Gal-9 in the gastric mucosa of pediatric patients with H. pylori infection. Ten pediatric patients with and ten patients without H. pylori infection who underwent biopsy to assess the cause of chronic abdominal symptoms using esophagogastroduodenoscopy were evaluated. Gal-1 and Gal-9 expression in the biopsy tissues of the gastric antrum and corpus was analyzed by immunohistochemical staining.

RESULTS

Gal-1 expression was significantly increased in the stromal cells of the corpus owing to H. pylori infection. No alterations in Gal-1 expression due to H. pylori infection were observed in the antral tissue. Helicobacter pylori infection considerably increased Gal-9 expression in all tissues. According to previous reports, the increased expression of Gal-9 associated with H. pylori infection is not observed in adults. Therefore, the increased expression of Gal-9 associated with H. pylori infection is specific to pediatric patients.

CONCLUSION

The increased expression of Gal-1 and Gal-9 may suppress Th1 and Th17 immune responses against H. pylori infection during childhood, promote H. pylori colonization, and reduce inflammation in the gastric mucosa of pediatric patients.

Study of Helicobacter pylori infection in patients with chronic atrophic gastritis and its relationship with lifestyle habits and dietary nutrient intake: A retrospective analysis

To explore Helicobacter pylori (Hp) infection status and its relationship with lifestyle habits and dietary factors in patients with chronic atrophic gastritis. Six hundred thirty-eight patients with chronic atrophic gastritis, who were admitted to our hospital from March 2021 to April 2023, were selected for the study. All patients underwent the 13C urea breath test. The relationship between the detection rate of Hp infection and the clinical characteristics, lifestyle habits, and dietary factors of the patients was analyzed. Among the 638 patients with chronic atrophic gastritis, 531 patients were tested positive for Hp infection, the positive rate for Hp infection was approximately 83.23%. Analyzing the clinical characteristics of the patients, it was found that age, family history of gastric cancer, degree of chronic inflammation, degree of glandular atrophy, presence of low-grade dysplasia, and intestinal metaplasia all have an impact on the positive detection rate of patients (P < .05). Analyzing the patients' lifestyle habits, it was found that BMI, smoking history, alcohol consumption, preference for spicy food, dining location, consumption of pickled foods, frequent consumption of grilled/barbecued foods, preference for strong tea, consumption of sweets, and work-related stress had an impact on the positive rate of Hp infection in patients (P < .05). The discovery showed that the levels of total protein, albumin, hemoglobin, cholesterol, and the intake of livestock and poultry meat, seafood, dairy products, vegetables, fruits, and fats have an impact on the positivity rate of Hp infection in patients (P < .05). A multiple logistic regression analysis was performed, and it was found that patients' age, family history of gastric cancer, degree of chronic inflammation, degree of glandular atrophy, presence of low-grade dysplasia, presence of wasting or obesity, history of alcohol consumption, preference for spicy food, dining location, frequent consumption of strong tea, high work pressure, high intake of fish and seafood, low intake of dairy products, low intake of vegetables, low intake of fruits, and low intake of fats all had an impact on the occurrence of Hp infection in patients (P < .05). There is a certain correlation between patients' lifestyle habits, dietary factors, and clinical characteristics with the occurrence of Hp infection. These factors can assist in the prevention of Hp infection.

Inflammatory microenvironment in gastric premalignant lesions: implication and application

Gastric precancerous lesions (GPL) are a major health concern worldwide due to their potential to progress to gastric cancer (GC). Understanding the mechanism underlying the transformation from GPL to GC can provide a fresh insight for the early detection of GC. Although chronic inflammation is prevalent in the GPL, how the inflammatory microenvironment monitored the progression of GPL-to-GC are still elusive. Inflammation has been recognized as a key player in the progression of GPL. This review aims to provide an overview of the inflammatory microenvironment in GPL and its implications for disease progression and potential therapeutic applications. We discuss the involvement of inflammation in the progression of GPL, highlighting Helicobacter pylori (H. pylori) as a mediator for inflammatory microenvironment and a key driver to GC progression. We explore the role of immune cells in mediating the progression of GPL, and focus on the regulation of inflammatory molecules in this disease. Furthermore, we discuss the potential of targeting inflammatory pathways for GPL. There are currently no specific drugs for GPL treatment, but traditional Chinese Medicine (TCM) and natural antioxidants, known as antioxidant and anti-inflammatory properties, exhibit promising effects in suppressing or reversing the progression of GPL. Finally, the challenges and future perspectives in the field are proposed. Overall, this review highlights the central role of the inflammatory microenvironment in the progression of GPL, paving the way for innovative therapeutic approaches in the future.

Helicobacter pylori-associated Chronic Atrophic Gastritis and Progression of Gastric Carcinogenesis

Chronic inflammation due to a Helicobacter pylori (H. pylori) infection is a representative cause of gastric cancer that can promote gastric carcinogenesis by abnormally activating immune cells and increasing the inflammatory cytokines levels. H. pylori infections directly cause DNA double-strand breaks in gastric epithelial cells and genetic damage by increasing the enzymatic activity of cytidine deaminase. Eventually, gastric cancer is induced through dysplasia. Hypermethylation of tumor suppressor genes is an important cause of gastric cancer because of a H. pylori infection. In addition, the changes in gastric microbiota and the mucosal inflammatory changes associated with a co-infection with the Epstein-Barr virus are associated with gastric cancer development. DNA damage induced by H. pylori and the subsequent responses of gastric stem cells have implications for gastric carcinogenesis. Although the pathogenesis of H. pylori has been established, many uncertainties remain, requiring more study.

Review of Phytochemical Potency as a Natural Anti-Helicobacter pylori and Neuroprotective Agent

Phytochemicals are plant secondary metabolites that show health benefits for humans due to their bioactivity. There is a huge variety of phytochemicals that have already been identified, and these compounds can act as antimicrobial and neuroprotection agents. Due to their anti-microbial activity and neuroprotection, several phytochemicals might have the potency to be used as natural therapeutic agents, especially for Helicobacter pylori infection and neurodegenerative disease, which have become a global health concern nowadays. According to previous research, there are some connections between H. pylori infection and neurodegenerative diseases, especially Alzheimer's disease. Hence, this comprehensive review examines different kinds of phytochemicals from natural sources as potential therapeutic agents to reduce H. pylori infection and improve neurodegenerative disease. An additional large-scale study is needed to establish the connection between H. pylori infection and neurodegenerative disease and how phytochemicals could improve this condition.

Efficacy and Tolerability of 14-Day Tegoprazan- versus Rabeprazole-Based Triple Therapy for Eradication of Helicobacter pylori: A Real-World Evidence Study

Background/Aims

Tegoprazan, a new, fast, and strong potassium-competitive acid blocker, has been approved for the treatment of gastric acid-related diseases in Korea. However, real-world clinical data regarding this drug are scarce. We aimed to compare the Helicobacter pylori eradication rates of tegoprazan- and rabeprazole-based triple therapy.

Methods

We retrospectively reviewed data from patients who received first-line treatment for H. pylori infection using tegoprazan- or rabeprazole-based triple therapy for 2 weeks (50 mg tegoprazan or 20 mg rabeprazole+1,000 mg amoxicillin+500 mg clarithromycin twice daily). The primary endpoint was the eradication rate as determined by intention-to-treat analysis.

Results

Of the 677 patients included in our study, 344 and 333 received tegoprazan-based and rabeprazole-based triple therapy, respectively. The eradication rate from intention-to-treat analysis was 76.7% (95% confidence interval [CI], 72.1% to 81.0%) for tegoprazan-based triple therapy and 75.4% (95% CI, 70.5% to 79.8%) for rabeprazole-based triple therapy. There was no significant difference in the eradication rates between the two groups (p>0.999). Per-protocol analysis also revealed no significant difference between the eradication rates of the two groups (tegoprazan 83.4% [95% CI, 79.0% to 87.2%] vs rabeprazole 83.5% [79.0% to 87.4%], p>0.999). Furthermore, there was no significant difference in adverse event rates between the two groups (tegoprazan, 27.6%; rabeprazole, 25.8%; p=0.604).

Conclusions

The eradication rate of tegoprazan-based triple therapy was similar to that of rabeprazole-based triple therapy. Further studies on the dose-escalation effect of tegoprazan for H. pylori eradication and the efficacy of tegoprazan in regimens other than conventional triple therapy are needed.

Impact of Age at Diagnosis on Clinicopathological Features, Prognosis, and Management of Gastric Cancer: A Retrospective Single-Center Experience from Spain

The impact of age on various aspects of gastric cancer (GC) remains controversial. Clarifying this issue can improve our understanding of the disease, refine risk stratification models, and aid in personalized therapeutic approaches. This study aimed to evaluate the influence of age at diagnosis on the clinicopathological features, prognosis, and management of a specific cohort of Spanish patients with resected GC. The study encompassed 315 patients treated at a single tertiary hospital in Spain, divided into two age-based subgroups: ≤65 years and >65 years. The mean and median ages at diagnosis were 72 and 76 years. Most tumors were diagnosed at pT3 stage (49.2%), and 59.6% of patients had lymph node metastases. 21.3% of cases were diagnosed with GC at age ≤ 65 years. Younger patients showed a significantly higher prevalence of flat, diffuse, high-grade tumors, signet-ring cells, perineural infiltration, D2 lymphadenectomies, and adjuvant therapy. They also exhibited a higher rate of recurrences, but had a significantly longer follow-up. Kaplan-Meier curves indicated no significant prognostic differences based on age. Finally, age did not independently predict overall survival or disease-free survival. Our results suggest that younger patients may require more aggressive treatment due to adverse clinicopathologic features, but the lack of prognostic differences among age groups in our cohort indicates the need for further investigation into the complex interplay between age, clinicopathologic factors, and long-term outcomes in GC.

The effectiveness of treatment with probiotics in Helicobacter pylori eradication: results from an umbrella meta-analysis on meta-analyses of randomized controlled trials

Background and aims: The purpose of this umbrella meta-analysis was to quantitatively summarize meta-analyses of randomized controlled trial (RCT) studies regarding the effects of probiotic supplementation on Helicobacter pylori (H. pylori) eradication. Methods: A thorough search of the electronic databases including PubMed, Web of Science, Embase, Scopus, and Google Scholar was carried out from the inception up to May 2022. For the evaluation of overall effect sizes, the pooled relative risk (RR) or odds ratio (OR) and their corresponding 95% confidence intervals (CI) were calculated. The random-effects model was used for the meta-analysis. Results: Overall, 18 eligible studies (47 278 participants in total) were included in the study. The findings revealed that probiotics have a beneficial impact on H. pylori eradication (pooled ESRR: 1.13; 95% CI: 1.11, 1.14, p < 0.01, and ESOR = 1.86, 95% CI: 1.70, 2.03, p < 0.01). Greater effects on H. pylori eradication were observed when higher doses (>10 × 1010 CFU) and mixed strains were supplemented. Conclusion: The present umbrella meta-analysis suggests that supplementation with probiotics may be considered as an efficient approach to ameliorate H. pylori complications, particularly probiotics with higher CFUs and mixed strains.

The Influence of Helicobacter pylori on Human Gastric and Gut Microbiota

Helicobacter pylori is a Gram-negative bacterium that is able to colonize the human stomach, whose high prevalence has a major impact on human health, due to its association with several gastric and extra-gastric disorders, including gastric cancer. The gastric microenvironment is deeply affected by H. pylori colonization, with consequent effects on the gastrointestinal microbiota, exerted via the regulation of various factors, including gastric acidity, host immune responses, antimicrobial peptides, and virulence factors. The eradication therapy required to treat H. pylori infection can also have detrimental consequences for the gut microbiota, leading to a decreased alpha diversity. Notably, therapy regimens integrated with probiotics have been shown to reduce the negative effects of antibiotic therapy on the gut microbiota. These eradication therapies combined with probiotics have also higher rates of eradication, when compared to standard treatments, and are associated with reduced side effects, improving the patient's compliance. In light of the deep impact of gut microbiota alterations on human health, the present article aims to provide an overview of the complex interaction between H. pylori and the gastrointestinal microbiota, focusing also on the consequences of eradication therapies and the effects of probiotic supplementation.

Linking dysbiosis to precancerous stomach through inflammation: Deeper than and beyond imaging

Upper gastrointestinal endoscopy is considered the gold standard for gastric lesions detection and surveillance, but it is still associated with a non-negligible rate of missing conditions. In the Era of Personalized Medicine, biomarkers could be the key to overcome missed lesions or to better predict recurrence, pushing the frontier of endoscopy to functional endoscopy. In the last decade, microbiota in gastric cancer has been extensively explored, with gastric carcinogenesis being associated with progressive dysbiosis. Helicobacter pylori infection has been considered the main causative agent of gastritis due to its interference in disrupting the acidic environment of the stomach through inflammatory mediators. Thus, does inflammation bridge the gap between gastric dysbiosis and the gastric carcinogenesis cascade and could the microbiota-inflammation axis-derived biomarkers be the answer to the unmet challenge of functional upper endoscopy? To address this question, in this review, the available evidence on the role of gastric dysbiosis and chronic inflammation in precancerous conditions of the stomach is summarized, particularly targeting the nuclear factor-κB (NF-κB), toll-like receptors (TLRs) and cyclooxygenase-2 (COX-2) pathways. Additionally, the potential of liquid biopsies as a non-invasive source and the clinical utility of studied biomarkers is also explored. Overall, and although most studies offer a mechanistic perspective linking a strong proinflammatory Th1 cell response associated with, but not limited to, chronic infection with Helicobacter pylori, promising data recently published highlights not only the diagnostic value of microbial biomarkers but also the potential of gastric juice as a liquid biopsy pushing forward the concept of functional endoscopy and personalized care in gastric cancer early diagnosis and surveillance.

The regulation roles of miRNAs in Helicobacter pylori infection

Helicobacter pylori is a kind of Gram-negative bacteria that parasitizes on human gastric mucosa. Helicobacter pylori infection is very common in human beings, which often causes gastrointestinal diseases, including chronic gastritis, duodenal ulcer and gastric cancer. MicroRNAs are a group of endogenous non-coding single stranded RNAs, which play an important role in cell proliferation, differentiation, autophagy, apoptosis and inflammation. In recent years, relevant studies have found that the expression of microRNA is changed after Helicobacter pylori infection, and then regulate the biological process of host cells. This paper reviews the regulation role of microRNAs on cell biological behavior through different signal pathways after Helicobacter pylori infection.

Relationship between Helicobacter pylori infection and gastrointestinal microecology

The prevalence of Helicobacter pylori (H. pylori) infection has exceeded 50% worldwide, and it is considered a high-risk factor for chronic gastritis, peptic ulcer, gastric adenocarcinoma, gastroesophageal reflux disease and functional dyspepsia. H. pylori drug resistance is a common problem worldwide. In recent years, the relationship between H. pylori infection and gastrointestinal microecology has received much attention. H. pylori infection changes the structure and composition of gastrointestinal microflora by regulating the gastrointestinal microecological environment, local pH value, cytokines and antimicrobial peptides, and immune response and then plays a crucial role in the occurrence and development of digestive system tumors, liver metabolism and extragastrointestinal diseases. The quadruple strategy of H. pylori eradication can also aggravate gastrointestinal microflora disorder. However, probiotics can reduce intestinal flora changes and imbalances through different mechanisms, thus enhancing the efficacy of H. pylori eradication therapy and reducing adverse reactions caused by eradication therapy. Therefore, this paper reviews the relationship between H. pylori infection and gastrointestinal microecology and its clinical application, providing a basis for clinical treatment.

Helicobacter pylori and the Role of Lipopolysaccharide Variation in Innate Immune Evasion

Helicobacter pylori is an important human pathogen that infects half the human population and can lead to significant clinical outcomes such as acute and chronic gastritis, duodenal ulcer, and gastric adenocarcinoma. To establish infection, H. pylori employs several mechanisms to overcome the innate and adaptive immune systems. H. pylori can modulate interleukin (IL) secretion and innate immune cell function by the action of several virulence factors such as VacA, CagA and the type IV secretion system. Additionally, H. pylori can modulate local dendritic cells (DC) negatively impacting the function of these cells, reducing the secretion of immune signaling molecules, and influencing the differentiation of CD4⁺ T helper cells causing a bias to Th1 type cells. Furthermore, the lipopolysaccharide (LPS) of H. pylori displays a high degree of phase variation and contains human blood group carbohydrate determinants such as the Lewis system antigens, which are proposed to be involved in molecular mimicry of the host. Lastly, the H. pylori group of outer membrane proteins such as BabA play an important role in attachment and interaction with host Lewis and other carbohydrate antigens. This review examines the various mechanisms that H. pylori utilises to evade the innate immune system as well as discussing how the structure of the H. pylori LPS plays a role in immune evasion.

An Anaerobic Environment Drives the Harboring of Helicobacter pylori within Candida Yeast Cells

Simple Summary

Helicobacter pylori is a pathogen that is associated with a number of gastric pathologies and has adapted to the gastric environment. Outside this organ, stress factors such as oxygen concentration affect the viability of this bacterium. This study aimed to determine if changes in oxygen concentration promoted the entry of H. pylori into the interior of yeast cells of the Candida genus. Co-cultures of H. pylori and Candida strains in Brucella broth plus 5% fetal bovine serum were incubated under microaerobic, anaerobic, or aerobic conditions. Bacteria-like bodies (BLBs) were detected within yeast cells (Y-BLBs) by optical microscopy, identified by molecular techniques, and their viability evaluated by SYTO-9 fluorescence. Co-cultures incubated under the three conditions showed the presence of Y-BLBs, but the highest Y-BLB percentage was present in H. pylori J99 and C. glabrata co-cultures incubated under anaerobiosis. Molecular techniques were used to identify BLBs as H. pylori and SYTO-9 fluorescence confirmed that this bacterium remained viable within yeast cells. In conclusion, although without apparent stress conditions H. pylori harbors within Candida yeast cells, its harboring increases significantly under anaerobic conditions. This endosymbiotic relationship also depends mostly on the H. pylori strain used in the co-culture.

Abstract

Helicobacter pylori protects itself from stressful environments by forming biofilms, changing its morphology, or invading eukaryotic cells, including yeast cells. There is little knowledge about the environmental factors that influence the endosymbiotic relationship between bacterium and yeasts. Here, we studied if oxygen availability stimulated the growth of H. pylori within Candida and if this was a bacterial- or yeast strain-dependent relationship. Four H. pylori strains and four Candida strains were co-cultured in Brucella broth plus 5% fetal bovine serum, and incubated under microaerobic, anaerobic, or aerobic conditions. Bacteria-like bodies (BLBs) within yeast cells (Y-BLBs) were detected by microscopy. H. pylori was identified by FISH and by PCR amplification of the 16S rRNA gene of H. pylori from total DNA extracted from Y-BLBs from H. pylori and Candida co-cultures. BLBs viability was confirmed by SYTO-9 fluorescence. Higher Y-BLB percentages were obtained under anaerobic conditions and using H. pylori J99 and C. glabrata combinations. Thus, the H. pylori–Candida endosymbiotic relationship is strain dependent. The FISH and PCR results identified BLBs as intracellular H. pylori. Conclusion: Stressful conditions such as an anaerobic environment significantly increased H. pylori growth within yeast cells, where it remained viable, and the bacterium–yeast endosymbiotic relationship was bacterial strain dependent with a preference for C. glabrata.