Genetic variation of Helicobacter pylori in the oral cavity and stomach detected using thymine adenine cloning in children with chronic gastritis

The relationship between Helicobacter pylori infection and recurrent aphthous stomatitis: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis was designed to provide new insights into the relationship between Helicobacter pylori (H. pylori) infection and recurrent aphthous stomatitis (RAS).

MATERIALS AND METHODS

We included and evaluated studies on H. pylori infection and RAS from PubMed, EMBASE, Cochrane Library, and Web of Science databases published up to January 31, 2023. The characteristics of these studies were collected, and the quality was evaluated by Newcastle-Ottawa Scale (NOS). The random effects model was used to calculate the pooled odds ratio (OR) and 95% confidence interval (CI). To further explore the sources of heterogeneity, meta-regression analysis and subgroup analyses were performed. Funnel plot, Egger's test, and Begg's test were used to assess publication bias.

RESULTS

In total, fifteen case-control studies with 1137 individuals (601 cases and 536 controls) were included. The H. pylori was found to be significantly associated with RAS (OR: 1.83 95% CI: 1.41-2.37, P = 0.001). In the subgroup analyses, studies that used PCR (OR: 2.03 95% CI: 1.31-3.15) or UBT (OR: 1.83 95% CI: 1.13-2.96) yielded a significant positive association, while a non-significant association (OR: 1.12 95% CI: 0.61-2.08) was found from studies that used ELISA method. Sensitivity analyses showed that the results were robust. No significant publication bias was found.

CONCLUSIONS

The current evidence does not rule out an association between H. pylori and RAS. The effect of H. pylori on RAS varies in detection methods and sources of sample. Large samples, multiple clinical studies, and improved methods are still needed to determine the exact effect of H. pylori on RAS.

CLINICAL SIGNIFICANCE

H. pylori infection may be a risk factor for the pathogenesis of RAS.

Is Helicobacter pylori Infection Prevalent in Middle East Countries?

Background: Helicobacter pylori is a pathogenic bacteria found in the gastric mucosa of both children and adults. Our goal was to use an endoscopic method to look at the prevalence of H. pylori in children with gastrointestinal complaints. Methods: This cross-sectional research was conducted in 2022 on pediatric patients who received gastric or duodenal biopsies by endoscopy. We collected data from medical reports regarding patients' age, gender, location of residence, type of gastrointestinal problems, and frequency of H. pylori infection. Results: A total of 2030 pediatric patients participated in the study. Helicobacter pylori infection was found in 259 cases (12.76%). There were no significant differences between the two genders regarding the prevalence of H. pylori infection (P = 0.094). This infection was more common in patients aged > 10 years (P < 0.001) and in residents of the Isfahan suburb (P < 0.001). Conclusions: In comparison to other locations, we found a similar incidence rate of H. pylori infection in children. According to our findings, greater ages are associated with a higher detection rate of H. pylori infection.

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.

Helicobacter pylori in the Oral Cavity: Current Evidence and Potential Survival Strategies

Helicobacter pylori (H. pylori) is transmitted primarily through the oral–oral route and fecal–oral route. The oral cavity had therefore been hypothesized as an extragastric reservoir of H. pylori, owing to the presence of H. pylori DNA and particular antigens in distinct niches of the oral cavity. This bacterium in the oral cavity may contribute to the progression of periodontitis and is associated with a variety of oral diseases, gastric eradication failure, and reinfection. However, the conditions in the oral cavity do not appear to be ideal for H. pylori survival, and little is known about its biological function in the oral cavity. It is critical to clarify the survival strategies of H. pylori to better comprehend the role and function of this bacterium in the oral cavity. In this review, we attempt to analyze the evidence indicating the existence of living oral H. pylori, as well as potential survival strategies, including the formation of a favorable microenvironment, the interaction between H. pylori and oral microorganisms, and the transition to a non-growing state. Further research on oral H. pylori is necessary to develop improved therapies for the prevention and treatment of H. pylori infection.

The Association Between Oral Helicobacter pylori and Gastric Complications: A Comprehensive Review

Helicobacter pylori (H. pylori) is linked to chronic gastritis, duodenal or gastric ulcers, and gastric cancer (GC). Because the oral cavity is the first component of the gastrointestinal tract (GIT) and the entrance point for H. pylori, it has been proposed as a possible reservoir of H. pylori. As a result, a putative oral-oral transmission pathway of H. pylori poses the possibility of whether personal contact, such as kissing or sharing a meal, might trigger H. pylori transmission. As a result, several investigations have been done on this issue using various approaches for detecting H. pylori in oral and stomach samples. Furthermore, the relationship between H. pylori and gastrointestinal disorders has yet to be studied. The evidence for the association between H. pylori and gastric diseases and their complications is still a controversial subject due to the existing literature in this review. The goal of this comprehensive review was to collect all available published articles and critically evaluate existing investigations looking into the relationship between oral H. pylori contamination and the danger of gastric complications. Few studies indicated an association between H. pylori and gastric diseases. Furthermore, more longitudinal randomized clinical studies to further investigate the association between H. pylori and gastric diseases are warranted.

Colonization of Helicobacter pylori in the oral cavity - an endless controversy?

Helicobacter pylori is associated with chronic gastritis, gastric or duodenal ulcers, and gastric cancer. Since the oral cavity is the entry port and the first component of the gastrointestinal system, the oral cavity has been discussed as a potential reservoir of H. pylori. Accordingly, a potential oral-oral transmission route of H. pylori raises the question concerning whether close contact such as kissing or sharing a meal can cause the transmission of H. pylori. Therefore, this topic has been investigated in many studies, applying different techniques for detection of H. pylori from oral samples, i.e. molecular techniques, immunological or biochemical methods and traditional culture techniques. While molecular, immunological or biochemical methods usually yield high detection rates, there is no definitive evidence that H. pylori has ever been isolated from the oral cavity. The specificity of those methods may be limited due to potential cross-reactivity, especially with H. pylori-like microorganisms such as Campylobacter spp. Furthermore, the influence of gastroesophageal reflux has not been investigated so far. This review aims to summarize and critically discuss previous studies investigating the potential colonization of H. pylori in the oral cavity and suggest novel research directions for targeting this critical research question.

Dysbiosis and Ecotypes of the Salivary Microbiome Associated With Inflammatory Bowel Diseases and the Assistance in Diagnosis of Diseases Using Oral Bacterial Profiles

Inflammatory bowel diseases (IBDs) are chronic, idiopathic, relapsing disorders of unclear etiology affecting millions of people worldwide. Aberrant interactions between the human microbiota and immune system in genetically susceptible populations underlie IBD pathogenesis. Despite extensive studies examining the involvement of the gut microbiota in IBD using culture-independent techniques, information is lacking regarding other human microbiome components relevant to IBD. Since accumulated knowledge has underscored the role of the oral microbiota in various systemic diseases, we hypothesized that dissonant oral microbial structure, composition, and function, and different community ecotypes are associated with IBD; and we explored potentially available oral indicators for predicting diseases. We examined the 16S rRNA V3–V4 region of salivary bacterial DNA from 54 ulcerative colitis (UC), 13 Crohn’s disease (CD), and 25 healthy individuals using Illumina sequencing. Distinctive sample clusters were driven by disease or health based on principal coordinate analysis (PCoA) of both the Operational Taxonomic Unit profile and Kyoto Encyclopedia of Genes and Genomes pathways. Comparisons of taxa abundances revealed enrichment of Streptococcaceae (Streptococcus) and Enterobacteriaceae in UC and Veillonellaceae (Veillonella) in CD, accompanied by depletion of Lachnospiraceae and [Prevotella] in UC and Neisseriaceae (Neisseria) and Haemophilus in CD, most of which have been demonstrated to exhibit the same variation tendencies in the gut of IBD patients. IBD-related oral microorganisms were associated with white blood cells, reduced basic metabolic processes, and increased biosynthesis and transport of substances facilitating oxidative stress and virulence. Furthermore, UC and CD communities showed robust sub-ecotypes that were not demographic or severity-specific, suggesting their value for future applications in precision medicine. Additionally, indicator species analysis revealed several genera indicative of UC and CD, which were confirmed in a longitudinal cohort. Collectively, this study demonstrates evident salivary dysbiosis and different ecotypes in IBD communities and provides an option for identifying at-risk populations, not only enhancing our understanding of the IBD microbiome apart from the gut but also offering a clinically useful strategy to track IBD as saliva can be sampled conveniently and non-invasively.

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.

Eradication of gastric Helicobacter pylori ameliorates halitosis and tongue coating

BACKGROUND

The influence of gastric Helicobacter pylori infection on the development of oral pathoses remains unclear. The aim of this study is to examine the influence of gastric H. pylori infection on occurrence of halitosis and coated tongue.

MATERIALS AND METHODS

Ninety-eight patients with dyspepsia were included in the study and their salivary samples and gastric biopsies were analyzed for the presence of H. pylori by Nested-PCR. Halitosis and coated tongue were assessed at the initial examination and 3 months after systemic eradication therapy against H. pylori.

RESULTS

Gastric biopsies of 66 patients were positive for H. pylori. Only one saliva sample was H. pylori positive. At initial examination, halitosis was observed in 20 patients (30.3%) out of 66 who had gastric H. pylori infection and in only 3 patients (9.4%) out of 32 without H. pylori infection (p = 0.0236). Coated tongue was diagnosed in 18 (27.2%) patients with the infection compared to only 2 (6.25%) patients negative for gastric H. pylori (p = 0.0164). Patients with gastric infection were treated with the triple eradication therapy (Amoxicillin, Clarythromycin, Pantoprazol) and their gastric biopsies and oral status were examined 3 months later. Halitosis was significantly more prevalent in the group of patients with persistent H. pylori infection (42.1%) compared to only 6.4% of patients in the group where infection was successfully eradicated (p = 0.0012). Coated tongue was diagnosed in 47.4% of patients where H. pylori was still present after eradication therapy and in only 6.4% where eradication succeeded (p = 0.0003).

CONCLUSION

Our findings suggest that eradication of gastric H. pylori significantly alleviates halitosis and coated tongue, the two oral conditions that may be considered as extragastric manifestations of this common chronic bacterial infection.

Helicobacter pylori and nonmalignant diseases

Peptic ulcer bleeding and recurrence rate are strongly linked to Helicobacter pylori infection even if nonsteroidal anti-inflammatory drugs (NSAIDs) play a relevant role in this setting. Further studies confirm that H. pylori eradication lowers the risk of recurrent peptic ulcer bleeding. Therefore, a test-and-treat strategy appears to be mandatory for patients with a history of ulcer bleeding and NSAIDs and/or aspirin use. Concerning gastroesophageal reflux disease (GERD), evidence clearly shows that H. pylori status has no effect on symptoms and treatment. Therefore, H. pylori treatment is not contraindicated in patients with GERD. The exact role of H. pylori in functional dyspepsia (FD) remains controversial. Novel possible mechanisms by which H. pylori may elicit dyspeptic symptoms include alterations of gastric motility, as well as endocrine and acid-secretory abnormalities. Hunger sensations, acid secretion, and gastrointestinal motility are regulated by ghrelin, particularly produced by the gastric enteroendocrine cell compartment. The improvement of symptoms correlates with enhanced plasma ghrelin levels. Apart from the need for more trials on this topic, these findings may give insight into the underlying pathophysiology of FD symptoms. Recent reports suggest that the presence of bacterial DNA in the oral cavity may be relevant to its transmission. A potential protective role of H. pylori on inflammatory bowel diseases needs to be better elucidated.

Concomitant Colonization of Helicobacter pylori in Dental Plaque and Gastric Biopsy

Frequently reported H. pylori antimicrobial therapy failures suggest that there might be a different niche where the bacteria can stay safe. Current study aims to examine potential role of oral colonization of H. pylori to feed reinfection after primary therapy. However, patients who were admitted to the gastroscopy section were chosen and gastric biopsy and dental plaque specimens were collected. Molecular and biochemical tests were applied to confirm H. pylori identity in different colonization niches. Results showed that 88.8% of dyspeptic patients had epigastric pains with nocturnal awakening when they were hungry (P = 0.023). All patients who received therapy already were again H. pylori positive while they are still carrying H. pylori in dental plaque (P = 0.001). Moreover, H. pylori infection was sought in 100% of gastric biopsy's dyspeptic patients who had ulcerated esophagitis and erosive duodenitis and who were H. pylori positive, and 75% of dyspeptic patients with duodenum deformity had this bacterium in gastric biopsies (P = 0.004). Present study showed that only successful eradication of gastric H. pylori cannot guarantee prevention of reinfection. Conclusively, a new strategy which indicates concomitant eradication in oral and gastric colonization can result in clearance of H. pylori infection.