Bacterial load and degree of gastric mucosal inflammation in Helicobacter pylori infection

Treatment of H. pylori infection and gastric ulcer: Need for novel Pharmaceutical formulation

Peptic ulcer disease (PUD) is one of the most prevalent gastro intestinal disorder which often leads to painful sores in the stomach lining and intestinal bleeding. Untreated Helicobacter pylori (H. pylori) infection is one of the major reasons for chronic PUD which, if left untreated, may also result in gastric cancer. Treatment of H. pylori is always a challenge to the treating doctor because of the poor bioavailability of the drug at the inner layers of gastric mucosa where the bacteria resides. This results in ineffective therapy and antibiotic resistance. Current treatment regimens available for gastric ulcer and H. pylori infection uses a combination of multiple antimicrobial agents, proton pump inhibitors (PPIs), H2-receptor antagonists, dual therapy, triple therapy, quadruple therapy and sequential therapy. This polypharmacy approach leads to patient noncompliance during long term therapy. Management of H. pylori induced gastric ulcer is a burning issue that necessitates alternative treatment options. Novel formulation strategies such as extended-release gastro retentive drug delivery systems (GRDDS) and nanoformulations have the potential to overcome the current bioavailability challenges. This review discusses the current status of H. pylori treatment, their limitations and the formulation strategies to overcome these shortcomings. Authors propose here an innovative strategy to improve the H. pylori eradication efficiency.

New insight on the role of Helicobacter pylori cagA in the expression of cell surface antigens with important biological functions in gastric carcinogenesis

BACKGROUND

Expression of cluster of differentiation (CD) antigens changes according to disease status and inflammation. Profiles of CD antigens expression in gastric cancer patients are different based on the status of H. pylori infection.

AIMS

We conducted this study to profile CD antigen markers in gastric adenocarcinoma cells (AGS cell line) infected with distinct cytotoxin-associated gene A (cagA) genotypes of H. pylori clinical isolates.

METHODS

The AGS cells were infected with H. pylori isolates with different cagA genotypes, and CD antigens expression was determined using DotScan™ antibody microarray. Formation of "hummingbird" phenotype was determined, and the percentage was calculated.

RESULTS

H. pylori strains harboring cagA upregulated the expression of CD antigen involved in cancer stem cell formation (CD55), but downregulated CD antigens involved in immune regulation (CD40 and CD186) and cell adhesion (CD44). CD54 (neutrophil adhesion) and CD71 (iron transfer) were highly downregulated in the gastric cells infected with Western cagA isolates compared with East Asian isolates. CD antigen expression was different in the cells infected with H. pylori harboring different CagA EPIYA (Glu-Pro-Ile-Tyr-Ala) numbers, in which higher repression of CD54 and CD15 (Lewis x antigen) were observed in the isolate with the highest number of EPIYA motif. Furthermore, higher downregulation of CD15 was observed in the infected gastric cells with high percentage of "hummingbird" phenotype than that of low percentage of "hummingbird" phenotype.

CONCLUSION

Our study demonstrated the critical roles of CD antigens in the CagA pathogenesis and should be investigated further.

The efficacy of Lactobacillus acidophilus and rhamnosus in the reduction of bacterial load of Helicobacter pylori and modification of gut microbiota-a double-blind, placebo-controlled, randomized trial

BACKGROUND

Probiotics may alter the gut microbiota and may reduce antibiotic-related dysbiosis after H. pylori eradication. However, whether probiotics are effective in reducing the bacterial load of H. pylori and modifying the gut microbiota remains unknown. We aimed to assess the efficacy of Lactobacillus acidophilus and Lactobacillus rhamnosus in reducing the bacterial load of H. pylori and modifying the gut microbiota.

MATERIALS AND METHODS

In this double-blind, randomized, placebo-controlled trial, we recruited 40 adult subjects with moderate to high bacterial loads of H. pylori, defined as a mean delta over baseline (DOB) value of the ¹³ C-urea breath test (¹³ C-UBT) of 10 or greater every 4 days 6 times. Eligible subjects were randomized in a 1:1 ratio to receive either probiotics containing Lactobacillus acidophilus and Lactobacillus rhamnosus or placebo twice daily for 4 weeks. ¹³ C-UBT was measured weekly from the beginning of treatment to 2 weeks after treatment. Amplification of the V3 and V4 hypervariable regions of the 16S rRNA was performed for fecal microbiota.

RESULTS

A total of 40 subjects were randomized to receive probiotics or placebo. The DOB value was significantly lower in the probiotic group than in the placebo group after 4 weeks of treatment (26.0 vs. 18.5, p = .045). The DOB value was significantly reduced compared to that at baseline in the probiotic group (18.5 vs. 26.7, p = .001) but not in the placebo group (26.0 vs. 25.0, p = .648). However, the eradication rate for H. pylori was 0% in both groups. There was no significant difference in the DOB values between the two groups 1 and 2 weeks after discontinuation of the probiotics. There were also no significant changes observed in the α-diversity and β-diversity at week 4 compared to baseline in the probiotic group (p = .77 and 0.91) and the placebo group (p = .26 and 0.67).

CONCLUSIONS

Although the use of Lactobacillus acidophilus and Lactobacillus rhamnosus may reduce the bacterial load of H. pylori, there were no significant changes in the composition of gut microbiota. This trial is registered with ClinicalTrials.gov, NCT02725138.

The effect of Lactobacillus reuteri supplementation in Helicobacter pylori infection: a placebo-controlled, single-blind study

Background

Helicobacter pylori is the major cause of chronic gastritis, and considered as a risk factor for peptic ulcer and gastric cancer. The H. pylori standard antibiotic therapy fails in about 25–30% of cases, particularly because of the increasing occurrence of resistance to antibiotics. The aim of the current study was to investigate whether the strain Lactobacillus reuteri DSM17648 which has been previously shown to reduce Helicobacter pylori load additionally improves gastrointestinal symptoms in H. pylori positive subjects when used in a 28 days supplementation.

Methods

In a single-blinded, placebo controlled study 24 H. pylori-positive adults (13 females, 11 males; median age: 43.5) with mild dyspepsia (mean GSRS score: 11.82) received placebo for 28 days followed by Pylopass™ containing the L. reuteri DSM 17648 (2 × 10¹⁰ cells per day) for the following 28 days. After 28 days of Pylopass™ supplementation the change in H. pylori load was measured by ¹³C urea breath test (¹³C-UBT) and the change in symptoms were determined by the Gastrointestinal Symptom Rating Scale (GSRS). In addition, blood assessments were conducted to measure the physiological changes relevant in terms of safety.

Results

After a 28-day supplementation phase with Pylopass™ there was a trend for reduction of H. pylori load in 62.5% of the subjects and for the overall GSRS scores in 66.7% of subjects. The overall GSRS scores from baseline to day 56 following all 24 subjects undergoing the placebo phase followed by the Pylopass™ phase was significantly decreased (p = 0.005). The mean 13C-UBT δ value decreased by 22.5% during the Pylopass™ supplementation phase (− 3.14), while the mean 13C-UBT δ increased by 37.3% (+ 3.79) in the placebo phase. No side effects were reported in either study phase.

Conclusion

The results demonstrated that L. reuteri DSM17648 has the potential to suppress H. pylori infection, and may lead to an improvement of H. pylori-associated gastro intestinal symptoms. Further studies with adequate power should be performed.

Trial registration

Clinicaltrials.gov: NCT02051348 (January 30, 2014).

Contribution of genetic amplification by PCR for the diagnosis of Helicobacter pylori infection in patients receiving proton pump inhibitors

Background

Helicobacter pylori detection by standard methods may be altered by proton pump inhibitor (PPI) use. However, some patients cannot or should not interrupt PPI use before undergoing testing for H. pylori. Polymerase chain reaction (PCR) could allow more reliable H. pylori detection even in patients taking PPIs.

Objective

The aim of our study is to compare the H. pylori infection diagnostic value of histological examination without and with immunohistochemical staining, bacterial culture and PCR, in PPI-treated vs untreated patients.

Methods

Patients undergoing a gastric endoscopy for upper digestive symptoms were included. Gastric biopsy samples were obtained. The impact of taking PPI on the diagnostic performance of the different methods was studied. PCR results were confirmed by sequencing the glmM gene.

Results

A total of 497 patients were included, of whom 192 were H. pylori positive. Fifty-two patients received PPIs during the 14 days preceding the endoscopy while 140 did not. All methods had lower sensitivity than PCR, in all cases (PPI treatment or not). PPI use did not change significantly the methods' sensitivities.

Conclusion

The PCR method showed the best performance for the detection of H. pylori in gastric samples, whether or not patients received previous PPI treatment. This diagnosis test could become a new gold-standard test, especially in patients undergoing PPI treatment.

Multiscale positive feedbacks contribute to unidirectional gastric disease progression induced by helicobacter pylori infection

Background

Helicobacter Pylori (HP) is the most common risk factor for gastric cancer. Nearly half the world’s population is infected with HP, but only a small percentage of those develop significant pathology. The bacteria itself does not directly cause cancer; rather it promotes an environment that is conducive to tumor formation. Upon infection, HP induces transcriptional changes in the host, leading to enhanced proliferation and host immune response. In addition, HP causes direct damage to gastric epithelial cells.

Results

We present a multiscale mechanistic model of HP induced changes. The model includes four modules representing the host transcriptional changes in response to infection, gastric atrophy, the Hedgehog pathway response, and the restriction point that controls cell cycle. This model was able to recapture a number of literature reported observations and was used as an “in silico” representation of the biological system for further analysis. Dynamical analysis of the model revealed that HP might induce the activation of multiple interplayed positive feedbacks, which in turn might result in a “ratchet ladder” system that promotes a unidirectional progression of gastric disease.

Conclusions

The current multiscale model is able to recapitulate the observed experimental features of HP host interactions and provides dynamic insights on the epidemiologically observed heterogeneity in disease progression. This model provides a solid framework that can be further expanded and validated to include additional experimental evidence, to understand the complex multi-pathway interactions characterizing HP infection, and to design novel treatment protocols for HP induced diseases.

Electronic supplementary material

The online version of this article (10.1186/s12918-017-0497-y) contains supplementary material, which is available to authorized users.

Helicobacter pylori Infection Increases Frequency of PDCA-1(+) (CD317(+)) B-cell Subsets

BACKGROUND AND AIMS

As a newly discovered B-cell subset, PDCA-1(+) B cells have been shown to participate in the immune clearance of invading pathogens. The prominence of PDCA-1(+) B cell immunity in the pathogenesis of Helicobacter pylori infection prompted us to explore the potential role of this subset in gastric H. pylori infection.

METHODS

H. pylori infection was determined by (14)C-urea breath test and Western blot. The frequency of the different sub-compartments of PDCA-1(+) B cells and their relation to serum cytokines was determined in 33 H. pylori-infected and 14 uninfected patients and in 12 healthy controls (HC).

RESULTS

In comparison to uninfected individuals, there was a significantly increased frequency of PDCA-1(+) B cells, PDCA-1(+)IgM(+) B cells, CD93(+)PDCA-1(+) B cells, CD93(+)PDCA-1(+)IgM(+) B cells, CD137(+)PDCA-1(+) B cells and CD137(+)PDCA-1(+)IgM(+) B cells were detected in patients with H. pylori infection, corresponding to increased levels of serum IFN-α and IgM in this group. Compared with H. pylori-positive (HP(+)) chronic non-atrophic gastritis patients, a larger proportion of PDCA-1(+) B cells, CD93(+)PDCA-1(+) B cells and CD137(+)PDCA-1(+) B cells were observed in HP(+) patients suffering from atrophic gastritis or HP(+) peptic ulcers.

CONCLUSIONS

The frequency of the PDCA-1(+) B cell compartment is increased during H. pylori infection. Our data support the potential role of this B-cell subset in the pathogenesis of H. pylori-dependent gastritis.

Significant Reduction in Helicobacter pylori Load in Humans with Non-viable Lactobacillus reuteri DSM17648: A Pilot Study

Reducing the amount of Helicobacter pylori in the stomach by selective bacterial-bacterial cell interaction was sought as an effective and novel method for combating the stomach pathogen. Lactobacillus reuteri DSM17648 was identified as a highly specific binding antagonist to H. pylori among more than 700 wild-type strains of Lactobacillus species. Applying a stringent screening procedure, the strain DSM17648 was identified as selective binder to H. pylori cells under in vivo gastric conditions. The strain DSM17648 co-aggregates the pathogen in vivo and in vitro. The specific co-aggregation occurs between Lact. reuteri DSM17648 and different H. pylori strains and serotypes, as well as H. heilmannii, but not with Campylobacter jejuni or other commensal oral and intestinal bacteria. Lact. reuteri DSM17648 was shown in a proof-of-concept single-blinded, randomized, placebo-controlled pilot study to significantly reduce the load of H. pylori in healthy yet infected adults. Reducing the amount of H. pylori in the stomach by selective bacterial-bacterial cell interaction might be an effective and novel method for combating the stomach pathogen. Lact. reuteri DSM17648 might prove useful as an adhesion blocker in antibiotic-free H. pylori therapies.

What is the impact of Helicobacter pylori density on the success of eradication therapy: a clinico-histopathological study

BACKGROUND AND OBJECTIVE

To investigate the presence of any possible association between H. pylori density in the stomach and the efficacy of triple (lansoprazole 30 mg b.i.d., clarithromycin 500 mg b.i.d. and amoxicillin 1g b.i.d. for 14 days) and bismuth-containing quadruple (colloidal bismuth subcitrate 300 mg q.i.d., lansoprazole 30 mg b.i.d., tetracycline 500 mg q.i.d. and metronidazole 500 mg t.i.d. for 14 days) eradication therapies.

METHODS

Eighty-five cases with H. pylori infection (proved by rapid urease test and histology) were studied. In each case, the density of H. pylori colonization was graded according to the updated Sydney classification. H. pylori eradication was determined via the (14)C-Urea breath test performed 4 weeks after the end of therapy.

RESULTS

The eradication rate of H. pylori was 50% (30 out of 60) in the triple therapy and 92% (23 of 25) in the quadruple therapy group. In the triple therapy group, the eradication rate of H. pylori decreased as the initial density of H. pylori increased (density of H. pylori: 1, 58.3%; 2, 54.5%; 3, 52.4%; 4, 38.5%; 5, 33.3%). In two cases with eradication failure after quadruple therapy, the grades of bacterial density were 1 and 3.

CONCLUSION

H. pylori density, as assessed by histological grading, may predict the usefulness of triple therapy. The higher the H. pylori density, the less effective triple therapy will be at successful eradication of H. pylori. Quadruple therapy does not seem to be negatively affected by bacterial density.

The association of interleukin-18 promoter polymorphisms and serum levels with duodenal ulcer, and their correlations with bacterial CagA and VacA virulence factors

BACKGROUND

We analyzed the impact of interleukin (IL)-18 promoter polymorphisms on IL-18 serum levels in Helicobacter pylori-infected duodenal ulcer (DU) patients and healthy asymptomatic (AS) carriers. We also aimed to determine the association of the H. pylori virulence factors CagA and VacA antibodies with serum concentrations of IL-18 in order to elucidate any correlation between them.

METHODS

Three groups of patients were enrolled: DU patients (67 individuals), AS carriers (48 individuals), and H. pylori-negative subjects (26 individuals). Serum concentrations of IL-18 were determined by ELISA. Patient sera were tested by Western blot method to determine the presence of serum antibodies to bacterial CagA and VacA. Genotyping of IL-18 promoter polymorphisms at positions - 137G/C and - 607C/A were performed by allele-specific primer PCR protocol.

RESULTS

Our study revealed that serum IL-18 levels are positively influenced by CagA-positive H. pylori strains, so that maximum levels of IL-18 were detected in DU patients with the CagA(+) phenotype, regardless of the presence of the anti-VacA antibody. Regarding IL-18 promoter polymorphisms, the AA genotype and A allele at position - 607C/A were found to be significantly lower in DU patients than in AS carriers and H. pylori-negative subjects (p = 0.032 and 0.043, respectively).

CONCLUSIONS

The IL-18 - 607C variant was associated with higher levels of serum IL-18 and an increased risk of DU. Moreover, our findings indicated that serum concentrations of IL-18 were influenced by CagA factor, irrespective of the VacA status, suggesting that high levels of IL-18 in CagA-positive subjects predisposes to susceptibility to DU.

Usefulness of a Helicobacter pylori stool antigen test for diagnosing H. pylori infected C57BL/6 mice

Among several diagnostic tests, a Helicobacter pylori stool antigen (HpSA) test may offer a useful noninvasive method for diagnosing infection without sacrificing animals. In this study, male C57BL/6 mice (n=6) were infected with H. pylori ATCC 49503 (1×10(8) CFU/mouse) by intragastric inoculation three times at 2-day intervals, and H. pylori infected stool specimens were collected 1, 3, 5, 7, 14, 21 days after infection to assess reliability of the HpSA test. Five of six specimens were positive at 5-21 days after infection, and the sensitivity of the HpSA test was 83.33%. The presence of H. pylori infection was confirmed by the rapid urease test and genomic DNA polymerase chain reaction (PCR), and showed the same results as the HpSA. However, the rapid urease test and genomic DNA PCR are invasive tests and require animal sacrifice to detect H. pylori in gastric biopsy samples. We suggest that an HpSA test kit would be useful and effective for monitoring H. pylori in various laboratory animals, as H. pylori can be easily monitored without sacrificing animals.

Circulating levels of interleukin (IL)-12 and IL-13 in Helicobacter pylori-infected patients, and their associations with bacterial CagA and VacA virulence factors

OBJECTIVE

The aim of this study was to determine the association of the Helicobacter pylori virulence factors, cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) antibodies, with serum levels of interleukin (IL)-12 and IL-13 in H. pylori-infected duodenal ulcer (DU) patients and H. pylori-infected asymptomatic (AS) carriers in order to elucidate any correlation between them.

METHODS

A total of 67 DU patients, 48 AS individuals, and 26 healthy H. pylori-negative subjects were enrolled in this study. Serum concentrations of IL-12 and IL-13 were determined by enzyme-linked immunosorbent assay (ELISA) method. Patient sera were tested by Western blot method to determine the presence of serum antibodies to bacterial virulence antigens p120 (CagA) and p95 (VacA). Serum concentrations of IL-12 and IL-13 were compared in 9 groups, including 4 AS phenotypes (CagA⁺VacA⁺, CagA⁺VacA⁻, CagA⁻VacA⁺, CagA⁻VacA⁻), 4 DU phenotypes (CagA⁺VacA⁺, CagA⁺VacA⁻, CagA⁻VacA⁺, CagA⁻VacA⁻), and 1 control group.

RESULTS

The results revealed that DU patients positive for CagA, independent of the anti-VacA antibody status, showed drastically elevated levels of IL-12 (251 ± 43 pg/ml) when compared with the other groups (p = 0.0001). No significant difference was found between groups regarding levels of IL-13 (p > 0.05).

CONCLUSIONS

Our findings indicate that in the DU group, the serum concentrations of IL-12 but not of IL-13 were influenced by bacterial CagA, independent of the VacA status, suggesting that high IL-12 levels may contribute to susceptibility to DU in CagA-positive individuals. These findings could possibly be considered to improve the predictive or prognostic values of inflammatory cytokines for DU, and also to design possible novel therapeutic approaches.