Optimal First-Line Treatment for Helicobacter pylori Infection: Recent Strategies

Leading Paediatric Infectious Diseases-Current Trends, Gaps, and Future Prospects in Oral Pharmacotherapeutic Interventions

Paediatric infectious diseases contribute significantly to global health challenges. Conventional therapeutic interventions are not always suitable for children, as they are regularly accompanied with long-standing disadvantages that negatively impact efficacy, thus necessitating the need for effective and child-friendly pharmacotherapeutic interventions. Recent advancements in drug delivery technologies, particularly oral formulations, have shown tremendous progress in enhancing the effectiveness of paediatric medicines. Generally, these delivery methods target, and address challenges associated with palatability, dosing accuracy, stability, bioavailability, patient compliance, and caregiver convenience, which are important factors that can influence successful treatment outcomes in children. Some of the emerging trends include moving away from creating liquid delivery systems to developing oral solid formulations, with the most explored being orodispersible tablets, multiparticulate dosage forms using film-coating technologies, and chewable drug products. Other ongoing innovations include gastro-retentive, 3D-printed, nipple-shield, milk-based, and nanoparticulate (e.g., lipid-, polymeric-based templates) drug delivery systems, possessing the potential to improve therapeutic effectiveness, age appropriateness, pharmacokinetics, and safety profiles as they relate to the paediatric population. This manuscript therefore highlights the evolving landscape of oral pharmacotherapeutic interventions for leading paediatric infectious diseases, crediting the role of innovative drug delivery technologies. By focusing on the current trends, pointing out gaps, and identifying future possibilities, this review aims to contribute towards ongoing efforts directed at improving paediatric health outcomes associated with the management of these infectious ailments through accessible and efficacious drug treatments.

Efficacy comparison of 7- and 14-day P-CAB based bismuth-containing quadruple regimen with PPI based bismuth-containing quadruple regimen for Helicobacter pylori infection: rationale and design of an open-label, multicenter, randomized controlled trial

BACKGROUND

Owing to its strong acid inhibition, potassium-competitive acid blocker (P-CAB) based regimens for Helicobacter pylori (H. pylori) eradication are expected to offer clinical advantages over proton pump inhibitor (PPI) based regimens. This study aims to compare the efficacy and adverse effects of a 7-day and a 14-day P-CAB-based bismuth-containing quadruple regimen (PC-BMT) with those of a 14-day PPI-based bismuth-containing quadruple regimen (P-BMT) in patients with high clarithromycin resistance.

METHODS

This randomized multicenter controlled clinical trial will be performed at five teaching hospitals in Korea. Patients with H. pylori infection who are naive to treatment will be randomized into one of three regimens: 7-day or 14-day PC-BMT (tegoprazan 50 mg BID, bismuth subcitrate 300 mg QID, metronidazole 500 mg TID, and tetracycline 500 mg QID) or 14-day P-BMT. The eradication rate, treatment-related adverse events, and drug compliance will be evaluated and compared among the three groups. Antibiotic resistance testing by culture will be conducted during the trial, and these data will be used to interpret the results. A total of 366 patients will be randomized to receive 7-day PC-BMT (n = 122), 14-day PC-BMT (n = 122), or 14-day P-BMT (n = 122). The H. pylori eradication rates in the PC-BMT and P-BMT groups will be compared using intention-to-treat and per-protocol analyses.

DISCUSSION

This study will demonstrate that the 7-day or 14-day PC-BMT is well tolerated and achieve similar eradication rates to those of 14-day P-BMT. Additionally, the 7-day PC-BMT will show fewer treatment-related adverse effects and higher drug compliance, owing to its reduced treatment duration.

TRIAL REGISTRATION

Korean Clinical Research Information Service registry, KCT0007444. Registered on 28 June 2022, https://cris.nih.go.kr/cris/index/index.do .

Efficacy and Safety of Potassium-Competitive Acid Blockers Versus Proton Pump Inhibitors as Helicobacter pylori Eradication Therapy: A Meta-Analysis of Randomized Clinical Trials

Helicobacter pylori is a gram-negative bacterium that chronically infects the gastric epithelium. Potassium-competitive acid blockers (P-CABs) are a promising alternative, being more potent than standard proton pump inhibitors (PPIs). The meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria were randomized controlled trials (RCTs) comparing P-CAB and PPI-based therapy, confirmed H. pylori infection, and measured eradication rates after at least four weeks. Subgroup analyses were conducted based on therapy type and trial location. Quality assessment used the Cochrane risk-of-bias tool, RoB 2.0, and statistical analysis was performed using ReviewManager (RevMan) 5.4 (2020; The Cochrane Collaboration, London, United Kingdom). A p-value of <0.05 is considered statistically significant. In the intention-to-treat (ITT) analysis, P-CABs demonstrated superior overall efficacy, consistently observed in the first-line treatment subgroup. However, no significant difference was found in the subgroup receiving salvage therapy. Another ITT subgroup analyzed the impact of geographical location, favoring P-CABs in the overall study population and the Japanese subgroup. However, no statistically significant differences were found in the subgroups of other countries. In the PPA, P-CABs showed superior efficacy overall, consistently seen in the first-line treatment subgroup. However, no significant difference was found in the subgroup receiving salvage eradication therapy. Another PPA subgroup analysis considered the geographical impact on eradication rates, revealing P-CABs as superior to PPIs in the overall study population and the Japanese subgroup, but not in other countries. No significant adverse event outcomes were observed. P-CAB-based triple therapy is more effective than PPI-based triple therapy as the primary treatment for H. pylori eradication, particularly in Japanese patients. Nevertheless, regarding salvage therapy, both treatments show comparable efficacy. Additionally, the tolerability of P-CAB-based and PPI-based triple therapy is similar, with a similar occurrence of adverse events.

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.

Tailored therapy for Helicobacter pylori eradication: A systematic review and meta-analysis

Background: Due to an increase in drug resistance, the eradication rate of H. pylori with empirical therapy has declined. Tailored therapy has been proposed as an alternative to standard empirical treatments. The necessity of personalized eradication therapy remains unclear. The aim of this study was to determine whether tailored therapy is superior to empirical therapy for H. pylori infection. Methods: We searched for eligible randomized controlled trials in the PubMed, Embase (Ovid), Wanfang, and Cochrane Central Register of Controlled Trials databases up to 10 December 2021. A random effects model comparing pooled relative risks (RRs) with 95% confidence intervals (CIs) was applied in the meta-analysis. Results: Twenty-one studies were included in the meta-analysis. In the first-line treatment, tailored therapy was more effective than empirical therapy (RR, 1.14 [95% CI, 1.08-1.21], I2 = 72.2%). In the second-line therapy setting, the results did not reveal significant differences between the two treatments (RR, 1.05 [95% CI, 0.84-1.30], I2 = 80.6%). A similar result was observed in mixed second- and third-line treatments (RR, 1.03 [95% CI, 0.96-1.11], I2 = 0.0%). Regarding adverse events, no significant differences were found between the two treatments (RR, 0.90 [95% CI, 0.80-1.01], I2 = 35.7%). Most of the results were highly heterogeneous. Conclusion: A tailored approach might provide a better eradication rate than empirical methods in first-line treatment. There might be no obvious advantage in second-line or mixed second- and third-line treatments third-line treatment. Due to the high heterogeneity, the results should be interpreted with caution. Further clinical studies are needed and justified.

miR-30c Increases the Intracellular Survival of Helicobacter pylori by Inhibiting Autophagy

Persistent Helicobacter pylori infection causes a variety of gastrointestinal diseases and even gastric cancer. H. pylori invades gastric epithelial cells to survive and proliferate, which is one of the key factors in persistent colonization. A Published study has confirmed that cells can eliminate intracellular H. pylori through xenophagy to maintain intracellular balance. However, a growing body of evidences indicate that H. pylori can inhibit xenophagy by miRNA through regulating the expression of key autophagy-related genes. Through western blot analysis, mRFP-GFP-LC3 transfection assay, and transmission electron microscopy, we found that H. pylori infection obstructed autophagy flux degradation stage in GES-1 cell lines. Gentamicin protection assay confirmed that inhibit xenophagy is benefit for intracellular H. pylori survive. miR-30c-1-3p and miR-30c-5p were upregulated in GES-1 cell lines after infecting with H. pylori, resulting in the negative regulation on xenophagy. Further studies through bioinformatics analysis and dual-luciferase reporter assays confirmed that ATG14 and ULK1 were the target genes of miR-30c-1-3p and that ATG12 was the target gene of miR-30c-5p. The overexpression of miR-30c-1-3p and miR-30c-5p reduces the expression of ATG14, ULK1, and ATG12 at mRNA level and also decreased intracellular H. pylori elimination in GES-1 cells. The above results suggested that the inhibition on xenophagy by miR-30c-1-3p and miR-30c-5p through ATG14, ULK1, and ATG12 targeting benefitted intracellular H. pylori in the evasion of xenophagy clearance.

Efficacy and safety of potassium-competitive acid blockers versus proton pump inhibitors as Helicobacter pylori eradication therapy: a meta-analysis of randomized clinical trials

BACKGROUND AND AIMS

Potassium-Competitive Acid Blockers (P-CABs) have been used in Helicobacter pylori (H. pylori) eradication therapies in recent years. However, the efficacy and safety of P-CABs compared to Proton-Pump Inhibitors (PPIs) in this setting remain controversial.

METHODS

The efficacy and safety of P-CABs and PPIs for H. pylori eradication were compared in a meta-analysis based on a systematic literature search of major electronic databases for relevant Randomized Controlled Trials (RCTs).

RESULTS

Seven studies and 1,168 patients were included. The pooled eradication rate determined by Intention-To-Treat (ITT) analysis was 90.2% for P-CAB-based and 75.5% for PPI-based triple therapy (pooled RR [95% CI] = 1.17 [1.08-1.28], p < 0.001). The Per-Protocol (PP) analysis also demonstrated significant superiority of P-CABs (pooled eradication rate = 92.4% vs. 77.8%; pooled RR [95% CI] = 1.14 [1.03-1.26], p < 0.01). In a subgroup evaluation, P-CABs were significantly better than PPIs as a first-line eradication therapy, in both the ITT analysis (pooled eradication rate = 91.8% vs. 76.4%; pooled RR [95% CI] = 1.18 [1.10-1.28], p < 0.0001) and the PP analysis (pooled eradication rate = 93.0% vs. 78.6%; pooled RR [95% CI] = 1.13 [1.02-1.26], p < 0.05). However, P-CABs were not superior to PPIs when administered as salvage therapy, as determined in the ITT (75.0% vs. 66.0%, pooled RR [95% CI] = 1.11 [0.69-1.78], p = 0.66) and PP (85.7% vs. 70.0%, pooled RR [95% CI] = 1.20 [0.82-1.75], p = 0.34) analyses. In a subgroup analysis limited to Japanese patients, both the ITT analysis (pooled eradication rate = 89.6% vs. 73.9%; RR [95% CI] = 1.21 [1.14-1.29], p < 0.01) and the PP analysis (pooled eradication rate = 92.0% vs. 75.7%; RR [95% CI] = 1.18 [1.06-1.32], p < 0.01) showed that P-CABs were significantly superior compared to PPIs as triple eradication therapy. However, in the subgroup analysis of patients from other countries, there was no significant difference in either the ITT analysis (pooled eradication rate = 93.8% vs. 85.2%; RR [95% CI] = 1.10 [0.99-1.22], p = 0.07) or PP analysis (pooled eradication rate = 95.0% vs. 90.8%; RR [95% CI] = 1.05 [0.98-1.14], p = 0.17). The incidence of adverse events associated with the two regimens did not significantly differ (P-CABs vs. PPIs: 33.6% vs. 40.0%; RR [95% CI] = 0.84 [0.71‒1.00], p = 0.05). The incidence of serious adverse events and dropout rate due to adverse events also did not differ (p = 0.44 and p = 0.67, respectively).

CONCLUSIONS

The efficacy of P-CAB-based triple therapy is superior to that of PPI-based triple therapy as a first-line approach to H. pylori eradication, particularly in Japanese patients. As salvage therapy, the efficacy of the two treatments did not significantly differ. The tolerability of P-CAB-based and PPI-based triple therapy was comparable, as was the incidence of adverse events.

Pharmacokinetic Interactions between Tegoprazan and Metronidazole/Tetracycline/Bismuth and Safety Assessment in Healthy Korean Male Subjects

PURPOSE

Tegoprazan is a potassium-competitive acid blocker used for gastric acid suppression, which may be used with Helicobacter pylori eradication therapies. The goal of this study was to evaluate the pharmacokinetic interaction between tegoprazan and triple-antibiotic therapy containing metronidazole, tetracycline, and bismuth.

METHODS

An open-label, 2-cohort, randomized, multiple-dose, crossover study was conducted in healthy subjects. In cohort 1, tegoprazan (100 mg/d) was administered orally with or without triple-antibiotic therapy (1500 mg/d metronidazole, 2000 mg/d tetracycline, and 1200 mg/d bismuth) for 7 days in each period. In cohort 2, triple-antibiotic therapy was administered orally with or without tegoprazan for 7 days in each period. Pharmacokinetic blood samples were collected within 24 h after the last dose. Safety assessments were performed.

FINDINGS

Eleven cohort 1 subjects and ten cohort 2 subjects were included in the pharmacokinetic analysis. The AUC_τ and C_max at steady state geometric mean ratios (90% CIs) were 0.78 (0.73-0.83) and 0.75 (0.68-0.82) for tegoprazan; 0.77 (0.68-0.88) and 0.84 (0.72-0.98) for tegoprazan metabolite M1; 1.03 (0.98-1.08) and 1.08 (0.99-1.18) for metronidazole; 0.63 (0.56-0.70) and 0.64 (0.56-0.74) for tetracycline; and 1.55 (0.99-2.44) and 1.38 (0.72-2.66) for bismuth, respectively. All reported adverse events were mild.

IMPLICATIONS

Changes in the tegoprazan, tetracycline, and bismuth pharmacokinetic parameters were detected after concurrent administration. These changes were considered mainly due to the pharmacodynamic effect of tegoprazan. The adverse events were predictable and reported as frequent adverse events during triple-antibiotic therapy. There were no significant differences in safety or tolerability between quadruple therapy, including tegoprazan and triple-antibiotic therapy. ClinicalTrials.gov identifier: NCT04066257.

Best Helicobacter pylori Eradication Strategy in the Era of Antibiotic Resistance

Antibiotic resistance is the major reason for Helicobacter pylori treatment failure, and the increasing frequency of antibiotic resistance is a challenge for clinicians. Resistance to clarithromycin and metronidazole is a particular problem. The standard triple therapy (proton pump inhibitor, amoxicillin, and clarithromycin) is no longer appropriate as the first-line treatment in most areas. Recent guidelines for the treatment of H. pylori infection recommend a quadruple regimen (bismuth or non-bismuth) as the first-line therapy. This treatment strategy is effective for areas with high resistance to clarithromycin or metronidazole, but the resistance rate inevitably increases as a result of prolonged therapy with multiple antibiotics. Novel potassium-competitive acid blocker-based therapy may be effective, but the data are limited. Tailored therapy based on antimicrobial susceptibility test results is ideal. This review discussed the current important regimens for H. pylori treatment and the optimum H. pylori eradication strategy.

Personalized therapy for Helicobacter pylori: CYP2C19 genotype effect on first-line triple therapy

BACKGROUND

Triple therapy efficacy against Helicobacter pylori is low worldwide, and thus, alternatives must be sought to improve eradication. The aim of the present study was to determine CYP2C19 genetic polymorphism effect on H pylori eradication.

METHODS

A randomized, single-blinded clinical trial including 133 participants was carried out. H pylori infection was confirmed by histologic and microbiologic test. Antibiotic susceptibility to amoxicillin and clarithromycin was performed. CYP2C19 polymorphisms *1, *2, and *3 were analyzed by real-time PCR (Roche ®), and nested PCR for CYP2C19*17 polymorphisms. Participants were randomized into two groups for different H pylori therapies, one with standard omeprazole doses and another with omeprazole doses depending on CYP2C19 polymorphism. H pylori eradication was verified by stool antigen tests (Meridian ®).

RESULTS

The most common CYP2C19 polymorphism was *1/*1 in 54.9% of the participants followed by *17/*17 in 21.1%. Triple therapy efficacy with standard omeprazole doses versus personalized therapy based on CYP2C19 polymorphism by ITT analysis was 84% (95% CI: 0.73-0.91) vs 92.2% (95% CI: 0.82-0.97) (P = 0. 14), respectively. The efficacy by PP analysis was 92.1% (95% CI: 0.82-0.97) vs 100% (95% CI: 0.92-0.01) (P = 0.027), respectively.

CONCLUSIONS

The most frequent polymorphism was extensive PPI metabolizers (62.4%). Effectiveness of guided therapies by susceptibility test was good, yet they can be further improved by customized therapy based on CYP genotype. Therefore, high PPI (80 mg/d) doses are recommended for H pylori eradication therapies in Colombia. ClinicalTrials.gov ID: NCT03650543.

Evaluation of the efficacy and safety of the hybrid scheme for eradication therapy of Helicobacter pylori infection

The aim is to conduct a comprehensive comparative study of the efficacy and safety of the hybrid scheme of eradication therapy (ET) in patients with peptic ulcer of the stomach or duodenum associated with Helicobacter pylori. Materials and methods. In a prospective, randomized comparative study, 180 patients were divided into three equal groups of 60 people, depending on the prescribed 10-day ET regimen. Group 1 - the standard triple scheme (omeprazole, amoxicillin and clarithromycin); group 2 - four-component therapy with preparations of bismuth (omeprazole, tetracycline, metronidazole, bismuth tricalium dicitrate); group 3 - hybrid scheme (first 5 days: omeprazole and amoxicillin, the next 5 days: omeprazole, amoxicillin, clarithromycin, metronidazole). The effectiveness of ET was determined with the help of a breath test a month after the end of therapy. Adverse events were recorded by patients in specially developed diaries. Pharmacoeconomic analysis was carried out using the "cost-effectiveness" method with calculation of the CER coefficient. Results and discussion. The effectiveness of standard triple therapy was 73.3% (ITT), 75.9% (PP); four-component therapy with bismuth preparations - 78.3% (ITT), 82.4% (PP); hybrid scheme - 85% (ITT), 91% (PP). Hybrid therapy proved to be significantly more effective than standard triple therapy with a odds ratio (OR) of 3.25; 95% confidence interval (CI) 1.08-9.73 (p=0.043, χ2=4.75, p-level=0.029298). The incidence of adverse events with the use of triple, four-component and hybrid ET regimens was 15; 18.3 and 28.3% respectively. The OR of at least one adverse event in patients receiving a hybrid ET regimen compared with triple therapy was 2.24 (95% CI 0.91-5.53, p=0.0823, χ2=3.14, p-level=0.076394), and compared with the four-component therapy - 1.76 (95% CI 0.74-4.17, p=0.2804, χ2=1.68, p-level=0.194924). According to the results of the pharmacoeconomic analysis, the most profitable from an economic point of view was a hybrid ET scheme with a CER of 20.1. The conclusion. Hybrid therapy showed the greatest effectiveness in comparison with the triple and four-component ET regimens, however, the incidence of side effects in patients receiving the hybrid ET scheme was higher, although it remained within the acceptable level for use in clinical practice. Pharmacoeconomic analysis also showed the advisability of designating a hybrid ET scheme. The obtained data allow to draw a conclusion about the necessity of further study of the efficiency and safety of the hybrid ET scheme.

Efficacy and safety of the use of rebamipide in the scheme of triple eradication therapy of Helicobacter pylori infection: a prospective randomized comparative study

Purpose of the study. To evaluate the effectiveness and safety of the use of rebamipide as part of the triple eradication therapy (ET) scheme of Helicobacter pylori infection. Materials and methods. A prospective, randomized comparative study included 94 patients with uncomplicated H. pylori-associated stomach / duodenal ulcer. In the process of randomization, patients are divided into three groups depending on the intended therapy. The first group (n=36) received a classical triple scheme of the first-line ET (omeprazole 20 mg twice a day, amoxicillin 1000 mg twice a day, clarithromycin 500 mg twice a day) for 10 days. Patients of the second group (n=33) were assigned a classical triple scheme of ET with the inclusion of rebamipide (omeprazole 20 mg twice a day, amoxicillin 1000 mg twice a day, clarithromycin 500 mg twice a day, rebamipide 100 mg 3 times a day day) for 10 days. Patients of the third group (n=25) were assigned a classical triple scheme of ET with the inclusion of rebamipide (omeprazole 20 mg twice a day, amoxicillin 1000 mg twice a day, clarithromycin 500 mg twice a day, rebamipide 100 mg 3 times a day) in for 10 days, with the prolongation of the administration of rebamipide for the next 20 days. The effectiveness of ET was determined by the respiratory test after 6 weeks after the end of treatment. Adverse events were recorded by patients in specially developed diaries. All patients with gastric ulcer at the 6th week underwent a histological examination of the biopsy specimens of the antrum and the body of the stomach, assessing the inflammatory activity of the process on a point system in accordance with the updated Sydney system. Results and discussion. Efficiency of H. pylori eradication in the first group was 77.7% (ITT), 82.3% (PP), in the second group - 81.8% (ITT), 84.4% (PP), and in the third group - 84% (ITT), 87.5% (PP). The use of rebamipide in the triple ET regimen was associated with an increase in H. pylori eradication efficiency, both with simultaneous use with the scheme [odds ratio (OR) 1.16; 95% confidence interval (CI) 0.32-4.24], and with subsequent prolonged admission (OR 1.5, 95% CI 0.34-6.7). A somewhat more pronounced dynamics of the epithelization of erosive and ulcerative changes in the mucous membrane of the stomach and duodenum to the 21st and 28th days in the third group of patients was noted. The incidence of adverse events between the groups was comparable: 22.2% in the first group, 24.2% in the second group and 20% in the third group. In the pathomorphological evaluation of biopsy specimens of patients with gastric ulcer at the 6th week after the treatment, significant differences were revealed between the first and third groups in terms of the inflammatory activity in the antrum stomach (2±0.63 vs. 1.4±0.52; p=0,0399). The conclusion. The inclusion of rebamipide in the classical triple scheme of H. pylori ET increases the effectiveness of treatment and does not affect the safety profile. In the post-eradication period, it is advisable to continue the use of rebamipide to potentiate the repair of the gastric mucosa and regress the inflammatory processes.

Review: A Japanese population-based meta-analysis of vonoprazan versus PPI for Helicobacter pylori eradication therapy: Is superiority an illusion?

BACKGROUND

Vonoprazan (VPZ) is a novel acid suppressant that has been used in Helicobacter pylori (H. pylori) eradication therapies in recent years. However, the efficacy and safety of VPZ vs proton-pump inhibitor (PPI) in H. pylori eradication therapies remain controversial.

OBJECTIVE

To perform a meta-analysis in order to assess the efficacy and safety of VPZ vs PPI for H. pylori eradication.

MATERIALS AND METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched up to July 10, 2017, for relevant randomized controlled trials (RCTs) and nonrandomized clinical studies (NRCTs). The pooled eradication rate (ER) and pooled occurrence rates of adverse events were used to compare the efficacy and safety of VPZ - and PPI-containing regimens.

RESULT

A total of 14 studies with 14 636 patients were included in this meta-analysis. The results showed that the pooled ER of VPZ -containing regimens was much higher than that of PPI-containing regimens when used as first-line therapies. This difference was significant for both intention-to-treat (85.1% vs 68.0%, P < .00001) and per-protocol analyses (89.0% vs 74.2%, P < .00001). Moreover, subgroup analysis indicated significant superiority of VPZ in both patients with clarithromycin-resistant strains (81.5% vs 40.9%, P < .00001) and those with clarithromycin-susceptible strains (94.9% vs 89.6%, P = .006). However, VPZ did not show superiority to PPI as part of a second-line triple therapy based on both intention-to-treat (83.4% vs 82.0%, P = .79) and per-protocol analyses (89.3% vs 90.1%, P = .06). Finally, RCT subgroup analysis showed the safety of VPZ -containing regimens to be better than PPI-containing regimens (26.4% vs 33.3%, P = .008), whereas there was no significant difference in this regard for the NRCT subgroup analysis (5.7% vs 4.7%, P = .08).

CONCLUSIONS

The efficacy of VPZ is superior to PPI in first-line H. pylori triple eradication therapies but not in second-line therapies. The safety of VPZ -containing regimens appears to be equal or even superior to that of PPI. However, most reports included in this study had low levels of evidence. Hence, adequate and high-quality RCTs will be needed to support our results.

Antibiotic susceptibility, heteroresistance, and updated treatment strategies in Helicobacter pylori infection

In this review, we discuss the problem of antibiotic resistance, heteroresistance, the utility of cultures and antibiotic susceptibility tests in Helicobacter pylori (Hp) eradication, as well as the updated treatment strategies for this infection. The prevalence of antibiotic resistance is increasing all over the world, especially for metronidazole and clarithromycin, because of their heavy use in some geographical areas. Heteroresistance (simultaneous presence of both susceptible and resistant strains in different sites of a single stomach) is another important issue, as an isolate could be mistakenly considered susceptible if a single biopsy is used for antimicrobial tests. We also examined literature data regarding eradication success rates of culture-guided and empiric therapies. The empiric therapy and the one based on susceptibility testing, in Hp eradication, may depend on several factors such as concomitant diseases, the number of previous antibiotic treatments, differences in bacterial virulence in individuals with positive or negative cultures, together with local antibiotic resistance patterns in real-world settings. Updated treatment strategies in Hp infection presented in the guidelines of the Toronto Consensus Group (2016) are reported. These suggest to prolong eradication therapy up to 14 days, replacing the old triple therapy with a quadruple therapy based on proton pump inhibitor (PPI), bismuth, metronidazole, and tetracycline for most of the patients, or as an alternative quadruple therapy without bismuth, based on the use of PPI, amoxicillin, metronidazole, and clarithromycin. The new drug vonoprazan, a first-in-class potassium-competitive acid blocker recently approved in Japan, is also considered to be a promising solution for Hp eradication, even for clarithromycin-resistant strains. Furthermore, there is growing interest in finding new therapeutic strategies, such as the development of vaccines or the use of natural resources, including probiotics, plants, or nutraceuticals.

[Molecular genetic predictors of resistance to anti-Helicobacter pylori therapy]

In current clinical practice, there is no optimal empirical therapy for Helicobacter pylori (H. pylori) infection and there is a progressive decrease in the efficiency of classical eradication therapy (ET) regimens. The variability in the efficiency of ET in a specific patient is largely due to the heterogeneous molecular genetic mechanisms underlying the resistance of the microorganism to the components of the treatment regimens. The basis of the mechanisms for antibiotic resistance in H. pylori is mainly the point mutations in some genes, which determine alterations in the mechanisms of action of drugs, such as clarithromycin (domain V of 23S rRNA), metronidazole (rdxA, frxA), amoxicillin (pbp1A), tetracycline (16S rRNA), and levofloxacin (gyrA). The predictors of resistance to ET are also the CagA-negative status of the microorganism and the presence of the vacA s2 allele. There are a number of host genetic determinants (the CYP2C19 genotype (*1/*1, *1/*17, *17/*17) and the MDR1 3435 T/T genotype (in an Asian population)) that reduce the efficiency of ET, by altering the pharmacokinetics of proton pump inhibitors. In addition, the IL-1β-511 C/C polymorphism that affects gastric acid secretion is a predictor of the inefficiency of ET.