With the rising prevalence of antimicrobial resistance, the treatment success of standard triple therapy has recently declined to unacceptable levels (i.e., 80% or less) in most countries. Therefore, several treatment regimens have emerged to cure Helicobacter pylori (H. pylori) infection. Novel first-line anti-H. pylori therapies in 2011 include sequential therapy, concomitant quadruple therapy, hybrid (dual-concomitant) therapy and bismuth-containing quadruple therapy. After the failure of standard triple therapy, a bismuth-containing quadruple therapy comprising a proton pump inhibitor (PPI), bismuth, tetracycline and metronidazole can be employed as rescue treatment. Recently, triple therapy combining a PPI, levofloxacin and amoxicillin has been proposed as an alternative to the standard rescue therapy. This salvage regimen can achieve a higher eradication rate than bismuth-containing quadruple therapy in some regions and has less adverse effects. The best second-line therapy for patients who fail to eradicate H. pylori with first-line therapies containing clarithromycin, amoxicillin and metronidazole is unclear. However, a levofloxacin-based triple therapy is an accepted rescue treatment. Most guidelines suggest that patients requiring third-line therapy should be referred to a medical center and treated according to the antibiotic susceptibility test. Nonetheless, an empirical therapy (such as levofloxacin-based or furazolidone-based therapies) can be employed to terminate H. pylori infection if antimicrobial sensitivity data are unavailable.

Bismuth quadruple therapy for H. pylori eradication can lead to short-term dysbiosis of gut microbiota. The increase in Proteobacteria in gut microbiota may attribute to the development of adverse effects during bismuth quadruple therapy.

In this prospective cohort study, all gastric malignancies, including adenocarcinoma and lymphoma, developed in H. pylori-infected patients. The finding implies that H. pylori is a necessary cause of most gastric malignancies. Follow-up for H. pylori-infected patients who have intestinal metaplasia is indicated.

e With the rising prevalence of antimicrobial resistance, the failure rate of the standard triple therapy for Helicobacter pylori infection is increasing. Sequential therapy and concomitant therapy have been recommended to replace standard triple therapy for H. pylori eradication in regions with high clarithromycin resistance. The aim of this prospective, randomized, and controlled study was to simultaneously assess the efficacies of 10-day sequential and 7-day concomitant therapies versus a 7-day standard triple therapy for treating H. pylori infection. Consecutive H. pylori-infected subjects were randomly assigned to a 7-day standard triple therapy (pantoprazole, clarithromycin, and amoxicillin for 7 days), a 10-day sequential therapy (pantoprazole and amoxicillin for 5 days, followed by pantoprazole, clarithromycin, and metronidazole for a further 5 days), or a 7-day quadruple therapy (pantoprazole, clarithromycin, amoxicillin, and metronidazole for 7 days). H. pylori status was confirmed 6 weeks after therapy. Three hundred seven H. pylori-infected participants were randomized to receive triple (n ‫؍‬ 103), sequential (n ‫؍‬ 102), or concomitant (n ‫؍‬ 102) therapies. The eradication rates by an intention-to-treat analysis in the three treatment groups were 81.6% (95% confidence interval [CI], 74.1% to 89.0%), 89.2% (95% CI, 83.2% to 95.2%), and 94.1% (95% CI, 89.5% to 98.7%). The seven-day concomitant therapy had a higher eradication rate than did the 7-day triple therapy (difference, 12.5%; 95% CI, 3.7% to 21.3%). There were no significant differences in the eradication rates between the sequential and standard triple therapies. All three treatments exhibited similar frequencies of adverse events (8.7%, 8.8%, and 13.7%, respectively) and drug compliance (99.0%, 98.0%, and 100.0%, respectively). In conclusion, the seven-day concomitant therapy is superior to the 7-day standard triple therapy for H. pylori eradication. Additionally, it is less complex than the 10-day sequential therapy because the drugs are not changed halfway through the treatment course. (This study has been registered at ClinicalTrials.gov under registration no. NCT1769365.)