Nat Clin Pract Gastroenterol Hepatol. the SQT-only group. As our data did not reach statistical significance, larger trials are warranted. contamination.1,2 However, the eradication rate of this triple therapy has been decreasing because of increasing antibiotic resistance;3,4 in fact, it is now reported to be 80%.5 Sequential therapy is one of the promising alternative regimens to standard triple therapy. Early meta-analyses reported that this eradication rate of sequential therapy is usually 90%.6C8 Therefore, this regimen is currently recommended as the alternative first-line treatment for infection by European guidelines.9 However, a recent meta-analysis concluded that although this regimen appears to be superior to standard triple therapy for infection in Asian adults, its pooled efficacy is lower than what was reported in earlier European studies.10 Therefore, it remains controversial whether sequential therapy (SQT) could replace standard triple therapy in Asia. Adjuvant brokers to the eradication regimen have been constantly studied to improve the efficacy of eradication therapy.11 One of these adjuvants consists of a material that destroys biofilm since several studied demonstrated that forms biofilm that likely helps it survive around the gastric mucosa epithelium.12,13 Among several candidates for antibio-film therapeutic brokers, N-acetylcysteine (NAC) has received attention.5 NAC, a compound that has mucolytic and antioxidant functions, has been widely used for respiratory and otolaryngologic diseases. In a mouse model, NAC was reported to inhibit the growth of antibiotic resistance in patients with a history of multiple eradication failure.17 The key theoretical basis of sequential therapy is the effect of amoxicillin around the bacterial cell wall. Amoxicillin, which is usually administrated in the first half of the regimen, damages the cell wall to overcome the antibiotic ADX88178 resistance and increase the eradication rate by two mechanisms. First, the injured cell wall could help the other antibiotics penetrate the strain. Second, with damaged cell walls cannot develop an efflux channel for clarithromycin.18,19 Therefore, we hypothesized that this addition of NAC to the first half of sequential therapy could increase the eradication rate by destroying the biofilm and weakening the cell wall together with amoxicillin. To test this hypothesis, we performed a randomized open-labeled pilot study comparing the eradication rates of using sequential therapy with and without NAC. MATERIALS AND METHODS 1. Patients Between July 2013 and January 2014, patients with infection were enrolled in this randomized open-labeled pilot study at Seoul National University Bundang Rabbit Polyclonal to TDG Hospital in South Korea. contamination was defined based on the results of at least one of the following three assessments: (1) a positive 13C-urea breath test (UBT) results; (2) histological evidence of ADX88178 in the stomach by modified Giemsa staining; and (3) a positive rapid urease test (CLO test; Delta West, Bentley, Australia) result by gastric mucosal biopsy. Because there was a report that NAC administration induced gastric ulcers in rats, patients with active peptic ulcer disease were excluded.20 Patients with a history of ADX88178 the use of PPIs, histamine-2 receptor antagonists, or antibiotics within the previous 2 months were also excluded. All patients were provided informed consent and this study was approved by the Institutional Review Board of Seoul National University Bundang Hospital (IRB number: B-1304/198-005). 2. Study design Patients were randomly assigned to the SQT-only or SQT+NAC group using a computer-generated table in blocks of four. The SQT-only.