The Efficacy of 10-day and 14-day Bismuth-based Quadruple Therapy in First-line H. Pylori Eradication

Helicobacter pylori (H. pylori) infection is the major cause of gastritis, peptic ulcer disease, and gastric cancer in adults. Bismuth-based quadruple therapy is recommended by a recent review to be the first-line treatment for H. pylori eradication, replacing clarithromycin-based triple therapy. It is because the eradication rates of triple therapy in adults have declined due to increasing clarithromycin resistance. The best regimen for H. pylori eradication should be the one which succeeds on the first attempt. However, the effectiveness and the optimal duration of bismuth-based quadruple therapy for first-line H. pylori eradication in adults are unknown. Moreover, the impacts on gut microbiota after H. pylori eradication should be concerned; for example, bismuth-based quadruple therapy decreases F. prausnitzii richness. The transient perturbation of the gut microbiota after H. pylori eradication were restored at 8 weeks and one year in subjects receiving clarithromycin-based triple therapy but not fully recovered in those receiving bismuth-based quadruple therapy. Therefore, the important issues are that the short-term and long-term gut dysbiosis and the recovery of gut F. prausnitzii depletion in H. pylori-infected adult patients after bismuth-based quadruple therapy. It is also uncertain the role of irreversible gut dysbiosis even though H. pylori is eradicated in gastric persist inflammation and progress to cancer, and whether probiotics could be helpful in recovering gut dysbiosis. The therapeutic strategy to eradicate H. pylori infection is based on antibiotics; however, this strategy not only increases drug resistant rates of the pathogen but also shapes the gut microbiota. The investigators hypothesize that bismuth-based quadruple therapy could be an optimal regimen for first-line H. pylori eradication in the era of increasing clarithromycin resistance; moreover, gut dysbiosis could be reversed after bismuth-based quadruple therapy. Furthermore, the efficacy of the10-day course is not inferior to that of the 14-day course in H. pylori eradication. The investigators also hypothesize that probiotics could restore gastric or gut dysbiosis, especially gut F. prausnitzii depletion.