Antibiotic resistance is the major cause of treatment failure for H. pylori and the rates of antibiotic resistance in H. pylori vary in different parts of the world. Reliable information on the prevalence of antibiotic resistance is crucial when choosing the best treatment regimen for each patient. In Thailand, we conducted a nationwide survey of antibiotic-resistant strains of H. pylori. The prevalence of antibiotic resistance in H. pylori was 7.2%, H. pylori as a gastric pathogen was refuted by the majority of GI opinion leaders at the time and research efforts took a decade before H. pylori became fully recognized as gastric pathogen by the medical community. The recognition of its role in peptic ulcer disease fi rst and in gastric neoplasia later changed the medical practice over time. The fi rst step of evidence was the proof of concept for H. pylori as the cause of chronic active gastritis. The fulfi llment of Koch’s postulate was achieved by B. Marshall when he underwent his courageous self-inoculation experiment. Selfi nfection, and accidental infection with H. pylori was experienced and reported by others and was extended to healthy individuals thereafter for research purpose. The human ‘H. pylori challenge’ model has more recently been used for the intention of vaccine development. The clinical most important step to date has been to drive the notion from peptic ulcer disease as an ‘acid disease’ to an infection triggered immunopathogenetic disease. Mechanisms initiated and maintained by H. pylori in peptic ulcer pathogenesis have been elucidated in great detail. Experimental evidence was successfully complemented by clinical trials with the demonstration of a defi nitive cure of peptic ulcer disease by H. pylori eradication. The secular achievement of peptic ulcer cure conferred the Nobel award to Warren and Marshal. The role of H. pylori in gastric carcinogenesis has fi rst been addressed by epidemiological fi ndings that indicated an increased risk for gastric cancer in H. pylori infected subjects. With the application of more rigorous methods of epidemiology, the reported risk initially estimated to be 3-fold to 6-fold has been set to 20-fold. The role of H. pylori in gastric carcinogenesis is studied through histological evolutive events in humans and animal experiments. Direct oncogenic effects of H. pylori have been shown in several experimental studies including tumor cell lines. Bacterial, host and environmental factors interact in the gastric carcinogenesis. Trials of gastric cancer prevention by H. pylori eradication have been successful. However the translation into meaningful strategies for gastric cancer prevention have only sporadically taken place so far. H. pylori and the induction of systemic diseases Studies on H. pylori have opened many clinical areas for consideration of the bacterium as a trigger for systemic diseases. The scientifi c debates in this area are ongoing. The role of H. pylori in Idiopathic Thrombocytopenic Purpura and Sideropenic Anemia after exclusion of other causes is the best established so far. The theory of the ‘good’ gastric pathogen One of the most persisting arguments against prevention of H. pylori related diseases is the claim for a benefi cial role of H. pylori in GERD and esophageal adenocarcinoma or the protection against atopic diseases such as asthma, or even against obesity. This is a grey zone we need to master with attentive and optimally planned studies. Guidelines—a useful exercise The discussions and debates pro and contra H. pylori therapy, the limitation and extension of indications for therapy has required to set up guidelines. The European H. pylori Study Group was fi rst to embark in the Maastricht consensus report, and was followed by a series of Asian–Pacifi c and Japanese consensus meeting that have adopted rigorous methodologies to setup management guidelines. The Maastricht concept with the last update in 2010 reconciles most of the divergent aspects in management and opens areas for clinical research activities. The future on H. pylori research is bright with many more aspects to be investigated. The future will focus on deepening our understanding of molecular mechanisms of the infection and on factors determining H. pylori related diseases. Ultimately it is a mission to invest in the development of a vaccine with the aim to provide a healthy H. pylori free stomach for our future generations.