Helicobacter pylori colonized the stomach since an immemorial time. More than 160 years before in 1852, it was reported that there is ammonia in the stomach. In 1930s, it was reported that the ammonia demonstrated in the stomach is due to the effect of a urease enzyme. In 1960s, it was confirmed that urease activity in the stomach is not a property of the stomach but it is due to the activity of a bacterium in the stomach. Early in 1980s, it was clearly emphasized that the ammonia detected in the stomach is not toxic or not in toxic amounts but it is even useful. In 1985, H. pylorus was rediscovered or as claimed by two Australian physicians; “I got it, a bacterium surviving in the stomach”. They accused it for causing gastric ulcers and cancer; hence, they started the antibiotic violence against this stomach bacterium in 1986 . Via personal communications between 2002 and 2003, some scientific research centers in the west and the author expressed to each other their inconvenience about the story claimed by the two Australian doctors; hence, a research investigation team and the author started an extensive work on the confusing subject of H. pylori .