in Human Stomach: The Inconsistencies in Clinical Outcomes and the Probable Causes.

Pathogenic potentials of the gastric pathogen, , have been proposed, evaluated, and confirmed by many laboratories for nearly 4 decades since its serendipitous discovery in 1983 by Barry James Marshall and John Robin Warren. is the first bacterium to be categorized as a definite carcinogen by the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO). Half of the world's population carries , which may be responsible for severe gastric diseases like peptic ulcer and gastric cancer.