Scanning electron Micrograph of Helicopterbacter pylori - as already mentioned this bacteria is found in the stomach lining and can increase the chances of stomach cancer (brown cells in photo) along with stomach ulcers.
Photograph by Martin Oeggerli, with support from School of Life Sciences, FHNW
(Source)
My favorite story about H. Pylori is the one about it’s discoverer. It’s as follows:
Helicobacter pylori was first discovered in the stomachs of patients with gastritis and stomach ulcers in 1982 by Dr. Barry Marshall and Dr. Robin Warren. At the time, the conventional thinking was that no bacterium could live in the stomach, as the stomach produced similar strength acid to that of a car battery. Marshall and Warren rewrote the textbooks with reference to what causes gastritis and gastric ulcers. In recognition of their discovery, they were awarded the 2005 Nobel Prize in Physiology or Medicine.
After many unsuccessful attempts at culturing the bacteria from the stomach, they finally succeeded in culturing and visualizing colonies in 1982, when they unintentionally left their Petri dishes incubating for 5 days over the Easter weekend. In their original paper, Warren and Marshall contended that most stomach ulcers and gastritis were caused by infection by this bacterium and not by stress or spicy food, as had been assumed before.
Although there was some skepticism initially, within several years numerous research groups verified the association of H. pylori with gastritis and ulcers. To demonstrate H. pylori caused gastritis and was not merely a bystander, Marshall drank a beaker of H. pylori culture. He became ill with nausea and vomiting several days later. An endoscopy ten days after inoculation revealed signs of gastritis and the presence of H. pylori. These results suggested H. pylori was the causative agent of gastritis. Marshall and Warren went on to demonstrate that antibiotics are effective in the treatment of many cases of gastritis. In 1994, the NIH published an opinion stating most recurrent duodenal and gastric ulcers were caused by H. pylori, and recommended antibiotics be included in the treatment regimen.