Which hypothesis was tested by warren and marshall during their research involving helicobacter pylori bacteria and stomach ulcers?

The hypothesis was that the cause of stomach-ulcers is Helicobacter pylori and not spicy food. Marshall and Warren were able to prove that the main cause of peptic ulcers was the bacterium Helicobacter pylori instead of the spicy foods and stress, which physicians believed were the main causes of peptic ulcers at the time.