Miniature human stomachs have been created from stem cells which could be used to study gastric diseases and develop new treatments in future.
The 3mm-wide hollow "organoids" have a complex 3D structure and are lined with various kinds of functioning cells mimicking those of a real stomach.
In tests, scientists used the tiny stomachs to study infection by Helicobacter pylori, the bacteria linked to peptic ulcers and stomach cancer.
The organoids potentially offer a better way to study human stomach diseases and drug treatments than animals, whose gut physiology is unlike that of humans.
Lead researcher Dr James Wells, from Cincinnati Children's Hospital Medical Center in the US, said: "The breakthrough that we've achieved is we can now generate fully in a petri dish stomach tissue.
"This is important because in the case of people with stomach disease like peptic ulcer disease, or ultimately people who get stomach cancer, we can now study the very early stages of that disease, and then use this as a research tool to try and identify therapies to prevent stomach disease.
"Up until now there's been no good way to study stomach diseases in humans. Human stomach is very different than the stomach of other animals.
"The different cells and their structure and arrangement in our stomach tissues in a dish were virtually identical to that which you would find in a stomach normally."
It may even be possible to generate tissue for plugging holes in the stomach caused by disease, he said.
The organoids were created from human "pluripotent" stem cells, typically originating from early-stage embryos, which have the ability to develop into virtually any kind of tissue.
A key element of the research, reported in the journal Nature, was identifying the natural steps involved in stomach formation during embryonic development.
By simulating these processes in a petri dish, the scientists coaxed the stem cells to follow a development path that transformed them into stomach-like hollow "spheroids".
Infecting the stomach tissue with H. pylori led to biochemical changes in the organs within 24 hours.
The organoids faithfully mimicked the early stages of gastric disease triggered by the bacteria, including activation of a cancer gene called c-Met.
Dr Wells added: "We're at a real critical junction now where we're really going to start seeing some important therapeutic milestones in the future, both through new drug discovery and longer-term replacement tissues for therapy."
Stem cell scientists have previously generated gut organoids mimicking the intestine, and brain organoids containing nerve tissue.
