A micro-sized human stomach has been grown in a dish for the first time by scientists in the US. The discovery will help scientists to understand how the intestinal system forms and also how it responds to diseases and infection.
Writing in Nature, Cincinnati Children's Hospital Medical Center scientist James Wells and his colleagues used a combination of growth factors similar to those present in a developing embryo to turn stem cells from both mice and humans to stomach tissue. Exposure to the right combination of growth signals, including factors called FGF, WNT and retinoic acid, simulates the environment of the developing gut and triggers the cells to specialise accordingly.
After a month or so in the dish, tiny 2-4 mm stomachs, complete with the correct lining cells and even digestive-juice secreting glands were formed. As well as displaying the same developmental steps and genetic signalling processes that are seen in a genuine growing embryo, the gastric organoids, as the team have dubbed them, can even be infected with gut bugs to study how intestinal tissues respond to microbes.
The team challenged the stomach tissues with the ulcer-causing bacterium Helicobacter pylori and were able to observe how cells responded to the assault. According to the Cincinnati team, "HGOs [human gastric organoids] should present new opportunities for drug discovery and also modelling the the early stages of gastric disease, including cancer."
Indeed, the remarkable system means that anti-ulcer, anti-microbial and even anti-cancer agents can be tested reproducibly and cheaply in the dish. Longer-term the work will also boost understanding of how tissues like the intestines form in the first place, potentially even paving the way for growing new guts for patients with intestinal diseases...