Researchers at Cincinnati Children's Hospital Medical Center grew three-millimetre 'gastric organoids' from human embryonic stem cells (hESCs) and iPS cells in order to study the Helicobacter pylori bacteria, a major cause of peptic ulcers and stomach cancer.
'Until this study, no one had generated gastric cells from human pluripotent stem cells,' principal investigator Dr James Wells of the Cincinnati Children’s Hospital Medical Center, said. 'In addition, we discovered how to promote formation of three-dimensional gastric tissue with complex architecture and cellular composition.'
The study is thought to be the first time researchers have produced a three-dimensional human embryonic foregut, which may provide the starting point for generating other organ tissues like the lungs and pancreas. The creation of stomach tissue from human cells also provides a laboratory model to simulate human biology that avoids the need to use mice, whose stomach biology and structure differs from humans.
In order to create the 'mini stomachs', the researchers needed to be able to direct the stem cells to develop into complex tissue: the stomach is made up of layers of muscle and stomach lining cells, as well as cells that make glands to produce the proteins and acids needed to digest food.
During the cell differentiation process, the scientists introduced chemicals at certain intervals (identified after observing normal stomach formation in embryos) in order to coax the stem cells into creating three-dimensional stomach tissue on which they tested the Helicobacter pylori bacteria.
'We were able to show that when we inject the bacteria or a little solution of Helicobacter into our little football-shaped mini-stomachs, the bacteria immediately know what to do and they behaved as if they were in the stomach,' Dr Wells told NBC News.
'They bound to the lining and they triggered the early stages of stomach disease. The cells, in response to the infection, started to replicate themselves.'
Gastric diseases, mostly caused by Helicobacter pylori infections, affect around 10 percent of the world's population. The researchers hope to understand why the bacteria, which are carried by two-thirds of the population, cause disease in some and not others, as well as gaining further understanding about how the stomach develops.