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Tiny Lab-Grown Stomachs Have Started Churning Out Acid


Rachael Funnell

Social Editor and Staff Writer

clockDec 16 2021, 13:06 UTC
gastric organoids

Cross-section of a 14-week transplanted, three germ layer human stomach organoid. Image courtesy of Alexandra Eicher

Researchers have cracked the recipe for harnessing human stem cells to create multi-layered mini stomachs capable of squirting out their very own acid. The achievement is an exciting one for fun-sized organoids, bringing us closer to creating a model that can be used in lab research that closely resembles the physiology of the human body.

This new research, published in the journal Cell Stem Cell, has successfully created the most advanced stomach organoids to date. What makes them so special? The organoids are composed of three germ layers: epithelium, smooth muscle, and neurons shown in white, red and green respectively in the cross-section below.


In order to piece together their multilayered organoid, the researchers developed the germ layers separately and then put the pieces together while the mini stomachs were still at an early stage. The multiple cell types means the mini organoids are able to contract and produce acid, two key processes in a functional stomach.

Once pieced together and after 30 days of development, the gastric organoids were transplanted into mice. Once inside, the researchers were amazed to find that the organoids were able to reach sizes unparalleled in test tube conditions.

The tiny stomachs grew to impressive sizes when transplanted into mice. Image courtesy of Alexandra Eicher

“The extreme increase in volumetric growth that the gastric organoids could achieve given the right supporting circumstances (i.e. the addition of both neural and mesenchymal cells) [was fascinating],” first author Alexandra Eicher told IFLScience.


“In vitro, organoids are only a few millimeters in size, but after transplantation, 3 germ layer gastric organoids can grow to almost a full centimeter in size, representing at least a hundredfold increase in volume.”

gastric organoids
Combining the three germ layers of human gastric organoids. Image courtesy of Alexandra Eicher

The researchers will now continue working with their gastric organoids to study the co-development of different cell types as well as modeling clinical diseases that impact more cell types than just the gastric epithelium in infected patients. They hope to achieve this by transitioning their mini stomachs into a tool and model system that can be used in future studies.

2021 has been a big year for mini organs, with labs across the globe churning out increasingly complex mini-mes of the body’s major organs. One eye-opening study discovered that miniature brains created from stem cells can spontaneously sprout embryonic eye-like structures called “optic cups.”


Elsewhere, researchers were able to develop self-organizing mini hearts called cardioids capable of beating after eight days of development. Something of a final puzzle piece for biomedical research that will likely open many doors for the future research of human heart disease.

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