An organoid is a tiny, simplified version of an organ derived from stem cells. They replicate much of an organ’s complexity and have become known from human research. For example, Wageningen University and research are growing mini-intestines from pigs and fish and mini-airways from cows and pigs to study animal nutrition and health. Animal scientists Soumya Kar and Esther Ellen answer five questions about their latest developments and future work.
1. In animal research, organoids are something new, right?
“Yes, within WUR we started developing organoids from pigs. Now we are still one of the pioneers in this particular field,” Kar said. “There are very few laboratories in the world that are currently working on the same thing. But, of course, much more research has been done on human organoids. This started around 2010 at the Hubrecht Institute. After a decade, these organoids have already achieved a lot in nutritional and pharmaceutical research and they’re also quite instrumental in diagnostics and even clinical treatment. So the human field is years ahead of what we’re doing in livestock. I think we’re just getting started.”
2. Why do we need these miniature organs in livestock research?
“We see organoids as a good tool to replace animal experiments. They help answer research questions in animal husbandry and nutrition,” Ellen said. “For example, why some pigs use feed more efficiently than other pigs. This is a rather complex trait of an animal. Organoid research can help us identify differences between individual animals. Our organoids are also useful to test specific ingredients of animal feed. In the future they could also be useful for pharmaceutical and animal health issues.”
“So we use pigs with different genes for our organoids,” Kar said. “Let’s say we have pigs with genes that provide high feed efficiency and other pigs with genes for low feed efficiency. Then we derive the organoids from their intestinal stem cells and try to understand the differences in how they function.”
‘If we can use organoids to understand complex traits, then we can also use them as a tool to select animals more specifically for new traits, without increasing the number of animal experiments. For example, traits such as using nutrients and manure production. That’s what we would like to achieve,” said Ellen.
3. Do you think it will make a big difference in the number of animal experiments?
“I think organoids will play a crucial role in finding alternatives to animal testing. This is our moral responsibility as animal researchers,” Kar said. “Theoretically, many organoids from different tissues can be obtained from a single animal. This will help reduce the use of animals in experiments. However, we cannot completely eliminate all animal experiments because organoids are still different from whole animals. But using organoids some animal experiments are no longer necessary.”
4. Can other researchers already knock on your lab door if they want to collaborate?
“Yes, we are very open to collaboration and we think this is important to further explore this emerging field in human and animal sciences,” Ellen said. “Researchers are very excited about our organoids, so we are continuing our pioneering work.”
5. What are your next steps as an organoid developer?
“There are still so many questions that need to be answered to make our system more reproducible and overcome practical problems,” Kar said. “We’re also working on other improvements. An organoid now contains a cell type, because we start with adult stem cells. They are programmed to proliferate and differentiate into their own lineages. That’s why blood vessels, neurons and immune cells are not yet part of the organoid. In the next few years we plan to study the mixing and matching of different cell lineages, for example an epithelial layer (food contact intestinal cells) with immune cells. A system like this can be used to understand the ‘host-microbe interactions or diet-host interactions’.