Researchers Grow Functioning Human Intestines, Nerves Using Stem Cells

Scientists are now able to use human pluripotent cells to grow human intestinal tissues with functioning nerves. This is a good next step not only for organ transplants but also to the study of diseases.

The stem cells were used to grow intestinal tissues that have functioning nerves, and they are now being used to study a severe intestinal nerve disorder called Hirschsprung's disease. This brings the usage of stem cells closer to the realm of regenerative medicine, and even make ready-to-transplant human intestines specially made for patients.

Authors Michael Helmrath, MD and Jim Wells, Ph.D. from the Cincinnati Children's Hospital Medical Center are hoping that the technology will soon be able to provide parts of the human intestines that can be transplanted.

Their research started with finding a model and study intestinal disorders in 3D human organ tissue with genetically-specific patient cells. This allows the researchers to test new therapeutics in actual functioning intestines before clinical trial. 

This can benefit patients as conventional methods lead to side-effects such as diarrhea, cramps and even impair intestinal motility. This can pave the way for drug screenings to look for toxicities and prevent side effects in the intestine. Meanwhile, the study so far could be used to look into nutritional health studies such as diabetes, severe intestinal diseases and to observe changes in the body. 

According to Science Daily, the researchers did their models by subjecting stem cells to a "biochemical bath" that triggers their formation into intestinal tissues. They lack an enteric nervous system, which enables waste to move through the digestive tract. This is essential because the gastrointestinal tract has the second-largest number of nerves in the human body. This means if they don't work properly, this can lead to diarrhea, constipation and even block the path of waste.

In order to circumvent this, they created embryonic-stage nerve cells in separate dishes and were manipulated to form precursor cells for enteric nerves. In the end, a mixture of the two methods led to enteric nerve precursor cells and intestines to grow together, thus the first evidence for generating functional 3-D intestinal organoids in petri dishes. 

The researchers are now trying to devise a way as to how to transplant these new organs in living organisms.