For years, a 25-year-old woman in China lived under the relentless burden of type 1 diabetes. Every day was a constant calculation — how much insulin to inject, when to eat, how to avoid dangerous spikes and crashes in her blood sugar. But then, one day, the math stopped. After receiving a transplant of stem cells, she no longer needed insulin injections. Her body, for the first time in years, began producing its own.

“I can eat sugar now,” the woman, who lives in Tianjin, said with a smile during a phone call with Nature. “I enjoy eating everything —especially hotpot.”

This remarkable turnaround is the result of a groundbreaking medical trial in China, where researchers reprogrammed stem cells from her own body to replace the damaged pancreatic cells responsible for producing insulin. The study marks a major milestone in the quest to cure type 1 diabetes, a disease that affects millions of people around the world.

A New Era for Diabetes Treatment

For decades, the idea of reversing type 1 diabetes seemed like a distant dream. The disease occurs when the immune system mistakenly attacks the islet cells in the pancreas that produce insulin, the hormone essential for regulating blood sugar. Without insulin, blood sugar levels can skyrocket, leading to serious health complications and, without treatment, death.

Scientists have long tried to replace these damaged islet cells, typically through transplants from donors. But there’s a problem: there are never enough donors, and patients who do receive transplants must take powerful drugs to prevent their immune systems from rejecting the foreign cells.

That’s where stem cells come in. These cells can be programmed to grow into any type of tissue in the body. Researchers hope they can create an unlimited supply of insulin-producing cells, tailored to each patient, so that their body accepts the new tissue as its own.

This is precisely what happened in the case of the 25-year-old woman. Led by cell biologist Deng Hongkui at Peking University in Beijing, the team extracted developed cells from her body, reverted them into a so-called “pluripotent state” where they could be turned into any kind of cell and then coaxed them into becoming clusters of insulin-producing islets. It’s a refined technique first demonstrated more than two decades ago by Shinya Yamanaka, which earned him a Nobel Prize in Physiology in 2012.

In June 2023, the researchers injected roughly 1.5 million of these newly formed islets into her abdomen. The target site in the body was picked carefully, allowing them to monitor the cells closely and remove them if necessary. Within 75 days, her body began producing insulin on its own. By the end of the year, her glucose levels were under control without any need for insulin injections.

Will This Be the Cure?

The success of this case is generating excitement, but experts caution that the journey to a full cure for type 1 diabetes is still far from complete. The trial involved only three patients, and while the woman’s results are promising, it remains to be seen whether the procedure can be scaled up and applied to the millions of people suffering from the disease.

One of the biggest concerns is whether the woman’s immune system will eventually attack the new islets, just as it attacked her original ones. An important factor is that she had previously undergone a liver transplant. She was already taking immunosuppressants, which may have prevented her immune system from rejecting the new cells.

In future patients, who may not be on such drugs, the outcome could be different. This is why doctors are following these phase 1 clinical trial patients closely for several more years. The outcomes of the other two participants are also reportedly “very positive”. They’ll soon hit the one-year mark of being free of insulin injections.

Despite these uncertainties, the results are simply stunning so far. Deng’s team is already preparing to expand the trial to include more patients, and other researchers are exploring different ways to use stem cells to treat the disease. Vertex Pharmaceuticals, a company based in Boston, is running a trial in which donated stem cells are used to create insulin-producing islets for transplant. Early results from their trial, though preliminary, have shown that some patients have become insulin-independent. All the patients from the Vertex trial are on immunosuppressants.

The next step for Deng and his colleagues will be to find out whether their approach can work without immunosuppressants. They are experimenting with new ways to modify the stem cells to evade the immune system’s attacks.

“If we can solve that problem,” said Deng, “we may be on the verge of something truly transformative.”

A Glimpse into the Future

For the woman in Tianjin, the future is already here. More than a year after her transplant, her body continues to produce insulin. She no longer has to think about the delicate balance of insulin and blood sugar that once dominated her life.

But for scientists, this is just the beginning. The success of this trial opens the door to a new era in diabetes treatment — one where stem cells could one day provide a permanent solution to a disease that affects nearly half a billion people worldwide.

The promise is immense, but so are the challenges. Stem cell therapies, though advancing rapidly, are still in their infancy. There have been many false starts in the history of diabetes research — promising beginnings that ended in disappointment. But this time, researchers are cautiously optimistic. The possibility of a cure may finally be within reach.

The findings appeared in the journal Cell.