For more than a century, doctors have wanted a pill that can replace insulin shots. The stomach and intestines break down insulin, so it never reaches the blood. Because of this, most patients still need daily injections.
Researchers at Kumamoto University, led by Associate Professor Shingo Ito, have found a new way to protect insulin inside the gut. They use a tiny ring‑shaped protein called the DNP peptide. This peptide can travel through the small intestine and carry insulin with it.
Two Ways to Help Insulin Cross the GutThe team tried two different tricks:
- Mixing method: They mixed a modified DNP peptide with insulin that was stabilized by zinc. When given to diabetic mice, the mixture lowered blood sugar quickly and kept it normal for three days with one dose each day.
- Linking method: They attached the DNP peptide directly to insulin using a chemical "click" reaction. This linked version worked just as well as the mix, proving that the peptide helps insulin move across the intestine.
Old oral insulin attempts needed huge doses—sometimes ten times more than a shot. The new system needs far less. It achieved about 33‑41% of the effect of a regular injection, a level that could be useful in real life.
What This Could Mean for Diabetes"Injections are a daily hassle for many people," said Professor Ito. "Our peptide platform could let patients take insulin by mouth and might work for long‑acting forms or other injectable medicines too."
The study was published in Molecular Pharmaceutics. The researchers plan to test the pill in larger animals and in models that mimic the human gut before moving toward human trials.