The middle intestine, or jejunum, senses glucose and plays a part in a gut-brain-liver axis to regulate glucose production by the liver reports a paper published online this week in Nature Medicine.
A classic hallmark of diabetes is high blood glucose levels. This elevation occurs because insulin cannot signal to the liver to reduce its endogenous glucose production, either owing to insulin resistance, as in type 2 diabetes, or a lack of the necessary hormone, as in type 1 diabetes. Tony Lam and his colleagues show that the jejunum can sense glucose levels and signal to the brain to order the liver to reduce glucose output through a neuronal relay. A surgical treatment for obesity consisting of duodenal-jejunal bypass surgery showed reduced blood glucose levels in two rat models of type 1 diabetes within two days of the surgery.
Although these results suggest a possible surgical correction of the increased serum glucose observed in type 1 diabetes, the bypass surgery used is still experimental, including in human patients. Also the effects on blood glucose levels were only examined in a narrow time frame, two weeks after surgery. How these effects occur still needs to be determined before any potential translation to human disease.