The Second Brain – Study shows the role of the stomach in diabetes

Researchers have found evidence of the second brain, or how the gut's nervous system influences glucose metabolism in the rest of the body. The Centers for Disease Control and Prevention estimates that more than 425 million people worldwidesuffer from type 2 diabetes. The study results could lead to new treatments for the so-called diabetes.

Type 2 diabetes causes the body's cells to become less sensitive to signals from insulin. This is a hormone that is responsible for regulating glucose levels in the blood. This low sensitivity is called insulin resistance and prevents cells from absorbing the extra glucose that enters the bloodstream after a meal. Over time, high levels of glucose in the blood damage tissue throughout the body, causing complications such as heart disease, vision loss and kidney disease.

Changes in diet, exercise and other aspects of life can improve symptoms and even reverse the condition in some people. Medications are also availableTreatment of type 2 diabetesavailable, but can have side effects such as nausea and diarrhea. Another disadvantage of some antidiabetic drugs is that they must be injected. Discovering oral treatments that are not only effective but also free of side effects is therefore a priority for researchers. A group of scientists now believe they are one step closer to developing such a treatment. They published their results in the journal Gut.

New approach to treatment

In type 2 diabetes, communication between the gut and the brain appears to break down. As a result, the brain does not send signals to the liver, muscles and fatty tissue after a meal. These signals are intended to tell the body to absorb more glucose from the bloodstream. This in turn leads to insulin resistance. Normally, the duodenum, the first part of the small intestine, signals the brain to relax the smooth muscles in its lining. However, in people with type 2 diabetes, these muscles are constantly contracted or so hypercontractile that a signal is not sent. Researchers believe friendly gut bacteria are the key to reversing contractility and restoring healthy glucose metabolism.

Nutrients that feed friendly bacteria are called prebiotics. In particular, carbohydrates called oligosaccharides are known to promote the growth of bacteria that improve glucose metabolism through the production of various lipids. However, the identity of these lipids has remained unknown. The researchers found that there were 38% fewer lipids called 12-HETE in the duodenums of people with diabetes. Finally, they showed that 12-HETE reduces muscle contraction in the duodenum by increasing the signal from a nerve receptor, the mu-opioid receptor. This restored communication between the gut and the brain. This study is one of the latest to show close relationships between the bacteria in the human gut, collectively called the microbiota, and health. Scientists are optimistic thattheir workwill inspire new treatments. Treatments could either increase the production of 12-HETE in the intestine or involve taking the lipid orally as a supplement.