Korean research team becomes first in world to map gut-brain communication pathway

The secret behind how weight loss drugs such as Wegovy curb appetite lies in the signals that travel between the gut and the brain — and Korean researchers say that they have now mapped that conversation for the first time in history.

A Korean research team has become the first in the world to map the actual pathway by which gut hormones signal nutritional deficits to the brain, the Ministry of Science and ICT announced on Thursday. The findings were published on Friday.

The research was led by Suh Seong-Bae, the director of the Center for Microbiome and Body-Brain Physiology at the Institute for Basic Science, in collaboration with researchers at Seoul National University and Ewha Womans University. The team showed that when the body runs short on protein, the gut detects the deficit first and signals the brain, prompting it to seek out the missing nutrients.

The gut is often referred to as the “second brain” because it regulates much of the body's metabolism, including blood sugar levels, appetite and the immune system. But the connection between how signals generated in the gut travel to the brain and translate into behavior had never before been proven. 

The team found that the process does not run through a single channel. Instead, it operates as a precise dual system, with a fast neural pathway carrying signals from the gut to the brain almost instantly, while a slower hormonal pathway travels through the blood. The researchers confirmed that the system works the same way in fruit flies and in mice, raising the likelihood that it applies to humans as well.

The findings also offer the first scientific account of how the mechanism of some of today's most prescribed weight loss drugs works. Wegovy and Saxenda are built from synthetic versions of Glucagon-like peptide-1 (GLP-1), a hormone secreted in the gut, but the precise route that GLP-1 takes to signal the brain had been unclear until now.

“This study uncovers the principles by which the gut and brain select nutrients,” Suh said. “It will serve as an important foundation for future research into treatments for obesity, metabolic diseases and eating disorders.”

This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom.

BY EO HWAN-HEE [[email protected]]