Discovery reveals new gut-brain neuronal circuit driving fatty food cravings

Amazing stuff! Impressive! Beware the cravings! 😊

When will we see new and better treatments for obesity? 

"... The research found cells in our gut sense the presence of fat in food and can directly talk to parts of our brain to make us keep eating. ...
Two years ago a landmark study discovered a direct pathway between the gut and brain that communicated the presence of sugar in the intestine. ...
This new research follows on from those prior findings to explore whether similar pathways between the gut and brain communicate responses to fatty foods. ...
Charles Zuker [Zucker German for sugar; no pun, a real last name], a researcher working on both this study and the 2020 sugar study, said the discovery of this novel gut-brain pathway offers the opportunity to develop anti-obesity treatments that block this signaling mechanism. ..."

"To search for that circuit, ... measured brain activity in mice while giving the animals fat. Neurons in one particular region of the brainstem, the caudal nucleus of the solitary tract (cNST), perked up. This was intriguing because the cNST was also implicated in the lab’s previous discovery of the neural basis of sugar preference.

... then found the communications lines that carried the message to the cNST. Neurons in the vagus nerve, which links the gut to the brain, also twittered with activity when mice had fat in their intestines. ..."

From the abstract:

"The perception of fat evokes strong appetitive and consummatory responses. Here we show that fat stimuli can induce behavioural attraction even in the absence of a functional taste system. We demonstrate that fat acts post-ingestively via the gut-brain axis to drive preference for fat. Using single-cell data, we identified the vagal neurons responding to intestinal delivery of fat, and showed that genetic silencing of this gut-to-brain circuit abolished the development of fat preference. Next, we compared the gut-to-brain pathways driving preference for fat versus sugar, and uncovered two parallel systems, one functioning as a general sensor of essential nutrients, responding to intestinal stimulation with sugar, fat and amino acids, while the other is activated only by fat stimuli. Lastly, we engineered animals lacking candidate receptors detecting the presence of intestinal fat, and validated their role as the mediators of gut-to-brain fat-evoked responses. Together, these findings revealed distinct cells and receptors using the gut-brain axis as a fundamental conduit for the development of fat preference."

P.S. Dr. Zuker works at the Zuckerman Institute of Columbia University [Zucker means sugar in German] 😊

Discovery reveals new gut-brain pathway driving fatty food cravings

Cravings for Fatty Foods Traced to Gut-Brain Connection Mouse research reveals fat sensors in the intestines that stimulate the brain and drive food desires

How Fat Signals Us to Eat More of It Scientists discover how fat triggers a gut-to-brain mechanism that drives us to keep consuming more of it. Their findings could one day lead to interventions to help treat obesity and associated disorders.

Gut-Brain Circuits for Fat Preference (no public access)

Vagal neurons that carry signals from the gut to the brain (nuclei shown in blue), with cells responsible for fat preference in green.