A blog post from the Stanford University School of Medicine attempts to answer the question: What's the deal with the gut-brain connection?

It affects your mood, your sleep, even your motivation to exercise. There's convincing evidence that it's the starting point for Parkinson's disease and could be responsible for long COVID's cognitive effects. And it sits about 2 feet below your brain. The gut plays an obvious role in our health by digesting what we eat and extracting nutrients. But there's a growing appreciation among scientists that our digestive systems affect our general well-being in a much broader fashion.

One fascinating aspect of the gut's widespread impact on health is its direct influence on and communication with the brain, a conduit known as the gut-brain axis. Through direct signals from the vagus nerve, [which] connects the brain and the gut, as well as through molecules secreted into the bloodstream from our gut microbes and immune cells that traffic from the gut to the rest of the body, our brains and our digestive tracts are in constant communication. And when that communication goes off the rails, diseases and disorders can result. The gut-brain connection is a key part of how the brain forms a picture of the rest of the body, a phenomenon known as interoception, explained Christoph Thaiss, PhD, an assistant professor of pathology at Stanford Medicine...
The gut also contains the largest number of neurons outside the brain of any structure in the body — more than 100 million neurons line the human digestive tract, from the esophagus to the anus. These cells make up what is known as the enteric nervous system, which some scientists refer to as a "second brain." The enteric nervous system is more brain-like than other peripheral nerves because it consists of lots of different types of neurons that communicate with each other, while other peripheral nerves primarily serve to communicate between the brain and the body, said Julia Kaltschmidt, PhD, the Firmenich Next Generation Faculty Scholar and an associate professor of neurosurgery. In fact, the gut's nervous system can act alone. Scientists have found that if they remove an animal's gut and bathe it in a special fluid designed to keep neurons alive, the gut continues to contract, pushing its contents from top to bottom.

[ Read more of this story ]( https://science.slashdot.org/story/25/03/09/0513235/how-your-gut-influences-your-brain?utm_source=atom1.0moreanon&utm_medium=feed ) at Slashdot.