10 Brainy Facts About Your Gut (It’s Smarter Than You Think)
Gut feelings get all the press, but your gut may be more of a thinker than you knew. Scientists now think of it as your second brain. While it won’t necessarily help you study for an exam or get a promotion, your gut can influence the chemistry of your mood, emotions, immune system, and long-term health. Research even suggests the gut can “learn” new tricks through conditioning. These powerful connections are part an emerging field of science called neurogastroenterology designed to study the gut-brain link. Here are 10 facts you may not know about your smart gut.
1. The gut is the only organ system that can perform its functions without the oversight of the brain.
You might think of your gut as the rebel against authority; it doesn’t wait for your brain’s impulses to do the important work of digestion. It doesn’t need to—it acts as its own “brain.” No other organ—not even the all-powerful heart—can pull that off.
2. There are over 100 million brain cells in your gut.
Your gut’s power to think for itself is no surprise; there are millions of brain cells, or neurons, in its lengthy coils (9 meters of intestines, from esophagus to anus). That’s more neurons than are found in the spinal cord or peripheral nervous system.
3. The gut has its own nervous system.
The enteric nervous system—the controlling mechanism of digestion and elimination—is the overlord of your gut, and functions all on its own. Some scientists see it as part of the central nervous system, while others consider it its own entity. It likely evolved to give the gut the go-ahead when the “got to go” impulse strikes, without requiring the brain’s sign-off, particularly when you consider the helplessness of an infant with its brand-new brain. (Or else the brain just doesn’t like to get its, er, hands dirty.)
4. The gut sends emotional signals to the brain—suggesting we "feel" with our guts first.
There’s one big, bad visceral nerve embedded in your gut—the vagus nerve. Research has revealed that up to 90 percent of its fibers carry information from the gut to the brain, rather than the other way around. In other words, the brain interprets gut signals as emotions. So you really should trust your gut.
5. GI conditions can be seen as the "mental illness" of your gut.
Some 95 percent of your body’s serotonin, that marvelous mood molecule that antidepressant drugs like Prozac keep in your body, can be found in the gut. Think about that. It’s no wonder that diet, medications, and antibiotics can wreak havoc on one’s mood.
6. A healthy gut may protect your bones.
In a study of the serotonin-gut relationship, scientists discovered an unexpected link between the gut and the bones. Inhibiting the gut’s release of serotonin counteracted the bone-density reduction of osteoporosis in mice. This research is going into studies on new osteoporosis-fighting drugs.
7. New research shows links between Autism and fewer strains of gut bacteria.
In as many as nine out of 10 cases, autistic people have common gut imbalances such as leaky gut syndrome, irritable bowel syndrome, and fewer strains of “good” bacteria. Research on mice is looking at possible treatments of some of the behavioral disorders of autism by balancing microbes in the guts, though many warn that such treatments can’t produce a “cure” for autism.
8. Food affects your mood, and not just “comfort food.”
Different foods, when introduced to the gut via feeding tubes, have been shown to change a person's moods without the person’s awareness of what they were "eating." Fat, for instance, increased feelings of happiness and pleasure (no surprise there, right?) as it appears to trigger the release of dopamine—the brain’s natural opiate. Whereas carbohydrate consumption stimulated the release of serotonin, the “feel good” neurotransmitter.
9. Your gut is your best friend in cold and flu season.
Not only does your gut hold brain cells, it also houses the bulk of your immune cells—70 percent—in the form of gut associated lymphoid tissue, or GALT, which plays a huge part in mounting the defense against killing and expelling the foreign invaders of illness. GALT and your gut microbiome—the trillions of bacteria that live, like an immense microbial universe, in your gut—work hard to help you get over what ails you. That’s all the more reason to be careful with the use of antibiotics, which wipe out the good bacteria along with the bad.
10. Your gut can become addicted to opiates, just like your brain.
Inside your gut are opiate receptors, which are also found in the brain. The gut is just as susceptible to addiction as the brain and may, in fact, contribute to the intense difficulty some addicts have trying to kick the habit.