You’re getting ready to give a big presentation at work, when suddenly nature calls.
Your nervous bathroom trips can be explained by the invisible thread connecting your head to your intestines, Dr Nicole Cain, who is based in Arizona, said.
Doctors have only recently begun examining the complex relationship between the brain and the digestive system.
‘The gut and the brain, they communicate on a bi-directional axis and that’s called the gut brain microbiome, or the gut brain microbial axis,’ Dr Cain told DailyMail.com.
‘And we have found that the gut bugs actually do a lot more talking than the brain.’
The stomach sensations you might feel when nervous are evidence of the gut-brain axis
Her advice is to practice deep, slow breathing, when you feel the anxiety building. Avoiding foods high in fiber and caffeine can also limit the effects.
Dr Cain started focusing on the gut-brain connection in medical school after seeing a patient with a crippling case of Crohn’s disease and anxiety.
The patient would spend days lying on the bathroom floor, with joint pain and chronic diarrhea, and no treatments were working.
Eventually, targeted treatment helped her get her GI symptoms under control, and at the same time, her anxiety seemed to miraculously disappear.
This, Dr Cain said, made her think: ‘There is something profound to this connection.’
Before a first date, big test or public speech, our brain may begin shooting off stress and anxiety signals.
These tell the body to release chemicals like cortisol, serotonin and adrenaline.
These messengers travel throughout the body, sending your heart rate and blood pressure into overdrive and attaching to receptors in the gut.
This causes a ‘tight, or churning’ feeling,’ stimulating your intestines and creating waves of contractions that tell you you need to head to the porcelain throne.
You might find that when the anxiety ceases, you don’t have to go anymore.
Other times, your body actually works something up in this storm, and only releases it when you’re able to relax, and your body is able to let go of the stool.
‘Immediately after the adrenaline rush is when everything may start to hit you at once,’ gastroenterologist Dr Christine Lee told the Cleveland Clinic.
On the flip side, depression can also impact the gut.
For some people dealing with depression, the condition is caused by an imbalance in chemicals called neurotransmitters.
Serotonin is a neurotransmitter which helps control sleep, sex drive, mood and digestion. Between 90 and 95 percent of it is manufactured in the digestive system, according to the University of Pennsylvania.
Dr Cain became attuned to the gut-brain axis after a patient with a severe case of Crohn’s disease and anxiety seemingly had both cured simultaneously
This has caused researchers to theorize that for some depression patients, the problem could originate in gut dysfunction – since its possible their digestive system just isn’t manufacturing enough serotonin to keep the brain running smoothly.
In addition, serotonin itself makes changes within the gut.
‘There are more serotonin receptors in the intestinal tract than in the brain. Because of this, serotonin has just as big of a role in the intestinal tract as it does in the brain’ Dr Lee said.
In the the GI tract, serotonin helps control how fast food moves through your intestines, how much fluid is produced to help break down and move food and how sensitive you are to sensations like fullness and gut pain.
Research has found similar, odd links, between gastrointestinal health and depression.
Implanting stool samples from people with depression into rats without bacteria led them to developing symptoms of depression, like disinterest in their normal activities, a 2016 University College Cork study found.
A large 2023 study which reviewed fecal samples from over 1000 people found that those with depression all had low levels of a bacteria called Eubacterium ventriosum, compared to individuals without depression.
This suggested that the lack of this bacteria could be contributing to the condition.
One final way the gut and brain connection is on display is through the Vagus nerve, Dr Cain said.
The hormones and neurotransmitters released during a stress response have many receptors in the gastrointestinal tract
The Vagus nerve is one of a set of 12 large nerves that extend directly from the brain into the body. It controls a whole host of functions that you can’t control by sheer will, including digestion, heart rate and the immune system.
One of its most important roles is to shift your body from stress to decompress. After leaving a situation you’re stressed in, your vagus nerve activates, steadying your heart rate, reducing anxiety and stimulating your immune system.
This also sets your gut back to rest, working on processing food and delivering energy at a calm speed.
Some naturopaths, like Dr Cain, say that this system can be ‘hacked’ to your benefit. If you notice yourself becoming anxious or stressed in a situation that doesn’t require it, you can try to activate your vagus nerve, setting your body, and gut, into a hard reset.
Deep breathing exercises, mindfulness, cold exposure and meditation can switch your vagus nerve back ‘on’ – calming you down, Dr Cain said.
Whether its through anxiety, depression or simple vagus nerve simulation, each of us has to deal with the odd interaction of the gut and brain, Dr Cain said, ‘instead of feeling shame and embarrassment about it, is understanding that this is your body giving you information.
‘We are, by and large, the products of our gut.’
