The Gut-Brain Connection to Chronic Pain, Anxiety and Depression

Possibly many of you have read or heard of the best-selling book by Dr. Perlmutter MD “Grain Brain” which explains the impact that a high carbohydrate diet has on your brain function. How a high carbohydrate diet can cause dementia, ADHD, anxiety, chronic headaches, depression, and much more. In his new book “Brain Maker” he explores the astonishing new research that reveals how the health of your brain is dictated by the state of your gut microbiome. How can this be?

Have you ever had a “gut-wrenching experience”? Told someone that you could no longer “stomach the situation”. Have you ever felt “butterflies in your stomach” when you’re anxious? We have intuitively recognized our gut-brain connection. For years now we have recognized the role that the brain plays in creating gastrointestinal disorders such as stress-induced gastric ulcers. However what is now coming clear is that the communication goes both ways our G.I. tract talks to our brain!

It turns out that our brain and central nervous system and the enteric or G.I. nervous system where created from the same tissue during fetal development. These two nervous systems are intimately connected via the vagus nerve or 10th cranial nerve that runs from our brainstem down into our gastrointestinal tract. Messages to control our digestive system are sent from our brain through the vagus nerve to our digestive organs. But what’s coming clear now is that messages are being sent back from our digestive tract through the vagus nerve to our brain.

Even more surprising it is that the vagus nerve is the route our gut bacteria use to transmit information to our brain. Yes, bacteria in your gut are talking to your brain, and they are sending good messages and bad messages. Some gut bacteria can release neurotransmitters just like your brain releases, therefore they can speak to your brain in its own language via this vagus nerve. Furthermore, pathogenic or bad bugs in your gut can cause your immune system to release inflammatory cytokine messengers throughout your body, and can even trigger a systemic stress response. This research has now shown that gut bacteria can directly impact your mental health, leading to issues with anxiety and depression. (just as if your boss was yelling at you or a tiger was chasing you, ). As if that wasn’t enough, consider that other unfavorable bacteria can release substances in the gut that will make you more sensitive to pain. This directly relates a possible impact to those suffering with chronic pain and fibromyalgia.

Don’t panic! There is the flip side.  Having the right type of commensal bacteria in high enough numbers, such as various species of Bifidobacterium and a Lactobacillus, can keep these bad bugs at bay. Even more interesting is that these beneficial bacteria can interact with your immune system in ways that turn off your inflammation and your chronic stress response, thereby reducing pain and anxiety.

Long and short; it’s vital to have “the right stuff” in your gut microbiota.

An imbalance of gut bacteria is known as dysbiosis and it is many times overlooked in a conventional approach to chronic health disorders. This gastrointestinal disorder is best understood as a condition where, an overabundance of non-acute, non-infectious GI microorganisms and/or a lack of beneficial bacteria, adversely affect the human host”. If you have chronic pain, anxiety or depression and dysbiosis has not been found, it may simply be that no one has been looking for it!

I have personally seen it time and time again with patients who tell me that they never felt depressed or anxious until they started experiencing problems with their gut or developed chronic pain or fibromyalgia sometime after the onset of G.I. health issues. A study recently conducted at UCLA found that women who consumed beneficial probiotics exhibited mood and cognition on MRI in both the resting state and in performing emotional recognition tasks.

Author Dr. Greg Fors

About Dr. Greg Fors

Dr. Greg Fors, D.C. is a Board-certified Neurologist (IBCN), certified in Applied Herbal Sciences (NWHSU) and acupuncture. As the director of the virtual Pain and Brain Healing Center, he specializes in a functional medicine approach to fibromyalgia, fatigue, brain fog, digestive disorders, depression and anxiety. He is a sought after international lecturer for various post-graduate departments and state associations. Dr. Fors is the author of the highly acclaimed book, “Why We Hurt” available through booksellers everywhere.


  1. Sigrid Marshall on August 21, 2021 at 10:49 am

    Suffering since August 5, 2021 with an anxiety condition through many health events with my husband and car accident 5 years ago. My nausea is no longer and I can eat often, small amounts…but lost weight since May 28th of this year and weigh 93 pounds. I will be 80 in September, this year.
    Meat, rice pasta, constpating…don’t do wheat/though I don’t show gluten intolerance.
    I am working with my medical doctor, but none of the meds have helped and some cause severe headaches…working with famiky who have undergone anxiety…taking Kava and find thst is a little helpful, taking half the amount suggested as I get wobbly legs…I might have Gastroparesis?
    My question is what do I eat to gain weight?
    Will your book be of help for me?
    I’ve always had a nice figure but always on the normal thin side until menopause, then akways looking to gain some weight.

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