The Gut Brain Connection And How It Can Affect Both Physical And Mental Health

I have mentioned, in passing, the connection between the gut and the brain elsewhere, but in this article, I want to go into more detail about this fascinating subject.

A Bit Of Basic Biology

Don’t freak out about this – I’m going to keep it short and sweet.

Most people have probably heard of the Central Nervous System (CNS) – it’s simply that part of our nervous system that includes both the brain and the spinal cord.

But more recent studies have confirmed the presence of a second major nervous system – the Enteric Nervous System (ENS).

And the word “enteric” basically means “relating to the intestines”.

So, the ENS is a nervous system that resides in your gut.

It comprises two super-thin layers that contain over 100 million nerve cells, which is actually more than your spinal cord contains.

Its purpose is to control the entire digestive process – deciding what enzymes to secrete, and when, and managing blood flow.

The theory is that this “second brain” evolved to optimize digestion – rather than have a whole bunch of signals travelling up and down the spinal cord to manage this complex process, it is more efficient to have those decisions handled locally.

So while the ENS is sometimes known as your “second brain”, this does not mean it works in anything like the same way as the brain in our heads. It cannot make logical decisions or hold philosophical conversations – it simply controls how our gut digests food.

However, the brain and the ENS are connected via the vagus nerve, which allows two-way communication (which is also known as the gut-brain axis).

OK, that’s the biology bit over with!

So How Does Mental Health Affect Your Gut?

You have probably already experienced this at a mild level, at least. For example, when you’re about to give a presentation, or perform on stage, you are likely to have felt those butterflies in your stomach (sometimes known as stage fright).

That feeling is the result of anxiety and stress, and it manifests itself in your gut (as well as in other places, such as sweaty palms).

Stress releases hormones such as adrenaline, cortisol, and norepinephrine, which trigger your “freeze, flight, or fight” response.

This is your body’s way of preparing for an emergency, and it causes all sorts of physical changes in your body. These include the sweaty palms I mentioned above, the platelets in your blood change shape so that they are more sticky should you be wounded, to help prevent blood loss, and there are several effects in your gut.

For example, nutrient absorption will decrease, oxygen supplies will be reduced, blood flow to your gut will be severely cut back, and enzyme output will also be slowed down.

This “freeze, flight, or fight” response is meant to be short term – the body perceives a threat and reacts to it, and when the threat goes away, your body is meant to return to normal.

However, chronic stress, where your body feels like it’s constantly in danger, leads to more serious issues, including inflammation, which is now believed to be at the heart of many other chronic conditions.

Even worse, prolonged stress or anxiety can alter your gut-brain connection, which can lead to several gastrointestinal disorders, such as:

• Crohn’s disease
• Dysbiosis (where the “good” and “bad” bacteria in your gut get out of balance)
• Food allergies
• Gastroesophageal reflux disease (GERD)
• Inflammatory bowel disease (IBD)
• Inflammatory bowel syndrome (IBS)
• Leaky gut syndrome
• Peptic ulcers
• and more.

Recent research confirms that the combination of chronic stress (as well as anxiety, depression, and PTSD) and gut damage can contribute to many inflammation-related problems, including:

• Allergies
• Chronic fatigue syndrome (CFS) / Myalgic encephalomyelitis (ME)
• Chronic skin conditions (e.g. eczema, psoriasis)
• Degenerative conditions (e.g. amyotrophic lateral sclerosis, osteoporosis, transverse myelitis)
• Fibromyalgia (often shortened to just fibro)
• Kidney problems
• Lupus
• Multiple sclerosis (MS)
• Osteoarthritis
• Rheumatoid arthritis
• Type 1 diabetes
• Ulcerative colitis
• Urinary conditions

This will not come as a surprise to an ever-increasing number of parents with children on the autism spectrum – it’s been known for around 20 years that there is a high correlation between austitic children and gastrointestinal issues, including chronic constipation or diarrhoea, Crohn’s disease, food allergies, and gluten intolerance,

What About The Gut Affecting The Brain?

As I said earlier, the vagus nerve allows for bi-directional communication between your brain and your gut.

I’ve just talked about how your brain (and mental affect) can have very real effects on your gastrointestinal health, so let’s look now at how the gut can affect your brain.

Hippocrates, a Greek physician who lived around 400 BC, is said to have claimed that all disease begins in the gut.

He may not have had access to the medical knowledge that exists today, and of course he’s not 100% correct, but in many ways, it turns out he was not far off the mark.

So, while the ENS may make local decisions about how best to digest food efficiently, it still sends signals up to your brain about what is happening down in the gut.

Remember from above that one symptom of stress and intestinal inflammation is leaky gut syndrome?

This is when the lining of your gut becomes more permeable than it should be, which allows substances such as proteins and bacteria into your bloodstream that should never be there.

Once those foreign substances enter your bloodstream, they can cause problems in any other part of your body – including your nervous system and brain.

In addition, dysbiosis can result in your immune system (at least three quarters of which is actually based in your gut) becoming overactive – which is one cause of inflammation.

Researchers are also discovering that gastrointestinal irritation can trigger mood changes via signals sent to the CNS.

And in some people, GI disorders can affect how they feel pain – for these unlucky souls, pain appears to be magnified. This is one common side-effect of fibro, for example.

Finally, for this section, researchers in Belgium found that people suffering from depression were missing two species of gut microbes compared to non-depressed individuals – Coprococcus and Dialister.

Treatment Implications

This new and exciting area of medical research brings into question traditional ways of treating both mental health and physical health.

For example, many parents of autistic children have found that treating their kid’s GI issues (e.g. via dietary changes) has resulted in improvements in their behaviour too.

Other doctors are starting to treat GI problems with prescription drugs that are designed to deal with mental health issues.

What Can You Do?

I’ve already written extensively about a number of mental health issues (e.g. anxiety, depression, PTSD, self-harming, stress), including suggestions and tips for dealing with those, and I will be adding more to that part of my site regularly, as it’s such a large topic.

There is also a growing number of articles about nutrition and health that cover the more physical aspects of health.

But here are a few ideas on how to deal specifically with the gut-brain matters:

1. Avoid processed foods. These foods (e.g. chips, snack cakes, and white bread) contain a whole bunch of unhealthy ingredients (e.g. sugar – see below). Whole, organic foods are much better for all of us, but for those with GI problems, they can make a world of difference.
2. Eliminate gluten. Doing this one thing can make a massive improvement to your microbiome.
3. High-fibre foods. These contain prebiotic fibres that can help reduce the production of stress hormones. Sources include many fruits, nuts, seeds, many vegetables, and whole grains.
4. Microbial transfer. This is a relatively new procedure and the jury is still out on whether it’s a safe and valuable way of dealing with dysbiosis and related health issues, but in essence, it involves the transfer of faecal matter from a healthy person to somebody whose microbiome needs a more diverse and balanced set of microbes.
5. Nuts. These are good sources of serotonin, so nibble on a handful of almonds, Brazil nuts, cashews, or walnuts.
6. Omega-3 fatty acids. These are found in fish (e.g. wild-caught Alaskan salmon) and they increase your good bacteria.
7. Polyphenol-rich foods. These include cocoa, coffee, green tea, and olive oil, and they can increase your healthy gut bacteria. There is some evidence that they also help improve your cognitive functions. However, be aware of the caffeine content of some of these, so consume them in moderation.
8. Prebiotics and probiotics. Because gut health is hugely dependent on a healthy microbiome, and we’ve already seen that this can be disrupted by stress, for example, then taking prebiotics and/or probiotics can help restore balance to your gut’s bacterial population. Options here include fermented foods (e.g. kefir, sauerkraut) and supplements, but you can read more about them via the link above.
9. Reduce sugar intake. Sugars (including fructose) can alter, in a negative way, the balance between the good and bad bacteria in your gut.
10. Sesame seeds. These are a good source of tyrosine, a dopamine-boosting amino acid.
11. Sleeping in total darkness. This might sound like a bizarre way of treating gut problems, but it turns out that this is crucial when it comes to optimizing the production of melatonin. This is the hormone that controls sleep – well, the entire sleep / wake cycle, to be precise – and according to a study published in the US National Library of Medicine, “melatonin, an important mediator of brain gut axis, has been shown to exhibit important protective effects against stress-induced lesions in the gastrointestinal tract.”
12. Tryptophan-rich foods. Tryptophan is used in the production of neurotransmitters such as serotonin, and you’ll find it in cheese, eggs, and turkey.
13. Vitamin B6. This is known to help with the production of neurotransmitters and mood-boosting One good source is shiitake mushrooms, but you can read about others here.
14. And lastly, try the GAPS diet. This was developed by Dr. Natasha Campbell-McBride, a neurologist and nutritionist, as a comprehensive healing protocol. It has helped many families with children who are neurologically damaged because it is designed to restore gut health.

Conclusion

This gut-brain connection is still a relatively new area of study, but even so, it’s discovering information and developing ideas that are challenging the traditional views of the medical world.

In the meantime, if you are suffering from either mental health or physical health issues, it may be worth giving some of these suggestions a try. If it works, great, and if not, no harm done.

Additional Resources

These are suggestions for those who wish to delve deeper into any of the above:

1. GAPS Diet