Gut-Brain Connection and How it Affects Your Mood

Perhaps you’ve tried medication, therapy, positive thinking, and meditation, but you still can’t seem to shake this 'low' feeling. If you can relate, please keep reading to discover the gut-brain connection, and what you can do improve your digestive health and mood at the same time!

The Connection Between Your Gut and Your Brain

Known as the gut-brain axis, the connection between your digestive system and your brain should not be underestimated.

In fact, you’re probably already aware of how your brain can talk to your gut. Think about the butterflies you get in your stomach when you’re excited or 'that feeling in the pit of your stomach' when you experience fear.

But you may not be aware that your gut does a lot of talking on its own, and the recipient of these messages is your brain. Your gut uses your central and peripheral nervous systems to impact your emotions and your cognition.

Everything from depression, anxiety, brain fog, hyperactivity, and distraction could be the result of messages you’re receiving from your gut.

You may be a bit skeptical considering your digestive system doesn’t seem to be anywhere near your head.

Last time you checked, your doctor never asked about your digestion when she/he was writing a script for anti-depressants. But just because your regular GP isn’t aware of this connection, doesn’t mean the gut-brain connection isn't demonstrated in the scientific literature.

What the Mice Are Telling Us About Our Guts

Mice are usually the frontline troops when it comes to new and exploratory research. And the research on the gut-brain axis is no exception. Much of what’s been done so far investigates what happens when we take mice who are born ‘germ-free’ and raise them in a sanitized environment.

Raising germ-free mice is a pretty tricky thing to do actually. Most of us pick up bacteria from our mothers when we’re born (if we were born vaginally).

Being a part of the world will result in picking up a variety of bacteria via the environment and the food we eat. To overcome this, scientists deliver mice babies through cesarean section. Then raise them in an enclosed and sanitized environment.

And what were the results from these ‘germ-free’ mice experiments?

The sanitized mice exhibited odd behaviours that probably would have gotten them killed if they were ever released into the wild. For example, they showed an unusual lack of fear. And although you might think that lack of fear is a good thing, when you’re a mouse it’s healthy to have a bit of hesitation if you want to avoid getting eaten.

In another experiment scientists transplanted bacteria from one mouse to another to test the effects. Transplanting bacteria from adventurous mice into shy mice would make the timid mice more bold and willing to explore their surroundings.

Scientists have even taken the bacteria from people with IBS (aka. Irritable Bowel Syndrome) and transplanted them into germ-free mice. The result was an increase in anxious behaviour in the mice. While transplanting bacteria from healthy people didn’t have an affect on the mice’s behaviour.

The Power of the Microbiome

What these mice studies tell us is that the microbiome (aka. the bacteria living in your gut) have a powerful influence on your brain by affecting your mood and your behaviour. Even though we now know that our microbiomes are an important part of a healthy state of mind, scientists are still learning what a healthy microbiome looks like.

It’s been estimated that there are up to 1000 different species and 7000 different strains of bacteria that could at any point in time be taking up residence in your gut. These bacteria exist in different proportions. With some inhibiting or supporting the existence of other types.

So even though you think you may be supporting the diversity of your microbiome with a cheap single-strain probiotic, it’s not exactly a science as to what we need to do to create the perfect microbiome.

That being said, even though we don’t know exactly what makes a ‘good’ microbiome, scientists are still researching how different strains of bacteria can affect the gut-brain connection.

A new and innovative field of science called ‘psychobiotics’ is investigating how powerful our gut bacteria can be in influencing depression, anxiety, and other mental health issues.

Gut Bugs and Your Brain: Physical Structure

Having the right balance of good to bad bacteria can even shape the structure of your brain. This can have a profound influence on your mood and how you think.

Some of the studies done on mice demonstrate that the microbiome will influence how the brain develops. Especially the areas of the brain involved in the stress response and those areas that regulate emotions like anxiety, stress, and depression.

The most serious repercussion of unsupported brain development can extend beyond a simple case of the blues. In fact, various psychiatric disorders including schizophrenia can result from nerves that are not properly myelinated.

Myelination is the process where your nerve cells become covered with a substance that is essential for conducting electrical signals. If you’re nerve cells aren’t properly myelinated it will be very difficult for your brain to be able to send important messages.

Gut Bugs and Your Brain: Neurotransmitters

In addition to changing the structure of your brain, your microbiome can also affect the neurotransmitters produced.

As a refresher, neurotransmitters are chemicals that relay information throughout your body. One of the most known neurotransmitters is serotonin. As the name is in many antidepressant medications.

For example, SSRIs are a specific type of antidepressant known as a ‘Selective Serotonin Reuptake Inhibitor’. What this means is that the medication blocks your body from reabsorbing serotonin, keeping it in circulation longer.

Serotonin affects everything from mood, social behaviour, appetite, digestion, sleep, memory, and libido. Often people who are depressed or suffering from a mood disorder don’t have enough serotonin. This is why many prescribed antidepressants involve trying to maximize the levels of serotonin in the body.

What you may not be aware of is that the bacteria in your gut play a big role in serotonin production. Metabolites, which are a byproduct of your bacteria’s metabolism, can increase serotonin production in your colon. Although the colon may seem like the last place you would expect your body to produce serotonin, up to 90% of all serotonin produced in the body is in the colon.

And to be clear, the serotonin made in your colon isn’t any different than the serotonin made in your brain. They’re both the exact same molecule, they’re just made in different places. One of the benefits of ensuring your colon is a serotonin-making machine are local effects such as improved digestion and appetite regulation (another one of serotonin’s many jobs in the body).

Serotonin is only one of the neurotransmitters that your microbiome has a hand in making. Other neurotransmitters you may not be as familiar with include acetylcholine and GABA.

Acetylcholine is an excitatory neurotransmitter, and is involved with memory and learning. GABA is an inhibitory neurotransmitter so it can be used by the body to reduce fear, anxiety, and panic.

Think of GABA like a natural tranquilizer that your body can make all by itself. Your gut bacteria also produce the building blocks, such as tryptophan. This is needed to make neurotransmitters such as melatonin and serotonin.

One study demonstrated that feeding mice probiotics found in yogurt resulted in higher levels of circulating GABA. And since GABA is used to reduce fear, anxiety, and panic, it wasn’t surprising that these mice behaved less anxiously, and were more adventurous.

What’s interesting is that if these scientists severed the vagus nerve, which connects the gut to the brain, the beneficial effects of the yogurt disappeared.

What’s the bottom line?

If you want the correct balance of beneficial neurotransmitters that can help regulate your mood. You will need to have a good diversity of beneficial bacteria in your gut.

Depression is Your Brain on Fire

Like obesity, heart disease, cancer, and diabetes. An increasing number of healthcare practitioners are starting to realize that depression could be manifestation of inflammation in the body.

But don’t go looking for the source of inflammation in your brain because that’s not where the root cause can be found. In fact, your gut is yet again playing a key role in the creation and maintenance of inflammation in the body.

A healthy person’s gut will digest food in the digestive tract, and absorb nutrients through the intestinal wall and into the bloodstream. The secret to good digestion is to only allow the nutrients to pass into the bloodstream when they are digested.

If food particles start sneaking through before they’ve been completely digested, your body will recognize them as invaders, and start an inflammatory reaction.

A byproduct of this reaction are LPS (lipopolysaccharides). An endotoxin that enters the bloodstream and can bypass the blood-brain barrier that usually keeps foreign substances out.

Many studies have demonstrated that rising LPS levels in the body are correlated with mood disorders including depression.

The key to reducing your LPS levels are to heal your ‘leaky gut’ that is allowing these undigested food particles to pass into your bloodstream.

How to Improve Your Gut-Brain Connection

At this point, you may be panicking wondering what you could do to improve that vital connection between your gut and your brain. Although many of the studies so far have been done on mice, that doesn’t mean there isn’t already a wealth of knowledge relating to how you can improve your microbiome.

And remember, just because you don’t have obvious digestive issues like gas, bloating, and diarrhoea, that doesn’t mean your gut couldn’t benefit from a bit of a tune up. In fact, the only symptoms you may have from an unbalanced microbiome and a leaky gut are mental and cognitive issues.

Follow this two-step plan for building a better gut!

Step 1: Heal and Seal Your Leaky Gut

To reduce the inflammation in your brain, you’re also going to need to heal and seal your leaky gut. 

  • Adopt a Whole Foods-Based Diet: It’s time to cut out the processed and packaged ‘foods’ laden with artificial sweeteners and preservatives. These foods are hard to digest and nutrient-poor. Often loaded with sugar, these foods will also feed yeasts like Candida, which can further exacerbate a leaky gut.
  • Consider an Elimination Diet: To heal and seal the gut, often eliminating certain foods may be necessary to give your digestive system a break. Gluten and dairy are common offenders that can create inflammation in the digestive tract, while often eliciting an immune response.
  • For some people, cutting out gluten and dairy may not be enough. If your gut is in really bad shape then you may need to cut all grains, legumes, and even nuts and seeds. These eliminations likely won’t be permanent, but cutting out hard-to-digest foods will give your body the chance it needs to heal.
  • Eat More Fat: Eating healthy fats like coconut oil, avocados, olive oil, and fish oil will help with digestion, while also providing an anti-inflammatory effect on the body.
  • Cook Your Food: Although salads and fruit smoothies are pretty trendy right now, raw food is much harder to digest for the body. And from a Chinese Medicine perspective, raw food is too yin meaning it has a cold and dampening effect on the body. Try to gently cook your food by steaming, baking, or using a slow cooker/crockpot.
  • Supplement Wisely: Certain supplements can help the gut heal including l-glutamine, arabinogalactin, slippery elm, colostrum, DGL licorice root, and quercetin.

Step 2: Build a Better Microbiome

While you’re healing and sealing your leaky gut, you’ll also want to be working on creating a more diverse flora in your digestive tract for neurotransmitter production. Read more about building a better microbiome here.

  • Eat Fermented Foods: Eating sauerkraut, miso, and/or kimchi on a daily basis will contribute to a diverse flora in your gut. For those not used to eating fermented foods it’s best to start with 1-2 tbsp/day and then work your way up to approximately ½ cup of fermented foods.
  • Fill Up on Fibre: Fibre is the food for the good bacteria in your gut. This is why people who eat fibreless fast food all day tend to have an unhealthy microbiome. They’re not providing their good bacteria with what they need to flourish. Good sources of fibre include vegetables like leafy greens, asparagus, carrots, artichokes, radishes, chia seeds and flaxseeds.
  • Take a High-Quality Probiotic: Opt for a multi-strain formula that has a higher number of CFUs (colony forming units).
  • Destress: Easier said than done, but relaxing and being mindful of stress is essential if you want to encourage a diverse microbiome. Being in a state of chronic stress has a detrimental impact on the good bacteria in our guts. Incorporate meditation, gentle exercise, and mindfulness into your daily routine.

What you need to remember about depression is that the solution is usually not as simple as a filling a prescription. It’s important to see depression as a symptom of larger underlying issues going on in the body.

So in addition to working with a therapist and doctor, consider improving the health of your gut to lighten your mood and ease the burden of living with a health issue that can prevent you from living a full and joyous life.

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