How Gut Bacteria Affects the Brain and the Body

Last updated May 3rd, 2021

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If you knew the foods and drinks you were eating were destroying your brain cells and disrupting your vital bodily functions, most of us would dump those habits in a heartbeat, right?

But did you know that the human body has a “second brain,” and that the modern diet is constantly damaging it?

The digestive tract, or enteric nervous system (ENS for short), is the entire digestive system that includes everything from your esophagus to your rectum.

It’s lined with more than 100 million nerve cells, and serves such a crucial and active role in your health that it is often referred to by experts as your body’s “second brain.”

While the ENS isn’t capable of thinking in the same manner as your cerebrum, it does communicate with your main brain.

The nerve signals, hormones and bacteria in the gut are all responsible for sending communications from the ENS to the rest of the nervous system, and any disruption can send your body into a tailspin of declining health.

With the average diet today consisting of loads of sugar, carbs, processed foods, and unnatural additives, it is extremely easy to disrupt the natural balance of bacteria in the gut.

This leads to a whole host of health issues, including weight gain, hormone imbalance, anxiety, depression, and more.

And since the root of the problem is your gut microbiome, taking medication, dieting, and exercising often have minimal impact or results.

If you’re ready to finally get control over your physical, mental, and emotional health, you need to start with your gut!

We’ll share exactly what your gut health can affect, and how to rebalance your gut microbiome so you can finally feel healthy again.

But first, let’s talk a little more about why your gut microbiome impacts your health so much.

Your Body Evolved to Depend on Bacteria

diagram of gut microbiome

Most of us think of bacteria as something bad that we don’t want to get into our systems.

We sanitize our hands, wash our food, cook it to the proper temperatures, and take antibiotics when we’re sick.

But it turns out that bacteria is absolutely necessary for us to live—as long as we have the right kind of bacteria, that it.

For every cell in our bodies, we have at least one bacterium living in or on our bodies. (1)

Bacteria thrive on our skin, in our mouths, and throughout our digestive system.

And before you decide to take a shower in hand sanitizer, you should know that without these bacteria, we would die.

These microbes help us break down food, build our immune systems, and regulate different hormones and bodily functions.

And of course, the bacteria in your enteric nervous system are the most important in your body, and the most impactful for your health.

In fact, researchers are finding that some bodily functions that they previously thought were regulated by your main brain may actually begin in your ENS.

It turns out that the part of your ENS responsible for most of this communication to your central nervous system isn’t the muscle or tissue, but the microbes in your gut that process the foods you eat, regulate hormone production, and synthesize vitamins and minerals.

The balance of gut bacteria, known as your gut microbiome, effects not only your digestion, health, and immune system, but also your mood and cognition.

And to keep this from sounding like some crunchy-granola, hippie mumbo-jumbo, let’s go over the scientific evidence to back it up.

Your Digestive System Creates its Own Feel-Good Neurotransmitters

serotonin molecular model on purple background

If you often feel unsatisfied, hungry, or down, the problem might be low serotonin production in your gut.

The vagus nerve connects the nerves in the digestive system to different areas of the brain. Neurotransmitters are the chemicals that create signals for neural communication.

Serotonin also contributes to happiness and wellbeing, and low serotonin levels are linked with depression.

According to researchers, some types of bacteria in the gut actually create the feel-good hormone serotonin.

Serotonin is known to regulate mood and appetite when it is released in the brain, but has not been extensively studied in the gut. (2)

Researchers theorize that even though the serotonin can’t cross from your gut into your brain, it actually stimulates the vagus nerve to send signals to the brain that serve the same purpose—helping you feel happy and satiated.

Digestive Disorders Are Linked With Anxiety and Depression

woman with anxiety or depression sitting on bed

According to experts at John’s Hopkins, people who suffer from irritable bowel syndrome (IBS), constipation, diarrhea, bloating and other digestive issues may be more likely to experience anxiety and depression. (3)

It was once thought that people with mood disorders reported digestive distress more often because they felt down.

Now, researchers have found that the opposite is actually true: if your gut is in distress, it communicates with the central nervous system, triggering mood changes.

In one experiment, researchers gave some subjects a prebiotic that encouraged the growth of Lactobaccilus and Bifidobacteria in the gut. The individuals who took the prebiotic had lower cortisol levels during a test that measures stress compared to the control subjects that weren’t given the prebiotic. (4)

In another study, a group of subjects who ate yogurt containing live active cultures of bacteria responded more calmly to images of emotional facial expressions than the control group.

Conversely, medications that are often prescribed for mood disorders, like antidepressants, may also work to alleviate the symptoms of irritable bowel syndrome.

On the other hand, creating a healthy gut environment can help the body produce more of the transmitters dopamine, serotonin and GABA, which help regulate mood.

Unhealthy Bacteria Can Create a Layer of Toxic Film in the Gut

chalkboard depiction of gut bacteria

Combining sugar with protein can create a biofilm, or mucus, in your intestines. A healthy biofilm is good; it helps bind to acids and toxins so they don’t harm the body.

A biofilm created by healthy bacteria also has anti-inflammatory properties, helps your body absorb nutrients and lubricates the gut.

If your body can’t properly absorb nutrients from the foods that you eat, your complete physical and mental health is affected.

When your gut is imbalanced and filled with unhealthy bacteria, parasites, or yeast, the biofilm is so thick that it:

  • prevents the proper absorption of nutrients,
  • protects the microbes that cause disease, making it harder for your body to fight them,
  • promotes inflammation, and
  • holds onto toxins.

This leads to a lot of really bad health issues, impacting your entire body.

Imbalanced Gut Bacteria Can Make You Feel Foggy

artistic drawing of brain fog

Have you ever just felt off? You can’t necessarily explain why, but you leave your car keys in the refrigerator and forget what you’re doing as you’re doing it?

It could be caused by the bacteria in your gut.

According to Natural Health 365, researchers have made a connection between healthy eating and a stronger capacity for memory. A diet that’s high in fat and sugar is linked to cognitive impairment.

In one study, mice that were fed a diet with high levels of fat and sugar showed changes in their gut microbiome. They also demonstrated impaired cognitive flexibility (8).

They were unable to think outside the box or create new ways of thinking. For example, when the normal route through their maze was blocked, they were unable to find a new way out.

This study was conducted on young mice. The implications are that older mice might experience more cognitive impairment from an unhealthy diet.

What’s more, the high-sugar diet seemed to have a greater effect than a high-fat diet.

One of the effects of eating too much sugar is increased levels of candida, a type of yeast, in the gut. Candida feeds on sugar, so the more sugar you eat, the more overgrowth you might experience.

A byproduct of candida is a toxic substance called acetaldehyde. This chemical can make your brain feel foggy, your body hurt and your muscles weak.

Want to know for sure if you have an overgrowth of candida? You can actually see it in your saliva with a simple, at-home test using a glass of water.

Click here to learn how to do a simple candida test at home right now.

Gut Bacteria Can Predispose You to Weight Gain

woman on scale in yellow bathroom

The 10 trillion microbes that live in the body are called the microbiome. The majority of these live in the digestive system.

Different bacteria are linked to different health characteristics. Researchers have found specifically that obese individuals have different microbiota than lean people (4).

In one study, researchers implanted some mice with bacteria from the gut of an obese woman and other mice with bacteria from the gut of her lean twin sister. Although they ate the same diet, the mice with the bacteria from the obese sister gained more weight than the other mice.

Unhealthy Gut Bacteria Can Lead to Insulin Resistance

The CDC says more than 1 in 3 Americans is prediabetic, and a vast majority of those people aren’t aware of it.

However, you might be insulin resistant even if you aren’t yet prediabetic—which means you’re well on your way towards prediabetes and diabetes, even if you don’t have any symptoms yet.

Insulin resistance is a major contributor to obesity, among other health problems, since it causes your body to be resistant to absorbing glucose and processing it into energy.

And it turns out that your gut microbiome may play a key role in developing or reversing insulin resistance.

In a recent study, researchers found that a bacterium called Akkermancia muciniphila is found in people and mice with normal bodyweight and insulin sensitivity, and is significantly reduced in people and mice that are overweight or obese.

They found that adding this bacteria into the gut actually improved insulin sensitivity without changing any other factors.

Researchers have also discovered that transplanting the gut bacteria from conventionally raised mice into the gut of mice raised in a sterile environment not only led to the kind of weight gain, fat gain, and specific areas of fat accumulation associated with insulin resistance; they also found that “the lean animal that received gut microbiota from an obese mouse developed more severe insulin resistance than would be expected from weight gain alone.” (5)

In studies on diet-induced insulin resistance, the biggest dietary contributors were foods that lead to a high level of inflammation, causing what we know as “leaky gut,” where bacteria pass through the intestinal walls into the bloodstream. (6)

Scientists are now proving that since the gut microbiome in people with type II diabetes is so different from people with normal insulin sensitivity, targeting your gut microbiota may be a highly effective treatment plan for reversing type II diabetes and metabolic syndrome. (7)

So if you are (or might be) insulin resistant, rebalancing your gut microbiome may be the only way you’ll be able to lose weight and keep it off!

Can Probiotics Heal Your Gut?

While taking a probiotic supplement without making other changes to your diet or lifestyle probably won’t fix all your problems, taking a good probiotic is the best place to start!

Not all probiotics are created equal, so you’ll want to make sure you choose one with AT LEAST 50 billion units of probiotics daily from a minimum of 10 different sources for best results.

You don’t need to spend extra money on refrigerated probiotics, but you should make sure the packaging is well sealed.

It’s also essential that the packaging is dark (or opaque, not transparent) to protect from light damage.

We have our own brand of Probiotics at Avocadu called Gut-13.

Our specially formulated probiotic supplement contains:

  • 50 Billion CFU’s Per Serving
  • 13 Different Gut Healing Strains
  • Delayed Release for Deeper Support
  • Made in the USA

You can read more about it and why it’s so important for not only gut health but overall health on our probiotics page.

Probiotics are one of the best solutions for healing your gut, helping you lose weight faster, and providing you with a healthy source of gut flora every day.

The Whole-Body Approach to Healing Your Gut and Losing Weight

Probiotics will help to get your gut started on the right track again, but it won’t make a very big impact if you are still eating a diet full of the WRONG foods that wreak havoc on your gut in the first place.

And if you’ve struggled to lose weight, you need to make major changes to your diet that focus on healing your gut and reversing the damage to your system.

If you’re like most people who find themselves with an unhealthy gut microbiome, you might feel overwhelmed trying to figure out what is good for your gut, and what isn’t.

And if you’re hesitant to start another program for health and weight loss because you feel like you’ve tried just about everything, and nothing has worked (or worked for long), then this is absolutely for you.

Many of our clients felt exactly the same way before starting our program—hopeless, exhausted, frustrated, and just over weight loss programs that don’t work for them.

We created our 21-Day Fat Loss Challenge for people exactly like you—people who feel like they’ve tried everything under the sun, but just can’t shed the weight or keep it off.

21-Day Fat Loss Challenge Program by Avocadu

Our challenge provides a step-by-step plan to help you lose up to 21 lbs in just 21 days, with far less effort than you may think!

Tons of our clients have turned it into a lifestyle diet and have lost as much as over 100 pounds with the challenge!

The best part? Besides just losing weight, the 21-Day Fat Loss Challenge was designed to heal your gut, rebalance your hormones, and retrain your tastebudsso you’ll actually be able to keep the weight off!

The Challenge is perfect for people with insulin resistance, as many of our clients have actually reversed their insulin resistance with the Challenge.

If you’re ready to make some changes in your life, this is the ONLY place you should start.  We’ll teach you exactly how to make the necessary changes in your diet and lifestyle, and how to keep them “beyond the diet.”

Take control of your life and start your 21 Day Fat Loss Challenge TODAY!

If you liked this article on how gut bacteria affects the brain and body or have any questions, please leave them in the comment section below!

Cathy Dean

Cathy Dean

Hey y’all. My name is Cathy, a former junk-food loving carb-aholic turned nutrition and fitness enthusiast. Here at Avocadu, we believe that a nutrient-rich diet is EVERYTHING when it comes to your health and well-being. Our motto is “Healthy from the Inside Out”! As a Certified Keto Coach, I specialize in teaching others how to lose weight through healthy, low-carb eating.

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Hey, y’all! I’m Cathy!

I’m SO excited you’re here! I’m super passionate about nutrition, and specialize in teaching others how to lose weight through healthy, low-carb eating. Here at Avocadu, we believe in quality over quantity and that diet is EVERYTHING when it comes to your health and well-being. In short, we believe in being healthy from the inside out. Learn more

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