The 9 Most Promising Psychobiotics for Anxiety

February 21, 2024 Jordan Fallis

I used to walk around ruminating, struggling with inner turmoil and nervousness all the time.

It never went away.

It was impossible to shake.

It wore me down and ruined the quality of my life.

There’s no doubt that fear and vigilance are helpful when you’re faced with an actual threat.

But an unnecessarily high state of worry and arousal when there is nothing threatening you? That's a nightmare.

It doesn’t have to be that way though.

If you have chronic anxiety, there are ways to manage and reverse it, like I have.

And psychobiotics are one way to do that.

Psychobiotics are probiotics and prebiotics that can improve your mental health by changing the mixture of bacteria in your gut (46-47).

It is estimated that 100 trillion bacteria, and 500 to 1,000 species of bacteria, live in the human gut. These gut bacteria, collectively known as the gut microbiome, help with digestion. But an increasing amount of research suggests that they also communicate with your brain through the microbiome-gut-brain axis, affecting your thoughts, feelings and behaviour (48-49).

Gut is playing chess with Brain. Gut says “Gutsy move for a brain…”.

A dysfunctional gut microbiome has been linked to a number of mental health problems and psychiatric conditions, including anxiety.

In fact, anxiety and gut health are very tightly linked.

Research shows that people who have digestive disorders are more likely to have anxiety, and those with anxiety have higher rates of gastrointestinal disease (50-52).

And studies show that when digestive disorders improve, anxiety improves as well (53).

Unfortunately, a lot of people have poor gut health today because of the widespread use of antibiotics, medications, herbicides, stress, infections, poor diet, etc.

But don’t worry. You can improve your gut health and anxiety at the same time with the use of psychobiotics.

Studies show that psychobiotics can improve anxiety by (54-55):

Stimulating the vagus nerve
Producing neurotransmitters, such as GABA and serotonin
Reducing stress hormone levels
Reducing inflammation, one of the major underlying causes of mental illness
Increasing BDNF levels
Crowding out pathogenic bacteria
Increasing nutrient production and absorption

Here are the nine best psychobiotics that have been shown in human and animal studies to decrease stress and help treat anxiety disorders.

They are truly the best probiotics for anxiety.

1. Lactobacillus rhamnosus

Lactobacillus rhamnosus is a bacterium found in the human gut. It is one of the most popular probiotic species found in supplements.

Preliminary research suggests that supplementing with lactobacillus rhamnosus can lower anxiety in humans (3).

GABA is the main inhibitory and relaxing neurotransmitter in the central nervous system, and studies suggest that lactobacillus rhamnosus may reduce anxiety by changing the expression of GABA receptors (1-2, 4).

In one study, researchers gave lactobacillus rhamnosus to mice, and it reduced their anxiety-like behaviours. But when researchers removed part of their vagus nerve, lactobacillus rhamnosus did not reduce their anxiety, suggesting that psychobiotics communicate with the brain and improve mental health through the vagus nerve (1-2).

“The mice [given lactobacillus rhamnosus] were more chilled out.”

— Dr. John Cryan, researcher and pharmacologist with the Alimentary Pharmabiotic Center at University College Cork, Ireland

Other studies have found that lactobacillus rhamnosus decreases stress-induced anxiety-like behaviour, and researchers have concluded that it can protect against anxiety (5, 7).

Lactobacillus rhamnosus has also been shown to reduce obsessive-compulsive disorder (OCD)-like behaviour in mice. In fact, researchers found it was just as effective as fluoxetine, an SSRI antidepressant commonly used to treat OCD (6).

So if you struggle with OCD or obsessive-compulsive tendencies, it’s worth trying this psychobiotic.

Lactobacillus rhamnosus can be found in some yogurt and dairy products, such as fermented and unpasteurized milk and semi-hard cheese. But I typically don’t recommend eating these foods unless you’re sure you can tolerate them.

2. Bifidobacterium longum

Bifidobacterium longum is another bacterium present in the human gut. It is often added to food as it can help prevent the growth of pathogenic organisms.

I previously wrote about how it’s been proven to help treat depression.

Bacteria. Bacteria can affect the mind through the gut-brain axis.

But it can also reduce anxiety.

Researchers have concluded that bifidobacterium longum can reduce cortisol and alleviate psychological distress in humans (including obsessions, compulsions, paranoia, anxiety) (28-30).

Lots of animal research also shows that bifidobacterium longum can significantly reduce anxiety-like behaviour (31-34).

One study found that a chronic infection in mice increased inflammation and caused anxiety-like behaviour, but bifidobacterium longum reduced anxiety and normalized behaviour (35-36).

Researchers have even figured out that it works by acting through the vagus nerve (27).

3. Lactobacillus plantarum

Lactobacillus plantarum is another probiotic species that can reduce anxiety.

In one study, researchers gave lactobacillus plantarum to patients with irritable bowel syndrome and it significantly reduced their anxiety and improved their quality of life (8).

Animal studies also show that lactobacillus plantarum can cause positive changes in emotional behaviours and significantly reduce anxiety-like behaviours. It does this by increasing dopamine and serotonin, lowering stress hormone levels, and reducing inflammation (9-11).

As a result, researchers have concluded that lactobacillus plantarum has psychotropic properties without physical side effects, and has great potential for treating neuropsychiatric disorders, including anxiety (9-11).

Lactobacillus plantarum is also commonly found in many fermented vegetables including sauerkraut, pickles, brined olives, kimchi.

4. Lactobacillus helveticus

Lactobacillus helveticus is a probiotic strain that has been shown to reduce cortisol and have anti-anxiety effects in humans (37, 39, 44).

One study found that it can even reduce paranoid and obsessive-compulsive thoughts (38).

Blue bacteria. Bacteria can influence our anxiety levels.

Animal research shows that a Western-style diet can negatively change the gut microbiome, increase brain inflammation, and contribute to anxiety. But lactobacillus helveticus can protect against this, reducing both neuroinflammation and anxiety (40-42).

One study even found that lactobacillus helveticus works better than citalopram, a common SSRI antidepressant, at reducing anxiety-like behaviour in rats. It also reduced their stress hormone levels and increased their serotonin levels (43).

Lactobacillus helveticus is also commonly found in American Swiss cheese and Emmental cheese, and sometimes other cheeses, such as Cheddar, Parmesan, Romano, provolone, and mozzarella.

I’m very sensitive to dairy so I can’t eat cheese regularly. But if you’re not and can tolerate them, you could try adding some of these cheeses into your diet.

5. Lactobacillus reuteri

Lactobacillus reuteri is a bacterium with anti-inflammatory effects that scientists first discovered in the 1980s.

It is usually found in the human gut. However, not all humans have it, and some people simply have very low levels of it. Therefore, you may need to supplement with it to introduce and maintain high levels of it.

Research shows that Lactobacillus reuteri can reduce anxiety-like behaviours in animals by reducing stress hormone levels and altering the expression of GABA receptors (13-14).

And one study found that the absence of lactobacillus reuteri causes social deficits in animals.

“We found that treatment with this single bacterial strain was able to rescue their social behavior.”

— Shelly Buffington, neuroscience researcher at Baylor College of Medicine

By adding it back in to the guts of the animals, the researchers were able to reverse some of their behavioural deficits, which were similar to symptoms of social anxiety and autism in humans (15-16).

Therefore, lactobacillus reuteri is definitely the psychobiotic strain worth trying if you struggle with social anxiety or symptoms of autism.

It's also found in breast milk, and some meat and dairy products.

6. Lactobacillus casei

Lactobacillus casei is another bacterium found in the human gut. It has antioxidant and anti-inflammatory effects.

In one double-blind, placebo-controlled trial, patients with chronic fatigue syndrome and digestive problems took Lactobacillus casei as a daily supplement for two months. At the end of the study, they had a significant decrease in their anxiety symptoms (17-19).

So this is a good psychobiotic to try if you struggle with a mixture of fatigue, digestive problems and anxiety.

Lactobacillus casei is the dominant species in naturally fermented Sicilian green olives, and can also be found in other fermented vegetables and dairy products.

7. Lactobacillus fermentum

Lactobacillus fermentum is another species that is part of the human microbiome and commonly found in fermented vegetables.

It hasn’t been studied as much as other lactobacillus probiotic species.

Bacteria. Psychobiotics are bacteria that affect our psychological state of mind.

But there still is some evidence that is may be able to help treat anxiety, especially if you have a long history of antibiotic treatment.

Research shows that antibiotics can trigger anxiety in animals by disturbing the microbiome.

But by giving animals lactobacillus fermentum, researchers can reduce the inflammation and reverse the psychological problems brought on by antibiotics, including anxiety-like behaviour (12).

So if you’ve taken a lot of antibiotics over the years, or noticed that your anxiety got worse after taking a course of antibiotics, taking a psychobiotic supplement with lactobacillus fermentum is worth a try.

8. Bifidobacterium breve

Bifidobacterium breve is a beneficial bacterium found in human breast milk and the human gut. The amount in your gut declines as you get older (20).

Research shows that bifidobacterium breve can reduce anxiety-like behaviour in animals (21).

Anxious animals also perform better on cognitive tests after being given it (22).

This makes bifidobacterium breve a great psychobiotic option if your anxiety impairs your cognition and interferes with your ability to complete tasks.

Bifidobacterium breve can be found naturally in some fermented foods.

9. Galacto-oligosaccharides

Not all psychobiotics are simply probiotics.

Psychobiotics can also include “prebiotics,” which are non-digestible soluble fibres that stimulate the growth of good gut bacteria, and therefore improve mental health and reduce anxiety.

Galacto-oligosaccharides (GOS) are a type of prebiotic that have been shown to do just that.

Picture of intestines. Our intestinal health can significantly affect our mental health.

In one study, GOS significantly decreased the secretion of cortisol, and participants paid more attention to positive information rather than negative information (23).

People who are anxious tend to have high levels of cortisol and often get caught up in negative thinking. So this study suggests that GOS has anti-anxiety effects.

Other research has demonstrated that people with irritable bowel syndrome (IBS) often have anxiety because of the lack of microbial diversity in their gut. However, when IBS sufferers supplement with a prebiotic mixture containing GOS, it significantly reduces their anxiety and improves the quality of their life (24-26).

What Psychobiotic Should You Take?

Ideally, you should buy and try one probiotic strain at a time to figure out how you respond to each one.

That's what I did over the span of several years.

I would buy and try one probiotic species and strain, take it for at least one month, and then monitor how I felt during that time.

Sometimes I would stop taking it if I felt worse.

I was my own guinea pig and tested and experimented with so many different probiotic supplements to find the ones that helped.

I usually recommend people follow the same process because many people like myself often experience a bad reaction to one strain, but a good reaction to another.

But I understand doing that can be time-consuming and tedious. Plus, clinical studies often demonstrate that probiotic mixtures with multiple strains are better at improving the diversity of gut bacteria than single strains (45).

So, to make it easier for you, I’ve now created my own psychobiotic supplement, called Optimal Biotics.

I created it because I want to give my clients and readers the very best psychobiotic supplement so that they can experience superior results.

I have found that many psychobiotic supplements on the market fall short and even cause side effects.

But Optimal Biotics doesn't, and it contains the 8 most well-researched and beneficial probiotic strains for your mental health.

I also recommend adding fermented foods into your diet and see how that goes. Fermented foods contain many strains of bacteria that have not been documented in the scientific literature. That said, the downside is that the bacteria in fermented foods will vary depending on the batch, and there is sometimes the risk of them containing pathogenic bacteria.

Here are some other steps you can take to increase the good bacteria in your gut.

And this anti-anxiety supplement also includes several other natural compounds that have helped me manage my anxiety over the years. It can help reduce stress and anxiety while you work to improve your gut health.

Conclusion

The microbiome and psychobiotics are at the cutting-edge of neuroscience and mental health research and treatment. It hasn’t been that long since researchers first discovered that there is a gut-brain connection.

Cartoon image of bacteria and psychobiotics.

When I first found out about it several years ago, I started consuming psychobiotics, and they have definitely helped me recover from chronic anxiety.

But it’s important to point out that psychobiotics alone were never enough.

I also had to make changes to my diet, take key supplements, improve thyroid health, and overcome trauma. There really is no quick fix or magic bullet.

Yet for some people, psychobiotics can be life changing, especially if you have digestive issues alongside your anxiety and worry.

Overall, I think they are absolutely worth a try.

I hope this article helps you, and please share it with anyone you think might benefit from it.

Enjoy This Article? You Might Also Like My FREE Food Guide for Optimal Brain and Mental Health!

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Jordan Fallis

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References:

(1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4370913/

(2) https://www.ncbi.nlm.nih.gov/pubmed/21876150/

(3) https://www.ncbi.nlm.nih.gov/pubmed/25879690

(4) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4934620/

(5) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5225647/

(6) http://www.ncbi.nlm.nih.gov/pubmed/24257436

(7) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4200314/

(8) https://www.ncbi.nlm.nih.gov/pubmed/25024629

(9) http://www.ncbi.nlm.nih.gov/pubmed/26620542

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(11) https://www.sciencedaily.com/releases/2016/11/161121160038.htm

(12) http://www.ncbi.nlm.nih.gov/pubmed/25869281

(13) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3754198/

(14) http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2982.2010.01664.x/full#b28

(15) https://www.sciencedaily.com/releases/2016/06/160616140723.htm

(16) http://www.cell.com/cell/fulltext/S0092-8674(16)30730-9

(17) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664325/

(18) https://gutpathogens.biomedcentral.com/articles/10.1186/1757-4749-1-6

(19) http://www.ncbi.nlm.nih.gov/pubmed/19338686/

(20) http://journal.frontiersin.org/article/10.3389/fmicb.2016.01204/full

(21) https://www.ncbi.nlm.nih.gov/pubmed/25251188

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(23) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4410136/

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(25) http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2036.2008.03911.x/abstract

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(40) https://www.ncbi.nlm.nih.gov/pubmed/23566632

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(50) https://www.ncbi.nlm.nih.gov/pubmed/?term=18819774

(51) https://www.ncbi.nlm.nih.gov/pubmed/21908055 5

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Can Bifidobacterium Probiotics Help With Depression? A New Study Says Yes

February 4, 2024 Jordan Fallis

A recent study has just been published showing that probiotics can reduce depression in humans, providing further evidence that the bacteria in your gut can affect your mood.

It is estimated that 500 to 1,000 species of bacteria live in the human gut. They help with digestion and the proper functioning of the gastrointestinal tract.

But an increasing amount of research suggests that they also communicate with your brain and affect your behaviour.

In a new randomized, double-blind, placebo-controlled trial, Canadian researchers at McMaster University studied whether one specific strain of beneficial gut bacterium – bifidobacterium longum – would affect patients with depression.

The researchers took 44 adults with irritable bowel syndrome (IBS) and mild to moderate depression, and randomly assigned them to two groups. One group was given the probiotic bifidobacterium longum every day for 6 weeks. The other was given placebo for 6 weeks.

Patients filled out a questionnaire at the beginning and end of the study, which allowed researchers to determine each participant’s level of depression and quality of life.

What’s interesting about this study is that researchers also performaned a Functional Magnetic Resonance Imaging (fMRI) test before and after the study. This allowed them to assess how the probiotic affected brain activation patterns.

What Were The Results?

At the end of the study, 64% of patients taking the probiotic bifidobacterium longum had a significant reduction in their depression, compared to just 32% of patients given placebo. Their quality of life score also increased

And the fMRI analysis showed that multiple brain areas that are associated with depression, including the amygdala and fronto-limbic regions, were less active. The probiotic bifidobacterium longum actually reduced their reaction to “negative emotional stimuli”. In other words, they weren't as negatively affected by sad experiences and images.

“What we found was that the patients that were treated with this probiotic bacterium improved their gut symptoms but, also surprisingly, decreased their depression scores. That means their mood improved. And this was associated also with changes in the brain imaging.

This study shows that consumption of a specific probiotic can improve both gut symptoms and psychological issues in IBS. This opens new avenues not only for the treatment of patients with functional bowel disorders but also for patients with primary psychiatric diseases.”

— Dr. Premysl Bercik, Associate Professor of Medicine at McMaster University

Even four weeks after the study had concluded, depression scores were still reduced in the patients who had been given the probiotic bifidobacterium longum.

Researchers concluded that the probiotic bifidobacterium longum can reduce depression and increase quality of life. And these improvements were associated with changes in brain activation patterns.

So if you currently struggle with depression, I think supplementing with bifidobacterium longum is worth a try.

Bifidobacterium longum is included in the Optimal Biotics supplement.

I created Optimal Biotics because I want to give my clients and readers the very best probiotic supplement so that they can experience superior results.

I have found that many probiotic supplements on the market fall short and even cause side effects.

But Optimal Biotics doesn't, and it contains the 8 most well-researched and beneficial probiotic strains for your mental health.

In the future, I imagine practitioners will be able to use genome sequencing techniques to determine the microbiome profiles of individuals, which could then be tweaked with probiotics. In other words, there may come a day when we can "biohack" our gut bacteria for optimal mental health.

In the meantime, you can try supplementing with bifidobacterium longum, and if you’re interested in learning more about this new study, you can read the entire abstract at the end of this post.

Other Research on Bifidobacterium Longum

This isn’t the first time that the probiotic bifidobacterium longum has been linked to reductions in depression and improvements in mental health.

Here are some other studies:

In a double-blind, placebo-controlled, randomized study, participants with mild depression took a probiotic that contained bifidobacterium longum and lactobacillus helveticus for 30 days. At the end of the study, the participants had a significantly reduction in depression, cortisol, anger, self-blame, and overall psychological distress. They also displayed higher problem-solving skills.
In another double-blind, placebo-controlled, randomized study, healthy volunteers took bifidobacterium longum and lactobacillus helveticus for 30 days, and the results showed a reduction in psychological stress and cortisol levels.
In an animal study, bifidobacterium longum improved learning and memory during cognitive tests.
In a study of mice under chronic psychological stress, bifidobacterium longum and lactobacillus helveticus reduced cell death in the emotion-processing parts of their brains. It did this by reducing stress hormones and increasing brain-derived neurotrophic factor (BDNF), a protein in the brain that can help reduce depression. Another animal study also found that bifidobacterium longum increases BDNF.
In a study of mice, bifidobacterium longum reduced schizophrenic behaviour.

Conclusion

Conventional medicine tries to correct depression by relying on medications. But unfortunately this often ends up creating new chemical imbalances and nutrient deficiencies.

Supplementation with bifidobacterium longum is a more evidence-based approach.

Human and animal studies show that the probiotic causes favourable biochemical and behavioural changes, leading to significant decreases in symptoms of depression.

For anyone experiencing depression, supplementing with it seems worthwhile and may allow you to reduce your reliance on prescription medication.

Enjoy This Article? You Might Also Like My FREE Food Guide for Optimal Brain and Mental Health!

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Jordan Fallis

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Probiotic Bifidobacterium longum Reduces Depression Scores and Alters Brain Activity: a Pilot Study in Patients With Irritable Bowel Syndrome.

Abstract

BACKGROUND & AIMS:

Probiotics can reduce symptoms of irritable bowel syndrome (IBS), but little is known about their effects on psychiatric comorbidities. We performed a prospective study to evaluate the effects of Bifidobacterium longum (BL) on anxiety and depression in patients with IBS.

METHODS:

We performed a randomized, double-blind, placebo-controlled study of 44 adults with IBS and diarrhea or a mixed-stool pattern (based on Rome III criteria) and mild to moderate anxiety and/or depression (based on the Hospital Anxiety and Depression scale) at McMaster University in Canada, from March 2011 to May 2014. At the screening visit, clinical history and symptoms were assessed and blood samples were collected. Patients were then randomly assigned to groups and given daily BL (n=22) or placebo (n=22) for 6 weeks. At week 0, 6 and 10, we determined patients' levels of anxiety and depression, IBS symptoms, quality of life, and somatization using validated questionnaires. At week 0 and 6, stool, urine and blood samples were collected, and functional magnetic resonance imaging (fMRI) test was performed. We assessed brain activation patterns, fecal microbiota, urine metabolome profiles, serum markers of inflammation, neurotransmitters and neurotrophin levels.

RESULTS:

At week 6, 14/22 patients in the BL group had reduction in depression scores of 2 points or more on the Hospital Anxiety and Depression scale, vs 7/22 patients in the placebo group (P=.04). BL had no significant effect on anxiety or IBS symptoms. Patients in the BL group had a mean increase in quality of life score compared with the placebo group. The fMRI analysis showed that BL reduced responses to negative emotional stimuli in multiple brain areas, including amygdala and fronto-limbic regions, compared with placebo. The groups had similar fecal microbiota profiles, serum markers of inflammation, and levels of neurotrophins and neurotransmitters, but the BL group had reduced urine levels of methylamines and aromatic amino acids metabolites. At week 10, depression scores were reduced in patients given BL vs placebo.

CONCLUSION:

In a placebo-controlled trial, we found that the probiotic BL reduces depression but not anxiety scores and increases quality of life in patients with IBS. These improvements were associated with changes in brain activation patterns that indicate that this probiotic reduces limbic reactivity.

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5 Ways to Increase Your Good Gut Bacteria For A Healthier Brain

February 4, 2024 Jordan Fallis

Picture of Hippocrates with his quote “All Disease Begins in the Gut!”

My brain totally broke in 2010 and I felt like I had developed ADHD, depression, and dementia all at once. By scouring the literature, interviewing and consulting with doctors and researchers, and experimenting with my own body and mind, I finally came to understand that it wasn’t just one thing that had caused my brain and body to break, but the accumulation of many things.

One of my main problems: I had an imbalance of healthy and unhealthy bacteria in my digestive system.

There are approximately 100 trillion microorganisms and 500 known bacterial species living in our guts. That means there is 10 times more bacteria cells in our bodies than human cells and over 90% of our cells are non-human. Simply put, we are more bacterial than we are human (1, 2).

Gut bacteria affect our nervous, hormonal and immune systems and play a key role in countless bodily functions, including the digestion of food and production of vitamins. So not surprisingly, the makeup of these bacteria in our system can affect how we feel physically and mentally.

But our modern lifestyle isn’t good for our gut bacteria. Stress, bad diet and medications can reduce probiotic (good) bacteria and increase bad bacteria in our digestive tract. A lot of people today have out-of-balance and dysregulated gut bacteria. So if we want to regain optimal brain health, it’s critical to restore and support the “good germs” in our gut.

In this post, I’ll show you how to increase your good bacteria and reduce your bad bacteria like I did, so that you’ll improve the health of your brain and experience more mental resilience.

Image of the gut and the brain - Can this influence this?

What the Cutting-Edge Research Says: You Need Healthy Gut Bacteria to Have a Healthy Brain

Impressive new research shows that there is a connection between our brain and our digestive tract, and that the bacteria in our gut can have a profound influence on our behaviour, thoughts and mood.

There’s evidence that healthy gut bacteria produce and regulate the amount of neurotransmitters in the brain (such as serotonin, dopamine and GABA), which can affect mood, pain and cognition (50-52).

Dr. Stephen Collins, a gastroenterology researcher at McMaster University, has done a lot of research in the field and discovered that unhealthy gut bacteria play a key role in causing abnormal behaviour (including anxiety and depression), while certain strains of good bacteria can reduce stress hormones and anxious behavior.

In one study, Collins took the gut bacteria of mice that were prone to anxious behaviour and transplanted it into calm mice. After the transplant, the calm mice started acting nervously. He has also seen the same results with humans (28 – 35).

“It’s increasingly clear that our gut bacteria, or microbiota, can communicate with the human brain.”

— Dr. Kathy Magnusson, PhD, Oregan State University

Studies by Dr. John Cryan, a neuropharmacologist and microbiome expert at the University College Cork, shows that gut bacteria can alter brain chemistry.

He found that after eliminating their good bacteria, mice act in ways that mimic human anxiety, depression and autism. And in one of his studies, two strains of bacteria were more effective than an antidepressant at treating anxiety and depression (36 – 42).

Lastly, research has found that mice with autistic-like behaviour have much lower levels of a common type of bacteria called “Bacteroides Fragilis” than normal mice. They were stressed, antisocial, and had the same digestive problems often found in autism. And when they were fed “Bacteroides Fragilis”, there was a reversal in their autistic symptoms. They became less anxious, communicated more effectively, and showed less repetitive behavior (43, 44).

This is just the tip of the iceberg. A growing number of scientists and practitioners around the world are researching and speaking out about this, explaining that the gut-brain connection can be hacked to treat psychiatric disorders.

So without further ado, here are five powerful ways to nurture your good bacteria and eliminate the bad bacteria in your gut. By following these steps, you’ll feel stronger both mentally and physically.

1. Take A High-Quality Probiotic

Simply increasing the amount of beneficial bacteria in your gut through probiotic supplementation might be one of the most powerful things you can do for your brain and mental health.

Probiotic supplements add good germs to your digestive system, and providing your body with a diverse array of friendly bacteria can significantly reduce your susceptibility to the negative effects of stress. Researchers have found that mice are less anxious when they are fed probiotics, and numerous studies have shown that humans experience less stress, anxiety, rumination, hostility, depression and aggression when supplementing with probiotics (3, 4, 5, 6, 7, 8, 9, 10).

Researchers are starting to uncover how probiotics work to support the brain. One study showed that probiotics can help you naturally produce more GABA, a relaxing amino acid and neurotransmitter. Amazingly, this same study showed that probiotics not only help your body produce more GABA, but they enhance the sensitivity of the GABA receptors in your brain, making you more susceptible to calming effects of your natural GABA production (8, 53). On the other hand, if you go to the doctor for anxiety, you’ll likely receive anti-anxiety medication, which works by activating GABA receptors in the brain.

Other species of probiotics have demonstrated an ability to reduce stress hormones and increase tryptophan, serotonin and omega-3 fatty acids in the brain, all of which play a role in proper mood and cognition (54, 55). So it’s critical to keep your insides flourishing with a healthy colony of good bacteria.

“These bacteria could eventually be used the way we now use Prozac or Valium. I think these microbes will have a real effect on how we treat these disorders. This is a whole new way to modulate brain function.”

— Dr. John F. Cryan, PhD, University College Cork

I’ve tried a number of different probiotics over the years. Some have helped me somewhat, while others haven’t helped me at all and even made me feel worse.

I’ve now created my own probiotic supplement, called Optimal Biotics.

I created it because I want to give my clients and readers the very best probiotic supplement so that they can experience superior results.

I have found that many probiotic supplements on the market fall short and even cause side effects.

But Optimal Biotics doesn't, and it contains the 8 most well-researched and beneficial probiotic strains.

2. Avoid antibiotics (unless absolutely necessary)

Seven years ago, I went to the doctor because my asthma was getting significantly worse. A lot of inflammation and phlegm was building up in my lungs. It felt like I was breathing through a straw all of the time.

The doctor incorrectly assumed I had a bacterial infection (I actually had gluten and dairy allergies), so he gave me a course of antibiotics. And then another course. And then another. They did anything.

Broad-spectrum antibiotics don’t differentiate between good and bad bacteria. These drugs not only kill bad bacteria, but they destroy good bacteria too. By the time I was done all three courses of antibiotics, a lot of the good bacteria in my gut was completely wiped out. And not only did my asthma get worse (and my body less able to handle the gluten and dairy I was eating), but my mental health deteriorated as well.

Moral of the story: Antibiotics can save lives, but they can also destroy your health if they aren’t completely necessary. Yet many conventional doctors hand them out like candy on Halloween.

“In most cases, those who suffer from mental health disorders like depression and schizophrenia, and from developmental disorders like autism, something has harmed the beneficial bacteria in their gut, sometimes before birth and sometimes later on in life.”

— Dr. Natasha Campbell-McBride, MD, Author of the Gut and Psychology Syndrome Diet

Studies show that antibiotic use can lead to profound changes and rapid loss of diversity in the composition of the gut bacteria and this can lead to other chronic health complications. American children are typically prescribed one course of antibiotics every year, and excessive and inappropriate use can cause serious long-term consequences without probiotic intervention. For example, antibiotics used to treat acne are associated with the development of inflammatory bowel disease (12, 13, 16, 17).

An article published in Nature highlights the negative long-term consequences of antibiotic over-prescription. It points out that antibiotics cause significant and possibly permanent changes in gut bacteria, and infants delivered via caesarean section and/or by a mother given antibiotics during pregnancy significantly will have an insufficient level of good bacteria (14, 15).

I don’t want to suggest that antibiotics are absolutely terrible and we should always avoid them. But they are excessively and inappropriately prescribed and their benefits come at a cost. You should be aware of this so you can make an informed choice. If you do decide to take antibiotics, make sure you take probiotics afterwards.

3. Feed the good guys with prebiotics and resistant starch

The existing probiotics in our gut need to be nourished and supported, and this can be done by eating or supplementing with prebiotics.

Prebiotics are substances that humans can't digest, so they pass through our gastrointestinal tract and promote the growth of many different strains of good bacteria in our lower bowel. They are essentially food for the good bacteria in our intestines.

Dr. Phil Burnet, a neurobiologist at Oxford University, published a paper in 2015 showing that people who ingested prebiotics have lower levels of cortisol, a key stress hormone, and focused more on positive feedback and less on negative stimuli. He said the results were very similar to when people take anti-depressants and anti-anxiety medication, but without the side effects.

Other research by Burnet shows that prebiotics support overall brain health in humans and foster the growth of probiotics in mice, which leads to increased levels of several neurotransmitters that reduced anxiety-like behaviour (19, 20, 21, 22).

Prebiotic-rich foods include sweet potatoes, carrots, onions, asparagus and squash. These foods are included in my free grocery shopping guide for optimal brain health and you should be eating them regularly. If you feed the good bacteria, you will feel healthier physically and mentally.

Resistant starch is one of the most potent ways to boost your prebiotic intake, and it’s been shown to help prevent and manage chronic disease (18).

A convenient way to incorporate more resistant starch into your diet is by using Unmodified Potato Starch. I’ve tried and recommend it. It's one of the easiest and cheapest ways to incorporate more resistant starch into your diet. It is bland so you can simply add it to beverages, smoothies and meals. It has to stay raw though, so don’t cook it.

Other high-quality resistant starches that I’ve tried include banana flour, plantain flour and waxy maize. I usually rotate between them.

Image of candy in a bowl and candy in an injectable needle

4. Don't feed the bad guys with sugar

Avoiding sugar is a critical aspect of preventing and treating brain and mental health challenges. Not only does high sugar consumption increase inflammation, but sugar is fuel for bad bacteria. Significantly limiting your sugar intake will starve the bad bacteria and allow the probiotic bacteria in your gut to thrive.

Diets high in sugar cause negative changes in gut bacteria that impair “cognitive flexibility”, which is the ability to adapt to changing situations. Sugar can also impair short and long-term memory (23).

In his book The Sugar Blues, William Duffy argues that sugar is an addictive drug and eliminating it can have a profoundly beneficial impact on mental health. For some people, cutting out refined sugar may be all they need to do to overcome their depression and other mental health challenges.

When I first cut out sugar several years ago, I actually went through withdrawal. I was incredibly tired, had increased anxiety and depression, and was sweating profusely at work. This makes sense in light of the research showing that people who drink more sweetened beverages are more likely to suffer from depression (24). My boss at the time thought I was sick, so he actually sent me home for the day. Eventually, I overcame the withdrawal and my mood and energy improved significantly.

So radically reducing your sugar intake will support your gut bacteria, brain chemistry and overall health.

5. Eat whole, probiotic-rich foods

Overall, you should also be eating a wide-variety of whole foods to support your gut health. Eating a standard Western diet for just one day can dramatically change your gut bacteria in a bad way, while eating lots of whole foods increases the diversity of good bacteria (45, 46, 47).

If you haven’t already, grab my Free Grocery Shopping Guide for Optimal Brain Health for a full-list of healthy whole foods.

And probiotics don’t just need to come in supplement form. You can also experiment with incorporating probiotic foods into your diet. Fermented foods include sauerkraut, kimchi, kombucha, natto and pickled cucumbers. The probiotic bacteria in these foods cause their fermentation. If you can tolerate dairy, foods like kefir and yogurt (unsweetened) are also high in nourishing bacteria.

By eating them, you’re promoting the proliferation of good bacteria in your gut, which will then support your brain. One study suggests that young adults experience less social anxiety if they eat fermented food, and another study shows that yogurt eaters experience positive changes in brain function that cause them to react more calmly to visual stimuli (25, 26).

“This was not what we expected, that eating a yogurt twice a day for a few weeks would do something to your brain.”

— Dr. Emeran Mayer, MD, Psychiatrist at UCLA

Probiotic foods tend to have a broad combination of bacteria too – more than what can be found in typical probiotic supplements. And people have been fermenting food for more than 8,000 years, yet most of us stopped after the invention of the refrigerator, which may explain the decreased diversity of good bacteria in our digestive tracts today.

Conclusion

Promoting the growth of beneficial bacteria through positive lifestyle choices can make our brains feel great and function optimally. Too much bad bacteria can make you feel mentally weak, tired and ill, and you may even see changes in your personality. I know I did.

Bacteria have lived inside humans for hundreds of thousands of years and therefore have lots of experience modifying our brains. They are more precise and subtle than pharmaceuticals, meaning means fewer side effects. As a result, changing the composition of our gut bacteria through lifestyle and dietary interventions is emerging as a very effective and practical way to treat anxiety, depression, autism and other mental health disorders (27, 48, 49).

So in conclusion, support and feed the good bacteria with:

And starve and fight off the bad bacteria in your gut by avoiding: