Probiotics for Anxiety

An up and coming health trend I am sure you have heard of are probiotics. Probiotics for anxiety is a branch of gut health that includes mental health too. Here we go over everything you need to know about probiotics for anxiety, stress, and mental wellness.

Anxiety is more and more common nowadays. “I’ve been so anxious lately” is something that you now hear all the time.

What is anxiety, though, exactly?

Research published in medical journal Depression and Anxiety in 2009 defined anxiety as a future-oriented state of mind. We can associate anxiety with preparation for upcoming, possibly negative events. 

Many people really struggle with it.

Anxiety is becoming the norm

According to a study published by Pharmacy & Tehrapeutics in 2013, about 13% of the U.S. population has experienced symptoms of an anxiety disorder. Anxiety is the most prevalent mental health disorder of this decade. 

Anxiety is very common nowadays

While you might associate anxiety mostly with mental symptoms, one of the symptoms of anxiety can actually be gut-related.

You’re certainly familiar with this basic effect. Think about the feeling of “butterflies in your stomach” when you’re nervous or excited.

Go back to the last time you argued with someone, had a big test, or were minutes away from an upcoming presentation.  You were experiencing mental stress and you felt it in your belly. 

The scientific medical name for this is the gut-brain axis.

The Gut-Brain Axis

Your gut manifests the symptoms of your daily stresses and anxieties. There is a real, physical connection between your brain and your digestive tract. The gut-brain axis will be the group of nerves that connect and send messages from your brain to your stomach (digestive tract) and back.

The gut brain axis is long and somewhat complex. In 2017, research published by Elsevier’s Neurobiology of Stress journal identified this two way pathways. Your gut and your brain form this axis with these main parts:

  • vagus nerve
  • immune system
  • gut hormones
  • gut bacterial metabolites
  • tryptophan metabolism

The fact that you have such important connections means that changes in your brain (i.e. stress or anxiety) can and will affect the function and health of your digestive system. 

Luckily, these influences are a two-way street. That means you can improve your mood and reduce your stress by boosting your gut health!

One of the best ways to do this is by consuming more probiotics.  

What are Probiotics?

Probiotics are often referred to as your “friendly bacteria”.  You might see the term:

  • “intestinal flora”
  • “microbiome”
  • Lactobacillus acidophilus
  • “good gut bacteria” 

How is that possible? 

Most of us grew up thinking that bacteria are bad. That they give us infections and make us sick. When we talk about probiotics, this is not the case. 

In fact, probiotics are becoming very popular as gut health becomes a trend in the medical and wellness world. The global market for probiotics in 2018 reached 49.4 billion USD and the forecast for 2023 is 69.3 billion USD.

Many people use probiotics for gut health, but they are also becoming popular for mental health and you will find supplements sold as ‘mood enhancers’.

So these bacteria (particularly the probiotics in your digestive tract) are definitely good for your health.  In fact, they are downright necessary for proper digestion and general wellbeing. Some probiotics benefits include: 

  • weight management
  • cholesterol level regulation
  • immune function
  • mental health

How Do Probiotics Help Reduce Anxiety?

Let’s take a look at how probiotics can regulate anxiety.


Firstly, a short recap on the HPA axis. The Hypothalamus Pituitary Adrenal axis is the main regulator of the stress response in our bodies. These structures in the brain and body regulate how we respond to stress.

When we experience anxiety, the HPA response is high. This is the physical and neurological manifestation of stress and anxiety. These glands, hormones and brain centers are responsible for this response.

Your brain has a lot of nerves that go to your gut!

By observing this part of our bodies (or in experiments in rats) scientists can observe how anxiety behaves physically.

Now, let’s visualize the relationship between probiotics and our stomachs. It seems like gut bacteria can activate the HPA axis. Research published by Elsevier’s Psychoneuroendocrinology in 2012 took a look at animals raised in a bacteria-free environment. This group had an irregular HPA response. Interestingly, adding probiotics to their environment improved this irregularity.

Balancing the HPA signalling: a sensitive brain center

The HPA axis is a delicate chain of brain areas and gland centers. Think of hormones and neurotransmitters as the messengers. They are in charge of transmitting a message from point to point.

Any alteration in the messengers, or the points themselves, can be modified. Modifications result in an irregular stress response. This can look like an overly responsive system, meaning your body reacts easily to external stimuli. Or it can be an underly active response, meaning your body has trouble perceiving ‘threats’ and reacting properly to it. None are good.

In the case of ingesting probiotics, scientists observed that the HPA axis reacted efficiently. Eating probiotics (or consuming supplements) can help regulate and balance an irregular stress response.

Researchers used the most common probiotic bacteria E.coli to observe its effects on the HPA axis. Researchers look at different factors. This study published in Psychoneuroendocrinology in 2012 found the group treated with probiotics had better corticosterone and prostaglandin levels. These two measures are reliable when observing the stress response.

Reducing cortisol

Meanwhile, at the end part of the HPA signaling pathway, we have cortisol. You might have heard it dubbed ‘the stress hormone‘.

Research published in 2016 by scientific magazine International Journal of Microbiology, checked stressed students’ cortisol. produced less cortisol when taking probiotics. They took salivary cortisol samples in young adults under the stress of upcoming academic exams. The population was divide in two: a placebo group and a probiotic bacteria treated group. The group treated with Lactobacillus plantarum 299v showed a decrease in salivary cortisol levels.

As a result, we can conclude probiotics reduce a physical measure of the stress response. This research is very neat because the sample includes people who are worried and thinking of future events. Probiotics helped these anxious students!

Serotonin production

Likewise, researchers have also looked at serotonin levels. Serotonin is another neurotransmitter (hormone) that regulates anxiety, happiness and mood.

Serotonin is one of the many hormones that make our brain receptive to stress

For example, researchers looked at the antidepressant properties of probiotics. A study published by the Journal of Psychiatric Research in 2008 explored the effect of probiotics on depressed and anxious rats.

Rats treated with the probiotic Bifidobacteria infants produced more tryptophan in the brain. This is a good indicator of enhanced mood! To clarify, tryptophan is the molecule that becomes serotonin, the hormone of happiness. In this model, probiotics helped regulate it.

Probiotics potentially regulate anxiety and depression by changing this part of the HPA system.

An environment with bacteria can be healthy

Meanwhile, this other research separated mice into bacteria-free and bacteria-associated groups. In this case, researchers used behavioral tests to observe and measure anxious behavior. They also measured neurotransmitters in different brain parts. Certainly science is looking to have many ways to measure how probiotics affect the brain and our body.

In conclusion, they found serotonin indexes were higher in the bacteria associated group of mice. Most importantly, this happened in many brain regions. Additionally, these mice also displayed less anxious behavior.

These findings published by medical journal Neurogastroenterology and Motility in 2013 show that environments with ‘good’ bacteria are positive when regulating anxiety.

That is to say, probiotics in your gut environment most likely help anxiety.

What Are the Best Sources of Probiotics?

Outside of the scientific world, you might associate probiotics to different types of foods. Maybe yogurt, maybe other fermented toppings. For a second, let’s forget all this medical jargon and the idea of ‘bacteria’ inside you.

Probiotics are natural. Different types of food have probiotics. You can easily incorporate these into your diet.

In fact, it happens to be that probiotic-rich foods are usually fermented foods.  This is because the fermentation process actually adds probiotic bacteria directly into the food. Then you can eat these probiotics!

Common fermented foods

Foods that you’ll likely be able to find at your supermarket include:

  • sauerkraut 
  • miso 
  • yogurt 
  • kimchi 
  • kefir
  • pickles 
  • kombucha 
  • olives
  • traditional buttermilk
  • fermented cheeses

Here’s a quick overview of each of these types of fermented foods:

Sauerkraut and kimchi

These are types of fermented cabbage. Firstly, kimchi is the Asian version typical to Korean culture and cuisine. Secondly, sauerkraut is the European version commonly found in German and Polish menus.

According to a study published by Global Advances in Health and Medicine in 2014, both sauerkraut and kimchi have anti-inflammatory, antioxidant, and immune-boosting properties.

International food markets nowadays sell both sauerkraut and kimchi.  Supermarkets are starting to offer these products, as well.  You can make them at home too! Here is an easy to follow recipe for sauerkraut.

Fermenting cabbage is part of the process of making kimchi and sauerkraut


This fermented beverage is gaining popularity in health circles. Kombucha has origins in the Manchurian region of China. Yet nowadays, it has been popularized and globalized. It is easy to find in cities all around the world.

Traditionally it is made by fermenting black tea with sugar. The main ingredient is SCOBY, a combination of bacteria and yeast. SCOBY means Symbiotic Culture of Bacteria and Yeast. Here are the probiotics that are good for your gut, and your brain!

According to researchers published by science journal Nutrients in 2019, there is growing evidence kombucha aids in certain gut health issues. Certainly, kombucha has been related to:

  • weight loss
  • regulated cholesterol levels
  • stable blood glucose
Kombucha is very refreshing and very healthy for you. Lots of probiotics and fermented goods!


Yogurt is the most common and known source of edible probiotics.  I am sure you have heard yogurt is good for your tummy.

Certainly, it’s a great breakfast meal and also a good snack.  Additionally, some types of yogurt (Greek, for example) have added the most well-studied probiotic strains (Lactobacillus acidophilus or Lactobacillus casei). They have a good amount and some brands add extra probiotics.

Definitely, by including yogurt in your diet, you’re adding benefits to both your digestive and mental health.

Miso soup

Sushi night, anyone?  Japanese restaurants always offer miso soup as an appetizer. Are you into this warm dish?

The main ingredient in miso soup — miso — are fermented soybeans with the probiotic bacteria A. orzae.  While most of us are used to enjoying miso in soup, it also comes as a paste, spread, or sauce. It’s surely a great item to explore in the kitchen and to add to your diet.

But let’s talk science. In this research, pregnant women that reported anxiety and depression tried adding fermented foods to their diet. According to this experiment published by the International Journal of Obstetrics and Gynecology in 2015, fermented food items can help depressive symptoms during pregnancy.

Miso soup contains A. oryzae, the main probiotic strain that makes it so healthy


Have you ever topped a sandwich or salad with pickles? Do you add them to burgers?

Pickles are fermented cucumbers. Curiously, they make an excellent probiotic-rich snack or meal topping!

According to this study published by Elsevier’s Psychiatry Research in 2015, fermented food consumption can have an effect on social anxiety.

Interestingly, pickles were used as one of the food items. The group eating foods containing probiotics showed a protective effect against social anxiety symptoms.

Do you top your food with pickles?

How Many Probiotics Should I Get Each Day to Treat Anxiety?

Probiotics are measured in CFU or “Colony Forming Units”.  A common daily dosage for children ranges from 5 to 10 billion CFUs. For adults, the range is 10 to 20 billion CFUs.

Some supplement servings might contain 1 billion, others up to 100 billion. This will vary and depend on the brand. In fact, the main variables are:

  • amount of strains supplement contains
  • the type of strains included in supplement (or food item)

The exact dosage that is best for treating anxiety isn’t yet 100% clear.  To sum up, it likely depends on the strain in your probiotic supplement. 

Different strains, different doses

For example, in this research published by Beneficial Microbes in 2019, participants taking 1 billion CFUs of  Lactobacillus plantarum DR7 showed reduced symptoms of stress and anxiety. Total psychological scores improved for the group consuming probiotics. In short, this strain helped anxiety and stress.

On the other hand, a study released by Clinical Nutrition journal in 2019 checked a similar strain. Lactobacillus plantarum P8 was found to be effective at 10 billion CFUs per day.

Clearly, effective doses can vary! To sum up, there is always a dose and type for a given purpose.

probiotics supplement for anxiety
Supplementing with probiotics is very common. It’s safe and it’s become the norm

Your best bet for finding a good fit for your body is to check in with your doctor or nutritionist.  Hopefully, they’ll be able to give you personalized recommendations specific to your situation. 

Meanwhile, if you just want to give an over-the-counter supplement a try, you can! 

Taking probiotics is safe. For example, you could opt for something that falls in the standard 10 to 20 billion CFUs per day.  

Read Next: Best Probiotic Supplements for Leaky Gut [Based on Research and Reviews]

How Long Does It Take For Probiotics to Ease Anxiety Symptoms?

In general, the amount of time it takes for probiotics to show an effect on mental health assumes and recommends will depend on:

  • the quality of the probiotic
  • CFU count
  • routine and how often you take the probiotic
  • other routines, such as diet and exercise

Naturally, if you have a steady routine, and start taking high-quality probiotics daily, you can see almost immediate results. Most people report improved mood and decreased anxiety on the first or second day of adding probiotics to their diet.

In fact, studies have found nearly immediate effects of high-quality probiotics on immune function. However, depending on what symptom and quantity of probiotics you are using, the effects can take from one day up to several weeks.

Time is relative… That being said, observe and recognize how your body usually adapts to your change in diet

That being said, depending on your body and your circumstance, it may take a little longer to really notice changes in your anxiety symptoms. 

Again, exactly when you’ll start seeing real relief will depend on a lot of factors that are completely personal to you! 

But, based on the research we have now (which, to be fair, is still pretty sparse), you can expect to be feeling better within about 3 to 6 weeks. According to this research published in Frontiers in Psychiatry journal in 2019, during this time frame, participants consuming probiotics had improved sleep, fatigue, and mood.

Could Probiotics Make Anxiety Symptoms Worse?

Certainly not!

It is highly unlikely that taking probiotics will worsen your anxiety symptoms.  Surely, anxiety hasn’t been reported as a side effect of probiotic in studies.

Side effects: just in case!

Meanwhile, let’s review side effects. Just in case you are unsure of what else could happen when adding probiotics to your diet. Don’t worry about these bacteria adding to your anxiety. They are here to help! Most side effects happen on other body parts.

For example, if you have a weakened immune system, probiotics can cause an intestinal infection. According to research released in the Journal of Clinical Microbiology back in 1998, immunocompromised patients can develop infections in the presence of probiotic strains.

Generally, if your immune system is healthy, you should not be at risk. In fact, it’s unlikely you’ll experience any negative side effects from using probiotics for your anxiety at all. 

Common side effects were studied by researchers in 2010 published in the American Journal of Health System Pharmacy. Most people report some flatulence and bloating that clears up on its own after a couple of weeks. 

Note: If you opt for fermented foods as your main source of probiotics, you can also develop a histamine imbalance. According to science and medicine journal Headache, a publication in 2016 confirmed that this imbalance can lead to

  • headaches
  • sneezing
  • itching
  • watery eyes
  • runny nose
  • flushing
  • wheezing
  • fatigue

To clarify, probiotic supplements don’t pose this risk. This can happen with some fermented foods and in some body types.

The Best Probiotics for Anxiety

Awesome. So probiotics are GOOD for anxiety. A stable gut-brain path means a stable gut and brain health. However, which probiotics?

That is to say, how do I choose a probiotic strain that will help my mood?

There are many, many options when buying probiotics supplements. As any big market, it can get pretty crazy.

However, you can narrow down the search! For instance, science already determined that there are strains of bacteria that specifically help anxiety and depression. Here’s the list:

  • Bifidobacterium longum and lactobacilus helveticus
  • Lactobacilus rhamnosus
  • Lactobacilus plantarum

Bifidobacterium longum and lactobacilus helveticus

This study briefly looked at the effect of a probiotic formula combining bifidobacterium longum and lactobacillus helveticus in human volunteers.

Researchers published by the British Journal of Nutrition in 2011 first looked at the probiotic formula’s effect in rats. They found that daily intake of these two probiotics reduced anxiety-like behavior.

In humans, they used psychological tests and other measures. They found that the group using this probiotic formula experienced less psychological distress and also reported reduced anxiety.

Lactobacilus rhamnosus

Research is just recently looking at probiotics and their anxiolytic effect. It seems like this strain has potential! According to research published by PLOS ONE medical journal in 2018, this probiotic strain reduced anxiety-like behavior in animals.

Lactobacilus plantarum

Research published by Elsevier’s Behavioural Brain Research in 2016 showed how mice were treated with PS128 probiotic strain. Then they tested the group for anxiety-like behavior.

Compared to the placebo group, the mice who received Lactobacilus plantarum in their diet displayed less depressive and anxious behavior. Additionally, serotonin and dopamine levels were higher in the striatum.

We can conclude that this strain helps anxiety!

5 Probiotic Brands We Recommend for Anxiety

We took the time to review and select five probiotics brands. We chose them carefully. They all bring wellbeing. These can help your anxiety by promoting a balanced gut health.

1. Garden of Life Probiotic and Mood Supplement

This probiotic brand is probably one of the top in the market!

It combines several strains to bring different benefits to your gut and to your brain. This blend has 16 different types including l. helveticus and b. longum for mood, relaxation, and emotional wellbeing. They have also added ashwagandha and Alaskan blueberries to this mix.

With 50 billion CFU, and a branding that promotes digestion support, immune support and claims to be a mood supplement, reviewers seem to be satisfied and happy.

Ranging from a person who treated his autistic kid to several people struggling with anxiety, most five star reviews highly recommend this bottle.

Amazon Button

Lower star reviews complain about wrong or broken packaging. Some mention that the capsules were empty.

Garden of Life is a respected health supplement company that has been around since 2000. Founder Jordan Rubin has a compelling story on how probiotics helped him heal. His vision is very honest. Garden of Life has a whole range of probiotics that you can find in your local co-op, Whole Foods and other health stores.

2. Lifted Naturals Mood Boosting Probiotic

This brand also titled this probiotic mix as ‘mood boosting’. And it actually is! It brings a blend of both strains b. infantis and b. longum, and others for more health benefits. They chose ‘feel good’ strains to relieve anxiety. The bottle has 60 capsules and each cap has 30 billion CFU.

Amazon Button

Happy reviewers are highly satisfied when talking about its effects on anxiety and depression. Most observe an improvement within two weeks and assure relief.

Unhappy reviewers mention side effects of increased anxiety, upset stomach or no effects at all. Most reviews are positive.

Lifted Naturals is a family-owned small business that specifically makes and sells probiotics for anxiety and stress.

3. Life Extension Florassist Mood Improve

This probiotic brand comes in a smaller bottle (only 30 capsules) but has added saffron extract for more benefits. They claim to balance mood and promote brain health, which seems to be the general review. With 3 billion CFUs and both l. helveticus and b. longum in this mix, you can surely treat your gut and your anxiety.

Amazon Button

Satisfied reviewers are happy and claim IBS (irritable bowel syndrome) is gone. Unsatisfied reviewers complain there is no effect and that the product is pricey. Life Extension created this blend to promote emotional well being and balance your mood.

4. Nutriotix’s Mood Boost Probiotic Anxiety Pills

Although the marketing can seem a bit different than other probiotics, this mood booster pill can help relieve anxiety. This product combines several bifidobacterium and lactobacillus strains, plus chamomile capsules, Jerusalem artichoke, elm bark and passion flower. All these ingredients together aim to naturally stimulate the gut brain connection and decrease anxiety and depression.

Amazon Button

With 50 billion CFUs and the added herbs, customers are very happy. Top reviews complement the ‘peaceful’ mood it can provide after a few days of using it. One review has not seen effects. The bottle has 30 capsules and they are gelatin, so technically these don’t classify as vegan.

5. New Chapter’s Mood Support Probiotic

Another probiotic that is mixed with herbs like lavender, lemon balm and Jerusalem artichoke, this supplement is sure to boost your mood. With 6 billion CFUs and 60 caps per bottle, this probiotic blend aims to aid digestion, brain health, immunity and wellbeing in general.

Amazon Button

Users describe more ‘balance’ and ability to handle stress. Reviews comment that it also smoothes digestion. They report it takes about a week to have full effects on the body. These supplements are also complimented on how easy they are to take and that no bloating, burping is noticed, in comparison to other probiotics with similar branding. Some users report no effects.

If you are having doubts about how to take probiotics, please read this guide: Why, How, and When to Take Probiotics? [Quick Guide]

Take Home Message

Probiotics CAN aid anxiety.

Anxiety is a mental health condition that is on the rise. Thankfully, there are many ways to manage and overcome it. Adding probiotic supplements or probiotic-rich foods to your diet can reduce your anxiety symptoms.

The more science discovers the deep and powerful connection between the brain and the gut, the more we must prioritize our gut health.


Please enter your comment!
Please enter your name here