Where the Science of Psychology Meets the Art of Being Human

Anxiety, Depression and the Surprising Role of Gut Bacteria

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Mounting evidence is pointing to a powerful connection between the gut and the human brain, with the latest research coming from neurobiologists at Oxford University. Their findings are compelling and have promise for the management and future direction for treatments of depression and anxiety.

Inside the human body are trillions of microbes, collectively knows as the microbiome. When taken together, they are estimated to weigh about twice the weight of the average human brain. Think about that.

They live in the gut and their job is to digest food, synthesize vitamins and fight infection. What we are discovering is that their reach extends far beyond the gut, and all the way to the brain.

Studies over the last decade have identified the role of gut microbiome in maintaining certain brain functions such as mood, emotion and appetite. Research is increasingly pointing to the role it plays in psychiatric and neurological disorders such as anxiety, depression and autism. 

Researchers at the University of Oxford have found that taking probiotics has an effect on anxiety and depression by influencing the neuroendocrine stress response and by altering the way people process emotional information. 


The Study – What They Did

45 women between the ages of 18 to 45 took either a prebiotic or a placebo every day for three weeks.

(Probiotics consist of strains of good bacteria. They use prebiotics – carbohydrates they break down for nourishment – to multiply.)

At the end of the three weeks, the participants performed a number of tests involving positive and negative words, to measure how they processed emotional information. 

What They Found

Those who took the prebiotic paid less attention to negative information and more attention to positive information compared with those who took the placebo.

This effect is similar to that facilitated by antidepressants or anti-anxiety medication.

The prebiotic group also had lower levels of cortisol (the stress hormone) compared with the placebo group. High cortisol levels have been linked with anxiety and depression.


 Adding to the promise of the findings is research out of France that found that people who took probiotics for 30 days had reduced levels of somatisation (physical symptoms such as pain and tightness that are brought on by psychological distress), depression, anger-hostility and anxiety.

Early evidence for a gut-brain connection came from a study led by Dr Kirsten Tillisch of UCLA’s School of Medicine.

In their study, women who ate probiotic yoghurt (containing containing probiotic strains such as Bifidobacterium animalis, Streptococcus thermophiles, and Lactobacillus bulgaricus) twice a day for a month showed alterations in brain function, particularly in the brain’s response to the environment.

This was compared to women who ate a dairy product without any living bacteria and another group who ate no dairy products.

Brain scans revealed that those who took the probiotics had reduced activity in the area of the  brain involved in processing emotions.

Tillisch explains, ‘When we consider the implications of the work, the old sayings, ‘you are what you eat’ and ‘gut feelings’ take on new meaning.’

‘Time and time again, we hear from patients that they never felt depressed or anxious until they started experiencing problems with the gut.

Though probiotic cocktails aren’t likely to replace conventional treatments any time soon, there is compelling evidence to suggest great potential in using them as part of a treatment or management plan for anxiety or depression. 

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36 Comments

Marlene Blake

Really need the knowledge to help understand how my daughter feels i am a great listener but i never have the answers to help her she was diagnosed last year. All of her communication now is about her anxiety and depression it has control of all of us right now we don’t know how to help her switch that feeling off.

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heysigmund

It can be so hard to know what to say and the truth is there is no ‘right thing’.Is your daughter seeing a counsellor? Did you have a look under the depression tab – there are other articles there that might help. You’ll find it under ‘Being Human’, then ‘Depression’. Exercise has been found to have the same effect on the brain as antidepressants and it’s also important for anxiety – it’s a natural end to the fight or flight response and is protective as well. If she’s depressed it’s likely that she won’t feel like going but if you can go with her for a walk that would be so good for her. Here is the link to the article just in case you haven’t read it yet http://www.heysigmund.com/fighting-depression/ . It really does make a difference. You’re doing the right thing just by being there.

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Linda

You use both probiotics and prebiotics – is this a typo, or are they two different things? Where would a person find either or both of these, and is it okay to just take/eat them yourself or does a doctor need to be consulted?

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heysigmund

Prebiotics are the food for probiotics (I know – it took me a bit to get my head around it!) I just get them from my pharmacy in the supplements section. The first time I bought them, I spoke to the pharmacist who was very well-informed about the research, so hopefully other pharmacists will be too. Hope that helps.

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Donna

I have been fighting with PTSD, depression and anxiety most of my life I take 4 different medications for it. This sounds to good to be true.

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Hey Sigmund

It’s certainly not a quick fix but there is a lot of research looking at the connection. Have a chat to your doctor about it, and remember that if you’re on medication it’s always important not to stop taking it without medical supervision.

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Charles brown

I have struggled with stomach problems and anxiety for over 25 years. I started probiotics about two months ago and it has made a world of difference in my thought pattern, anxiety, mood and gut distress. I have always said that all my issues started in my gut and sure enough the research is proving me right. Now if we can only get the Doctors on board with this new research discovery.

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Hey Sigmund

Intuition is pretty amazing isn’t it. I’m pleased you’re finally finding some relief. Thank you for sharing your story. It’s important and you never know who will be helping.

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Marielle

I have struggle with gut(lack of urge to go) and anxiety for decades. With no relief. Tried so many things with no luck. Its like my brain in times of anxiety just turns my digestion off and then more anxiety is created by not going. Its this horrible vicious cycle with no relief. Tried probiotics but caused me such pain. Any thoughts/suggestions. Been to western Dr(s) and naturopath. Always address diet but no luck as eat clean and exercise daily.

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Hey Sigmund

Marielle what you are describing about your your anxiety and digestive issues is not unusual. With probiotics is it important not to have a massive dose too quickly as it can make symptoms worse. This is because when probiotics kill the pathogens in your gut, the pathogens release toxins. It is possibly these toxins that are causing your symptoms, and when there is a surge of them they will initially make your symptoms worse. It is impossible for me to say with any certainty, but it might be one track to investigate if other possible causes have been investigated and have lead nowhere. I would suggest speaking to another naturopath or doctor who can discuss other options or who can guide you through a more gentle introduction of probiotics.

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Natalie

Marielle, something else to consider. Some probiotic blends contain beneficial yeasts (and other organisms), like saccharomyces boulardii, that you don’t find in a lot of supplements. For people with yeast sensitivity like myself ingesting s. boulardii can raise inflammation in the body due to an immune response to the yeast (or other offending organisms/ingredients). Raised levels of inflammation can affect your mood negatively. Point being, if you are sensitive to something in your probiotic blend, it can make you feel worse. It’s not necessarily that the probiotics are bad or don’t work for you, but you may need to try a different one. For the record, Prescript Assist has several saccharomyces organisms in it as well as many other soil-based organisms that are different from the “usual” ones you would find in most supplements. It seems to work very well for some people, and not so well for others. I would guess this is probably due to sensitivities which would vary from person to person. These things can be determined through testing. Good luck!

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Natalie

Sorry, my last comment was directed at Britt, below. My mistake. Think I need to get some coffee in me.

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Britt

I also have had anxiety and gut issues (IBS C ) for most of my life. I am now paleo AIP and that has helped but not solved it. I tried probiotics (biokult) for two months and noticed no difference. I then switched to prescript assist and they made me feel really weird and more anxious. Any ideas ? What would be considered a mild probiotic to help me ? Biokult didn’t work. I’m a little lost. Thanks

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Hey Sigmund

I would really suggest working closely with a naturopath. There are so many different bacteria in the gut and it may depend on the type of probiotic you use. It is also important to introduce the change slowly. When probiotics kill of pathogens, they release toxins. It is these toxins that are likely to be already contributing to the symptoms. If probiotics are introduced too much too soon, the release of toxins will increase suddenly and may potentially lead to to a worsening of the symptoms. This may have been why you felt worse when you switched. Don’t give up though – there is no one size fits all for this, which is why a naturopath may be the way to go.

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Kelly

I started using a great probiotic about a year ago and have noticed amazing results without any weird side effects. I wasn’t even really aware of the benefits of probiotics until then but I don’t go a day without it now. I’d love to share more with you if you’re interested.

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Cherie

I have recently started drinking kombucha and kefir amazing probiotics in them. I am diagnosed bipolar 2 disorder and have noticed an emense change in how i feel better than the anti depressant medication!!

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Lara

A fantastic article…thank you for posting! Prebiotics and probiotics are saving me from years of anxiety and depression. Note that many probiotics aren’t strong enough and won’t colonise in the gut, especially if you suffer from leaky gut (which most of us do). To heal leaky gut in as little as 2 months, PLEASE research ‘bovine colostrum’ on the Net. It also serves as the best prebiotic out there. (The brand is vital. Two of the best are Immune Tree and Synertek.) Nothing has every made such a difference to my health – and anxiety/depression – as colostrum. Hope and blessings.

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Josie

Oh! I had heard of bovine colostrum before but had completely forgotten about it. Thanks for the reminder. 🙂

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Trish

Hi there
Interesting stuff, thank you.
My husband is allergic to penicillin, so can’t eat probiotic yoghurt. Any suggestions re alternatives which could achieve the same effect with regard to depression?

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Hey Sigmund

Trish I would really encourage you to speak with a naturopath, doctor or pharmacist. They should be able to set you on track with this and hopefully help you to find something for your husband that will support his gut health without triggering any negative side effects.

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Mary Kelly

I healed my depression, anxiety, PTSD and IBS by following a highly probiotic diet called GAPS. Dr Natasha Campbell-McBride needs to get some credit: she has been promoting the gut brain connection for over 20 years, and has been healing kids with behavioral disorders by the thousands. The key for us was not just probiotics off the shelf but probiotics with huge variety (more than 6 strains).
So pleased to see this information getting some research to confirm what clinical studies have been saying for years (and have been derided for for years).

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Therese

Yes! Just picked up a book from Dr Campbell-McBride about GAPS diet from my mum, who has just been on the diet for a few weeks now. After decades of problems with her digestion/bowels, suspected IBS & a recent discovery that she carries a gene for coeliac disease (?), she is now feeling SO much better, both physically & mentally. She also suffered anxiety & mild depression over the years. The diet has been a big adjustment though, not easy, but worth it…My teenage daughter is on meds now for anxiety & depression and, although I am very doubtful that she will consider the diet in its entirety, I am hoping she might take a probiotic supplement. My mum had been recommending this for a long time, so good to hear others have benefited (or why they haven’t)

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Fraser

The bacteria in our guts can vary tremendously from one person to another – my intuition is that what works for one person will not necessarily work for another, and treatment would depend on whether or not there are important bacteria which can only be obtained from the gut of another human being. There has been some interesting work in this field recently and I wonder if it is possible to look at the influence of probiotics in isolation without considering a person’s initial gut flora to start with?

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Palwasha

Spot on
When ever i take med for gut problems IBS they dont work whenever i take them with meds for depresion they do magic
My pains my moods i mean everythng seems better when i take these two toghtr
So if someone has IBS n their med not workin ask ur doc if he can add mild anti depressants with it n thn c in a week

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Tracie in Kansas

Gut health equates to brain health. Too bad so many mainstream doctors don’t understand…

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Debi

When I read this article a while back (after binge-reading your articles in an effort to help my then 14 yr old!) I figured it couldnt hurt, so bought probiotics. Added them to her routine of Magnesium 400 mg (was recommended by her counselor) hoping it would give her a little boost and I have to say, it has changed her entire situation!!! I am now an avid fan of probiotics in teens with anxiety!! She now uses ALL the things in her “tool box” to keep her anxiety at bay (that I found on your website, like mindfulness, SmilingMind, etc!!) and is completely blowing our minds with her bravery! She is now on the drama team at church, is in student leadership, a team leader at youth camps, and does things (tubing down a river!) that she would have NEVER done before. I have to say, I can point clearly to your website for the information to help in redirecting her anxiety. Tummy aches (were daily) are now maybe once a month, and last an hour at most!!) I told you in a comment years ago when you first got on facebook that you should charge for this, I would pay….. a lot! It would be worth EVERY PENNY for our family! Bless you, Karen. You are simply amazing and I am one grateful Mama for your knowledge!!

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Karen Young

Yes you’re absolutely right. The way to sustain probiotics is with probiotics. Prebiotics are food for probiotics. Sources of probiotics include whole grains, peas, avocado and apple cider vinegar.

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J

People have been using the GAPS diet (“Gut and Psychology Syndrome”) for better mental health with great success! Our family used it to fix some food intolerances. Check it out!! Gut flora (bacteria, yeast, etc.) has a huge influence on how our brains function.

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Jane

I’ve been brewing kombucha tea and making my own homemade yogurt and kimchi for a few months now – I just need my daughter to actually believe the science stuff and start to eat and drink this stuff.
I’m showing her this article because right now, I think she thinks I’m making it up!

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Michelle

This article is great! I have had anxiety and chronic fatigue since my early teens. Dr’s couldn’t figure out why, so basically I just needed to learn to live with it. a few months ago I was introduced to Plexus to try help with my energy. And it has! But it also really helped with my anxiety! I couldn’t believe it! I started researching why, and this is exactly it! Gut healing! It includes fantastic pre and probiotic supplements along with an all natural detoxer, including magnesium and vit C! check it out! Plexus worldwide.com! If you do, and want to know more, please email me I would love to share and help you!

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