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Probiotics and Mood

April 13, 2009 Written by JP    [Font too small?]

One of the primary differences between holistic and conventional medicine is that they often have different objectives. In conventional medicine, you’re often given prescription medications or surgical interventions to help address problematic symptoms. In the holistic medical model, your physician will often want to discover the root cause of your “dis-ease” and try to help heal the imbalance. The difference may seem ambiguous, but it essentially boils down to actual healing as opposed to simply masking or getting rid of troublesome symptoms.

If you walk into a typical medical doctors office complaining of feelings of anxiety and depression, he’ll likely examine you and if nothing is obviously wrong you’ll probably be given a prescription for some form of anxiolytic (anti-anxiety) or antidepressant medication. If, however, you go to a naturopathic doctor, you’ll likely be asked a much longer list of questions. Some of the inquiries may even seem irrelevant, but the condition of seemingly unrelated systems in the body may contribute to mental health.

Meet the Bacteria

These microorganisms have been shown to boost health in scientific studies:
Strain(s) Benefits Product
Bifidobacterium animalis DN-173 010 (marketing name: Bifidis Regularis) Supports gut health and faster digestion Dannon Activia yogurt
Bifidobacterium infantis 35624 Alleviates symptoms of (IBS) Irritable Bowel Syndrome Procter & Gamble’s Align supplement
Bifidobacterium lactis Bb-12 Helps immune system and digestive health Yo-Plus yogurt, Nestle Good Start infant formula
Lactobacillus casei Shirota Supports immune function, digestive and emotional health Yakult fermented dairy drink
Lactobacillus casei DN-114 001 (marketing name: L.casei immunitas) Promotes healthy immunity; lessens duration of colds and flus Dannon’s DanActive dairy drink
Lactobacillus rhamnosus GR-1 in combination with Lactobacillus reuteri Improved vaginal health; helps eradicate (UTIs) urinary tract infections PreHresh Pro-B and Fem-Dophilus dietary supplements
Lactobacillus reuteri 55730 Helps manage colic, gingivits, antibiotic-associated diarrhea BioGaia tablets, drops and lozenges
Saccharomyces boulardii yeast Helps prevent and treat antibiotic-related diarrhea Florastor dietary supplement

A study that appeared in the March 2009 issue of Gut Pathology offers an alternate view of how we may be able to manage anxiety naturally. The focus of the research was on the use of a special strain of healthy bacteria (probiotic) called Lactobacillus casei Shirota (LcS). Probiotics are a class-friendly bacteria commonly associated with cultured or fermented foods like kefir, sauerkraut and yogurt. They serve many functions in the body, including participating in the digestion of food, the production of essential nutrients and supporting immune function.

In this current scientific trial, 39 patients with chronic fatigue syndrome (CFS) were given 24 billion units of LcS per day or a placebo for 2 months. The intent was to determine whether LcS could help alleviate one of the common symptoms associated with CFS: anxiety. The reason that a probiotic was chosen for testing is that previous research indicated that CFS sufferers sometimes have an imbalance between the friendly and pathogenic bacteria in the digestive system.

In order to examine the possible connection between good and bad intestinal bacteria and anxiety, the researchers tested for both physical and psychological changes in the following ways:

  1. The patients provided stool samples at the beginning of the study and after its completion.
  2. All the participants took standardized tests known as the Beck Depression and Beck Anxiety Inventories prior to and post study.

Of the original 39 patients, 35 completed the study. Two patients from both the placebo and LcS group dropped out for reasons unrelated to the trial. Here are the findings of the researchers:

  • The group receiving the probiotics showed significant increases in two forms of beneficial bacteria (Lactobacillus and Bifidobacteria) in their stools.
  • The LcS participants also exhibited a dramatic improvement in the Beck Anxiety Inventory score.
  • No serious side effects were reported in either group.

The authors of the study offered this cautious appraisal, “Overall the results suggest that specific strains of probiotic bacteria may have a role to play in mediating some of the emotional symptoms of CFS and other related conditions. However, it is important to note that this is a small pilot study and broad conclusions cannot be drawn at this time.”

Anxiety Disorders

More research is indeed called for. But it’s also true that some previous trials seem to support the findings of the first experiment just illustrated. Below are highlights from a few other interesting studies that looked into the role that probiotics may play in promoting mental health.

  • In the December 2006 issue of the European Journal of Clinical Nutrition, a study was presented that found that a probiotic milk drink could improve mood in a group of depressed older adults. The results were apparent in as little as 10 days.
  • A different healthy strain of bacteria, Bifidobacteria infantis, helped to lower inflammation and increased the levels of serotonin precursors in a group of rats. Both functions are known to be associated with an antidepressant effect.
  • Other research, such as this 2007 study, is beginning to illustrate a communication pathway between microbes residing in the gastrointestinal tract and various regions in the brain that control emotions.

These preliminary experiment offer tantalizing clues about the role that intestinal health may play in keeping our emotional systems in good order. If you’ve tried other methods of addressing anxiety and depression without success, perhaps you might consider the role that your “gut instinct” may be playing in the process.

Be well!


Posted in Bone and Joint Health, Mental Health

10 Comments & Updates to “Probiotics and Mood”

  1. Anna M Says:

    I recently read about this study as well. I’ve been into probiotics for digestive and immune health for a while, and my comapany makes a probiotic product called Flora Calm for sleep and relaxation support. But, this info on probiotics to help with CFS and more is really fascinating! I’ve always associated gut health with overall well-being, so the link between probiotics and CFS makes a lot of sense. Thanks for your very thorough article.
    ~ Anna M

  2. JP Says:

    I’m glad you found it to be of interest, Anna.

    I’ll continue to keep an eye out for additional research that’s published on this topic.

    Be well!


  3. Caroline Says:

    Fantastic article and very informing! I am a true believer in the powerful effects of probiotics and how they can really work wonders on our body. Our son who is 4 has suffered from severe food allergies and Eczema since he was a baby and nothing helped him. We saw specialists, he was put on meds including steroids, tests tests tests, and many sleepless nights caused from itching and bleeding skin. It seemed as though no one had answers for us and like you said “wanted to just cover up the symptoms” which really didn’t even work either. We wanted answers. After many prayers, our miracle came in the form of a probiotic called Vidazorb kids chewables and it has virtually healed him! He can eat all kinds of foods finally and looks and feels great! Thanks to his Zorbee he is living a “normal” life these days. Anyway- I know through all of this I have suffered to from a lot of anxiety issues. I never even thought of there being a chance at helping me to feel better too. I will be looking into his Vidazorb for more info! Thanks a bunch! Caroline*mommy of 2 wonderful babes

  4. JP Says:

    Thanks for sharing such a hopeful story, Caroline.

    I’m happy to know that your son is healthy now … naturally.:)

    Be well!


  5. Gene Says:

    Hello — I like this chart, and would love to use it in a book I am writing on the secrets of people who never get sick — one of those secrets is probiotics.

    Is this your chart? Would you allow me to reproduce it in the book for a (very) small fee and (lots of) credit?

  6. Greg Says:

    I have had air born allergies for decades. I would have to take oral steroids 2-4 times a year. I would pop antihistamines like M&M’s. The allergies produced a somewhat chronic asthma which resulted in my lung tissue restructuring which resulted in emphysema and COPD.I started taking probiotics last year as Kefer, Kombucha, Primal Defense and NSI brand from VitaCost.com. This spring I have had very few allergy issues. I have taken maybe 6-12 antihistamines, no steroids and feel the best I have felt in decades.

    There are more bacteria cells in and on the human body than their are human cells. One might think that they are the host for us to live rather than us being the host for them. We do have a symbiotic relationship with these guys. We need to care for and nurture them.

    I might also mention that I also have had bouts of depression and severe anxiety. These have dissipated as well. I really believe that inflammation can engulf our entire systems, including our brains.

    There are a few studies regarding probiotics and bacteria in children helping the immune system and particularly allergies. there are no such adult studies as most health studies are done by pharmaceutical companies. The have no interest in conducting studies that will not enhance their profits. So when it comes to health and probiotics, trust your gut.

  7. JP Says:


    Thank you so much for sharing your inspirational story!

    I understand your frustration re: adult studies on probiotics and allergies. However I did find a few trials that may be of interest to you:




    There are certainly other studies out there and hopefully more to come in the future. In the meantime, personal accounts such as yours are so very important to know about.

    Be well!


  8. JP Says:

    Updated 07/30/15:


    Brain Behav Immun. 2015 Aug;48:186-94.

    Altered fecal microbiota composition in patients with major depressive disorder.

    Studies using animal models have shown that depression affects the stability of the microbiota, but the actual structure and composition in patients with major depressive disorder (MDD) are not well understood. Here, we analyzed fecal samples from 46 patients with depression (29 active-MDD and 17 responded-MDD) and 30 healthy controls (HCs). High-throughput pyrosequencing showed that, according to the Shannon index, increased fecal bacterial α-diversity was found in the active-MDD (A-MDD) vs. the HC group but not in the responded-MDD (R-MDD) vs. the HC group. Bacteroidetes, Proteobacteria, and Actinobacteria strongly increased in level, whereas that of Firmicutes was significantly reduced in the A-MDD and R-MDD groups compared with the HC group. Despite profound interindividual variability, levels of several predominant genera were significantly different between the MDD and HC groups. Most notably, the MDD groups had increased levels of Enterobacteriaceae and Alistipes but reduced levels of Faecalibacterium. A negative correlation was observed between Faecalibacterium and the severity of depressive symptoms. These findings enable a better understanding of changes in the fecal microbiota composition in such patients, showing either a predominance of some potentially harmful bacterial groups or a reduction in beneficial bacterial genera. Further studies are warranted to elucidate the temporal and causal relationships between gut microbiota and depression and to evaluate the suitability of the microbiome as a biomarker.

    Be well!


  9. JP Says:

    Updated 07/30/15:


    Nutr Rev. 2015 Aug;73 Suppl 1:28-31.

    Microbiota and the gut-brain axis.

    Changes in gut microbiota can modulate the peripheral and central nervous systems, resulting in altered brain functioning, and suggesting the existence of a microbiota gut-brain axis. Diet can also change the profile of gut microbiota and, thereby, behavior. Effects of bacteria on the nervous system cannot be disassociated from effects on the immune system since the two are in constant bidirectional communication. While the composition of the gut microbiota varies greatly among individuals, alterations to the balance and content of common gut microbes may affect the production of molecules such as neurotransmitters, e.g., gamma amino butyric acid, and the products of fermentation, e.g., the short chain fatty acids butyrate, propionate, and acetate. Short chain fatty acids, which are pleomorphic, especially butyrate, positively influence host metabolism by promoting glucose and energy homeostasis, regulating immune responses and epithelial cell growth, and promoting the functioning of the central and peripheral nervous systems. In the future, the composition, diversity, and function of specific probiotics, coupled with similar, more detailed knowledge about gut microbiota, will potentially help in developing more effective diet- and drug-based therapies.

    Be well!


  10. JP Says:

    Updated 07/30/15:


    Brain Behav Immun. 2015 Aug;48:258-64.

    A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood.

    BACKGROUND: Recent insights into the role of the human microbiota in cognitive and affective functioning have led to the hypothesis that probiotic supplementation may act as an adjuvant strategy to ameliorate or prevent depression.

    OBJECTIVE: Heightened cognitive reactivity to normal, transient changes in sad mood is an established marker of vulnerability to depression and is considered an important target for interventions. The present study aimed to test if a multispecies probiotic containing Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, Lactobacillus casei W56, Lactobacillus salivarius W24, and Lactococcus lactis (W19 and W58) may reduce cognitive reactivity in non-depressed individuals.

    DESIGN: In a triple-blind, placebo-controlled, randomized, pre- and post-intervention assessment design, 20 healthy participants without current mood disorder received a 4-week probiotic food-supplement intervention with the multispecies probiotics, while 20 control participants received an inert placebo for the same period. In the pre- and post-intervention assessment, cognitive reactivity to sad mood was assessed using the revised Leiden index of depression sensitivity scale.

    RESULTS: Compared to participants who received the placebo intervention, participants who received the 4-week multispecies probiotics intervention showed a significantly reduced overall cognitive reactivity to sad mood, which was largely accounted for by reduced rumination and aggressive thoughts.

    CONCLUSION: These results provide the first evidence that the intake of probiotics may help reduce negative thoughts associated with sad mood. Probiotics supplementation warrants further research as a potential preventive strategy for depression.

    Be well!


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