Do Probiotics Help with Anxiety and Depression?

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Okay, if you haven’t heard all the fanfare for probiotics from watching TV commercials, visiting your local grocery store, or even reading my blog posts, then you might be asking yourself, what are probiotics?  As I’ve previously posted, probiotics are essentially dietary supplements or functional foods that contain potentially beneficial bacteria or yeast.

Research suggests that probiotics may have beneficial effects at preventing traveler’s diarrhea, treating allergic rhinitis, and reducing gastrointestinal symptoms.  Recently, Canadian researchers from Toronto, published a study in the journal, Gut Pathogens, on the effects of probiotic cultures on the emotional symptoms in Chronic Fatigue Syndrome (Rao et al, 2009).  Chronic Fatigue Syndrome (CFS) is a complex illness with no clearly understood etiology or specific cause.  Emotional symptoms of CFS are most commonly of an anxiety nature.

Probiotics for Chronic Fatigue Syndrome Study:

Patients with CFS in this study were randomized to receive 24 billion colony forming units of Lactobacillus casei strain Shirota (LcS) or placebo daily for 2 months.  Researchers found a significant rise in both Lactobacillus casei as well as bifidobacteria in the stools of the intervention group.  Additionally, the researchers found a significant decline in anxiety symptoms (Beck Anxiety Inventory) in those taking LcS (p=0.01).

  • In patients with CFS, supplementation with Lactobacillus casei strain Shirtoa for 2 months, resulted in statistically signficant reduction in anxiety symptoms.

[box type="important"]Bottom line: Keep in mind that the results of this study are specific to this species/strain of probiotic. Participants in this study also suffered from chronic fatigue syndrome. More research is necessary to clarify the role of specific probiotics for relieving anxiety symptoms.[/box]


  • Rao AV, Bested AC, Beaulne TM, Katzman MA, Iorio C, Berardi JM, Logan AC.  A randomized, double-blind, placebo-controlled pilot study of a probiotic in emotional symptoms of chronic fatigue syndrome.  Gut Pathog. 2009 Mar 19;1(1):6.

10 thoughts on “Do Probiotics Help with Anxiety and Depression?

    Randy said:
    April 22, 2009 at 1:45 am

    I can attest to this finding myself. When I run out of my probiotic, I definitely notice a change in anxiety levels. Thanks for the info.

    S. Wojcik said:
    April 24, 2009 at 4:16 pm

    Great article find. Ive been reading everything I can about Probiotic! Keep up the good work.

    Jarret Morrow said:
    May 21, 2009 at 4:42 pm

    Randy and S. Wojcik, thanks for the feedback!

    Patricia said:
    June 24, 2009 at 5:17 pm

    I’ve been hearing many different things about probiotics lately. But this is the first time I’ve read about them helping with anxiety and depression. Thanks for the info.

    Jarret Morrow said:
    June 29, 2009 at 5:43 pm

    CS, thank you for your comment.

    GetHealthyHQ said:
    November 21, 2009 at 10:38 pm

    Hi Jarret,

    I just came across your site, and I really love the facts you have on here. Thanks for all the references. It’s really interesting to know that pro-biotics can reduce anxiety. Does this happen with non-CFS sufferers as well?


    Mike said:
    January 31, 2010 at 12:09 am

    Optimize your blog to place so high in this keyword “depression symptoms” is so difficult. How did you optimize your blog?^_^

    Jill said:
    November 2, 2010 at 6:45 am

    Jarret , of you don’t have CFS, can you still take probiotics as a preventative for anxiety?

      Jarret Morrow, M.D. said:
      November 4, 2010 at 5:34 pm

      Hi Jill, that’s a fair question. For this study, the test subjects were patients with CFS and had anxiety symptoms as well. At this point, research on probiotic use for anxiety prevention is still quite new. I’ve came across at least one more study recently on this topic, but more research is still necessary to make that type of recommendation.

    debra said:
    May 19, 2013 at 4:50 pm

    I started trubiotics 5/14/2013. I have more energy than I ever have!!! I stress less and I feel great!

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