By Stephen Harrington
Anxiety and mood disorders are now being recognized as major medical and societal issues.
In a unique discovery, two specific probiotic organisms have been identified that show impressive reductions in the manifestation of stress, anxiety, and depression.
Human studies on these two unique probiotics show notable results. For example, one study showed a 50%decrease in depression scores while another showed a 55% improvement in anxiety scores.1,2
While it may seem remarkable that a probiotic can have effects outside of the gastrointestinal tract, a massive accumulation of data suggests that the gut is, in fact, practically a “second brain,” with a powerful and lasting impact on mood.3
Depression and anxiety are highly prevalent in the US (and around the world), affecting approximately 6.7%and 18.1% of Americans respectively.4,5
Until quite recently, these mental health disorders were viewed as primarily related to brain function, since it has long been believed that the brain is solely responsible for thoughts, feelings, and behavior.
There is an increasing awareness among scientists of the role played by the microorganisms that live in the gastrointestinal tract in affecting other body systems, including the brain.6 At nearly 100 trillion individual organisms, these cells outnumber the body’s own cells by 10 to 1, possessing nearly 100 times as many genes.7 That gives them a lot of leverage.
In fact, the close relationship between the microbes in the gastrointestinal tract and the biochemical functioning of brain cells and structures has given rise to the term gut-brain axis, indicating that what happens in the gut can affect the brain, and vice versa.8,9
Conversely, early life stresses can change the makeup of the gastrointestinal flora, accompanied by increases in stress hormones such as cortisol, in immune system responses, and in intestinal pain sensations.10
Therefore, deliberately introducing changes to the gastrointestinal flora through supplementation with probiotics is an exciting new way to introduce changes in how the brain functions, including how people experience emotions.6,11-13
Human Studies Show Dramatic Reductions in Anxiety and Depression
Human randomized, placebo-controlled trials are so important to understanding the relation between probiotics and the role it plays in supporting positive moods. Such studies have now been carried out using the probiotic Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 combination.
A human study of 55 participants with mild depression or anxiety, ages 30 to 60, was conducted to determine the effects of the probiotic combination on anxiety, depression, stress, and coping strategies.1 Subjects were given 3 billion colony-forming-units (CFUs, a measure of the number of individual organisms) of the probiotic, or a placebo, for 30 days.
The probiotic-supplemented subjects had a significantly larger drop in measures of anxiety and depression than did placebo recipients as follows:
- 49%drop in the global severity index, a measure of overall psychological distress
- 50%decrease in depression scores
- 60%decrease in anger-hostility scores
- 36%decrease in the hospital anxiety and depression score (HADS)
- 13%decrease in urinary free cortisol, a hormonal measure of chronic stress, which was not seen in placebo patients
Supplemented patients also displayed reductions in self-blame and higher problem-solving skills after the study.1
Even people who don’t consider themselves “high-stress” may attain a serenity boost from this novel probiotic combination. When the same research team analyzed data on 25 original study participants whose baseline cortisol was below the median, indicating generally lower stress, they found that these individuals also experienced marked improvements in mood scores.2
Another human study evaluated the impact of the probiotic combination on stress-induced digestive symptoms, a common manifestation of stress even in basically healthy people. Subjects ages 18 to 60, with at least two self-reported symptoms of stress (nervousness, irritability, anxiety, sleeping problems, gastrointestinal disturbances), were randomly assigned to receive either placebo or the probiotic combination at the same dosage as in the other studies.
Compared with placebo, supplemented subjects had a significant 7.6-fold greater reduction in stress-induced abdominal pain, and a significant 2.1-fold greater reduction in stress-induced nausea and vomiting.
- Messaoudi M, Lalonde R, Violle N, et al. Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects. Br J Nutr. 2011;105(5):755-64.
- Messaoudi M, Violle N, Bisson JF, et al. Beneficial psychological effects of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in healthy human volunteers. Gut Microbes. 2011;2(4):256-61.
- Ridaura V, Belkaid Y. Gut microbiota: the link to your second brain. 2015;161(2):193-4.
- Available at: http://www.nimh.nih.gov/health/statistics/prevalence/major-depression-among-adults.shtml. Accessed November 23, 2015.
- Available at: http://www.nimh.nih.gov/health/statistics/prevalence/any-anxiety-disorder-among-adults.shtml. Accessed November 23, 2015.
- Foster JA, Lyte M, Meyer E, et al. Gut microbiota and brain function: An evolving field in neuroscience. Int J Neuropsychopharmacol.
- Forsythe P, Sudo N, Dinan T, et al. Mood and gut feelings. Brain Behav Immun. 2010;24(1):9-16.
- Alonso C, Vicario M, Pigrau M, et al. Intestinal barrier function and the brain-gut axis. Adv Exp Med Biol. 2014;817:73-113.
- Petra AI, Panagiotidou S, Hatziagelaki E, et al. Gut-microbiota-brain axis and its effect on neuropsychiatric disorders withsuspected immune dysregulation. Clin Ther. 2015;37(5):984-95.
- O’Mahony SM, Marchesi JR, Scully P, et al. Early life stress alters behavior, immunity, and microbiota in rats: implications for irritable bowel syndrome and psychiatric illnesses. Biol Psychiatry. 2009;65(3):263-7.
- Forsythe P, Kunze WA. Voices from within: gut microbes and the CNS. Cell Mol Life Sci. 2013;70(1):55-69.
- Cryan JF, Dinan TG. Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour. Nat Rev Neurosci. 2012;13(10):701-12.
Bienenstock J, Collins S. 99th Dahlem conference on infection, inflammation and chronic inflammatory disorders: psycho-neuroimmunology and the intestinal microbiota: clinical observations and basic mechanisms. Clin Exp Immunol. 2010;160(1):85-91