--- title: Probiotic Strains Associated with Positive Mental Health description: Specific Lactobacillus and Bifidobacterium strains support mood and cognition, with trials linking them to reduced anxiety, depression, and stress markers. image: https://www.casi.org/hubfs/casi/featured/5-14-probiotic-improved-mental-health_0.jpeg --- An **educational publication of Designs for Health** [For Practitioners →](https://www.designsforhealth.com) [![casilogoresize2-2](https://www.casi.org/hubfs/casilogoresize2-2.png)](https://www.casi.org/) [Home](https://www.casi.org/) [Science Update](https://www.casi.org/articles/tag/science-update) [Research & Education](https://www.casi.org/articles/tag/research-education) [Archive](https://www.casi.org/articles/all) Search articles Search Research & Education # Probiotic Strains Associated with Positive Mental Health AT Antonia Toupet, PhD May 14, 2024 ![Probiotic Strains Associated with Positive Mental Health](https://www.casi.org/hs-fs/hubfs/casi/featured/5-14-probiotic-improved-mental-health_0.jpeg?width=960) ## The role of probiotics in mental health Probiotics are microorganisms in the gastrointestinal tract, such as beneficial bacteria and yeasts, that have a [positive health benefit for their host](https://ods.od.nih.gov/factsheets/Probiotics-HealthProfessional/). The main probiotic genera are *Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Escherichia,* and *Bacillus.* [Prebiotics](https://ods.od.nih.gov/factsheets/Probiotics-HealthProfessional/) are complex carbohydrates, such as inulin and various oligosaccharides, that provide metabolic fuel for the probiotics. Products containing both prebiotics and probiotics are often referred to as [synbiotics](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9599591/) and can have powerful antioxidant properties due to their complementary and synergistic effects. The term [psychobiotics](https://pubmed.ncbi.nlm.nih.gov/31268916/)has been introduced to designate probiotics that can influence central nervous system functions and brain networks involved in emotional and cognitive response.   Probiotics and prebiotics can help [support mental health](https://pubmed.ncbi.nlm.nih.gov/31914909/) and may be clinically beneficial to those with depression, anxiety, attention deficit hyperactivity disorder (ADHD), Alzheimer’s, and autism spectrum disorder by [promoting beneficial microbiota while helping to attenuate the proliferation of harmful ones](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10384867/). Probiotics can have a [direct impact on the CNS](https://pubmed.ncbi.nlm.nih.gov/27413138/) by affecting brain-derived neurotrophic factor (BDNF), gamma-aminobutyric acid (GABA), dopamine, and serotonin. They have also been shown to decrease corticosteroid levels and [mitigate the hypothalamic–pituitary–adrenal (HPA) stress response](https://pubmed.ncbi.nlm.nih.gov/27413138/), thus regulating mood and emotions.  Alzheimer’s disease is the most common manifestation of progressive dementia and affects nearly [50 million people worldwide](https://pubmed.ncbi.nlm.nih.gov/33362788/). It is believed to be caused by the formation of insoluble [amyloid deposits](https://pubmed.ncbi.nlm.nih.gov/35010895/) in the brain. [Changes in the microbiome](https://pubmed.ncbi.nlm.nih.gov/35010895/) and [elevated biomarkers of inflammation and oxidative stress](https://pubmed.ncbi.nlm.nih.gov/31914909/) are reported to take part in the pathogenesis of neurodegenerative diseases of the CNS, including Alzheimer’s. Probiotics have the potential to [decrease inflammation and increase acetylcholine levels](https://pubmed.ncbi.nlm.nih.gov/31914909/) in the CNS and have the potential to play a supportive role in [alleviating the progression of neurodegenerative conditions](https://pubmed.ncbi.nlm.nih.gov/35010895/).   Depression and anxiety are mental disorders of increasing concern. According to the World Health Organization, approximately [280 million people](https://www.who.int/news-room/fact-sheets/detail/depression) worldwide suffer from depression and more than [300 million people](https://www.who.int/news-room/fact-sheets/detail/anxiety-disorders) have an anxiety disorder. Microbiome dysbiosis can increase the [release of lipopolysaccharides (LPS)](https://pubmed.ncbi.nlm.nih.gov/31478105/) which can activate a gastrointestinal inflammatory response. Pro-inflammatory cytokines can in turn impact the HPA axis inducing symptoms associated with anxiety and depression. Probiotics can produce metabolites from the fermentation of prebiotics that can affect brain processes and immune responses. These metabolites include certain fatty acids, tryptophan mediators, neurotransmitters, and neuropeptides, which are clinically relevant to those with [anxiety and depression](https://pubmed.ncbi.nlm.nih.gov/31914909/). A [systematic review and meta-analysis of five randomized controlled trials](https://pubmed.ncbi.nlm.nih.gov/27509521/) (n = 458) observed that individuals receiving probiotic supplements displayed significant reductions in the incidence of depression.   Autism spectrum disorder is a complex neurodevelopmental condition with a wide range of symptoms expressed by challenges with social abilities and behavior, speech, and nonverbal communication. According to the Centers for Disease Control and Prevention, [1 in 36 children has been identified with ASD](https://www.cdc.gov/ncbddd/autism/data.html) in the United States. Gastrointestinal dysfunction and permeability have been identified as the most prevalent physiological symptoms of ASD, suggesting a [potential role for probiotics to influence the pathogenesis and severity of ASD](https://pubmed.ncbi.nlm.nih.gov/34960049/). In a [randomized controlled trial](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6848227/) (n=37), children with ASD were randomly selected for treatment with six grams per day of a probiotic powder containing six strains of bacteria with one billion colony-forming units (CFUs) per gram. After four weeks, ASD-related symptoms and gastrointestinal symptoms decreased more in the treatment group compared to the control.  **Which probiotic strains are associated with improved mental health?** There are several strains that have been shown to promote CNS function, balanced mood, normal stress responses, and support memory capabilities. These include *L. acidophilus, L. rhamnosus, L. plantarum, L. casei, B. infantis, B. longum*, and *B. breve*. Probiotic bacteria from the genera *Lactobacillus* and *Bifidobacterium* can have neuroprotective properties due to the [production of neurotransmitters and neuropeptides](https://pubmed.ncbi.nlm.nih.gov/31914909/), including GABA, serotonin, BDNF, and [acetylcholine](https://pubmed.ncbi.nlm.nih.gov/33362788/), which can influence brain physiology, emotional status, and mood. Multiple studies have demonstrated that *Bifidobacterium* and *Lactobacillus* strains can play a supportive role for individuals with [anxiety, depression, obsessive-compulsive disorder (OCD), and autism spectrum disorder (ASD)](https://pubmed.ncbi.nlm.nih.gov/27980495/). A [systematic review of fifteen clinical studies](https://pubmed.ncbi.nlm.nih.gov/27413138/) (n =  1,209) reported that subjects taking *B. longum, B. breve, B. infantis, L. helveticus, and L. rhamnosus* with doses between 108 and 1010 CFUs showed efficacy in improving psychiatric symptoms associated with anxiety, depression, ASD, OCD, and memory abilities.  Certain probiotic strains, alone or in combination with prebiotics, have shown [positive implications for mental health](https://pubmed.ncbi.nlm.nih.gov/27980495/): - *L. plantarum* can [support normal stress responses and help to lower occasional anxiety](https://pubmed.ncbi.nlm.nih.gov/30266270/) and may have a [protective effect against memory deficit](https://pubmed.ncbi.nlm.nih.gov/31914909/) due to its ability to produce acetylcholine. - *L. rhamnosus* significantly [decreased depression and anxiety](https://pubmed.ncbi.nlm.nih.gov/28943228/) scores for women in the postpartum period (n = 423) and enhanced the psychological and physiological quality of life in [stressed adults](https://pubmed.ncbi.nlm.nih.gov/34681433/) (n = 12). - *L. reuteri* can [decrease LPS-induced intestinal inflammation](https://pubmed.ncbi.nlm.nih.gov/20798357/). - *L. casei, L. acidophilus,* and *B. bifidum* probiotic supplementhad a [beneficial impact on depression](https://pubmed.ncbi.nlm.nih.gov/26706022/) scores, insulin resistance, and C-reactive protein concentrations (n = 40). - *B. longum*, combined with oligosaccharides, has been shown to [decrease inflammatory markers](https://pubmed.ncbi.nlm.nih.gov/31914909/), such as CRP, tumor necrosis factor-alpha, serum aspartate aminotransferase (AST), and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). A [randomized controlled trial](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6615936/) (n = 40) showed that *B. longum* 1714™ administered for four weeks at a dose of 109 CFUs per day attenuated responses to psychological and physiological stress. Another study with healthy volunteers (n = 22) demonstrated that *B. longum* 1714™ was associated with [reduced stress and improved memory](https://pubmed.ncbi.nlm.nih.gov/27801892/). - *B. breve* may [attenuate psychiatric and gastrointestinal manifestations](https://pubmed.ncbi.nlm.nih.gov/34875345/) associated with major depression disorder. - *B. bifidum* has been shown to [support intestinal integrity](https://pubmed.ncbi.nlm.nih.gov/20501441/) and decrease permeability. Currently available research provides compelling evidence that there may be a role for probiotics in supporting mental health. Further research in the form of human randomized controlled trials may be warranted to elucidate the effect of probiotics on the pathogenesis and severity of mental health disorders and the corresponding mechanisms of action.  **Learn more about probiotics:**  [Recent Meta-analysis Investigates Relationship Between Probiotics and Prediabetes](https://www.casi.org/articles/meta-analysis-investigates-relationship-between-probiotics-and-prediabetes) [New Review Investigates the Efficacy of Different Probiotics in IBS](https://www.casi.org/articles/efficacy-of-different-probiotics-in-ibs) [The Latest on Probiotics and Periodontal Health](https://www.casi.org/articles/probiotics-and-periodontal-health) [Recent Randomized Controlled Trial Investigates Efficacy of Synbiotics (Prebiotics + Probiotics) on Immune Health](https://www.casi.org/articles/efficacy-of-synbiotics-immune-health) [Recent Randomized Controlled Trial Explores Efficacy of Probiotics on Chronic Urticaria](https://www.casi.org/articles/recent-randomized-controlled-trial-explores-efficacy-of-probiotics-on-chronic-urticaria) On this page Share [LinkedIn](https://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.casi.org%2Farticles%2Fprobiotic-strains-associated-with-positive-mental-health) [X](https://twitter.com/intent/tweet?url=https%3A%2F%2Fwww.casi.org%2Farticles%2Fprobiotic-strains-associated-with-positive-mental-health&text=Probiotic+Strains+Associated+with+Positive+Mental+Health) [Email](mailto:?subject=Probiotic%20Strains%20Associated%20with%20Positive%20Mental%20Health&body=https%3A%2F%2Fwww.casi.org%2Farticles%2Fprobiotic-strains-associated-with-positive-mental-health) AT ### Antonia Toupet, PhD Clinical Application ## Clinical Considerations in Practice In clinical practice, practitioners considering the topics discussed above may also weigh nutrient form, delivery and formulation, alongside individual patient variability. ### Practitioner Formulation Example ![Probiotic Supreme DF™](https://cdn.sanity.io/images/lemtscrs/production-www/8eabb991e312e44332a4b025d9bb2e57cf2c4d17-2000x2000.png?w=128&h=128&fit=max&auto=format) Probiotic Supreme DF™ 15 billion CFU multi-strain probiotic blend · Caplets [Explore Formulations →](https://www.designsforhealth.com/products/probiotic-supreme) ## Continue your research #### [Research & Education How Akkermansia Supports GLP-1 Production and Metabolic Function May 27, 2026](https://www.casi.org/articles/akkermansia-supports-glp-1-production-metabolic-function) #### [Research & Education Overcoming the Anaerobic Barrier: A New Approach to Probiotic Manufacturing May 12, 2026](https://www.casi.org/articles/overcoming-the-anaerobic-barrier-a-new-approach-to-probiotic-manufacturing) #### [Science Update A Case Report on Anaerostipes caccae Supplementation in a 47-Year-Old Female with Long-Term Food Intolerances Apr 09, 2026](https://www.casi.org/articles/a-case-report-on-anaerostipes-caccae-supplementation-in-a-47-year-old-female-with-long-term-food-intolerances) #### [Research & Education Sleep Support Beyond Melatonin: Targeting the Gut–Brain Axis with L. gasseri CP2305 Feb 23, 2026](https://www.casi.org/articles/sleep-support-gut-brain-axis-l-gasseri-cp2305) ![casilogoresize2-2](https://www.casi.org/hubfs/casilogoresize2-2.png) An educational publication of [**Designs for Health**](https://www.designsforhealth.com). 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