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Gut dysbiosis is increasingly considered a contributor to an array of health-related issues, including mental health issues. For example, poor gut health, as well as inflammation of the gut, have been closely associated with anxiety. (Clapp, Aurora, Herrera, Bhatia, Wilen, Wakefield, 2017)

Fortunately, probiotics, as part of a holistic healthcare program, may provide relief.

We discuss the science behind probiotics and anxiety below, as well as detail specific strains.

However, if you and your healthcare provider agree probiotics are right for you, we recommend:

The Link Between Anxiety and the Gut

The health of your gut can directly impact your mental health — largely due to the gut-brain axis. The gut communicates with the brain via the enteric nervous system, also known as the second brain. (Furness, Callaghan, Rivera, Cho, 2014)

Specifically, the enteric nervous system communicates with the central nervous system through the vagus nerve — the main line of communication between the gut and the brain.

How does this impact mental health, though?

The gut is home to an estimated 100 trillion microorganisms and up to 1,000 species of bacteria. When the gut is not healthy, it impacts our well-being. This is because the gut is involved in a wide variety of biological processes and communicates with the brain.

95% of serotonin is produced by nerves and bacteria inside the gut (although most of that serotonin is used by the gut for functions such as peristalsis). This partly explains why a range of mental health issues can stem from an imbalanced gut microbiota — or dysbiosis. (Martin, Osadchiy, Kalani, Mayer, 2018)

There are four ways dysbiosis contributes to anxiety and other mental health disorders:

  • Influencing our stress response
  • Through the development of leaky gut
  • As a source of chronic inflammation
  • Through the production of peptides, which can be harmful

Risk Factors and Symptoms

Although dysbiosis can occur almost anywhere in or on the body, gut dysbiosis occurs when there is an imbalance of good to bad bacteria within the gut. Gut dysbiosis can be the result of the following environmental factors:

  • A poor diet consisting of too much sugar and fatty foods
  • Consuming foods that haven’t been appropriately washed and still have pesticides on them
  • Drinking too much alcohol
  • Taking antibiotics
  • Chronic stress, which can weaken the immune system

Common symptoms of gut dysbiosis are:

  • Abdominal pain
  • Diarrhea
  • Constipation
  • Nausea
  • Yeast infections
  • Bloating
  • Gas
  • Fatigue
  • Brain fog
  • Anxiety
  • Depression
  • Headaches
  • Weight gain
  • Sugar cravings

8 Probiotics That Help With Anxiety

Gut dysbiosis is easy to treat with probiotics. However, these are not just any probiotics. These probiotics are often coined as psychobiotics. When taken in adequate quantities, they can benefit people suffering from a range of psychiatric disorders. (Dinan, Stanton, Cryan, 2013)

Research shows that these probiotics can improve anxiety by:

  • Stimulating the vagus nerve
  • Increasing the production of neurotransmitters
  • Reducing stress hormones such as cortisol
  • Reducing chronic inflammation
  • Getting rid of bad bacteria
  • Increasing nutrient absorption

The following eight probiotic species have been shown in numerous human and animal studies to help treat anxiety:

Lactobacillus rhamnosus

Research has shown that supplementing with this probiotic species reduces anxiety. (Mohammadi, Jazayeri, Khosravi-Darani, Solati, Mohammadpour, Asemi, Adab, Djalali, Tehrani-Doost, Hosseini, Eghtesadi, 2016)

This is done by changing the functioning of GABA receptors in the brain. (Leung, Thuret, 2015) This species of probiotic can often be found in yogurt, kefir, unpasteurized milk, and semi-hard cheeses.

Bifidobacterium longum

Researchers have found that Bifidobacterium longum reduces cortisol levels and helps to alleviate numerous psychological side effects such as anxiety, paranoia, and obsessive behaviors and thoughts. (Messaoudi, Lalonde, Violle, Javelot, Desor, Nejdi, Bisson, Rougeot, Pichelin, Cazaubiel, Cazaubiel, 2011)

In animal studies, Bifidobacterium longum significantly reduced behaviors linked to anxiety. (Savignac, Tramullas, Kiely, Dinan, Cryan, 2015)

Lactobacillus plantarum

One study showed this probiotic to not only reduce the symptoms of irritable bowel syndrome, but it also significantly reduced patients’ anxiety. (Lorenzo-Zúñiga, Llop, Suárez, Alvarez, Abreu, Espadaler, Serra, 2014)

This is because Lactobacillus plantarum increases dopamine and serotonin while lowering cortisol as well as reducing inflammation. You can get Lactobacillus plantarum by eating fermented vegetables such as kimchi and sauerkraut.

Lactobacillus helveticus

This species of probiotic reduces cortisol and anxiety. It can even reduce obsessive-compulsive thoughts. In one study, Lactobacillus helveticus was found to treat anxiety better than antidepressants.

It was also able to reduce cortisol and increase serotonin levels. (Liang, Wang, Hu, Luo, Li, Wu, Duan, Jin, 2015)

This strain of probiotic is often found in cheeses.

Lactobacillus casei

This probiotic contains both antioxidant and anti-inflammatory properties. In one human study, it was shown to reduce anxiety symptoms and chronic fatigue in patients significantly. (Rao, Bested, Beaulne, et al., 2009)

Lactobacillus fermentum

This probiotic reduces anxiety, especially in those who have used antibiotics. Research has shown it to reduce inflammation and reverse psychological issues that are a result of antibiotic use such as anxiety. (Wang, Hu, Liang, Li, Wu, Wang, Jin, 2015)

Bifidobacterium breve

This probiotic has been found to reduce anxiety in mice. It was also found to improve cognition. (Savignac, Kiely, Dinan, Cryan, 2014)


This is a prebiotic. It's been shown to decrease cortisol secretion dramatically. (Schmidt, Cowen, Harmer, Tzortzis, Errington, Burnet, 2015)

This prebiotic was also shown to reduce anxiety and improve the quality of life in those with irritable bowel syndrome. (Silk, Davis, Vulevic, Tzortzis, Gibson, 2009)

And, as always, you can get gut updates and stunning nature imagery from our popular Facebook page. Also, scroll down for our best gut articles.

Research Citations

  • Clapp M, Aurora N, Herrera L, Bhatia M, Wilen E, Wakefield S. Gut microbiota's effect on mental health: The gut-brain axis. Clinics and Practice. 2017;7(4):987. doi:10.4081/cp.2017.987.
  • Furness JB, Callaghan BP, Rivera LR, Cho HJ. The enteric nervous system and gastrointestinal innervation: integrated local and central control. Advances in Experimental Medicine and Biology. 2014;817:39-71. doi: 10.1007/978-1-4939-0897-4_3.
  • Martin CR, Osadchiy V, Kalani A, Mayer EA. The Brain-Gut-Microbiome Axis. Cellular and Molecular Gastroenterology and Hepatology. 2018;6(2):133–148. doi:10.1016/j.jcmgh.2018.04.003.
  • Dinan TG, Stanton C, Cryan JF. Psychobiotics: a novel class of psychotropic. Biological Psychiatry. 2013;74(10):720-6. doi: 10.1016/j.biopsych.2013.05.001.
  • Mohammadi AA, Jazayeri S, Khosravi-Darani K, Solati Z, Mohammadpour N, Asemi Z, Adab Z, Djalali M, Tehrani-Doost M, Hosseini M, Eghtesadi S. The effects of probiotics on mental health and hypothalamic-pituitary-adrenal axis: A randomized, double-blind, placebo-controlled trial in petrochemical workers. Nutritional Neuroscience. 2016;19(9):387-395.
  • Leung K, Thuret S. Gut Microbiota: A Modulator of Brain Plasticity and Cognitive Function in Ageing. Healthcare (Basel). 2015;3(4):898–916. doi:10.3390/healthcare3040898.
  • Messaoudi M, Lalonde R, Violle N, Javelot H, Desor D, Nejdi A, Bisson JF, Rougeot C, Pichelin M, Cazaubiel M, Cazaubiel JM. Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects. The British Journal of Nutrition. 2011;105(5):755-64. doi: 10.1017/S0007114510004319.
  • Savignac HM, Tramullas M, Kiely B, Dinan TG, Cryan JF. Bifidobacteria modulate cognitive processes in an anxious mouse strain. Behavioral Brain Research. 2015;287:59-72. doi: 10.1016/j.bbr.2015.02.044.
  • Lorenzo-Zúñiga V, Llop E, Suárez C, Alvarez B, Abreu L, Espadaler J, Serra J. I.31, a new combination of probiotics, improves irritable bowel syndrome-related quality of life. World Journal of Gastroenterology. 2014;20(26):8709-16. doi: 10.3748/wjg.v20.i26.8709.
  • Liang S, Wang T, Hu X, Luo J, Li W, Wu X, Duan Y, Jin F. Administration of Lactobacillus helveticus NS8 improves behavioral, cognitive, and biochemical aberrations caused by chronic restraint stress. Neuroscience. 2015;310:561-77. doi: 10.1016/j.neuroscience.2015.09.033.
  • Leung K, Thuret S. Gut Microbiota: A Modulator of Brain Plasticity and Cognitive Function in Ageing. Healthcare (Basel). 2015;3(4):898–916. doi:10.3390/healthcare3040898.
  • Rao AV, Bested AC, Beaulne TM, et al. A randomized, double-blind, placebo-controlled pilot study of a probiotic in emotional symptoms of chronic fatigue syndrome. Gut Pathogens. 2009;1(1):6. Published 2009 Mar 19. doi:10.1186/1757-4749-1-6.
  • Wang T, Hu X, Liang S, Li W, Wu X, Wang L, Jin F. Lactobacillus fermentum NS9 restores the antibiotic induced physiological and psychological abnormalities in rats. Beneficial Microbes. 2015;6(5):707-17. doi: 10.3920/BM2014.0177.
  • Savignac HM, Kiely B, Dinan TG, Cryan JF. Bifidobacteria exert strain-specific effects on stress-related behavior and physiology in BALB/c mice. Neurogastroenterology and Motility. 2014;26(11):1615-27. doi: 10.1111/nmo.12427.
  • Schmidt K, Cowen PJ, Harmer CJ, Tzortzis G, Errington S, Burnet PW. Prebiotic intake reduces the waking cortisol response and alters emotional bias in healthy volunteers. Psychopharmacology (Berl). 2015;232(10):1793–1801. doi:10.1007/s00213-014-3810-0.
  • Silk DB, Davis A, Vulevic J, Tzortzis G, Gibson GR. Clinical trial: the effects of a trans-galactooligosaccharide prebiotic on faecal microbiota and symptoms in irritable bowel syndrome. Alimentary Pharmacology and Therapeutics. 2009;29(5):508-18. doi: 10.1111/j.1365-2036.2008.03911.x.
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