The mind-gut connection is made of a network of nerves that allows the brain and digestive tract to communicate with each other.
An imbalanced gut microbiome and inflammation in the digestive tract can cause gut-brain-axis dysfunction, creating symptoms like brain fog, depression, and anxiety.
The brain regulates the movement of food through the digestive tract, and alterations in the brain (caused by stress) can disrupt GI function, such as in the case of irritable bowel syndrome (IBS).
The beneficial effects of probiotics on both gut and brain health help to solidify the important role that these two systems have on one another.
You’re probably already familiar with the brain-gut connection if you’ve ever experienced “gut feelings.” When thinking about brain health, it’s nearly impossible to separate it from what’s occurring inside your gut. In fact, these two systems are so similar that scientists have deemed the nerve cells of the digestive tract to be our “second brain.”
The mind-gut connection is so powerful that when one of these seemingly distinct organs is imbalanced, it can send the other into a state of distress. Perhaps one of the clearest examples of this is irritable bowel syndrome (IBS), which is known to be highly influenced by chronic stress. Even more, neurological and cognitive concerns like brain fog and memory loss, as well as mood disorders, are all thought to be associated with an unhealthy gut.
When we look at these systems as two pieces of the same puzzle, we can begin to more effectively treat dysfunction in the brain by targeting dysregulation in the gut. Balancing the gut microbiome and reducing inflammation in the digestive tract are often highly beneficial for treating neurological and psychological symptoms and disease.
Exploring the Mind-Gut Connection
The digestive system and the brain are connected to each other through a highly intricate network of neurons (primarily the vagus nerve), which transmit signals from the GI tract to the brain and vice versa.
Chemical messengers — known as neurotransmitters — are made in the gut and travel along the vagus nerve to the brain. When they reach the central nervous system, these neurotransmitters have a strong influence on our mood, appetite, memory, and even pain perception [1, 2].
The complex community of microorganisms that live in our gut is known as “the gut microbiome” and it plays a highly influential role in our overall health. When these trillions of tiny organisms are out of balance, they can lead to inflammation in our digestive tract and cause dysregulation of the gut-brain axis [3, 4].
Research now recognizes that when the gut ecosystem becomes imbalanced, otherwise known as dysbiosis, it also can alter brain function by producing inflammation in the brain [3, 4, 5, 6, 7]. Inflammation in the brain is one of the main drivers behind many neurological symptoms and conditions, one of which most of us have experienced from time-to-time: brain fog.
Breaking Down Brain Fog
Brain fog is an exceedingly common symptom that’s marked by cloudy thinking, poor mental stamina and mental fatigue, an inability to focus, and forgetfulness . Neuroinflammation (inflammation in the brain) appears to be a significant underlying factor, and even one of the primary causes, for brain fog [9, 10, 11]. As we already know that inflammation in the gut can create neuroinflammation, it’s really not a surprise that the following digestive conditions are associated with chronic brain fog:
Small intestinal bacterial overgrowth (SIBO) [12, 13]
Inflammatory bowel disease (IBD), including Crohn’s disease 
Celiac disease and non-celiac gluten sensitivity (NCGS) [15, 16, 17]
Even chronic health conditions that are typically associated with significant brain fog, like chronic fatigue syndrome, fibromyalgia, and hypothyroidism, are all thought to have some sort of underlying imbalance in the gut.
Many of these conditions that can affect our brain function appear to have a similar underlying factor — an unhealthy gut. However, as a quick mention, if you have any neurological complaints like brain fog, headaches, and mood disorders, you may have an imbalanced gut even if you aren’t having any digestive issues.
When Harman first arrived at the clinic she had been experiencing severe brain fog for years. It had begun to affect her work performance to the point where she was concerned about losing her job, and she started to experience symptoms of depression. She had seen seven other practitioners for her brain fog, but found no improvements.
She was aware of the gut-mind connection and was also combating several food sensitivities that she believed to be linked to her brain fog. In an attempt to resolve her symptoms she was on an extremely restrictive diet, consisting of just chicken and carrots.
In just four months after starting treatment, which focused on expanding her dietary options and treating an underlying gut dysbiosis with probiotics and antimicrobials, her brain fog and food sensitivities were completely gone.
Harman’s case not only highlights the significance of focusing on the gut when treating brain fog, but shows that this doesn’t have to be in a way that severely restricts your diet and compromises your quality of life.
The Brain’s Influence on the Gut: IBS
Now that we’ve explored the role that the gastrointestinal tract plays in our brain health, let’s take a look at how the brain affects our digestive health. While the gastrointestinal tract has its own nervous system, known as the enteric nervous system (ENS), the central nervous system also plays a leading role in digestion.
The brain helps control digestion by regulating gastric motility, or the waves of muscular contractions that move food along the GI tract. Because of the brain’s direct influence on digestion, certain stimuli, like stress, can have a significant impact on our gut health.
Changes in the gut-brain communication are thought to lie behind irritable bowel syndrome (IBS), and low levels of the neurotransmitter serotonin can affect digestive motility, increase the perception of pain, and alter mood in those with IBS [18, 19]. In fact, those with IBS are three times more likely to experience anxiety and depression .
Stress is well-known to be a common trigger for IBS symptoms, which frequently include:
Gas and bloating
Interventions that focus on stress reduction and restoring the gut-brain axis have shown to be highly effective in mitigating symptoms, reducing anxiety and depression, and improving overall quality of life in those with IBS .
Cognitive behavioral therapy (CBT), hypnotherapy, yoga, and meditation all work to alleviate stress and restore a normal response in the nervous system. They’ve shown to be highly beneficial for those with IBS, further solidifying the gut-mind connection [22, 23, 24, 25, 26, 27].
Probiotics for Better Brain Health
There’s perhaps no other supplement that better exemplifies the tightly interwoven mind-gut connection than probiotics.
The relationship between probiotics and the nervous system is well-documented, and probiotics can be effectively used to treat anxiety, depression, brain fog, headaches, and a wide spectrum of neurological conditions.
Probiotics work to rebalance the gut microbiota, which helps heal the gut-brain axis . They also assist in restoring optimal gut health by:
Increasing the diversity of the gut microbiota (live bacteria in the GI tract) 
Fighting off pathogens (harmful gut microbes) and the toxins that they produce
Supporting a healthy immune system and response in the gut [29, 30]
The above benefits of probiotics make it a standout supplement when it comes to treating neurological conditions. In one research study, those with multiple sclerosis (MS) who took a probiotic supplement for 12 weeks had less inflammatory markers and disability over those who took the placebo .
Probiotics for Cognitive Impairment
Research shows that probiotics are beneficial for improving cognitive function, likely by reducing inflammation, which, remember, is the main driver of brain fog [35, 36, 37, 38, 39, 40]. In healthy adults, probiotics changed the balance of gut bacteria, and improved cognitive function and mood .
However, the beneficial effects of probiotics on enhancing cognitive function appear to be higher in those who are already dealing with cognitive decline or dementia [41, 42].
Probiotics may be particularly helpful for those who experience cognitive decline or cognitive dysfunction, such as those who have Alzheimer’s disease, bipolar disorder, and fibromyalgia [36, 37, 38, 43].
Probiotics for Mental Health
When the gut becomes inflamed due to various factors, it breaks down the barrier lining the GI tract and allows for certain foreign bodies and toxic substances to slip through and enter the bloodstream (otherwise known as leaky gut). When these toxic substances reach the brain, they’re thought to contribute to mental health conditions like anxiety-spectrum disorders and depression [44, 45].
Probiotics help reverse this process and repair the lining of the gut, partially explaining the profound effect that they can have on regulating mood [31, 32, 33].
Furthermore, when the digestive tract isn’t healthy, it disrupts the normal flow of neurotransmitters to the brain, including serotonin, dopamine, and gamma aminobutyric acid (GABA), which likely contributes to various mood disorders. By healing the GI tract, probiotics can help restore the normal flow of communication from the gut to the brain.
There’s a strong body of research that shows probiotics to be significantly helpful in reducing symptoms of depression, particularly in those struggling with major depressive disorder [46, 47, 48, 49, 50].
One study found that multiple strains of probiotics were more effective in treating depression , which is why we recommend a triple probiotic therapy that utilizes strains from three different categories of probiotics.
Probiotics may also be beneficial in reducing symptoms of anxiety, though the evidence isn’t quite as strong [51, 52, 53, 54, 55, 56]. In one well-designed clinical trial, 12 weeks of probiotic use lowered stress and anxiety symptoms in a group of highly stressed adults. Even more, they benefited from improvements in memory, social cognition, and verbal learning .
As probiotics are highly effective at healing the gut and reducing inflammation, it makes them an attractive therapy for healing the mind-gut connection and bringing you back to optimal health. Furthermore they’re safe, easy to use, and certainly don’t have to be expensive.
Healing the Mind-Gut Connection
The gut plays an important role in regulating our cognition and mood, and has a strong influence on our brain health. An imbalanced gut microbiome and inflammation in the gut can be the driving force behind several neurological symptoms and conditions.
The brain also plays an important role in the brain-gut axis, as it helps regulate digestion. Stress can easily disrupt this two-way street of communication, and its effects are most notable in those dealing with IBS.
The beneficial effects of probiotics on the gut and the brain further bolster the role that these two organ systems have on each other, and are a highly effective therapeutic for treating various digestive and neurological conditions. For more information on the gut-brain axis, check out my book, Healthy Gut, Healthy You.
You can also reach out to our clinic at the Ruscio Institute for Functional Medicine for help with healing your gut and brain, and restoring your overall well-being.
The Ruscio Institute has developed a range of high-quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.
Arneth BM. Gut-brain axis biochemical signalling from the gastrointestinal tract to the central nervous system: gut dysbiosis and altered brain function. Postgrad Med J. 2018 Aug;94(1114):446–52. DOI: 10.1136/postgradmedj-2017-135424. PMID: 30026389.
Tran N, Zhebrak M, Yacoub C, Pelletier J, Hawley D. The gut-brain relationship: Investigating the effect of multispecies probiotics on anxiety in a randomized placebo-controlled trial of healthy young adults. J Affect Disord. 2019 Jun 1;252:271–7. DOI: 10.1016/j.jad.2019.04.043. PMID: 30991255.
Kennedy PJ, Cryan JF, Dinan TG, Clarke G. Irritable bowel syndrome: a microbiome-gut-brain axis disorder? World J Gastroenterol. 2014 Oct 21;20(39):14105–25. DOI: 10.3748/wjg.v20.i39.14105. PMID: 25339800. PMCID: PMC4202342.
Bravo JA, Julio-Pieper M, Forsythe P, Kunze W, Dinan TG, Bienenstock J, et al. Communication between gastrointestinal bacteria and the nervous system. Curr Opin Pharmacol. 2012 Dec;12(6):667–72. DOI: 10.1016/j.coph.2012.09.010. PMID: 23041079.
Dopkins N, Nagarkatti PS, Nagarkatti M. The role of gut microbiome and associated metabolome in the regulation of neuroinflammation in multiple sclerosis and its implications in attenuating chronic inflammation in other inflammatory and autoimmune disorders. Immunology. 2018 Jun;154(2):178–85. DOI: 10.1111/imm.12903. PMID: 29392733. PMCID: PMC5980216.
Sun M-F, Shen Y-Q. Dysbiosis of gut microbiota and microbial metabolites in Parkinson’s Disease. Ageing Res Rev. 2018 Aug;45:53–61. DOI: 10.1016/j.arr.2018.04.004. PMID: 29705121.
Lin L, Zheng LJ, Zhang LJ. Neuroinflammation, gut microbiome, and alzheimer’s disease. Mol Neurobiol. 2018 Nov;55(11):8243–50. DOI: 10.1007/s12035-018-0983-2. PMID: 29524051.
Ocon AJ. Caught in the thickness of brain fog: exploring the cognitive symptoms of Chronic Fatigue Syndrome. Front Physiol. 2013 Apr 5;4:63. DOI: 10.3389/fphys.2013.00063. PMID: 23576989. PMCID: PMC3617392.
Theoharides TC, Stewart JM, Hatziagelaki E, Kolaitis G. Brain “fog,” inflammation and obesity: key aspects of neuropsychiatric disorders improved by luteolin. Front Neurosci. 2015 Jul 3;9:225. DOI: 10.3389/fnins.2015.00225. PMID: 26190965. PMCID: PMC4490655.
Conti P, D’Ovidio C, Conti C, Gallenga CE, Lauritano D, Caraffa A, et al. Progression in migraine: Role of mast cells and pro-inflammatory and anti-inflammatory cytokines. Eur J Pharmacol. 2019 Feb 5;844:87–94. DOI: 10.1016/j.ejphar.2018.12.004. PMID: 30529470.
Jones KA, Thomsen C. The role of the innate immune system in psychiatric disorders. Mol Cell Neurosci. 2013 Mar;53:52–62. DOI: 10.1016/j.mcn.2012.10.002. PMID: 23064447.
Takakura W, Pimentel M. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome – An Update. Front Psychiatry. 2020 Jul 10;11:664. DOI: 10.3389/fpsyt.2020.00664. PMID: 32754068. PMCID: PMC7366247.
Rao SSC, Rehman A, Yu S, Andino NM de. Brain fogginess, gas and bloating: a link between SIBO, probiotics and metabolic acidosis. Clin Transl Gastroenterol. 2018 Jun 19;9(6):162. DOI: 10.1038/s41424-018-0030-7. PMID: 29915215. PMCID: PMC6006167.
van Langenberg DR, Yelland GW, Robinson SR, Gibson PR. Cognitive impairment in Crohn’s disease is associated with systemic inflammation, symptom burden and sleep disturbance. United European Gastroenterol J. 2017 Jun;5(4):579–87. DOI: 10.1177/2050640616663397. PMID: 28588890. PMCID: PMC5446137.
Volta U, Bardella MT, Calabrò A, Troncone R, Corazza GR, Study Group for Non-Celiac Gluten Sensitivity. An Italian prospective multicenter survey on patients suspected of having non-celiac gluten sensitivity. BMC Med. 2014 May 23;12(1):85. DOI: 10.1186/1741-7015-12-85. PMID: 24885375. PMCID: PMC4053283.
Isasi C, Tejerina E, Morán LM. Non-celiac gluten sensitivity and rheumatic diseases. Reumatol Clin. 2016 Feb;12(1):4–10. DOI: 10.1016/j.reuma.2015.03.001. PMID: 25956352.
Barbara G, Cremon C, Carini G, Bellacosa L, Zecchi L, De Giorgio R, et al. The immune system in irritable bowel syndrome. J Neurogastroenterol Motil. 2011 Oct 31;17(4):349–59. DOI: 10.5056/jnm.2011.17.4.349. PMID: 22148103. PMCID: PMC3228974.
Jin D-C, Cao H-L, Xu M-Q, Wang S-N, Wang Y-M, Yan F, et al. Regulation of the serotonin transporter in the pathogenesis of irritable bowel syndrome. World J Gastroenterol. 2016 Sep 28;22(36):8137–48. DOI: 10.3748/wjg.v22.i36.8137. PMID: 27688655. PMCID: PMC5037082.
Zamani M, Alizadeh-Tabari S, Zamani V. Systematic review with meta-analysis: the prevalence of anxiety and depression in patients with irritable bowel syndrome. Aliment Pharmacol Ther. 2019 Jul;50(2):132–43. DOI: 10.1111/apt.15325. PMID: 31157418.
Jandaghi G, Zia-Tohidi A, Firoozi M. Psychological Interventions for Irritable Bowel Syndrome: A Meta-Analysis of Iranian Randomized Trials. Arch Iran Med. 2021 Jun 1;24(6):496–504. DOI: 10.34172/aim.2021.71. PMID: 34488313.
Zhao S-R, Ni X-M, Zhang X-A, Tian H. Effect of cognitive behavior therapy combined with exercise intervention on the cognitive bias and coping styles of diarrhea-predominant irritable bowel syndrome patients. World J Clin Cases. 2019 Nov 6;7(21):3446–62. DOI: 10.12998/wjcc.v7.i21.3446. PMID: 31750328. PMCID: PMC6854400.
Lackner JM, Jaccard J, Keefer L, Brenner DM, Firth RS, Gudleski GD, et al. Improvement in gastrointestinal symptoms after cognitive behavior therapy for refractory irritable bowel syndrome. Gastroenterology. 2018 Jul;155(1):47–57. DOI: 10.1053/j.gastro.2018.03.063. PMID: 29702118. PMCID: PMC6035059.
Peters SL, Muir JG, Gibson PR. Review article: gut-directed hypnotherapy in the management of irritable bowel syndrome and inflammatory bowel disease. Aliment Pharmacol Ther. 2015 Jun;41(11):1104–15. DOI: 10.1111/apt.13202. PMID: 25858661.
Miller V, Carruthers HR, Morris J, Hasan SS, Archbold S, Whorwell PJ. Hypnotherapy for irritable bowel syndrome: an audit of one thousand adult patients. Aliment Pharmacol Ther. 2015 May;41(9):844–55. DOI: 10.1111/apt.13145. PMID: 25736234.
Kavuri V, Raghuram N, Malamud A, Selvan SR. Irritable bowel syndrome: yoga as remedial therapy. Evid Based Complement Alternat Med. 2015 May 6;2015:398156. DOI: 10.1155/2015/398156. PMID: 26064164. PMCID: PMC4438173.
Shah K, Ramos-Garcia M, Bhavsar J, Lehrer P. Mind-body treatments of irritable bowel syndrome symptoms: An updated meta-analysis. Behav Res Ther. 2020 May;128:103462. DOI: 10.1016/j.brat.2019.103462. PMID: 32229334.
Leblhuber F, Steiner K, Schuetz B, Fuchs D, Gostner JM. Probiotic Supplementation in Patients with Alzheimer’s Dementia – An Explorative Intervention Study. Curr Alzheimer Res. 2018;15(12):1106–13. DOI: 10.2174/1389200219666180813144834. PMID: 30101706. PMCID: PMC6340155.
Toribio-Mateas M. Harnessing the power of microbiome assessment tools as part of neuroprotective nutrition and lifestyle medicine interventions. Microorganisms. 2018 Apr 25;6(2). DOI: 10.3390/microorganisms6020035. PMID: 29693607. PMCID: PMC6027349.
Stenman LK, Lehtinen MJ, Meland N, Christensen JE, Yeung N, Saarinen MT, et al. Probiotic With or Without Fiber Controls Body Fat Mass, Associated With Serum Zonulin, in Overweight and Obese Adults-Randomized Controlled Trial. EBioMedicine. 2016 Nov;13:190–200. DOI: 10.1016/j.ebiom.2016.10.036. PMID: 27810310. PMCID: PMC5264483.
Mujagic Z, de Vos P, Boekschoten MV, Govers C, Pieters H-JHM, de Wit NJW, et al. The effects of Lactobacillus plantarum on small intestinal barrier function and mucosal gene transcription; a randomized double-blind placebo controlled trial. Sci Rep. 2017 Jan 3;7:40128. DOI: 10.1038/srep40128. PMID: 28045137. PMCID: PMC5206730.
Sindhu KNC, Sowmyanarayanan TV, Paul A, Babji S, Ajjampur SSR, Priyadarshini S, et al. Immune response and intestinal permeability in children with acute gastroenteritis treated with Lactobacillus rhamnosus GG: a randomized, double-blind, placebo-controlled trial. Clin Infect Dis. 2014 Apr;58(8):1107–15. DOI: 10.1093/cid/ciu065. PMID: 24501384. PMCID: PMC3967829.
Lamprecht M, Bogner S, Schippinger G, Steinbauer K, Fankhauser F, Hallstroem S, et al. Probiotic supplementation affects markers of intestinal barrier, oxidation, and inflammation in trained men; a randomized, double-blinded, placebo-controlled trial. J Int Soc Sports Nutr. 2012 Sep 20;9(1):45. DOI: 10.1186/1550-2783-9-45. PMID: 22992437. PMCID: PMC3465223.
Kouchaki E, Tamtaji OR, Salami M, Bahmani F, Daneshvar Kakhaki R, Akbari E, et al. Clinical and metabolic response to probiotic supplementation in patients with multiple sclerosis: A randomized, double-blind, placebo-controlled trial. Clin Nutr. 2017 Oct;36(5):1245–9. DOI: 10.1016/j.clnu.2016.08.015. PMID: 27669638.
Kim C-S, Cha L, Sim M, Jung S, Chun WY, Baik HW, et al. Probiotic Supplementation Improves Cognitive Function and Mood with Changes in Gut Microbiota in Community-Dwelling Older Adults: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial. J Gerontol A Biol Sci Med Sci. 2021 Jan 1;76(1):32–40. DOI: 10.1093/gerona/glaa090. PMID: 32300799. PMCID: PMC7861012.
Akbari E, Asemi Z, Daneshvar Kakhaki R, Bahmani F, Kouchaki E, Tamtaji OR, et al. Effect of Probiotic Supplementation on Cognitive Function and Metabolic Status in Alzheimer’s Disease: A Randomized, Double-Blind and Controlled Trial. Front Aging Neurosci. 2016 Nov 10;8:256. DOI: 10.3389/fnagi.2016.00256. PMID: 27891089. PMCID: PMC5105117.
Tamtaji OR, Heidari-Soureshjani R, Mirhosseini N, Kouchaki E, Bahmani F, Aghadavod E, et al. Probiotic and selenium co-supplementation, and the effects on clinical, metabolic and genetic status in Alzheimer’s disease: A randomized, double-blind, controlled trial. Clin Nutr. 2019 Dec;38(6):2569–75. DOI: 10.1016/j.clnu.2018.11.034. PMID: 30642737.
Roman P, Estévez AF, Miras A, Sánchez-Labraca N, Cañadas F, Vivas AB, et al. A pilot randomized controlled trial to explore cognitive and emotional effects of probiotics in fibromyalgia. Sci Rep. 2018 Jul 19;8(1):10965. DOI: 10.1038/s41598-018-29388-5. PMID: 30026567. PMCID: PMC6053373.
Alexandrov P, Zhai Y, Li W, Lukiw W. Lipopolysaccharide-stimulated, NF-kB-, miRNA-146a- and miRNA-155-mediated molecular-genetic communication between the human gastrointestinal tract microbiome and the brain. Folia Neuropathol. 2019;57(3):211–9. DOI: 10.5114/fn.2019.88449. PMID: 31588707.
Morris G, Fernandes BS, Puri BK, Walker AJ, Carvalho AF, Berk M. Leaky brain in neurological and psychiatric disorders: Drivers and consequences. Aust N Z J Psychiatry. 2018 Oct;52(10):924–48. DOI: 10.1177/0004867418796955. PMID: 30231628.
Lv T, Ye M, Luo F, Hu B, Wang A, Chen J, et al. Probiotics treatment improves cognitive impairment in patients and animals: A systematic review and meta-analysis. Neurosci Biobehav Rev. 2021 Jan;120:159–72. DOI: 10.1016/j.neubiorev.2020.10.027. PMID: 33157148.
Kelly JR, Allen AP, Temko A, Hutch W, Kennedy PJ, Farid N, et al. Lost in translation? The potential psychobiotic Lactobacillus rhamnosus (JB-1) fails to modulate stress or cognitive performance in healthy male subjects. Brain Behav Immun. 2017 Mar;61:50–9. DOI: 10.1016/j.bbi.2016.11.018. PMID: 27865949.
Reininghaus EZ, Wetzlmair L-C, Fellendorf FT, Platzer M, Queissner R, Birner A, et al. The Impact of Probiotic Supplements on Cognitive Parameters in Euthymic Individuals with Bipolar Disorder: A Pilot Study. Neuropsychobiology. 2018 Sep 18;1–8. DOI: 10.1159/000492537. PMID: 30227422.
Camilleri M. Leaky gut: mechanisms, measurement and clinical implications in humans. Gut. 2019 Aug;68(8):1516–26. DOI: 10.1136/gutjnl-2019-318427. PMID: 31076401. PMCID: PMC6790068.
Maes M, Kubera M, Leunis J-C. The gut-brain barrier in major depression: intestinal mucosal dysfunction with an increased translocation of LPS from gram negative enterobacteria (leaky gut) plays a role in the inflammatory pathophysiology of depression. Neuro Endocrinol Lett. 2008 Feb;29(1):117–24. PMID: 18283240.
Ng QX, Peters C, Ho CYX, Lim DY, Yeo W-S. A meta-analysis of the use of probiotics to alleviate depressive symptoms. J Affect Disord. 2018 Mar 1;228:13–9. DOI: 10.1016/j.jad.2017.11.063. PMID: 29197739.
El Dib R, Periyasamy AG, de Barros JL, França CG, Senefonte FL, Vesentini G, et al. Probiotics for the treatment of depression and anxiety: A systematic review and meta-analysis of randomized controlled trials. Clin Nutr ESPEN. 2021 Oct;45:75–90. DOI: 10.1016/j.clnesp.2021.07.027. PMID: 34620373.
Huang R, Wang K, Hu J. Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2016 Aug 6;8(8). DOI: 10.3390/nu8080483. PMID: 27509521. PMCID: PMC4997396.
Goh KK, Liu Y-W, Kuo P-H, Chung Y-CE, Lu M-L, Chen C-H. Effect of probiotics on depressive symptoms: A meta-analysis of human studies. Psychiatry Res. 2019 Dec;282:112568. DOI: 10.1016/j.psychres.2019.112568. PMID: 31563280.
Akkasheh G, Kashani-Poor Z, Tajabadi-Ebrahimi M, Jafari P, Akbari H, Taghizadeh M, et al. Clinical and metabolic response to probiotic administration in patients with major depressive disorder: A randomized, double-blind, placebo-controlled trial. Nutrition. 2016 Mar;32(3):315–20. DOI: 10.1016/j.nut.2015.09.003. PMID: 26706022.
Yang B, Wei J, Ju P, Chen J. Effects of regulating intestinal microbiota on anxiety symptoms: A systematic review. Gen Psych. 2019 May 17;32(2):e100056. DOI: 10.1136/gpsych-2019-100056. PMID: 31179435. PMCID: PMC6551444.
Rao AV, Bested AC, Beaulne TM, Katzman MA, Iorio C, Berardi JM, et al. 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. DOI: 10.1186/1757-4749-1-6. PMID: 19338686. PMCID: PMC2664325.
Liu B, He Y, Wang M, Liu J, Ju Y, Zhang Y, et al. Efficacy of probiotics on anxiety-A meta-analysis of randomized controlled trials. Depress Anxiety. 2018 Oct;35(10):935–45. DOI: 10.1002/da.22811. PMID: 29995348.
Liu RT, Walsh RFL, Sheehan AE. Prebiotics and probiotics for depression and anxiety: A systematic review and meta-analysis of controlled clinical trials. Neurosci Biobehav Rev. 2019 Jul;102:13–23. DOI: 10.1016/j.neubiorev.2019.03.023. PMID: 31004628. PMCID: PMC6584030.
Reis DJ, Ilardi SS, Punt SEW. The anxiolytic effect of probiotics: A systematic review and meta-analysis of the clinical and preclinical literature. PLoS ONE. 2018 Jun 20;13(6):e0199041. DOI: 10.1371/journal.pone.0199041. PMID: 29924822. PMCID: PMC6010276.
McKean J, Naug H, Nikbakht E, Amiet B, Colson N. Probiotics and Subclinical Psychological Symptoms in Healthy Participants: A Systematic Review and Meta-Analysis. J Altern Complement Med. 2017 Apr;23(4):249–58. DOI: 10.1089/acm.2016.0023. PMID: 27841940.
Lew L-C, Hor Y-Y, Yusoff NAA, Choi S-B, Yusoff MSB, Roslan NS, et al. Probiotic Lactobacillus plantarum P8 alleviated stress and anxiety while enhancing memory and cognition in stressed adults: A randomised, double-blind, placebo-controlled study. Clin Nutr. 2019 Oct;38(5):2053–64. DOI: 10.1016/j.clnu.2018.09.010. PMID: 30266270.
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