Introduction and objective:
In recent years, there has been a rapid increase in the number of people suffering from mental disorders, including depression and anxiety disorders. Data indicate that conventional treatments have not been sufficiently effective, leading to the exploration of alternative methods for treating and preventing these conditions. One of the areas of research is the gut microbiota and its potential role in these disorders. The aim of this study is to summarize the latest evidence linking gut flora to depression and anxiety disorders, and to present ways to alleviate the symptoms of these disorders through proper diet, including the use of prebiotics, probiotics, and synbiotics.

Brief description of the state of knowledge:
Research suggests that changes in the gut microbiota may be associated with mental disorders, such as depression and anxiety. Analyses in this area are complex due to the diversity of micro-organisms and the influence of external factors. Treatment methods based on the gut microbiota are becoming a therapeutic alternative for individuals with mental disorders, but further clinical research is required.

There is a strong correlation between gut dysbiosis, depression and anxiety disorders. These disorders can be effectively alleviated or controlled through modulation of the gut microbiota via proper diet and supplements. Further research is necessary to better understand the relationship between gut dysbiosis and mental disorders and to effectively and safely implement appropriate treatment.

World Health Organization. Mental disorders. World Health Organization. (access: 8.06 2022r.).
World Health Organization. Mental Health and COVID-19: Early Evidence of the Pandemic’s Impact. World Health Organization, 2022. JSTOR. (access: 6.04.2024r.).
Pan KY, Kok AAL, Eikelenboom M, et al. The mental health impact of the COVID-19 pandemic on people with and without depressive, anxiety, or obsessive-compulsive disorders: a longitudinal study of three Dutch case-control cohorts. Lancet Psychiatry. 2021 Feb 1;8(2):121–9.
Xiong R-G, Li J, Cheng J, Zhou D-D, et al. The Role of Gut Microbiota in Anxiety, Depression, and Other Mental Disorders as Well as the Protective Effects of Dietary Components. Nutrients. 2023;15(14):3258.
Wang PS, Aguilar-Gaxiola S, Alonso J, et al. Use of mental health services for anxiety, mood, and substance disorders in 17 countries in the WHO world mental health surveys. Lancet. 2007 Sep 8;370(9590):841–50.
Nobis A, Zalewski D, Waszkiewicz N. Peripheral Markers of Depression. J Clin Med. 2020; 9(12):3793.
Wittchen HU, Kessler RC, Pfister H, et al. Why do people with anxiety disorders become depressed? A prospective-longitudinal community study. Acta Psychiatr Scand Suppl. 2000;(406):14–23.
de Graaf R, Bijl RV, Spijker J, et al. Temporal sequencing of lifetime mood disorders in relation to comorbid anxiety and substance use disorders-findings from the Netherlands Mental Health Survey and Incidence Study. Soc Psychiatry Psychiatr Epidemiol. 2003 Jan;38(1):1–11.
Modesto Lowe V, Chaplin M, Sgambato D. Major depressive disorder and the gut microbiome: what is the link? Gen Psychiatr. 2023 Feb 17;36(1):e100973.
Kunugi H. Gut microbiota and pathophysiology of depressive disorder. Ann Nutrit Metab. 2021;77:11–20.
Kumar A, Pramanik J, Goyal N, et al. Microbiota in Anxiety and Depression: Unveiling the Relationships and Management Options. Pharmaceuticals. 2023;16(4):565.
Irum N, Afzal T, Faraz MH, et al.The role of gut microbiota in depression: an analysis of the gut-brain axis. Vol. 17, Frontiers in Behavioral Neuroscience. Frontiers Media SA; 2023.
Kennedy PJ, Murphy AB, Cryan JF, et al. Microbiome in brain function and mental health. Trends Food Sci Technol. 2016 Nov 1;57:289–301.
Godos J, Currenti W, Angelino D, et al. Diet and Mental Health: Review of the Recent Updates on Molecular Mechanisms. Antioxidants. 2020;9(4):346.
Hao Z, Meng C, Li L, et al. Positive mood-related gut microbiota in a long-term closed environment: a multiomics study based on the “Lunar Palace 365” experiment. Microbiome 2023;11:88.
Bhatia NY, Jalgaonkar MP, Hargude AB, et al. Gut-Brain Axis and Neurological Disorders-How Microbiomes Affect our Mental Health. CNS Neurol Disord Drug Targets. 2023;22(7):1008–1030. doi:10.2174/1871527321666220822172039. PMID: 36017855.
Evans-Lacko S, Aguilar-Gaxiola S, Al-Hamzawi A, et al. Socio-economic variations in the mental health treatment gap for people with anxiety, mood, and substance use disorders: results from the WHO World Mental Health (WMH) surveys. Psychol Med. 2018;48(9):1560–1571.
World Health Organization. Depressive disorder (depression).
Rush AJ, Trivedi MH, Wisniewski SR, et al. Bupropion-SR, sertraline, or venlafaxine-XR after failure of SSRIs for depression. N Engl J Med. 2006 Mar 23;354(12):1231–42.
Gaynes BN, Warden D, Trivedi MH, et al. What did STAR*D teach us? Results from a large-scale, practical, clinical trial for patients with depression. Psychiatr Serv. 2009 Nov;60(11):1439–45.
Ferrari AJ, Charlson FJ, Norman RE, et al. Burden of Depressive Disorders by Country, Sex, Age, and Year: Findings from the Global Burden of Disease Study 2010. PLoS Med. 2013 Nov;10(11).
Woody CA, Ferrari AJ, Siskind DJ, et al. A systematic review and meta-regression of the prevalence and incidence of perinatal depression. J Affect Dis. 2017: 86–92.
Chen Z, Li J, Gui S, et al. Comparative metaproteomics analysis shows altered fecal microbiota signatures in patients with major depressive disorder. Neuroreport. 2018;29(5):417–25.
Lin P, Ding B, Feng C, et al. Prevotella and Klebsiella proportions in fecal microbial communities are potential characteristic parameters for patients with major depressive disorder. J Affect Disord. 2017 Jan 1;207:300–4.
Valles-Colomer M, Falony G, Darzi Y, et al. The neuroactive potential of the human gut microbiota in quality of life and depression. Nat Microbiol. 2019;4:623–632.
Gu Y, Zheng L, Kumari S, et al. The relationship between Helicobacter pylori infection and depressive symptoms in the general population in China: The TCLSIH cohort study. Helicobacter. 2019 Oct 1;24(5).
Li D, Sun T, Tong Y, et al. Gut-microbiome-expressed 3β-hydroxysteroid dehydrogenase degrades estradiol and is linked to depression in premenopausal females. Cell Metab. 2023 Apr 4;35(4):685–694.e5. Available from:
Liu Y, Wang H, Gui S, et al. Proteomics analysis of the gut–brain axis in a gut microbiota-dysbiosis model of depression. Transl Psychiatry 2021;11:568.
Wu J, Chai T, Zhang H, et al. Changes in gut viral and bacterial species correlate with altered 1,2-diacylglyceride levels and structure in the prefrontal cortex in a depression-like non-human primate model. Transl Psychiatry 2022;12:74.
Medina-Rodriguez EM, Watson J, Reyes J, et al. Th17 cells sense microbiome to promote depressive-like behaviors. Microbiome 2023;11:92.
Kim CS, Shin GE, Cheong Y, et al. Experiencing social exclusion changes gut microbiota composition. Transl Psychiatry 2022;12:254.
Jiang HY, Zhang X, Yu ZH, et al. Altered gut microbiota profile in patients with generalized anxiety disorder. J Psychiatr Res. 2018 Sep;104:130–136.
Malan-Müller S, Valles-Colomer M, Palomo T, et al. he gut-microbiota-brain axis in a Spanish population in the aftermath of the COVID-19 pandemic: microbiota composition linked to anxiety, trauma, and depression profiles. Gut Microbes. 2023 Jan-Dec;15(1):2162306.
Yuan X, Chen B, Duan Z, et al. Depression and anxiety in patients with active ulcerative colitis: crosstalk of gut microbiota, metabolomics and proteomics. Gut Microbes. 2021 Jan-Dec;13(1):1987779.
Nikolova VL, Cleare AJ, Young AH, et al. Acceptability, Tolerability, and Estimates of Putative Treatment Effects of Probiotics as Adjunctive Treatment in Patients With Depression: A Randomized Clinical Trial. JAMA Psychiatry. 2023 Aug 1;80(8):842–847.
Kim CS, Cha L, Sim M, 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.
Chahwan B, Kwan S, Isik A, et al. Gut feelings: A randomised, triple-blind, placebo-controlled trial of probiotics for depressive symptoms. J Affect Disord. 2019 Jun 15;253:317–326.
Green JE, Berk M, Mohebbi M, et al. Feasibility, Acceptability, and Safety of Faecal Microbiota Transplantation in the Treatment of Major Depressive Disorder: A Pilot Randomized Controlled Trial. Can J Psychiatry. 2023 May;68(5):315–326.
Doll JPK, Vázquez-Castellanos JF, Schaub AC, Schweinfurth N, Kettelhack C, Schneider E, et al. Fecal Microbiota Transplantation (FMT) as an Adjunctive Therapy for Depression-Case Report. Front Psychiatry. 2022 Feb 17;13:815422.
Cai T, Shi X, Yuan LZ, et al. Fecal microbiota transplantation in an elderly patient with mental depression. Int Psychogeriatr. 2019 Oct;31(10):1525–1526.
Liu L, Wang H, Chen X, et al. Gut microbiota and its metabolites in depression: from pathogenesis to treatment. EBioMedicine. 2023 Apr; 90:104527.
Guo Q, Lin H, Chen P, et al. Dynamic changes of intestinal flora in patients with irritable bowel syndrome combined with anxiety and depression after oral administration of enterobacteria capsules. Bioengineered. 2021;12(2):11885–97.
Hadi A, Sepandi M, Marx W, Moradi S, Parastouei K. Clinical and psychological responses to synbiotic supplementation in obese or overweight adults: A randomized clinical trial. Complement Ther Med. 2019 Dec 1;47.
Haghighat N, Rajabi S, Mohammadshahi M. Effect of synbiotic and probiotic supplementation on serum brain-derived neurotrophic factor level, depression and anxiety symptoms in hemodialysis patients: a randomized, double-blinded, clinical trial. Nutr Neurosci. 2021;24(6):490–9.
Alli SR, Gorbovskaya I, Liu JCW, et al. The Gut Microbiome in Depression and Potential Benefit of Prebiotics, Probiotics and Synbiotics: A Systematic Review of Clinical Trials and Observational Studies. Int J Mol Sci. 2022 Apr 19;23(9):4494.
Mysonhimer AR, Cannavale CN, Bailey MA, et al. Prebiotic Consumption Alters Microbiota but Not Biological Markers of Stress and Inflammation or Mental Health Symptoms in Healthy Adults: A Randomized, Controlled, Crossover Trial. Journal of Nutrition. 2023 Apr 1;153(4):1283–96.
Moludi J, Khedmatgozar H, Nachvak SM, et al. The effects of co-administration of probiotics and prebiotics on chronic inflammation, and depression symptoms in patients with coronary artery diseases: a randomized clinical trial. Nutr Neurosci. 2022;25(8):1659–68.
Ben Othman R, Ben Amor N, Mahjoub F, et al. A clinical trial about effects of prebiotic and probiotic supplementation on weight loss, psychological profile and metabolic parameters in obese subjects. Endocrinol Diabetes Metab. 2023 Mar 1;6(2).
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