How does the gut microbiome influence mental health conditions like depression and anxiety?
October 8, 2024
The gut microbiome significantly influences mental health conditions, particularly depression and anxiety, through the microbiota-gut-brain axis, highlighting complex interactions between gut microbiota, the central nervous system (CNS), and mental health (1, 2). Alterations in gut microbiota, known as dysbiosis, have been linked with mental health conditions, showing that microbes modulate neurotransmission, immune responses, and endocrine functions, affecting behaviors linked to stress, depression, and anxiety (2, 3, 6). Key mechanisms include the modulation of neurotransmitters like serotonin and dopamine by gut microbes, immune system activation, and hormonal pathways involving the hypothalamic-pituitary-adrenal (HPA) axis (2, 4, 7, 19). Fecal microbiota transplants, probiotics, and dietary interventions have been explored as potential treatments targeting gut microbiome alterations to alleviate mental health symptoms (1, 5, 12, 21). However, further research is required to elucidate the causal relationships and understand the bidirectional influence where stress and mental health conditions themselves alter the microbiome (8, 16, 24, 23). Interactions through neuroimmune, neuroendocrine, and sensory neural pathways reinforce this bidirectional communication, potentially modulating emotional and cognitive functions based on microbial composition and signaling (13, 14, 20).
Although preclinical models strongly support these interactions, translating findings from animal models to human clinical applications requires more robust studies (9, 11, 26). Emerging evidence underscores the need to integrate microbiome research into clinical practice and mental health models to explore new therapeutic avenues for mental health disorders, considering the individual's diet and lifestyle as influencing factors on gut microbiota composition and subsequently on mental health (18, 28, 36, 45). Given the intricate interplay between the gut microbiome and brain functions, a holistic approach to mental health treatment, focusing on the gut-brain axis, is anticipated to provide innovative therapeutic strategies for disorders like depression and anxiety (10, 27, 47).
References
1. Halverson, Tyler, and Kannayiram Alagiakrishnan. "Gut microbes in neurocognitive and mental health disorders." Annals of Medicine 52.8 (2020): 423-443.
2. Bhatia, Nirav Y., et al. "Gut-brain axis and neurological disorders—how microbiomes affect our mental health." CNS & Neurological Disorders-Drug Targets 22.7 (2023): 1008-1030.
3. Foster, Jane A., and Karen-Anne McVey Neufeld. "Gut–brain axis: how the microbiome influences anxiety and depression." Trends in neurosciences 36.5 (2013): 305-312.
4. Peirce, Jason M., and Karina Alviña. "The role of inflammation and the gut microbiome in depression and anxiety." Journal of neuroscience research 97.10 (2019): 1223-1241.
5. Malan-Müller, Stefanie, et al. "The gut microbiome and mental health: implications for anxiety- and trauma-related disorders." OMICS: A Journal of Integrative Biology 22.2 (2018): 90-107.
6. Methiwala, Hasnain N., et al. "Gut microbiota in mental health and depression: Role of pre/pro/synbiotics in their modulation." Food & Function 12.10 (2021): 4284-4314.
7. Huang, Fei, and Xiaojun Wu. "Brain neurotransmitter modulation by gut microbiota in anxiety and depression." Frontiers in cell and developmental biology 9 (2021): 649103.
8. Aslam, Hajara, et al. "Fermented foods, the gut and mental health: a mechanistic overview with implications for depression and anxiety." Nutritional Neuroscience 23.9 (2020): 659-671.
9. Dinan, Timothy G., and John F. Cryan. "Brain–gut–microbiota axis and mental health." Psychosomatic medicine 79.8 (2017): 920-926.
10. Simpson, Carra A., et al. "The gut microbiota in anxiety and depression—a systematic review." Clinical Psychology Review 83 (2021): 101943.
11. Dinan, Ted G., and John F. Cryan. "Melancholic microbes: a link between gut microbiota and depression?." Neurogastroenterology & Motility 25.9 (2013): 713-719.
12. Lucas, Grace. "Gut thinking: the gut microbiome and mental health beyond the head." Microbial Ecology in Health and Disease 29.2 (2018): 1548250.
13. Lach, Gilliard, et al. "Anxiety, depression, and the microbiome: a role for gut peptides." Neurotherapeutics 15.1 (2018): 36-59.
14. Limbana, Therese, Farah Khan, and Noha Eskander. "Gut microbiome and depression: how microbes affect the way we think." Cureus 12.8 (2020).
15. Rogers, G. B., et al. "From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways." Molecular psychiatry 21.6 (2016): 738-748.
16. Winter, Gal, et al. "Gut microbiome and depression: what we know and what we need to know." Reviews in the Neurosciences 29.6 (2018): 629-643.
17. Shoubridge, Andrew P., et al. "The gut microbiome and mental health: advances in research and emerging priorities." Molecular Psychiatry 27.4 (2022): 1908-1919.
18. Flowers, Stephanie A., and Vicki L. Ellingrod. "The microbiome in mental health: potential contribution of gut microbiota in disease and pharmacotherapy management." Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy 35.10 (2015): 910-916.
19. Appleton, Jeremy. "The gut-brain axis: influence of microbiota on mood and mental health." Integrative Medicine: A Clinicians Journal 17.4 (2018): 28.
20. Skonieczna-Żydecka, Karolina, et al. "Microbiota—the missing link in the gut–brain axis: focus on its role in gastrointestinal and mental health." Journal of Clinical Medicine 7.12 (2018): 521.
21. Bear, Tracey L.K., et al. "The role of the gut microbiota in dietary interventions for depression and anxiety." Advances in Nutrition 11.4 (2020): 890-907.
22. Bear, Tracey, et al. "The microbiome–gut–brain axis and resilience to developing anxiety or depression under stress." Microorganisms 9.4 (2021): 723.
23. Yarandi, Shadi S., et al. "Modulatory effects of gut microbiota on the central nervous system: how gut could play a role in neuropsychiatric health and diseases." Journal of Neurogastroenterology and Motility 22.2 (2016): 201.
24. Suda, Kazunori, and Kazunori Matsuda. "How microbes affect depression: underlying mechanisms via the gut–brain axis and the modulating role of probiotics." International Journal of Molecular Sciences 23.3 (2022): 1172.
25. Wilmes, Lars, et al. "Of bowels, brain and behavior: a role for the gut microbiota in psychiatric comorbidities in irritable bowel syndrome." Neurogastroenterology & Motility 33.3 (2021): e14095.
26. Lee, Younjung, and Yong-Ku Kim. "Understanding the connection between the gut–brain axis and stress/anxiety disorders." Current Psychiatry Reports 23 (2021): 1-7.
27. Wong, Ma-Li, et al. "Inflammasome signaling affects anxiety- and depressive-like behavior and gut microbiome composition." Molecular Psychiatry 21.6 (2016): 797-805.
28. Cenit, María Carmen, Yolanda Sanz, and Pilar Codoñer-Franch. "Influence of gut microbiota on neuropsychiatric disorders." World Journal of Gastroenterology 23.30 (2017): 5486.
29. Luna, Ruth Ann, and Jane A. Foster. "Gut brain axis: diet microbiota interactions and implications for modulation of anxiety and depression." Current Opinion in Biotechnology 32 (2015): 35-41.
30. Verma, Ankita, Sabra S. Inslicht, and Aditi Bhargava. "Gut–Brain Axis: Role of Microbiome, Metabolomics, Hormones, and Stress in Mental Health Disorders." Cells 13.17 (2024): 1436.
31. Hayes, Christina L., Brett J. Peters, and Jane A. Foster. "Microbes and mental health: Can the microbiome help explain clinical heterogeneity in psychiatry?." Frontiers in Neuroendocrinology 58 (2020): 100849.
32. Gawlik-Kotelnicka, Oliwia, and Michał Polguj. "Can microbiology affect psychiatry? A link between gut microbiota and psychiatric disorders." Psychiatria Polska 52.6 (2018): 1023-1039.
33. Bruce-Keller, Annadora J., J. Michael Salbaum, and Hans-Rudolf Berthoud. "Harnessing gut microbes for mental health: getting from here to there." Biological Psychiatry 83.3 (2018): 214-223.
34. Dinan, Katherine, and Timothy Dinan. "Antibiotics and mental health: The good, the bad and the ugly." Journal of Internal Medicine 292.6 (2022): 858-869.
35. Mohajeri, M. Hasan, et al. "Relationship between the gut microbiome and brain function." Nutrition Reviews 76.7 (2018): 481-496.
36. Mason, Brittany L. "Feeding systems and the gut microbiome: gut-brain interactions with relevance to psychiatric conditions." Psychosomatics 58.6 (2017): 574-580.
37. Liang, Shan, et al. "Recognizing depression from the microbiota–gut–brain axis." International Journal of Molecular Sciences 19.6 (2018): 1592.
38. Dong, Zaiquan, et al. "Gut microbiome: a potential indicator for differential diagnosis of major depressive disorder and general anxiety disorder." Frontiers in Psychiatry 12 (2021): 651536.
39. Borrego-Ruiz, Alejandro, and Juan J. Borrego. "An updated overview on the relationship between human gut microbiome dysbiosis and psychiatric and psychological disorders." Progress in Neuro-Psychopharmacology and Biological Psychiatry 128 (2024): 110861.
40. Simpson, Carra A., et al. "Feeling down? A systematic review of the gut microbiota in anxiety/depression and irritable bowel syndrome." Journal of Affective Disorders 266 (2020): 429-446.
41. Liu, Richard T. "The microbiome as a novel paradigm in studying stress and mental health." American Psychologist 72.7 (2017): 655.
42. Allen, Andrew P., et al. "A psychology of the human brain–gut–microbiome axis." Social and Personality Psychology Compass 11.4 (2017): e12309.
43. Horn, J., et al. "Role of diet and its effects on the gut microbiome in the pathophysiology of mental disorders." Translational Psychiatry 12.1 (2022): 164.
44. Rieder, Ryan, et al. "Microbes and mental health: A review." Brain, Behavior, and Immunity 66 (2017): 9-17.
45. Schnorr, Stephanie L., and Harriet A. Bachner. "Focus: microbiome: integrative therapies in anxiety treatment with special emphasis on the gut microbiome." The Yale Journal of Biology and Medicine 89.3 (2016): 397.
46. Capuco, Alexander, et al. "Current perspectives on gut microbiome dysbiosis and depression." Advances in Therapy 37 (2020): 1328-1346.
47. Person, Hannibal, and Laurie Keefer. "Psychological comorbidity in gastrointestinal diseases: Update on the brain-gut-microbiome axis." Progress in Neuro-Psychopharmacology and Biological Psychiatry 107 (2021): 110209.
48. Reid, Gregor. "Disentangling what we know about microbes and mental health." Frontiers in Endocrinology 10 (2019): 81.
49. Socała, Katarzyna, et al. "The role of microbiota-gut-brain axis in neuropsychiatric and neurological disorders." Pharmacological Research 172 (2021): 105840.
50. Farmer, Adam D., Holly A. Randall, and Qasim Aziz. "Its a gut feeling: how the gut microbiota affects the state of mind." The Journal of Physiology 592.14 (2014): 2981-2998.