Article

Anxiety and Gut Health

Published on Wednesday, June 15, 2022
by Andy De Santis

Health & Wellness

The Gut-Brain Connection: Can Gut Health Affect Anxiety?

Anxiety disorders represent some of the most common mental health conditions worldwide. As research surrounding the gut-brain axis continues to evolve, scientists and healthcare professionals alike have become increasingly interested in how nutrition and gut health may influence anxiety symptoms.

The relationship between the digestive system and mental health is complex. While nutrition is not a replacement for mental health treatment, emerging evidence suggests that the gut microbiome may play a role in mood regulation, stress responses, and emotional wellness.

Understanding the Gut-Brain Axis

The gut and brain are closely connected through what is commonly referred to as the gut-brain axis. This communication network links the central nervous system with the digestive tract through neural, hormonal, immune, and microbial pathways.

Research suggests a bidirectional relationship between the gut microbiome and mental health, meaning the brain may influence the gut, and the gut may also influence mood, cognition, and emotional regulation. Dysbiosis, which refers to an imbalance in gut bacteria, and inflammation within the digestive tract, have both been identified as potential contributors to anxiety and depression.

While this area of research is still developing, scientists continue exploring whether improving gut health may help reduce anxiety severity in some individuals.

Anxiety and Probiotics

Any discussion surrounding gut health today will likely include probiotics. Probiotics are live microorganisms that may provide health benefits when consumed in adequate amounts.

However, when it comes to anxiety, the research remains mixed.

A 2021 systematic review and meta-analysis published in Clinical Nutrition ESPEN evaluated 16 studies involving more than 1,000 participants and found that probiotic supplementation improved some measures of anxiety and depression, although other outcomes showed no statistically significant effect.

Researchers concluded that probiotics may offer some benefit for clinically diagnosed anxiety and depression, which aligns with earlier findings published in Neuroscience & Biobehavioral Reviews suggesting probiotics may have a small but statistically significant effect on mood disorders.

One important observation across much of the literature is that benefits appear more consistent in individuals with diagnosed anxiety or depression rather than in otherwise healthy individuals without clinical disorders. Additionally, evidence supporting dietary interventions tends to be stronger for depression than for anxiety overall.

Most studies used probiotic supplements containing strains from the Lactobacillus and Bifidobacterium families. However, because probiotic strains, dosages, and study designs vary widely, there is currently insufficient evidence to recommend a specific probiotic product for anxiety management, although multi-strain supplements may generally be more effective.

Prebiotics, Fermented Foods, and Anxiety

Probiotic supplements are not the only way to influence the gut microbiome. Researchers have also explored whether prebiotics and fermented foods may support mental health.

Prebiotics are fibers that feed beneficial gut bacteria, while fermented foods naturally contain live microorganisms that may support microbial diversity.

A 2021 study published in Scientific Reports found that a four-week prebiotic intervention using galacto-oligosaccharides (GOS) in young women increased levels of beneficial Bifidobacterium bacteria and demonstrated some potential anti-anxiety effects.

Foods naturally rich in GOS include legumes such as lentils and chickpeas.

Fermented foods have also attracted attention. An observational study published in Psychiatry Research in 2015 found that higher fermented food intake may help reduce symptoms of social anxiety in certain predisposed individuals.

Examples of fermented foods include:

Yogurt
Kefir
Kimchi
Sauerkraut
Kombucha

While these findings are encouraging, the evidence remains limited, and researchers caution against overstating the effects of fermented foods or prebiotics on anxiety symptoms.

Inflammation, Omega-3s, and Anxiety

Inflammation has also been proposed as one potential contributor to worsening mental health symptoms, including anxiety.

Because of this, researchers have explored whether anti-inflammatory nutrients and supplements may support emotional wellness. Preliminary evidence suggests omega-3 fatty acids and curcumin may have potential anti-anxiety effects, although additional research is needed.

Long-chain omega-3 fatty acids such as DHA and EPA are found primarily in fatty fish, including salmon, trout, and sardines. These foods are also among the richest natural dietary sources of vitamin D, another nutrient under study for its potential relationship to mood and mental health.

What Does This Mean for Gut Health and Anxiety?

Despite anxiety disorders being highly prevalent, research surrounding dietary interventions for anxiety remains relatively limited.

Current evidence does not support the idea that probiotics, fermented foods, or supplements alone can “cure” anxiety. However, emerging research suggests that supporting gut health through a balanced diet, dietary variety, fiber intake, and overall lifestyle habits may potentially play a supportive role in mental wellness for some individuals.

For individuals living with both digestive concerns and anxiety, this relationship may feel especially relevant, as stress and anxiety themselves can also influence digestive symptoms through the gut-brain axis.

The Bottom Line

The connection between gut health and anxiety is an exciting and rapidly evolving area of research. While evidence surrounding probiotics, prebiotics, fermented foods, and anti-inflammatory nutrients continues to grow, current findings remain preliminary and inconsistent in many areas.

Still, supporting gut health through balanced nutrition, fiber-rich foods, and dietary variety remains a generally low-risk approach that may benefit both digestive and overall health.

As always, individuals struggling with anxiety symptoms should work with qualified healthcare professionals to develop comprehensive treatment strategies tailored to their needs.

_{Bandelow, B., & Michaelis, S. (2015). Epidemiology of anxiety disorders in the 21st century. Dialogues in clinical neuroscience, 17(3), 327–335.}_{https://doi.org/10.31887/DCNS.2015.17.3/bbandelow}
_{Desbonnet, L., Clarke, G., Shanahan, F., Dinan, T. G., & Cryan, J. F. (2014). Microbiota is essential for social development in the mouse. Molecular psychiatry, 19(2), 146–148.}_{https://doi.org/10.1038/mp.2013.65}
_{El Dib, R., Periyasamy, A. G., de Barros, J. L., França, C. G., Senefonte, F. L., Vesentini, G., Alves, M. G. O., Rodrigues, J. V. D. S., Gomaa, H., Gomes Júnior, J. R., Costa, L. F., Von Ancken, T. S., Toneli, C., Suzumura, E. A., Kawakami, C. P., Faustino, E. G., Jorge, E. C., Almeida, J. D., & Kapoor, A. (2021). Probiotics for the treatment of depression and anxiety: A systematic review and meta-analysis of randomized controlled trials. Clinical nutrition ESPEN, 45, 75–90.}_{https://doi.org/10.1016/j.clnesp.2021.07.027}
_{Esmaily, H., Sahebkar, A., Iranshahi, M., Ganjali, S., Mohammadi, A., Ferns, G., & Ghayour-Mobarhan, M. (2015). An investigation of the effects of curcumin on anxiety and depression in obese individuals: A randomized controlled trial. Chinese journal of integrative medicine, 21(5), 332–338.}_{https://doi.org/10.1007/s11655-015-2160-z}
_{Firth, J., Marx, W., Dash, S., Carney, R., Teasdale, S. B., Solmi, M., Stubbs, B., Schuch, F. B., Carvalho, A. F., Jacka, F., & Sarris, J. (2019). The Effects of Dietary Improvement on Symptoms of Depression and Anxiety: A Meta-Analysis of Randomized Controlled Trials. Psychosomatic medicine, 81(3), 265–280.}_{https://doi.org/10.1097/PSY.0000000000000673}
_{Hilimire, M. R., DeVylder, J. E., & Forestell, C. A. (2015). Fermented foods, neuroticism, and social anxiety: An interaction model. Psychiatry research, 228(2), 203–208.}_{https://doi.org/10.1016/j.psychres.2015.04.023}
_{Johnstone, N., Milesi, C., Burn, O., van den Bogert, B., Nauta, A., Hart, K., Sowden, P., Burnet, P. W. J., & Cohen Kadosh, K. (2021). Anxiolytic effects of a galacto-oligosaccharides prebiotic in healthy females (18-25 years) with corresponding changes in gut bacterial composition. Scientific reports, 11(1), 8302.}_{https://doi.org/10.1038/s41598-021-87865-w}
_{Kazemi, A., Noorbala, A. A., Azam, K., Eskandari, M. H., & Djafarian, K. (2019). Effect of probiotic and prebiotic vs placebo on psychological outcomes in patients with major depressive disorder: A randomized clinical trial. Clinical nutrition (Edinburgh, Scotland), 38(2), 522–528.}_{https://doi.org/10.1016/j.clnu.2018.04.010}
_{Liu, R. T., Walsh, R. F. L., & Sheehan, A. E. (2019). Prebiotics and probiotics for depression and anxiety: A systematic review and meta-analysis of controlled clinical trials.}_{Neuroscience & Biobehavioral Reviews, 102}_{, 13–23.}_{https://doi.org/10.1016/j.neubiorev.2019.03.023}
_{National Institute of Mental Health. (2024).}_{Anxiety disorders}_._{https://www.nimh.nih.gov}
_{Su, K. P., Tseng, P. T., Lin, P. Y., Okubo, R., Chen, T. Y., Chen, Y. W., & Matsuoka, Y. J. (2018). Association of Use of Omega-3 Polyunsaturated Fatty Acids With Changes in Severity of Anxiety Symptoms: A Systematic Review and Meta-analysis. JAMA network open, 1(5), e182327.}_{https://doi.org/10.1001/jamanetworkopen.2018.2327}
_{Tarr, A. J., Galley, J. D., Fisher, S. E., Chichlowski, M., Berg, B. M., & Bailey, M. T. (2015). The prebiotics 3'Sialyllactose and 6'Sialyllactose diminish stressor-induced anxiety-like behavior and colonic microbiota alterations: Evidence for effects on the gut-brain axis. Brain, behavior, and immunity, 50, 166–177.}_{https://doi.org/10.1016/j.bbi.2015.06.025}
_{Zhu, C., Zhang, Y., Wang, T., Lin, Y., Yu, J., Xia, Q., Zhu, P., & Zhu, D. M. (2020). Vitamin D supplementation improves anxiety but not depression symptoms in patients with vitamin D deficiency. Brain and behavior, 10(11), e01760.}_{https://doi.org/10.1002/brb3.1760}
_{Zhu, H., Tian, P., Zhao, J., Zhang, H., Wang, G., & Chen, W. (2022). A psychobiotic approach to the treatment of depression: A systematic review and meta-analysis. Journal of Functional Foods, 91, 104999.}_{https://doi.org/10.1016/j.jff.2022.104999}