Brain-Gut Connection Regulates Your Stress Response

by Lillian So Chan

Stress response regulation is an important aspect of the brain-gut connection.

Stress, an unavoidable part of daily life, has varied biological, physiological, and psychological effects. These effects are increasingly recognized as including modulation of our gut microbes. The gut microbiome, in turn, influences our stress responses and the associated consequences.

Stress-induced changes in the gut environment result in microbiome dysbiosis. This further compromises gastrointestinal function by allowing harmful gut microbes and their metabolites into blood circulation through a permeable gut wall, resulting in detrimental health consequences.

Many stressors can affect gut microbiome composition and function, either directly on the microbiome or indirectly through effects on the gut and immune function. These stressors include psychological and emotional stress, external environmental factors (such as altitude, heat, cold, humidity, and noise), physical stress (such as genetic factors, physical activity, sleep deprivation, and circadian disruption), and other elements introduced to the gut (such as diet, antibiotics, and enteric pathogens).

Recent research finds:

  • The gut microbiome is a key player in regulating the gut-brain axis, especially during real or perceived stress.
  • Diet is one of the most important modifying factors of the microbiome-gut-brain axis. Stress is another. The gut microbiome is a key facilitator of stress adaptation and immune response in the body. Gut content and complexity can affect anxiety and fear responses.
  • The routes of communication between the microbiome and brain are slowly being unraveled, and include the vagus nerve, gut hormone signaling, the immune system, tryptophan metabolism, and microbial metabolites (such as short-chain fatty acids).
  • We are starting to understand the importance of the early-life gut microbiome in shaping adult health.

Preclinical studies indicate that alterations of the early microbial composition can result in long-term modulation of stress-related physiology and behavior. Coupled with genetic influence, these factors include antibiotic exposure, lack of breastfeeding, birth by Caesarean section, infection, stress exposure, and other environmental factors.

The gut microbiome has been implicated in a variety of stress-related conditions including anxiety, depression, irritable bowel syndrome, autism, and post-traumatic stress disorder. The concept of psychobiotics is being developed by neurobiologists. This will help us understand how the microbiome influences the neurobiology of stress, and aid in the development of therapies that target the microbiome to improve mental health outcomes.

About the Author

Lillian So Chan is the founding editor of WellnessOptions, a print magazine and website, and author of the book WellnessOptions Guide to Health published by Penguin Books. With over thirty years of experience in journalism and editing, Lillian has established unique editorial directions for several award-winning publications. She has worked for Maclean’s, Canada's largest news magazine, and served as a Governor and Deputy Chairperson of the Board of Governors at the Simon Fraser University, British Columbia, Canada.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interested in learning more about Ixcela? Check out Ixcela’s microbiome test, personalized nutrition and fitness plans, and other tools to help you optimize your health.


Karl, J. Philip, et al. “Effects of Psychological, Environmental and Physical Stressors on the Gut Microbiota.” Frontiers in Microbiology, U.S. National Library of Medicine, 11 Sept. 2018,

Foster J. A., et al. “Stress & the gut-brain axis: Regulation by the microbiome.” Neurology of Stress, U.S. National Library of Medicine, 19 Mar. 2017,

Rea, Kieran, et al. “The Microbiome: A Key Regulator of Stress and Neuroinflammation.” Neurobiology of Stress, Elsevier, 4 Mar. 2016,