Story at a Glance
The association between your stress reaction and circadian rhythms—the natural 24-hour cycles that govern your body—is greatly influenced by your gut microbiota. Researchers have discovered that the microorganisms living in your gut have a big say in how much of the hormone corticosterone gets made. And because corticosterone is so essential for both the stress response and for keeping your body in circadian rhythm, it will be hard to fully grasp the association between these three things without first appreciating the gut’s role in the conversation.
Key Highlights:
Certain bacteria, including Lactobacillus reuteri, show peak activity at specific times to help keep the maintenance of balanced stress responses.
An unbalanced or depleted gut microbiota disturbs brain regions that control emotions, making a person more anxious and less able to adapt to stressful situations.
Patterns of gut bacteria that promote anti-inflammatory responses and better emotional regulation are found only in highly resilient individuals. This signals, not surprisingly, that resilience is both a psychological and biological condition.
The gut barrier, beneficial bacteria, and inflammation are all seriously affected by chronic stress. These three entities are the cornerstone of profound mental health. And it is the gut that is profoundly affected by these three chronic stressors.
Gut health restoration centers on cellular energy restoration and processed food avoidance, not just probiotics.
The Gut–Brain Connection
When the gut microbiome is disrupted, it affects the gut’s rhythm, which in turn affects the bacteria that live in the gut, nearly all of which are found in the large intestine. The large intestine houses many kinds of bacteria (the healthy gut microbiome contains around 30 different species and many different strains) that exist in careful balance and work together. These bacteria serve many functions. They help break down food, regulate the gut’s immune system, and even communicate with the brain. The latter function is particularly important when it comes to understanding the gut microbiome’s role in managing stress.
The core link between the gut and the brain is particularly important in the regions of the brain known as the hippocampus and the amygdala, which regulate emotions and stress. When there is insufficient gut microbiota, the gene expression in these areas of the brain is altered, disrupting pathways that are related to stress and circadian systems. For instance, when mice are raised without gut bacteria or when animals are treated with antibiotics to significantly reduce their gut bacteria, they experience huge disruptions in stress-related genes and metabolic pathways. One big consequence of this is that their brains produce an exaggerated amount of corticosterone (the main stress hormone in these animals) during certain times, leading to a state of “poorly managed stress” that lasts for a long time.
Altered patterns were also seen in key neurotransmitters such as glutamate, which are crucial for emotional balance and stress responses. Without healthy microbial activity, the animals’ corticosterone rhythms were all but nonexistent, yet the animals were somehow more vulnerable to stress than the lab animals usually were. Studies found that the effects of the deficient microbiome were most evident during the peak of the animals’ circadian stress response, which is the time one researcher noted their lab animals are least anxious. The work underscores how important it is for gut health to have balanced gut microorganisms, which we think is vital for organisms to adapt to stress optimally.
The Role of Lactobacillus reuteri
In the research, Lactobacillus reuteri proved to be a principal modulator of corticosterone release. The diurnal rhythm of this bacterium aligns perfectly with the body’s stress response and circadian rhythm. Researchers found when they restored L. reuteri levels in germ-free mice, they achieved a level of normalcy that approximated wild-type mice in terms of the patterns of corticosterone they saw in both groups. These mice also normalized along the stress-sensitive behavior spectrum.
Gut Microbiome and Resilience
Bouncing back from emotional and mental challenges is not merely a matter of individual psychology; it is also deeply biological. Studies in the field of precision psychiatry are revealing that the resilience we see in some people but not in others is, to a significant degree, a gut story. (Surely, you’ve heard the saying “We’re all gut when it comes to resilience.”) People endowed with high resilience also have a gut microbiome that plays nice and, in a sense, allows them to have a harmonized gut-brain axis.
The research also discovered that resilient individuals have gut bacteria that are more active in energy metabolism, gene repair, and environmental adaptation. Their gut bacteria produce increased levels of metabolites such as N-acetylglutamate and dimethylglycine, which support stress adaptation and anti-inflammatory responses.
Stress and Gut Health
The HPA axis is triggered by chronic stress to release corticotropin-releasing factor (CRF), which then goes on to disrupt the gut microbiota and weaken the intestinal barrier enough to be called “leaky gut.” In this scenario, harmful bacteria and toxins get into the bloodstream and make their already inflamed hosts even more inflamed. Stress also reduces beneficial gut bacteria like Bifidobacterium and Lactobacillus, which are necessary for producing short-chain fatty acids (SCFAs). These substances are crucial for maintaining the gut barrier and regulating inflammation. Neurobiology has recently turned renewed attention to the significance of gut bacteria and SCFAs for mental health.
Gut damage caused by stress disrupts not only digestion but also the loop in which gut inflammation exacerbates mental health. When the gut is inflamed, it releases cytokines like interleukin-6 and tumor necrosis factor-alpha, which travel to the brain and disrupt the pathways that are supposed to keep our moods stable. We’re supposed to be in a good mood because our brains work well, but when gut-induced inflammation comes into play, we’re more likely to be anxious and depressed. On top of that, stress endangers the absorption of another essential component for neuronal health: magnesium.
Building Resilience Through the Gut-Brain Axis
To construct resilience, it is vital to have a diverse and balanced gut microbiome, especially as we face the trials of life. An imbalance of gut bacteria, or dysbiosis, makes us much more susceptible to mental health disorders, particularly anxiety, depression, and bipolar illness. Gut disorders frequently stem from dysfunction of the mitochondria, our cells’ energy factories. When the mitochondria are not working properly, they are not producing enough fuel for the cell, which in turn makes it less capable of regenerating and repairing itself. That energy shortage impairs the ability of our gut to maintain its oxygen-free environment, allowing harmful bacteria to reproduce like crazy.
To tackle this issue, we must optimize mitochondrial function to deliver enough energy to maintain a sound gut environment. The way to do that starts with the colonocytes—the cells that line the colon. We must eliminate all the mitochondrial toxins that are currently hacking the energy vibe of the colonocytes. Then we need to up the ante and make sure that the colonocytes are producing enough energy for their good health and for the gut’s overall good health. When that happens, the conditions are right for the beneficial bacteria that are part of the gut microbiome to flourish.
Dietary Strategies for Gut Health
Gut health cannot be restored by probiotics alone. The problem for many probiotics is not that they are not probiotic enough, but that they cannot survive the oxygen-rich environment of the small intestine and cannot get to the large intestine, where their actions are most beneficial. It s crucial to pay attention to eating and lifestyle habits. Cut down on eating fake foods—some of which cannot even be classified as food. For several reasons, avoiding these foods reduces inflammatory damage to our gut microbiota.
For the great majority of people, shifting to a plant-based lifestyle composed of whole fruits, nuts, vegetables and grains (non-GMO) can resolve many moderate digestive disorders. Its also important to remember its not only what you are eating, but also what’s eating you—because when stress is in the picture, your gut-brain axis isn’t working anywhere close to optimally.
Conclusion
An intricate link ties gut health to not just mental, but also physical health. This connection is especially crucial when considering how good gut health is foundational to maintaining emotional balance and cognitive clarity, which allows us to better handle stressful situations. Why? Well, “good health” in the gut serves as an excellent ground state from which we can achieve “peak wellness.” It’s almost ludicrous to even mention “peak wellness” without first discussing gut health, since everything is tied to the quality of life we can lead when our microbiome is functioning well.
These statements have not been evaluated by the Food and Drug Administration. This article is for
educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.
See:
- 1, 2 Cell Metabolism January 7, 2025
- 3, 4 Nature Mental Health 2024, 2, 935-950
- 5 UCLA Health June 18, 2024
- 6, 7, 8, 9 The Journal of Nutrition April 2023, Volume 153, Issue 4, Pages 924-939
- 10 Asian Journal of Psychiatry July 2024, Volume 97, 104068, Introduction
- 11 Scientific Reports March 31, 2023
