Numerous studies suggest a bidirectional relationship between a person’s gut and mental health. Probiotics and diet may help a person to improve both anxiety and gut health.

According to the National Alliance on Mental Health (NAMI), anxiety disorders are the most common mental health concern in the United States. At the same time, digestive diseases account for 100 million ambulatory care visits annually.

Research exploring whether anxiety and gut disorders are linked has focused on the “gut-brain axis,” a complex system of communication between the two organs, and the role of microorganisms in people’s gastrointestinal tract.

This article explores the link between gut health and anxiety, gut issues that cause anxiety, anxiety symptoms, and ways to manage anxiety and gut health.

A person eating a yoghurt to help with their gut health.Share on Pinterest
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The gut or gastrointestinal system (GI) is a series of organs, nerves, hormones, and bacteria that work together to enable food digestion. The brain is directly connected to the GI by the central nervous system (CNS), and signals flow between the two to control some aspects of digestion.

Learn more about digestion.

Within the lining of the GI lies another important control hub, the enteric nervous system (ENS). The ENS has 100 million nerve cells and can operate independently from the brain. Scientists believe it may play a role in the relationship between the gut and a person’s state of mental health.

According to a 2015 review on the gut-brain axis, the ENS and brain communicate to control gastrointestinal processes, linking cognitive and emotional function centers in the brain with GI mechanisms. Researchers suggest this communication system may affect motivation and higher cognitive function.

Experts believe the ENS may also trigger big emotional shifts in people experiencing Irritable Bowel Syndrome (IBS) and other digestive disorders. Irritation in the GI may send signals to the CNS that trigger mood changes.

How does gut health affect anxiety?

Numerous studies have focused on the connection between gut microbiota and anxiety. The gut microbiota is a system of microorganisms in a person’s GI, comprising trillions of bacteria, fungi, and viruses that the body needs for optimal health.

Gut microbiota plays an important role in regulating the immune system and processing energy from digested food. Changes in the microbiota can affect these functions, and scientists believe mental health can be affected too.

A 2019 review suggests that stress and depression can reshape the gut microbiota’s composition through stress hormones, inflammation, and autonomic alterations. The gut microbiota responds by releasing metabolites, toxins, and neurohormones that can alter eating behavior and mood.

A 2017 review further explores this relationship, suggesting that inflammation in the GI places stress on microbiota by releasing cytokines (small proteins) and neurotransmitters. Researchers suggest that increased levels of inflammatory cytokines directly correlate with symptoms of depression and anxiety.

Learn more about inflammation here.

IBS, a GI condition involving inflammation and suspected gut microbiota alterations, has a co-occurrence of between 44 and 88% with anxiety and depression. More research is needed to assess whether this relationship is causal.

The above 2015 review references studies on animals showing that microbiota also influences stress reactivity and anxiety-like behavior. According to a 2021 review, gut microbiota plays a role in the development and function of the hypothalamic-pituitary-adrenal (HPA) axis. The HPA coordinates a person’s adaptive stress response, and a dysfunctional HPA is often associated with anxiety and depressive disorders.

Gut microbiota also regulate the production of neurotransmitters such as serotonin, a chemical that scientists believe plays a role in mood stabilization.

Everyone experiences some form of anxiety. But if a person experiences excessive worry that prevents them from leading their day-to-day life, they may have an anxiety disorder.

According to the NAMI, anxiety disorders are a group of related conditions, each with unique symptoms. But people with anxiety disorders typically experience persistent fear or worry in situations that are not threatening.

Anxiety and depression are both associated with continual low-grade inflammation. People with inflammatory diseases that involve suspected gut microbiota alterations, such as IBS, also have a high co-occurrence of mental health conditions such as anxiety and depression.

People with an anxiety disorder may also experience one or more of the following symptoms:

Learn more about the symptoms and signs of anxiety.

Several treatment options can help people manage anxiety symptoms.

Healthcare professionals may recommend a combination of methods, and treatment will vary depending on a person’s symptoms, preferences, and general health.


Psychotherapy or “talk therapy” is a common treatment for anxiety. Several types are effective for anxiety disorders, including:

  • Cognitive behavioral therapy (CBT): Numerous studies have shown CBT’s efficacy in treating anxiety disorders. CBT focuses on finding strategies to reduce beliefs and behaviors that contribute to anxiety.
  • Exposure therapy: This behavioral therapy can help people overcome specific phobias. Psychiatric professionals guide people to expose themselves to situations or stimuli that trigger fear or panic; over time, these feelings reduce.
  • Acceptance and Commitment Therapy (ACT): This type of therapy uses goal-setting and mindfulness to reduce anxiety. ACT is a newer form of psychotherapy, but research has associated ACT with improved mental health and quality of life.

Learn more about types of therapy here.


Healthcare professionals may also prescribe medication to treat anxiety disorders. Medication is not a cure for anxiety but can help relieve symptoms.

The most common types of medication for anxiety disorders include:

Learn more about the different types of medication for anxiety.

Relaxation techniques

There are various stress relaxation techniques a person can try to reduce anxiety, including:

A 2019 study surveyed 1,151 adults, including those who meditated and those that didn’t meditate. Researchers found that mindfulness decreased anxiety by increasing cognitive reappraisal (an emotional regulation strategy) and reducing worry, rumination, and suppression of emotions.


A 2020 study found that physical activity protects against anxiety disorders in clinical and nonclinical settings. Exercise, a subset of physical activity, also significantly reduced anxiety symptoms.

The mechanisms through which physical activity reduces anxiety symptoms are unclear, but researchers believe it is likely to be a combination of biological and physiological factors.

Learn more about exercises for anxiety.

Scientists believe taking steps to improve gut health may also help to manage anxiety.

Research has focused on the benefits of adding probiotics to a person’s diet and promoting healthy gut bacteria through high fiber and low saturated fat diets.


Probiotics are live microorganisms found in fermented foods and dietary supplements. Probiotics may help a person’s body maintain a healthy community of microorganisms or help it return to a healthy condition after being disturbed.

Learn more about the health benefits of probiotics here.

Various studies have explored the potential of probiotics to restore the balance of gut microbiota that has been disturbed by stress and anxiety and whether this improves anxiety symptoms.

A 2021 study showed a potential link between probiotic-induced gut microbiota regulation and stress/anxiety alleviation in stressed adults. And a 2019 study showed that ingesting the probiotic strain, Lactobacillus (L.) plantarum P-8, for 12 weeks could alleviate the stress and anxiety of stressed adults.

A 2019 review further highlights a study involving Japanese medical students in which probiotic supplementation improved sleep, autonomic balance, and bowel habits and reduced stress and cortisol levels.

Fermented foods are a natural source of probiotics. Common types include:

Learn more about the best probiotic foods for a healthful diet.


Researchers have also examined how diet can impact a person’s gut microbiota and how this relates to stress and anxiety.

The 2019 review mentioned above suggests that diet shapes gut bacteria composition, with macronutrients impacting gut microbiota populations.

Researchers highlighted the following foods as supporting healthy microbiota:

This was in contrast to excessive consumption of animal protein, saturated fats, and refined or artificial sugars.

The study further suggests that adhering to high quality diets, such as the Mediterranean diet, reduces the risk of depression.

The Mediterranean diet has anti-inflammatory benefits (inflammation is a risk factor for anxiety and depression), is low in saturated fats and has a high dietary fiber content, further strengthening its role in supporting a healthy microbiota.

Learn more about the Mediterranean diet here.

A person should speak with a healthcare or psychiatric professional if they experience symptoms of an anxiety disorder. They can advise a person about treatment options and direct them to the necessary support.

Similarly, people should seek medical advice if they experience persistent digestive issues. A healthcare team will be able to determine any underlying issues that may be causing them, including if they are related to an anxiety disorder.

It may also be worth speaking with a qualified nutritionist about how to improve one’s diet and how to increase the intake of probiotics.

Gut health and anxiety disorders are common health concerns in the United States. Researchers exploring the link between these conditions have focused on the “gut-brain axis,” a complex system of nerves, hormones, and bacteria that allows these two organs to communicate.

Research has shown stress can change the composition of gut microbiota, a system of microorganisms in the gastrointestinal tract that plays an important role in people’s health. A person’s gut microbiota is also involved in the development and function of their adaptive stress response.

Adding probiotics to a person’s diet may help regulate their gut microbiota, which may also help improve stress and anxiety symptoms. Following a healthy diet can further support a healthy gut microbiota composition and reduce the risk of depression.

People experiencing symptoms of anxiety or digestive issues should speak with a healthcare professional, who will be able to advise them on treatment options.