Digestive Health Affects Mental Health

July is Digestive Health month here at Nature’s pHarmacy®, as gut health affects overall health and mental health. There is an intricate relationship between the digestive system and the brain that is only now coming more into focus. The human digestive system, more specifically the large intestine (or “gut”) is home to trillions of microorganisms, known as the gut “microbiota.” These tiny little organisms have been shown to affect digestion, immunity and overall health, and can affect behavior and brain function through a variety of mechanisms.

First, the digestive microbiota can produce short-chain fatty acids, neurotransmitters and their precursors, and other metabolites that can travel through the bloodstream. Some can cross the blood-brain barrier and directly influence brain function and behavior.

Second, the nervous systems are connected. There is a complex network of more than 400 million neurons lining the gastrointestinal tract, called the Enteric Nervous System (ENS), that is often referred to as the “second brain. It regulates blood flow through the digestive system, moves the food through the GI tract, and is responsible for immunological defense, among other things. It communicates with the central nervous system (CNS) through the vagus nerve, and this interaction can affect emotional and cognitive functions.

Finally, inflammation in the body has been linked to various mental health disorders, including depression and anxiety. Chronic inflammation in the gut can lead to systemic inflammation with the same result.

Supporting Evidence

Mood Disorders

There have been some interesting studies supporting the correlation between gut health and mood disorders. One study showed that individuals with major depressive disorder had altered gut microbiota compared with healthy controls. Another study using germ-free rats found that rats transplanted with fecal microbiota from individuals with depression developed behaviors consistent with anxiety and depression. In another study, probiotics were shown to positively affect mental health. Finally, there is evidence that individuals with irritable bowel syndrome (IBS) are more likely to experience depression and anxiety.

Alzheimer’s Disease

Studies have shown that chronic inflammation in the brain can lead to cognitive changes such as those seen in Alzheimer’s Disease. Gut dysbiosis (an imbalance of organisms in the gut) has been strongly linked to the progression of Alzheimer’s disease.

Autism Spectrum Disorders (ASD)

Studies show that both children and adults with ASD frequently experience gastrointestinal problems, and changes in the composition of gut microbiota have been noted in these individuals.

Stress and Gut Health

Chronic stress can alter gut permeability and composition of the microbiota, negatively affecting gut health and leading to conditions such as leaky gut syndrome. Conversely, a healthy gut can enhance the body’s stress response, highlighting the bidirectional nature of the gut-brain axis.

Effective Strategies for Supporting Gut and Mental Health

Choose Whole Foods

To support a healthy gut, consume a diet filled with whole foods, including fruits, vegetables, fiber, and fermented foods. Avoid processed foods, sugar, and artificial sweeteners. Read our “Twelve Nature’s pHarmacy Principles to Eat By”, parts 1 and 2 for more tips.

Add Prebiotics, Probiotics and More

Include probiotics (“good” bacteria) and prebiotics (food for these bacteria) in your diet to support a healthy gut microbiota. Fermented foods and high-fiber foods are helpful in that regard. Supplementing with digestive health supplements can ensure that you are getting all of the nutrients and healthy bacteria needed to support your digestive health. Our blog post, Digestive Health Symphony, dives deeply into the phases of digestion, and highlights five supplemental products we recommend to support each step of the process.

Measure your Digestive Transit Time

You can also assess how quickly and efficiently food is moving through your digestive system with a simple self-test. A healthy gut reflects an ideal digestive transit time of 12-18 hours.

Stay Hydrated

Remaining hydrated is essential for digestive health as it aids in nutrient absorption, prevents constipation, and supports a healthy gut microbiome. Proper hydration also benefits mental health by enhancing cognitive function, mood, and energy levels, thereby supporting the overall well-being of both the digestive system and the brain.

Consider adding more low-sodium broths and soups to your meals. Enjoy warm or cold herbal teas with and between meals. Try adding muddled fruit or a splash of lime to your mineral water. Avoid sugary drinks and plastic bottles. Learn more healthy hydration tips in our post, “Hydrate and Renew.” 

Manage Stress

Stress can significantly impact the gut-brain connection by altering gut microbiota composition, increasing gut permeability, and affecting the gut’s immune response. There are a few activities known to help reduce stress: Abdominal breathing can reduce stress hormones in the body. Regular physical exercise, hatha yoga, and meditation can also help to support both digestive and mental health, as can as can choosing the right stress-busting foods.

There are also adaptogens and herbs that can help support a healthier balance of adrenal hormones. Dr. Jaffe discusses an adaptogenic blend as well as other supportive nutrients in this video where he discusses the best ways to manage stress.

Get Restorative Sleep

Getting adequate sleep is essential for maintaining both gut health and mental health. Poor sleep can disrupt the gut microbiome, leading to digestive problems and inflammation. It can also impair cognitive function and increase the risk of mental health disorders such as anxiety and depression.


As we have shown above, digestive health and mental health are intertwined in a way that supports a holistic approach to well-being. By taking the Nature’s pHarmacy approach to what you eat, drink, think, and do, you can make choices that promote both gut and mental health, thereby enhancing your overall quality of life.

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