5 Mental Health Conditions Linked to an Unhealthy Gut

5 Mental Health Conditions Linked to an Unhealthy Gut

Embarrassing gas. Bloating. Weight gain. These are things people typically associate with gut problems. But did you know that many mental health disorders are also connected to unhealthy bacteria in the gastrointestinal tract?

The Gut-Brain-Mental Health Connection

The human gut is lined with about 100 million neurons, which is why it is often referred to as the second brain. Your gut has more neurons than your peripheral nervous system. It even has more neurons than you have in your spinal cord. These neurons communicate directly with the brain between your ears, which is why you get an upset stomach when you’re stressed or butterflies when you fall in love.

With all these neurons in the gut “talking” to your brain, it’s no surprise that having a healthy gut is important if you want to have a healthy brain and a healthy mind. A healthy gut needs healthy bacteria.

Approximately 100 trillion micro-organisms (bacteria, yeast, and more) live in the human GI tract, and they are referred to as the microbiome.” Some bacteria promote health and wellness while other bacteria cause trouble. The gut needs about 85% beneficial bacteria to maintain health and wellness. When the harmful bacteria numbers rise over about 15%, it can lead to a variety of problems. In fact, a growing body of evidence is pointing to a link between an unhealthy gut and mental health issues.

Here are 5 psychiatric conditions that scientists say are tied to the microbiome.


Most people who experience anxiety think it’s all in their head, but a growing body of evidence suggests that symptoms of anxiety are often related to gut dysbiosis. A 2019 review of 21 studies in General Psychiatry showed that more than half of them found that anxiety symptoms were reduced following the regulation of intestinal bacteria with probiotics or dietary changes.


A 2019 study in Natura Biology analyzed the gut microbiome of people with depression compared with others who did not suffer from a mood disorder. The researchers found that depressed people were missing several species of gut bacteria that were present in their healthy counterparts. And the people with the depressive disorder had higher levels of gut certain harmful bacteria associated with Crohn’s disease.


Increasingly, science is pointing to a link between ADD/ADHD and gut dysbiosis. It is common for children with ADHD to have sensitivities to foods, such as gluten, artificial dyes like red dye #40, and dairy, among others. These reactions to foods can lead to problems with the immune system and trigger inflammation. A 10-week trial published Scientific Reports in 2019 found that children with ADHD who took micronutrient supplements—vitamins and minerals—had reduced levels of harmful bacteria associated with the condition and higher levels of healthy bugs.


A growing number of researchers are finding that the microbes that live in our gastrointestinal tract may play a role in schizophrenia. A 2019 study in Science Advances found that people with schizophrenia have less diversity of bacteria in the microbiome compared with those who don’t have the condition. What’s more remarkable about this research is the fact that people with schizophrenia had a unique type of bacteria in the gut that wasn’t found in the healthy study participants. When the researchers transplanted bacteria from the schizophrenic participants to mice, the rodents began exhibiting behaviors similar to schizophrenia.

Alzheimer’s Disease

Problems in the gut are also linked to memory loss and Alzheimer’s disease, the most common form of dementia. A 2017 animal study found that unhealthy intestinal flora can accelerate the development of Alzheimer’s disease. When the scientists transferred harmful gut bacteria from mice suffering from Alzheimer’s disease to disease-free mice, the healthy mice began to develop more beta amyloid plaque associated with the disease. The researchers suggested that this study indicates that harmful gut bacteria can contribute to the development of neurodegenerative diseases.

Anyone who is suffering from these mental health conditions should learn the everyday habits that may be causing a proliferation of bad gut bacteria and start practicing helpful strategies to boost good gut bacteria. What’s good for your gut is good for your brain.

At Amen Clinics, we take a comprehensive approach to diagnosing and treating our patients. Through our brain imaging, lab work, and an extensive assessment of your personal history, we are able to identify biological, psychological, social, and spiritual factors that may be contributing to your symptoms. With this information, we can help you optimize areas of your life to nourish overall brain and gut health to help decrease your symptoms.

If you want to join the tens of thousands of people who have already enhanced their brain health, overcome their symptoms, and improved their quality of life at Amen Clinics, speak to a specialist today at 888-288-9834. If all our specialists are busy helping others, you can also schedule a time to talk.


  1. Neuro feedback is a CURE for Attention deficit disorder. I have watched 2 of my grandchildren suffer with ADD. If you can find specialist in your area it can change a child’s life.

    Comment by Roger — June 26, 2020 @ 3:11 AM

  2. Hello Roger, thank you for your comment! We have more information on Neurofeedback under our list of services: https://amenclinics.com/services/.

    Comment by Amen Clinics — June 26, 2020 @ 7:10 AM

  3. Is there a brand or type of probiotic mix that you recommend for when people have recently come off a course of antibiotics? Both ADHD & Autism spectrum diagnoses run in my family, I was plagued with intestinal issues that took YEARS of elimination diets & supplements to get under control. I recently finished a round of antibiotics for a throat infection and want to get my microbiome back on track as soon as possible. Thank-you for any advice you can offer.

    Comment by Selene — August 11, 2020 @ 8:38 AM

  4. Hello Selene, thank you for reaching out. You can find Dr. Amen’s brain-directed supplements here: https://brainmd.com/. It would be best to have a consultation or evaluation with one of our Amen Clinics specialists to determine the best course of action to complement your history. For more information, please contact our Care Coordinators here: https://amenclinics.com/schedule-visit/.

    Comment by Amen Clinics — August 20, 2020 @ 10:21 AM

  5. on I have many stomach issues, IBS, constipation and bloating. Lately was diagnosed with psoriasis and now on gluten-free, dairy and chocolate diet. This has been helpful but interested in more .

    Comment by Judith Benavides — March 12, 2022 @ 7:54 AM

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