Mental Health

Who’s Really In Control? How Your Gut Microbiome Impacts Your Mental Health


Our incredible minds are what differentiate us from other creatures. We have the unique ability to reason, think abstract thoughts, and experience deep emotions. Yet, emerging research is finding that our gut microbes are the invisible hand influencing our mental well-being.

That’s right – there is a two way street of communication along what’s called the gut-brain axis occurring at all times between the enteric system in your gut and the central nervous system – and your microbes play a dominant role. Increasing evidence has found the gut microbiome plays a more dominant role in this conversation than we originally thought. 1

Your gut microbiome even helps create neurotransmitters and metabolites that act on your brain via the vagus nerve. This has lead to a wave of new studies investigating how the gut microbiome influences our brain and how we can leverage this to improve our mental health.

Neuroscientist John Cryan from University College Cork in Ireland has been studying the power of the gut microbiome in fascinating experiments using mice models. By altering, eliminating, or preventing the development of a healthy microbiome in the  the mouse, Cryan found:

  • Mice without gut microbes (germ-free) experience neurochemical changes within the brain 2

  • Germ-free mice are unable to recognize other mice around them, making them unable to socialize 3

  • Germ-free mice exhibit high-risk behavior 2

  • Mice without microbes are unable to remember scary situations, suggesting the microbiome impacts neurological pathways involved in fear conditioning 4

Another team of researchers from McMaster University in Ontario, Canada found that when microbes were taken from a ‘normal’ mouse and transplanted to the gut of a germ-free mouse through a procedure known as fecal microbiota transplantation, it altered the brain chemistry and behavior of the formerly germ-free mouse. Essentially, the mouse adopts a similar personality to its donor. 5

Pretty incredible, isn’t it?

It makes you wonder, who’s really in control here?

The gut microbiome is clearly influential in certain actions and behaviors that were fully credited to the brain, suggesting it’s time we stop thinking of our brain is in full control.

Research Suggests Food is Medicine

Based on his studies, Cryan concludes, “ dietary treatments could be used as either adjunct or sole therapy for mood disorders.” 6

This touches on one of the most exciting insights that has come from gut microbiome research, which is that we have the power to change the composition of our gut microbiota through our diet. Each microbe prefers certain food – just like you and me, making every meal you eat important because you are feeding your microbes.

Until recently we’ve been treating mental health with medications to target chemical imbalances of the brain, but it appears we may have been looking at the wrong brain.

When you imagine your body, imagine you have two brains – your classic brain and your gut.

Understanding Your Second Brain

Due to how powerful your gut is in influencing your mental state, it’s earned itself the nickname – the second brain. Your enteric nervous system (ENS) is embedded in the walls of your gut and contains between 200-600 neurons, which is more than your spinal cord. Your ENS is incredibly impressive and works both independently and together with central nervous system (CNS). 7

The gut microbiome directly influences the development, function, and activity of the ENS. 8 One of the ways the gut microbiota is able to communicate with the nervous systems is through intrinsic primary afferent neurons (IPANs). IPANs are specific neurons that reach into the gut lining and respond to changes in the gut lumen. IPANs are transducers, meaning they can take physiological stimuli and change them into electrical signals. 9

Examples of physiological stimuli IPANs respond to include:

  • Changes in gut chemistry (including gut microbial activity)

  • Movement of the villi (finger-like folds in the gut lining)

  • Distortion of gut lining (normal for digestion)

  • Contractions of intestinal muscle (also, normal for digestion)

Through IPANs and the neurotransmitters created by the gut microbiome, what happens in our gut can be communicated to the brain.

Due to this intricate connection between our two brains, the study of the gut microbiome is arguably the fastest growing area of mental health research. We’ve already discussed the strong association between anxiety, depression and the gut microbiome .

But what about other areas of mental health?

The Gut Microbiome and Mental Health

Now that we have a better understanding of how our two brains communicate, let’s look at what science is uncovering about the relationship between the gut microbiome and mental health conditions.

  • Autism spectrum disorder (ASD) – Gastrointestinal symptoms are common in people with autism, which raises suspicions that changes in the gut microbiome could somehow be involved. Research has found specific alterations in the gut microbiome composition  characteristic of autism. 10 Specifically, colonization of Candida albicans has been associated to increased autistic behaviors in children with ASD – though it’s important to note it’s more than just Candida albicans associated with ASD. 11

  • Attention deficit hyperactivity disorder (ADHD) – Preliminary studies have found certain bacterial strains appear at higher levels in the gut microbiome of people with ADHD. Microbial alterations seem to influence normal reward anticipation, which leads to impulsivity – a hallmark behavior of ADHD. 12

  • Obsessive compulsive disorder (OCD) – Stress and antibiotics have occasionally been found to trigger obsessive compulsive tendencies in those with OCD through alterations of the gut microbial composition. Researchers are hopeful that through (re)introduction of beneficial microbes to the microbiome, we could help those with struggling with OCD. 13

  • Schizophrenia and bipolar disorder – Research on the gut microbiome and its influence  on schizophrenia and bipolar disorder is still in its infancy. But early studies are finding the gut microbiome may play a role in the onset and development of both conditions. 14

A new avenue for improving mental health may involve improving the health of your gut – psychobiotics, fecal microbiota transplants, and sometimes antibiotics that target specific microbes are all exciting possibilities. 15

Your Microbes Are Your Buds

It’s time to start thinking of microbes as our buds. This means we have to stop blasting them with antibiotics, harsh cleaning chemicals, sanitizers, and anything else that hurts their chances of survival.

Most of your gut microbes live in a mutualistic relationship with you. They selfishly want you to stay healthy so that they can thrive. Your microbes participate in many biological functions including maintaining your body’s homeostasis – primarily by supporting your immune system. For these little guys to do their jobs and live happy, healthy lives they need just the right environment, which you control through your diet.

The gut microbiome is an active habitat of microbes and just like any other environment, it is  healthiest when it’s balanced. We often refer to the environment of the gut microbiome as the milieu. As part of the human species, our gut microbiomes have core similarities, though we each have a unique microbial profile – think of this as your microbial fingerprint.

Because each person’s gut microbiome is particular to them, there is no universal diet that’s good for everyone. This is where Viome comes in.

Viome’s powerful metatranscriptomic technology and revolutionary AI analysis helps you identify the perfect diet for you and your gut microbiome. Viome isn’t claiming to cure any of the above diseases but instead offers deep insight into your gut microbiome. Your Viome recommendations tell you exactly what to eat to feed beneficial microbes, and balance the microbiome.

“Viome – it took a technology this advanced to remind us that food is thy medicine.”
– Naveen Jain

If you want to dig deeper into the science behind Viome and all it can offer you, we encourage you to check out Dr. Helen’s The Power of Precision Wellness video.

In this video you’ll learn:

  • Why fad diets like the Paleo diet can be bad for some people

  • How some probiotics pass right through you and are therefore are a complete waste of money

  • How the fungal microbiome was largely overlooked until now

  • Why certain “healthy” foods like spinach aren’t great for everyone

  • How increasing microbial diversity means better overall health

  • Why food must be personalized