What’s your gut feeling? The links between your gut microbiome and your mental health

May 10, 2021

Our research has confirmed that the microbes that live inside our digestive system - known collectively as the gut microbiome - are closely linked to heart and metabolic health. But did you know that the effects of your microbiome might reach as far as your brain, influencing how you feel and behave?

The interplay between gut health, microbiome, brain, and mood - known as the ‘psychobiome’ -  is a hot area of research right now. 

In this post, we’re taking a look at what we know so far about the connection between your gut, brain, and mental health, and the role that gut health plays in mental health conditions like anxiety and depression.

What we know about the microbiome and mood

  • Changes to the gut microbiome have been linked to several mental health disorders.
  • There are hints that improving your gut health could help combat mental health problems and improve mood, but more research is needed in this area.
  • Your gut microbiome is unique, it impacts your metabolic health, and influences your responses to food.

The gut-brain connection and mental health

Scientists have found relationships between the microbiome and several mood disorders, including depression, anxiety, bipolar disorder, and schizophrenia. 

For example, research has shown that people with depression have altered microbiome compositions, including reduced diversity and increases in particular microbe strains compared with people without depression. 

But finding associations like this still leaves questions about which way the relationship goes: do your gut microbes influence your mood and behavior, or do your mood and behavior influence your gut microbes?

To find out, scientists took the gut of depressed humans and transferred it into rats using a technique called fecal transfer - basically, a poop transplant.

They found that the animals began displaying signs of depression, suggesting that the microbiome can influence mood and behavior (at least, in rats). 

How do your gut microbes affect your brain?

There’s a lot of interest in the connection between gut health and mental health conditions like anxiety and depression. But the big question is how the microbes in your gut are able to influence what is going on in your brain and how you feel.

Scientists think that several two-way communication channels between the brain and the gut, known as the gut-brain axis, are involved.

The first channel focuses on the gut’s nerve system, known as the enteric nervous system (ENS). This nerve network is connected to your brain via the vagus nerve, which carries messages both from the brain to the gut and back again and has an important connection to mental health. Gut microbes can send information to your brain by stimulating this vagus nerve pathway.

The second channel in the gut-brain axis involves the molecules that circulate in your body. Your gut bugs consume and produce lots of substances called metabolites, some of which can influence other parts of your body. 

For example, the microbes in your gut produce up to 90% of your body’s serotonin, a neurotransmitter that helps stabilize mood and is responsible for feelings of happiness and wellbeing. Your gut microbes can also stimulate cells in the lining of your gut to produce hormones that travel around your body and influence how you feel.   

The third pathway involves the interactions between the microbes in your gut and your immune system. These interactions help to regulate both your immunity and your gut microbiome. 

Some changes to your microbiome can trigger inflammation responses and the release of chemical signals called inflammatory cytokines, which have been linked to changes in mood and conditions like depression.

Can you improve your mood by changing your microbiome?

We know that your microbiome composition isn’t permanent, and you can influence your microbiome by changing what you eat.

Scientists are currently researching ways to improve mental health and treating anxiety and depression by altering the microbiome using probiotics, prebiotics, fecal transplants, and diet changes. 

Our research shows that what you eat influences the makeup of your microbiome, so it makes sense that changing your diet might improve your mood and mental health. 

A recent study showed that improving diet reduced the symptoms of people suffering from depression, as well as antidepressant medication, although the trial was relatively small, and they did not directly investigate the microbiome’s role. 

What’s more, several observational studies have shown that eating a high-quality diet reduces your chance of suffering from depression.

Eating to support your “good” gut bugs

There’s growing interest and excitement in the microbiome’s role in physical and mental well-being. But we still have a lot to learn about the links between your microbiome, your food, and your mood.

In the meantime, we are here to help you understand your microbiome to improve your metabolic and overall health. 

Finding the foods that work best for your unique community of gut bacteria starts with understanding which bugs are living in there right now and which foods will help them thrive. 

That’s why when you join the ZOE Program, you’ll take an easy poop test at home. We can identify which “good” and “bad” microbes live in your gut and give you tailored food advice to improve your gut health. 

Want to learn more about your unique microbiome and discover your unique responses to food? Join the ZOE Program today and start your journey towards a healthier gut. 

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