#1 Victorian uni for graduate employment1
#1 in the world for sport science2
#1 Victorian uni for course satisfaction3
Ever had a ‘gut feeling’? Those butterflies in your stomach before a big event or the gnawing ache when you’re stressed aren’t just in your head—they’re in your gut. Many people don’t know that there is a powerful connection between their gut and their brain, known as the gut-brain axis. We think the gut-brain axis plays a crucial role in influencing your mood and overall well-being. Your poo might just hold the key to exploring this gut-brain connection?
Meet Emma Todd, a PhD student at Deakin University, who’s diving deep into this vital gut and mood connection through the unconventional method of sifting through people’s poo samples. By sifting, we mean ‘analysing’ these poo samples using next-generation sequencing technology. Emma is exploring how the trillions of microbes in our gut—the gut microbiome—impact our emotional health.
Yes, you read that right—your poo could be the missing piece in understanding your mental well-being.
Think of your poo as a detective’s notebook, filled with clues about what’s going on in your gut. In this case, Emma is like a gut detective, using high-tech tools to decode these clues. She’s looking at the mix of microbes in your gut, the chemicals these tiny organisms produce, signs of inflammation and special fats made by gut bacteria.
‘The samples allow us to get a snapshot of what’s going on in the lower GI tract,’ Emma explains. ‘[We can see] the types of tiny organisms that are there and the things that they’re able to do depending on the depth of sequencing we’re able to perform.’
Emma, in collaboration with the Geelong Osteoporosis Study, is ultimately looking at how lifestyle factors such as diet, sleep and exercise, and your the gut microbiome influence your mental health. By collecting and analysing poo and saliva samples, Emma’s research suggests that your poo could offer early clues about your mood (including early signs of depression risk), potentially even before you notice changes yourself.
To get to the bottom of why poo is so revealing, let’s first wrap our heads around how your gut and mood are besties through the gut-brain axis — their own private hotline.
‘The gut-brain axis is a term that we use to describe the relationship between gut health and brain health,’ Emma explains.
It involves sophisticated communication pathways like neural, immune and endocrine systems, linking your brain’s emotional and cognitive centers with your gut. Key players include the vagus nerve and gut immune cells that send signals affecting brain function.
Think of your gut as a bustling metropolis, home to trillions of microbes known as the gut microbiome. These tiny inhabitants are hard at work producing things like serotonin and gamma-aminobutyric acid (GABA), which plays a huge role in brain function and behaviour. Fun fact: about 90% of the body’s serotonin, the mood-regulating superstar, is produced in the gut.
Beyond its digestive duties, the gut is a crucial player in immune function, neurotransmitter production and inflammation regulation. A healthy gut barrier protects against pathogens, while the gut microbiota helps keep inflammation in check.
And those poo samples? They’re basically a report card for your gut microbiome, providing detailed insights into the types of organisms present and their activity.
Simply put, yes — your gut can affect your mood. Just as your morning coffee can boost your energy, the state of your gut plays a significant role in how you feel. The gut-brain axis is a two-way street: the brain sends signals to the gut, and the gut sends signals to the brain.
This interaction means a healthy gut can contribute to a healthier mind. Studies have shown that when we experience depression, we have a fundamentally different gut microbiome to those who aren’t depressed. Researchers are even beginning to use poo transplants to treat depression!
Your gut is often called the ‘second brain’ because it has over 100 million neurons working hard to produce hormones, neurotransmitters and regulate immune responses. This intricate relationship underscores the significance of keeping a balanced gut microbiome for mental health.
‘Gut health is connected to mood primarily through those tiny, microscopic organisms that live in the gut’ Emma explains. ‘They help us to produce special messenger chemicals that go to the brain called neurotransmitters. They also help to produce special building blocks for life called amino acids, especially important ones like tryptophan, which are very involved in mental health.’
When it comes to mood disorders, your gut health might be more involved than you think. The bacteria, fungi and viruses in your gut microbiome interact with neurotransmitters and other chemicals that affect brain function and mood.
Some gut bacteria can lead to inflammation and altered neurotransmitter production, contributing to mood disorders such as depression and anxiety.
‘Throughout the years, we’ve found that people with certain GI conditions like IBS [irritable bowel syndrome] and inflammatory bowel disease (IBD) tend to be more at risk for various neurocognitive and mental health conditions,’ Emma explains. ‘And vice versa, people with mental health problems tend to have more risk for those GI disorders.’
If you’ve ever experienced the emotional rollercoaster that comes with PMS or felt hangry (hungry + angry), you’ve seen the power of your gut over your mood firsthand. Your gut microbiome doesn’t just influence long-term mood – it can also affect your day-to-day emotions too.
Your poo may be able to act like a microscopic mood ring for your gut, offering insights that go beyond what you might feel day-to-day. Changes in your poo composition might signal mood changes before you even feel them, potentially allowing for early intervention in mood disorders.
One day, we hope that your unique gut makeup will help tailor treatments for the blues, like suggesting specific probiotics or dietary tweaks. And that regular poo check-ups could show if your mood-boosting efforts are paying off, right down to the microscopic level.
Researchers are also looking at your microbes to find overall gut health indicators. The presence or absence of certain bacteria may be able to signal how well your gut is functioning, which we now know can directly affect your mood.
With an academic background in science, specifically microbiology and genetics, Emma’s journey into unraveling the connection between gut and mood was driven by a profound personal motivation.
‘I’ve always been a very big picture person, and I like how gut microbiome science is all about how interconnected we are as humans with the environments within us and outside of us.
‘When my supervisor asked about my dream PhD, I wanted to look at something in the gut-brain axis area, specifically relating depression to the gut microbiome, because I have had my life touched by depression.’
Emma found her perfect fit at The Food and Mood Centre, a world-leading Deakin University research hub in Victoria, where she found a project combining her passions. Her PhD project aims to use machine learning techniques to predict depression risk, focusing on lifestyle and the gut microbiome data from the collected poo samples.
Her goal? ‘I would like my research to form the basis of a risk assessment tool that your GP could use to determine whether you’re at risk of depression and help you to find personalised preventative interventions, stopping depression before it starts.’
Emma also aims to explore how the gut microbiome could influence responses to depression treatments.
This pioneering approach harnesses the intricate link between the gut and mood and also holds promise for personalised interventions. Imagine a future where a simple poo sample could help tweak your lifestyle to boost mental health and prevent depression.
Emma’s research suggests that a healthy gut may play a role in supporting both your physical and mental well-being. If you’re looking to nurture your microbial residents and boost your mental health, consider taking some practical steps to keep your gut and mood in good shape.
to improve your gut health and mood:
Probiotics, such as those found in yoghurt, kefir, sauerkraut, kimchi and kombucha, contain live beneficial bacteria that are being researched as they may help support your gut microbiome. There is ongoing research to find certain probiotic strains to reduce symptoms of depression and anxiety by promoting a healthier gut environment. Fermented foods are also tasty and full of nutrients – and making your own can be a really fun project!
The power of your poo
Your poo is more than just smelly waste — it could be a window into your health, particularly the connection between your gut and mood.
Emma’s poo-focused research not only opens exciting possibilities for the future of mental health care, potentially predicting and preventing mood disorders, but also highlights the ongoing importance of supporting our digestive well-being.
Nurturing good gut and mood is an ongoing journey that thrives on consistent, healthy habits. Whether you‘re trying to up your colourful veggie consumption, cook with more olive oil, or experiment with making your own ferments, every little bit counts.
Remember, taking care of your gut isn’t just about feeling good physically—it’s about feeling good all around. The next time you’re feeling off, it might be time to tune into your gut. And your poo? It might just hold the key to unlocking a happier, healthier you!
If you’re experiencing severe symptoms of depression or anxiety, it’s important to seek professional help. Don’t hesitate to call emergency services if you’re in crisis. Support is available at Beyond Blue on 1300 22 4636, Lifeline on 13 11 14, MensLine on 1300 789 978, 13YARN on 13 92 76 for Aboriginal and Torres Strait Islander peoples, and ACON on (02) 9206 2000 for LGBTQ+ communities.