Gut Feeling

Does what you eat and the health of your digestive tract hold the answers to reducing anxiety and depression? And could making changes to both increase your happiness and mood levels? Gut Feeling

WRITTEN BY RONELLE RICHARDS

Over recent years, ‘going with your gut instinct’ has been transformed from folklore to science. Researchers now widely accept that your gut and brain have regular chats through the gutbrain axis, with wide-reaching physical and mental effects. But could this mind/gut connection also be partly responsible for what defines you as a person – impacting everything from personality traits to how good you feel – and even predict your chances of developing conditions such as anxiety, depression and obesity? Ben Markham, Naturopath and Health Scientist for Activated Probiotics in Melbourne says absolutely yes, likening the gut-brain axis to a multilane freeway with traffic moving in both directions. “The brain and the gut are two worksites at opposite ends of the road that depend on each other for raw materials,” he says.

“One lane would be the immune system, one would be the endocrine system, and the other would be the nervous system. Each lane has traffic that provides different types of essential materials to keep both worksites up and running. “A crash, a flat tyre, or a breakdown at any point interrupts the flow of traffic and can impact what happens at a worksite – and if left unfixed, will eventually impact both.”

Mental health connection Now the analogy is done, here’s the evidence. A study in the Journal of Psychiatric Research found that transferring gut microbiota from depressed patients to microbiotadepleted rats resulted in the rats displaying behavioural and physiological symptoms of depression – meaning your gut imbalances could actually be causing mental health concerns. Carra Simpson is a PhD candidate and Health Promotion Consultant at the University of Melbourne, with a keen interest in all things gut microbiome. Her most recent study, published in the Journal of Affected Disorders, demonstrated a real life ‘gut feeling’. “We know that about 70 per cent of individuals with Irritable Bowel Syndrome (IBS) – or other really common gastrointestinal issues – meet criteria for depression or anxiety,” she says. “Broadly speaking, individuals with both IBS and anxiety and depression can be easily distinguished from looking only at their gut microbes.” Simpson is now finalising recruitment for a new ‘bugs and brains’ study, examining this link even further. “Watch this space for research later this year – we are collecting a lot of data including the potential impact of medication, diet and lifestyle on the gut microbiome,” she says.

Simpson’s work is being mirrored by other researchers, including one Deakin University study from February this year, which found that children with lower levels of the gut bacteria ‘Prevotella’ had a higher prevalence of anxiety-type behaviours such as shyness, sadness and an internal focus. Study leader Professor Peter Vuillermin said Prevotella was much more common in the guts of people living in non-Westernised environments. “Growing evidence supports the idea that antibiotics, poor diet and other factors in the modern world are leading to the loss of our traditional gut bacteria, and in turn causing health problems,” he says.

Happy guts Just as gut imbalances can make you sad or anxious, a healthy gut seems to also have the ability to lift your mood. It’s now estimated that 90 per cent of our happiness hormone serotonin is made in our digestive tracts.

“The ‘bad bugs’ create inflammation, which causes low mood, while ‘good bugs’ produce neurotransmitters such as serotonin and GABA – the brain’s home-made Valium,” explains Robyn Chuter, Certified Lifestyle Medicine Practitioner and Director at Empower Total Health. “Thanks to a protective ‘filter’ known as the blood-brain barrier, these gutderived neurotransmitters don’t make it into our brains. But they do influence the activity of our central nervous system, promoting feelings of calmness and positive mood.”

Markeham agrees. “A healthy gut microbiota is also involved in increasing the production of neurotransmitter precursors, which help to produce specific neurotransmitters in the brain and maintain optimal mental health.

Did you know?

There are more than 100 trillion micro-organisms that exist in our gastrointestinal tract, known collectively as your microbiome. A 2019 study from Harvard Medical School catalogued all of the genes in the human microbiome and found 46 million of them. That’s more genes than stars in the observable universe.

“An example is tryptophan, which supports the production of serotonin,” he says. Conversely, says Chuter, eating too much saturated fat – especially excessive dairy – causes your body to produce excessive amounts of hydrogen sulphide gas, which irritates your gut wall and causes IBS-type symptoms, and may eventually lead to poor mental health outcomes.

However, it’s important to remember that this isn’t a one-way street. Just as your gut can impact your brain and how you feel mentally, having poor mental health can also disrupt gut health and have you feeling physically sick. “This is especially true for chronic uncontrolled stress, which has a proinflammatory effect on the body and will contribute to the development of intestinal dysbiosis and leaky gut,” says Markeham.

Good gut recipe So how do we end up with a ‘bad’ gut? Our experts agree there are several leading factors that lead to poor gut health, including the overuse of antibiotics, poor diet and stress. These can cause inflammation in the body and alter your gut bacteria.

A poor diet is one filled with processed foods, sugars and low-nutrient foods, clarify our experts. Smoking and alcohol can also have a detrimental effect.

The good news, says Simpson, is that our microbiome matures early on.

“Microbiome maturity is between age three to five, so it will respond within days to positive change,” she says. “It can be resistant to longer-term change, but by maintaining a consistently diverse diet, then it’s likely to have favourable changes. “Because we’re so complicated, we don’t know what the ‘best’ microbiome composition looks like yet. So it’s hard to work out if the probiotics you are taking are the ones you actually need.”

Four top tips for a healthy gut Always chat to your GP or a gastroenterologist for persistent gut problems. But for those who want to know how to make the ‘good’ gut bacteria grow and keep the ‘baddies’ at bay, here’s our experts’ advice:

1. Eat a whole food diet Avoid refined, processed foods and try to eat a variety of different plant foods to keep your gut bacteria varied. Omega-3s, complex carbohydrates and fermented foods are key. 2. Avoid antibiotics unless really necessary Chat to your GP and seek alternatives to antibiotics unless truly needed. Your GP can help advise a probiotic boost to help replenish your potentially depleted microbiota after a course of antibiotics. 3. Be mindful We know you’re sick of hearing it, but keeping stress down through meditation practice can help soothe inflammation, especially if your bad gut is brought on by chronic stress. 4. ‘Rewild’ yourself Chuter suggests getting outside and interacting with different bacteria through gardening, bushwalking, walking your dog or being in nature, which can help re-expose our bodies to microorganisms you’ve sanitised through overly clean living. Plus, it’s soothing!

Mood-boosting foods

A study in the World Journal of Psychiatry explored this idea of depressionfighting foods and found that of the 34 known essential nutrients humans need, 12 can help in the prevention and treatment of depressive disorders:

• • • • • • Folate Iron Long-chain omega-3 fatty acids (EPA and DHA) Magnesium Potassium Selenium Thiamine Vitamins A, B6, B12 and C Zinc

So eat more: • Bivalves (oysters and mussels) • Seafood • Organ meats • Leafy greens • Lettuce • Peppers • Cruciferous vegetables. S