
Gut feeling. Your gut is more than just swirling links of tissues that mix and churn your food. In fact, your gut is implicated in everything from sleep, hormone control, mental health, sweet cravings and immunity. The credit goes to your microbiome.
You are never alone
Your gut is home to trillions of microorganisms that form a community known as the “gut microbiota”. These microorganisms are mostly made up of bacteria, however viruses, fungi and parasites are also present. The vast range of microorganisms are collectively known as your “microbiome” which, ever present, could be your best or worst friend depending on how you treat it. Just like the Amazon the gut microbiome is a dense ecosystem that needs balance and harmony to thrive. Disharmony in the gut creates “dysbiosis”, a damaging state responsible for many metabolic, immune and mental conditions
The gut-brain connection
A healthy brain actually starts with the gut. While they may seem like very separate organs, your gut and your brain are in constant communication with each other via the vagus nerve. This relationship is known as the “gut-brain axis” and, like all relationships, can be healthy or disfunctional. It explains why stress can wreak havoc on your digestive system and why digestive problems can affect your mental health.
Microbiome and mental health
Did you know that 90% of serotonin is produced in the gut? 50% of dopamine is as well. Gut microbes produce neurotransmitters and hormones which have control over mood, energy and motivation. This is where mental health can be affected. If you damage or impair gut bacteria, you damage serotonin and other hormonal balances leading to changes in mood. A perfect example of this is irritable bowel syndrome (IBS). Around 50-90% of IBS sufferers experience anxiety and depression with IBS symptoms being exacerbated by daily stress. As a result, IBS is therefore considered a “gut-brain disorder” with research indicating that gut microbes are solely responsible for all mood and digestive symptoms of IBS.
The bottom line: a change in the composition of your gut microbiome can influence your mood and mental state.
Microbiome and sleep
Your microbiome has it’s very own circadian clock that works in sync with your circadian rhythm. Different microbes are more active at certain times of the day in support of your metabolic functions. Disruptions to your sleep and circadian rhythm can bring an imbalance to your gut microbiome leading to endocrine, immune and mental disorders. This is particularly evident in shift workers who frequently experience sleep disruptions.
I don’t know about you, but I get really snacky after a poor night’s sleep or a late night. Relatable? Sleep loss suppresses leptin, the hormone that makes you feel satisfied after a meal, and increases ghrelin secretions which makes you feel ravenous. It’s the perfect recipe for overeating.
However, recent research shows that a healthier microbiome full of harmony and diversity of microbes is associated with better sleep quality and lower levels of fatigue. This is important because it means that by bolstering your microbiome, you can improve your sleep, realign your circadian rhythm and therefore boost your vitality.
You are what you eat
Seriously. The foods you eat are directly feeding your gut microbes, the good and the bad. Different microbes like different food preferences and can actually control your cravings and manipulate eating behaviour. This is due to the gut-brain axis. Have you noticed that the more often you eat sugar the more you crave it? You are feeding sugar loving microbes that begin to proliferate and demand more sugar for their rapidly growing numbers. It’s a vicious cycle. Fortunately this can also happen with healthy foods and you can train your gut microbes to crave and love foods that are actually good for you. But how do we do this? The best way to create a happy and balanced gut is to increase the microbial diversity of the gut.

The key to microbial balance = diversity
“The single greatest predictor of a healthy gut microbiome is the diversity of plants in one’s diet”
This is a quote from Dr Rob Knight, the creator of the American Gut Project. The project started in 2012 and is the largest study of microbes and microbiomes in the industrialised world. The more different plant types a person eats, the higher the microbial diversity of the gut. The study showed that people who ate 30 or more different plant types a week had microbiomes that were more diverse than people who ate only 10 plant types or less per week. Eating this way has nothing to do with identifying as an omnivore, vegetarian or vegan. It is just about getting more diversity of plants in your diet. By all means don’t stop at the 30. The more you eat the better it gets.
30 plants a week sound daunting? It’s easier than you think. Here’s a sample of 30 plants that my partner and I generally eat in a week and this isn’t even everything! (By the way, “plants” doesn’t mean just vegetables and fruit, it includes wholegrains, legumes, herbs, nuts, seeds and spices)
- spinach
- broccoli
- bananas
- blueberries
- ginger
- lemons
- capsicum
- mushrooms
- onion
- garlic
- carrots
- cherry tomato
- corn
- bean sprouts
- radish
- cucumber
- apples
- mint
- coriander
- basil
- cumin seeds
- kimchi
- spring onion
- chilli
- canned chickpeas
- plant milk
- chia seeds
- hemp seeds
- oats
- brazil nuts
Need some help adding in a few more? Here are my top tips to include more plant diversity and gut-loving foods into your diet:
- Buy seasonally: produce grown closer to the time of harvesting has far more nutrients and antioxidants. Also, it tastes better fresh and is cheaper. My favourite ways to do this are to get seasonal vegetable boxes delivered (most cities and towns will have this) or go directly to markets and buy them.
- Eat the rainbow: many of the colours you see in plants are the result of their phytochemicals (plant nutrients) which have a vast array of benefits to your health. For example, spinach and kale have chlorophyll and lutein which protect against cancer and protect your eyes. The purple in grapes, plums and red cabbage are thanks to resveratrol which lowers cholesterol and protects against clots. Aim for lots of colour on your plate!
- Introduce a new fruit/vegetable each week: put yourself out there, try something new and create more diversity of your microbes.
- Make plant packed meals: choose to make meals like salads, buddha bowls and stirfries which you can cram loads of different vegetables into.
- Add ferments: fermented foods are gut-nutrition powerhouses that actively fight bad bacteria and feed the good guys. Try to fit a small amount in daily – sauerkraut, kimchi, tofu, tempeh and miso are great options.
- Spice it up: get creative with flavours! Use spices like cumin and coriander seeds to flavour your meals instead of sauces.
- Record it: List how many you get in a week and improve on it the next.
Happy gut = happy life
An imbalance in the gut creates dysbiosis. Dysbiosis is the perfect breeding ground for disease including metabolic, autoimmune and endocrine illnesses. However, thanks to the strong connection between your gut and brain, what you eat can affect neurological health and is likely implicated in mental illness and sleep disorders. I have zero doubts about the power and influence that the microbiome has within the body. By harnessing this knowledge I have been able to keep my own autoimmune condition in check. Truly, it is so empowering to be in control of our own health and know that the decisions we make each day are improving and lengthening our lives.
Have you done a stock-take of your weekly plant diversity? How many did you get? Comment below.