The main thought most of us have given to our stomachs has been what divine taste sensation we would supply it with next. But as startling new research comes to light linking a healthy gut with everything from better immunity to weight loss, disease prevention and even a happier mind, it's safe to say our guts – specifically, the over 100 trillion bacteria that call our intestines home, otherwise known as our gut microbiome, gut microbiota or gut flora – are the new black.
In fact, more than 90 per cent of the scientific literature on the role of the microbiome in health and illness has been published in the last five years, as we're increasingly coming to realise that what we put into our mouths has implications far beyond our tastebuds.
"Suddenly, we have come to understand that events going on within the gut, and specifically within the microbiome, have a dramatic effect in terms of virtually every important metabolic process that occurs within the human body," explains Dr David Perlmutter, US neurologist and brain-gut health guru. "This opens up vast areas of opportunity for lifestyle modification geared at allowing people to regain their health and become more resistant to disease."
While new discoveries are being made almost daily, some of the key findings include our gut health's strong links to our immune system – in fact, 70-80 per cent of our immune tissue resides in our digestive system. "You definitely need a good gut microbiome to have a fully functioning immune response and be less prone to pathogen infection," explains Dr Nicola Angel, sequencing facility manager and microbiome expert at the Australian Centre for Ecogenomics.
Also key is the role gut microbes play in regulating the degree of inflammation in the human body, with inflammation linked to such diseases as Alzheimer's, coronary artery disease, diabetes and cancer. Meanwhile, an incorrect balance or absence of certain bacteria has been linked to an inability to lose weight or maintain weight loss.
Perhaps most interesting are the links between our microbiome and our brains. "We know the organisms in your gut provide signals to your brain and your brain then sends signals back to your gut, which has a lot of implications in terms of depression and mental health," says Angel.
Explains naturopath and gut expert Dr Helena Davis, "We produce so many neurotransmitters in our gut – around 90 per cent of serotonin comes from the gut as well as the impact our gut flora has on our mood."
A gut imbalance can also be the hidden culprit for everything from fatigue to learning and behavioural difficulties in children, asthma and skin conditions such as eczema and rosacea, to name just a few.
Thanks to some incredible technological breakthroughs, more and more people are now monitoring their stools for a better understanding of their guts.
"We offer a service here that provides a full breakdown of all of the bacteria, viruses, fungus, antibiotic resistance, whatever you've currently got in your gut," says Angel, while Davis says a comprehensive stool analysis allows her to see if her patients are experiencing bacterial infections, parasite infections or yeast overgrowth, which could also be affecting the gut bacteria.
Now we know how crucial a healthy gut is, here are our experts' tips to keeping ours in good working order:
"Prebiotics are the ingredients good gut bacteria use as fuel to nourish their own growth and activity," explains Perlmutter, with the richest sources including garlic, onions, leeks, bananas, asparagus, chicory, Jerusalem artichoke and dandelion greens.
Eat more fibre and fermented foods
A high fibre diet – plant foods, legumes, whole grains, nuts and seeds – is essential for gut bacteria diversity, while probiotic-rich fermented foods are hugely beneficial for promoting good bacteria. Sources include yoghurt with live cultures, kafir, sauerkraut, miso, tempeh, tamari, kimchi and kombucha. Ironically though, these foods can be troublesome for people with digestive issues, who may need to look at healing the gut first before repopulating.
Consider probiotic supplements
Our experts advise that probiotic supplements can be an essential tool to good gut health, but recommend choosing wisely.
"If you take something that peels off in the stomach acid environment and is not making its way to the lower gut, it's not doing you much good," says Nicola, who recommends "a scientifically formulated probiotic".
Avoid unnecessary antibiotic use
While nobody is suggesting we don't take antibiotics when we need them, our experts are nonetheless unanimous about the havoc they wreak on our good bacteria levels. "It really does wipe out what you have and it's very hard to bring that back towards normal, so it's about avoiding those speculative antibiotics or anything not strictly necessary," advises Angel.
Avoid inflammatory foods
When it comes to inflammatory foods, highly processed and sugary foods are at the top of the list.
"Sugar is very inflammatory, it's going to feed your bad bacteria and upset your balance of good and bad flora," cautions Lee Holmes, nutritionist and whole food chef, who runs a four week Heal Your Gut program on her website, Supercharged Food.
Adds Angel, "A lot of autoimmune diseases weren't prevalent until our diet became highly processed. If you look at the microbiome of ancient people, as well as hunter gatherers who still exist today, they're markedly different and you don't have the correlation of diseases we have."
Seek out anti-inflammatory foods
For those whose guts needs healing, Holmes recommends plenty of good fats to "help maintain and heal the gut barrier", as well as soothing foods such as "slippery elm, to soothe the lining of the gut, turmeric and aloe vera, which are very anti-inflammatory". Davis also stresses the importance of staying hydrated. "Your gut is a major detox organ of your body, so think of it like a river," she explains. "You don't want a stagnant river, you want it to be free-flowing."
Manage your stress
"We know your gut affects your psychological wellbeing, but the same message is going back the other way down to your gut, so if you could minimise stress that would only improve things," says Angel. Meditation, exercise and yoga can also assist – Holmes' program offers specific yoga poses to help with issues like bloating and constipation.
Step away from the sanitiser
With gut flora diversity essential, we're doing ourselves no favours by diligently sanitising, sterilising, or using anti-bacterial products. "It's OK to occasionally let your kids eat dirt or kiss the dog, in fact it's good for you!" asserts Angel.
Lee Holmes' Anti-inflammatory hot toddy
Heat 250 millilitres of cashew milk in saucepan until warmed. Add ½ teaspoon ground turmeric, ¼ teaspoon each of ground cardamom, ground cinnamon and freshly grated ginger, two star anise, a pinch of vanilla powder and freshly cracked black pepper and stir to remove lumps. Remove from heat and pour through fine sieve. Add six drops liquid stevia, to taste. Enjoy warm.
Gut Healing Salmon Chowder
1 tbsp extra virgin coconut oil
4 salmon fillets (skin and bones removed)
½ onion, diced
2 garlic cloves, chopped
1 celery stalk, diced
½ tsp curry powder
1L chicken stock
2 turnips, peeled cut into 2.5cm cubes
1 tsp dried parsley
250ml additive-free coconut milk
Celtic sea salt and freshly cracked black pepper, to taste
fresh flat-leaf parsley, to garnish
1. Melt half the coconut oil in a large frying pan over medium heat. Add the salmon and cook for three minutes on each side or until just cooked. Set aside until cool enough to handle, then flake into pieces.
2. Melt the remaining oil in a large saucepan over medium heat. Add the onion, garlic, celery and curry powder, and cook, stirring frequently, for 3-4 minutes or until the onion is translucent. Add the stock, turnip and parsley, and cook, covered, for 20 minutes or until the turnip is soft.
3. Add the coconut milk and stir to combine, then remove from the heat and allow to cool slightly. Transfer to a food processor or blender with the flaked salmon and puree until smooth. Season to taste, garnish with fresh parsley, and serve. Serves four.
Slippery Elm Porridge
1-2 tbsp of slippery elm inner bark powder (found in any health food store)
¼ tsp powdered stevia
½ tsp vanilla
¼ tsp cinnamon
1 cup almond milk
1. Place the slippery elm into a blender. Add the stevia, vanilla, cinnamon and almond milk and blend until smooth.
2. Pour mixture into a small saucepan, and over a low heat bring it gently to a simmer while stirring constantly until it thickens. When it's ready, (it should be the consistency of soft porridge) remove from heat and spoon into a bowl. Eat immediately.
Variations: Substitute the almond milk for hot water or coconut, if desired. Mix in half a teaspoon of cacao powder, or sprinkle with chia seeds and shredded coconut.