The mind-gut connection
More than 2,000 years ago Hippocrates proclaimed “all disease begins in the gut”. The link between the brain and gut is part of our common vernacular (we talk about ‘gut feelings’ and ‘trusting our gut instinct’), but modern science is only now starting to confirm just how substantial the mind-gut connection may be. Recent studies have shown that when the gut is aggravated, it may impact the brain and lead to psychological dysfunction. Studies have also shown that managing gut health through various foods can affect everything from acne, autism and depression.
None of this comes as a surprise to Dr Miin Chan. As a doctor working in Victorian hospitals Chan became aware of the outcomes of antibiotic overuse and antiseptic environments. “Having spent time on a colorectal unit I noticed a rise in chronic inflammatory bowel disease and food allergies and intolerances,” she says. “During extensive travel and studies in permaculture, regenerative practice and community design I began to understand the links between disease and the environment and the importance of gut health and fermentation in these complex, interconnected systems.”
Having grown up Chinese in Malaysia, Chan was “surrounded by a myriad of delicious ferments, which we enjoyed for both health and taste”. Fermented foods contain live bacteria, or probiotics, which impact the nature of the bacterial colonies that live in our gut. Fermentation is the oldest and healthiest way of preserving food.
“Since time immemorial, humans have been fermenting food and drinks,” Chan says. “Fermentation not only helps us preserve food and create flavour … [but] it also promotes our health through the activity of microbes, bacteria, yeasts, molds and fungi. On a gut level, fermented foods contain probiotics, enzymes and beneficial aids which balance our gut microbiome, leading to improved immune and metabolic function as well as influencing our mental health.” Indeed, a 2015 study published in Psychiatry Research found regular consumption of fermented foods like sauerkraut or kimchi predicted fewer social anxiety symptoms in young adults.
Eat your [fermented] vegetables
Many of our favourite foods are traditionally fermented, says Chan. Just think about coffee, chocolate, cheese, tea, spirits, wine, beer, yoghurt, bread, vinegar, soya sauce, meats and olives. “It is no surprise that we find these the most delicious, as fermentation brings out the complexity of flavours and transforms often indigestible foods into compounds we can safely consume,” she says.
Now there seem to be benefits to fermentation beyond taste. From a Chinese medicine perspective fermentation (‘Fa Jiao Fa’) is a method of preparation (‘Pao Zhi’) to transform foods and herbs to create new herbal properties. “In some cases this is to have more affinity with and to support the digestive system and the organs of the stomach and spleen,” says acupuncturist and herbalist Shura Ford. “In other cases it may be to make actions more or less potent than in the unfermented state.”
Ford lists fermented soybeans (‘Dan Dou Chi’) as a preparation classically used in remedies to clear heat in cases of fever or restlessness, as well as fermented leaven (‘Shen Qu’ – a mix of fermented herbs and yeast) to support the energies of the stomach and spleen. “The fermentation process allows these herbs to be processed by the body more easily,” says Ford.
Traditional foods for gut and brain health
Almost every culture in the world has a traditional dish that relies on the help of good bacteria for their preparation. Around one-third of the human diet globally is made up of fermented foods and beverages. What would a visit to Germany be without sampling sauerkraut, pickled gherkins and sourdough pretzels? The French love their crème fraîche, Turkish people their ayran (a salty yoghurt drink) and the Italians adore their salami and olives. Not to mention the countless Asian countries where locals love their miso, kimchi, soya sauce, kombucha or lassi.
Looking after your mental health has never tasted so good.
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SBS On Demand: Michael Mosley - Guts