Your Gut, The Second Brain
30 May 2019
2500 years ago, ancient Greek physician Hippocrates said that ‘all disease begins in the gut’. Whilst we’ve since proven that isn’t strictly true, he was certainly onto something. Most people generally have a basic-to-good understanding of the relationship between good/bad nutrition, gut health, and overall health. What may surprise you, though, is how interlinked the gut and your mental health are.
You are a walking, talking, microbial ecosystem. Bet you’ve never heard that one before, but it’s true! Our bodies are host to trillions of microbes, fungi and viruses living all over you both inside and out, in every nook and cranny – they actually outnumber your human cells 3 to 1. One of the most crucial colonies of microbes in our bodies lives within our gut; this is called the ‘microbiome’ or ‘microbiota’, and it helps to control your blood sugar, cholesterol, metabolism, absorption of nutrients, influences your bone strength, and supports your immune system. This microbiome is perfectly, delicately balanced for gut health, but it is also super sensitive to change, disruption and imbalance. The Gut Report 2018 found that one in five people had had to take time off work due to digestive issues, and around 28% avoided going out for the same reason.
The gut has been called ‘the second brain’, due to how closely it is linked to your wider physiology and the influence it has over it. This is in large part due to the positioning of the vagus nerves, which run the entire length of your spine from brain to gut (this is one of the central nerves that chiropractic works to release tension on and improve communication across, too!). The neurons in our digestive systems exist in close proximity to these nerves, meaning that they are prone to influence our emotional state and vice versa. The most common example of this is the effect that stress has on the body. The ‘fight or flight’ response to stress, and all of the physiological reactions involved within that response, directly affects your microbiome and how well your gut works, which can trigger bowel issues. Many people who suffer from IBS find that stress and/or anxiety is a common trigger for them for this exact reason.
The effects happen in reverse, too. Your gut influences around 70% of our immune system function, and 95% of our body’s serotonin is produced there too (this is the ‘happy’ hormone). If you’re eating a poor diet which is low in essential micro- and macro-nutrients such as probiotics, prebiotics and fibre, your gut biome will be disrupted, and so will all of the systems it supports. You’re likely to be more prone to sickness due to lowered immune system, and low mood and stress due to suppressed serotonin production. You’re also more likely to overeat on more nutrient-scarce foods as levels of ghrelin, the hunger hormone, fly out of whack. All-round not great.
So, whilst all disease may not begin in the gut, the gut certainly is very central to many of your bodily processes. Usually when something is going on in your body, your gut will be one of the first places to let you know about it. This also works in reverse; disrupting the natural balance of microbiota can have knock-on health and wellbeing effects throughout the body. This is even true of the microbiota on your skin and elsewhere in and on your body. Important microbes can be affected by overusing antibiotics, hand sanitisers, bad diets and general ‘Western’ lifestyles.
The takeaway from this? It’s of equal importance to take excellent care of both your gut and your mental health, as they coexist in symbiosis. You cannot affect one without the other experiencing disruption.
Here are some food groups you should pay attention to in order to keep your gut in healthy balance.
Where to get it: Yogurt, kimchi, miso, sauerkraut, kefir, kombucha.
Probiotics support your immune system and contribute to the health of the gut microbiome.
Where to get it: Onion, garlic, leeks, chicory, Jerusalem artichokes (prebiotic king), bananas, asparagus, olives, plums, apples, bran, almonds.
Prebiotics stimulate the growth of beneficial bacteria in the gut. It’s important to maintain a good balance of pro- and prebiotics, as they function in tandem with one another. Eating too much of one and neglecting the other can upset your gut (we told you it was sensitive!)
Where to get it: fruit and vegetables, whole grains, pulses, beans and oats.
Health experts are constantly banging on about fibre, but for good reason. Fibre slows down the breakdown of sugars found in carbohydrates, which helps to stabilise your energy levels. It also helps the absorption of water in the gut so that it keeps the bowel moving at a healthy pace (which, by the way, should be at least once a day). You should be getting at least 30g of fibre a day from a variety of sources, as there are different types of fibre which hold different properties within your gut.
Where to get it: Broccoli, cauliflower, sprouts, cabbage, turnips, collards, kale, bok choy.
Cruciferous vegetables (brassicas) contain sulforaphane, which is a plant chemical currently being investigated for its anti-inflammatory properties.
Other gut-friendly foods
Strawberries & blueberries are back in season! Eat loads of these, they’re full of polyphenols (antioxidants) which are excellent for your gut. You can also find polyphenols in green tea and dark chocolate.
Turmeric is a powerhouse of a spice when it comes to wellbeing. It has anti-inflammatory properties which can help to calm any inflammation you may cause by upsetting your tum.
Peppermint is widely used to calm sensitive stomachs and acid reflux. You can get peppermint capsules from health food shops, or try drinking peppermint tea.
Now, go forth and take care of your digestive tract, for gut’s sake.