Good Gut Health is vital for a strong Immune System
In February, after the first few UK case of coronavirus were confirmed, I was asked to write an article for the Daily Mail, which focussed on the importance of the immune system in fighting infection and preventing disease. 2 million people read the feature, and it was shared more than 20,000+ worldwide:
I received emails from numerous readers across the world, commenting on the “fascinating feature”. In particular, the majority of reader’s comments thanked me for information they hadn’t known, such as the importance of gut health in promoting a strong immune system. Strengthening your immune system is vital as the coronavirus outbreak spreads across the UK and the world. One of the most important factors for a healthy, fighting fit immune system is good gut health, since a huge proportion of your immune system (approximately 70%) is actually in your gut.
Research shows that there is a huge amount of interaction between the body’s immune system and bacteria in the gut. Beneficial gut bacteria species have been demonstrated to impact both the innate (present right from birth) and acquired immune systems (acquired during the course of life). They have also been shown to significantly shorten the duration of having a common cold, and decrease the severity of the symptoms. So, we need to focus on optimising our gut health, strengthening the gut lining and re-inoculating (re-populating your gut with bacteria by eating prebiotic and probiotic rich foods). In turn, this will then help promote a strong immune system.
The collection of bacteria living in our guts is called the microbiome, and this consists of approximately a hundred trillion bacteria. There are ten times more of these cells than there are human body cells, and these genes outnumber your human genes by an incredible 150:1. It is currently believed that factors, such as diet, lifestyle and genetics have the greatest influence on shaping the gut microbiome. And, whilst we can’t change our genes, we can affect the composition of the different species of bacteria in our guts, through diet and lifestyle. We need lots of variety when it comes to gut bacteria, so it is important to make sure our guts have as many different bacteria species as possible. Luckily, for us, this can be achieved by eating a variety of different foods, rich in different species of bacteria - all of which promote a healthy gut lining, microbiome and consequently a healthy immune system.
Foods to boost gut health
Prebiotics and probiotics work together to maintain a healthy digestive system and promote a strong immune system. Prebiotics are the non-digestible component of food, which feed the "friendly" gut bacteria. A high fibre diet is naturally rich in prebiotics, and this will help to obtain the subsequent health benefits of probiotics.
Best prebiotic food sources: apples, asparagus, artichokes, bananas, broccoli, cauliflower, fennel, garlic, legumes, leeks, onions, pak choi, wheat and oats (avoid if you have a gluten intolerance).
Probiotics are microorganisms and the "friendly" gut bacteria. They provide many health benefits, such as improving the intestinal microbial balance and boost the immune system.
Best probiotic food sources: fermented foods such sauerkraut, fermented tempeh (type of soya), miso, kefir and yogurt.
Other good gut health foods especially for promoting a healthy gut lining, include:
Pumpkin, sweet potatoes, squash, nuts, chicken stock (the collagen promotes a healthy and strong gut lining).
There are other certain nutrients, which are vital for an optimal immune system, and deserve a mention, including:
While there is currently no official recommended daily allowance for antioxidants or antioxidant foods, generally speaking the more you consume each day from real wholefoods in your diet the better. Most fruits, vegetables and herbs contain antioxidants such as vitamin C, vitamin E, lutein, beta-carotene, flavonoids and lycopene.
The following foods are excellent sources of antioxidants: blueberries, green leafy vegetables, such as spinach and kale, onion, oregano, turmeric, cumin, basil, ginger, garlic, cayenne pepper, dark chocolate (70% minimum cocoa solids), green and white tea.
Vitamin C is an antioxidant found in abundance in fruits and vegetables. It is a significant nutrient for boosting immunity and may help to slightly reduce the severity and duration of a common cold.
Food sources include: broccoli, Brussel sprouts, kale, kiwi fruit and oranges.
Zinc is a very important mineral needed for a healthy immune system. However, it is paramount that you keep to the recommended daily requirements and the upper level of zinc (through supplementation), since exceeding this may, in fact, suppress the immune response and result in unwanted, negative side effects.
Food sources include: meat, poultry, seafood, legumes, lentils, cereals and dairy products.
In addition to good gut health and a balanced diet, it is also important to consume at least two litres of water a day (ideally filtered), adopting moderate cardio and resistance exercise and also, reducing stress in your life.