The best foods to eat to support your gut health and immune system during the coronavirus (COVID-19) pandemic‍

The microbes that live in your gut (microbiome) play an important part in maintaining your immune system and your overall health. Eating the right foods for your microbiome may help to support your immune system and overall health.

• Your immune system protects you against viruses like coronavirus, but an immune overreaction can be be a problem
• Your gut plays an important role in regulating your immune responses
• What you eat can support your gut health and your immunity
  

These are worrying times. COVID-19 (the illness caused by the new coronavirus SARS-CoV-2) has put the whole world on high alert, and it has officially been declared a pandemic by the World Health Organisation. Countries have closed their borders, sporting events have been cancelled, bars and restaurants are shuttered, and people are panic buying staples like toilet paper and pasta. 

While it might feel like everything is out of control, there are still many positive things you can do to protect your health and that of the people around you.

First and foremost, follow the Public Health England guidance for preventing COVID-19: avoid spreading the coronavirus and cut your chances of catching it by regularly washing your hands, avoiding touching your face, and reducing contact with others.

You can also support your immune system by eating healthily to support your gut microbiome - an important line of defence against infectious diseases.

But if you’re about to take a trip to your local grocery store, it’s worth thinking about which foods to prioritise to help keep your immune system and gut health in top shape. And that’s important for fighting off any infections that come your way - not just coronavirus.

Fighting coronavirus is all about a proportional immune response

When your body is infected with a virus, your immune system detects and attacks it. Many people infected with the new coronavirus will only have mild symptoms like a regular cold or flu, while some may not even realise they are infected at all (known as asymptomatic infection).

But in some cases, the immune system can overreact and damage the lungs and other vital organs, in what’s known as a cytokine storm.These excessive immune responses can cause respiratory failure and death.

So, to protect you against COVID-19, your immune system needs to respond swiftly to fight the coronavirus infection, but not overreact to the presence of the virus (or any other infection you happen to catch). 

Your immune system is a complex beast, and lots of factors can influence how it functions. But one thing that you can influence immediately is the health of your gut microbiome. ‍

Your gut microbiome regulates your immune system ‍

Your gut is home to trillions of microbes that make up your microbiome, including bacteria, viruses and yeasts. 

These bugs aren’t just hanging out in your belly for fun - they have a range of jobs that help to keep us healthy including digesting fiber and producing vitamins and other useful molecules. 

Recent research has shown that your gut microbiome is important for regulating your immune system, making sure that it responds in a proportionate way to any threats and avoids over-reacting,

The interaction between your microbiome and your immune system is not yet well understood. But we do know that your gut bugs enhance anti-inflammatory responses and can, for example, activate vitamin A from your food - a vital vitamin that helps to control your immune system.

‍How to keep your gut microbiome (and your immune system) healthy‍

A diverse microbiome is a healthy microbiome, with lots of different microbes that can perform a range of functions and fend off infections. Your microbiome diversity naturally drops with age, so you need to work harder to keep a good mix of microbes as you get older

You can increase the diversity of your microbiome by eating lots of plant-based foods, which are high in fibre, and limiting ultra-processed and junk food. If you’re unsure of where to start, take a look at our Top Ten Tips to get more plants in your diet. ‍

Recent research has shown that following a Mediterranean diet can improve your gut diversity and reduce inflammation, which may put you in a better position to fight pathogens like coronavirus. ‍

This involves eating plenty of fruit, vegetables, nuts, seeds, whole grains, legumes and pulses; healthy fats like high-quality extra virgin olive oil; and lean meat or fish for those who wish. At the same time, keep your gut bugs healthy by limiting alcohol intake, salt, sweets and sugary drinks. 

You can also support your microbiome by including probiotic-rich foods like natural yoghurt, kefir (fermented milk) or kombucha (fermented tea), which all contain live microbes. Or take a tip from the Koreans and tuck into some kimchi - a tasty mix of fermented vegetables like cabbage with chili and garlic.

Perhaps unsurprisingly, many of the foods recommended in the Mediterranean diet contain a variety of different nutrients that play a role in ensuring that our immune system functions as it should.

Many different vitamins and minerals play a key role in supporting our immune function. Vitamin A, which can be found in brightly coloured fruit and vegetables including spinach, carrots, sweet potatoes, red peppers, mango, papaya and apricots, is just one example. 

It’s worth noting that there is no evidence that taking vitamin or mineral supplements can prevent you from catching infections like COVID-19. Some vitamin supplements can be harmful if taken in large doses, so the best way to ensure that you’re getting enough of these nutrients is to eat a healthy, varied diet

You might be worrying about how to get hold of fruit and vegetables if you are stuck in self-isolation or quarantine, but remember that frozen fruit, berries and veg are just as good for you as their fresh counterparts and will last much longer than two weeks. Canned fruit, beans and pulses are also a useful long-lasting option.

‍Staying healthy in the coronavirus pandemic‍

If you want to do the best thing to support your health during the COVID-19 pandemic, maintaining a healthy gut is probably more important than stockpiling toilet paper. 

To support your immune defenses or those of an elderly relative or friend:

• When you hit the grocery store, head for the whole grains, fruit, veg, legumes, lean meats, oily fish, eggs, nuts, seeds, berries and olive oil 
• Get some natural probiotics like yogurt and kefir to have as a daily shot or make your own.
• Avoid processed foods, salt, sweets and alcohol
• Avoid artificial sweeteners and similar additives in foods
• Don’t forget to wash your hands!
  

Trying to manage your stress and anxiety levels, as well as staying active and getting enough sleep, will also help to keep your immune system in good shape.

Learn more about the link between the gut microbiome and the foods that we eat

ZOE is working together with leading scientists and thousands of volunteers, combining large-scale data and machine learning, to predict personal nutritional responses to any meal and harness the power of the trillions of microbes found in our gut to improve human health.

Join our scientists at the American Society of Nutrition's live online conference to learn more about how we are pioneering the latest science on the microbiome, inflammation and how genes impact our metabolic health.

You can register for this free event here, which will be held on June 2nd.

Find out more:

• How Coronavirus Hijacks Your Cells – The New York Times
• Variation in the human immune system is largely driven by non-heritable influences – Cell
• Nutrition, immunity and COVID-19 - BMJ
• Interactions between the microbiota and the immune system – Science 
• Gut microbiome regulates the intestinal immune system - ScienceDaily
• Role of Vitamin A in the Immune System – Journal of Clinical Medicine 
• Mediterranean diet intervention alters the gut microbiome in older people reducing frailty and improving health status: the NU-AGE 1-year dietary intervention across five European countries – Gut Microbiota

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