Shoring up your defences

If stopping yourself from getting ill is your primary aim – and I’m not saying this needs to be your main concern by any means – then as we saw last year, hiding away and not seeing anyone else that is contagious is one way of doing this, as you can’t get infected if you don’t go anywhere near a dodgy germ…

However, for most of us this is miserable: A fraction of the life we want to live, and indeed no longer viable, especially when we have little ones (or not-so-little-anymore ones) who are all living it up from 9 to 3 in those hotbeds of infection masquerading as educational establishments.

Building a bubble?

What then? Can we build our own little bubbles where we are protected from viruses and bacteria and all things small and horrible, and go about our daily business feeling untouchable?

Well – not quite… But given our long history of interacting with microbes – a history that started when we came into existence, and whose more recent chapters recognise that many viruses and bacteria (and their ancestors) actually make up a large part of who we are – our body has made sure that we aren’t by any means defenceless.

Yes, we know we can launch an immune attack with antibodies and T-cells to get rid of any invaders, but of huge significance – and potentially less widely discussed – are our barrier defences. These are as close as you are going to get to having your own protective bubble, and can be thought of much in the way you would the defences of the castle. Prevention, as we know is better than cure, so if we can stop most of the germs actually breaching these barriers, that would be a lot more efficient than launching a vigorous attack on something that’s already got inside.

Our barrier defences

How well do these barrier defences work? Well, it depends – but you can certainly take steps to shore them up a bit…

First up, the walls (or membranes): made up of skin cells, and the cells lining all the cavities that look as though they are inside us,  but are still in touch with the outside world. Things like the lining of our lungs, nose and mouth, and our digestive and urinary tracts. Ideally we need these walls to be robust, with no holes in – so we need to give our bodies the many nutrients (fats, protein, vitamins, minerals) it needs to grow new cells and the time (asleep) to repair as needed.  Ideally we’d also stop constantly bombarding these barriers with things that might damage them  – think alcohol, non-steroidal anti-inflammatories like Ibuprofen, smoke particles, cleaning products etc…

Second, the moat: Mucus to be exact. These membranes are all lined with mucus which can stop bugs actually reaching the walls, and helps keep the bugs moving along. If we think there’s something out there we’d rather not let in, we set about making more of the stuff, to help flush things out… Some emulsifiers added to food products, like carrageenan or carboxymethylcellulose can reduce the thickness of mucus in the digestive tract, so if your aim is to shore up your barriers, then these are probably best avoided.

Third: The boiling oil/water, cannons, arrows etc… are substituted internally with secreted anti-microbial peptides – which can target a range of bacteria, viruses and fungi – and antibodies, which are more selective (think programmable missiles). Some of these we make ourselves, and some we get our resident commensal bacteria to make for us. How do we know what antibodies to make, well, immune cells who are safely ‘inside the castle’ underneath the gut lining (or other membrane), send long arms out to spy on what is going on outside the city walls, and bring home a few samples. They then chew them up, and present the remnants to other cells in the immune system, who decide if there were any ‘undesirables’ amongst them. If so, the production of selective antibodies is authorised. These antibodies are secreted into the hollow space, specifically targeting the bad guys – binding them up and making them so big that they can’t possibly get inside (probably just me thinking of the inflatable pink bubble gum gun in Despicable Me 3 at this point).

Vitamin D can support production of these anti-microbial peptides, so ensuring sufficiency is really important to support optimal defences.

We also have some other secret weapons: Hair-like cilia in the lungs waft any falling debris back up the windpipe and back into the outside world, and hairs in our nose (if you haven’t pulled them all out for your Instagram pics) can help trap particles and bacteria in with the mucus…

Recruiting mercenaries

I like to think of the bacteria and other microbes that we have resident on our membranes as mercenaries. These guys have colonised all our exposed surfaces though the majority hang out in our digestive tract. They do an amazing job for us, in fact, without them our immune systems just wouldn’t develop properly at all. They take up space to crowd out any invaders,  produce their own anti-microbial agents to target other bacteria, and generate short chain fatty acids from fermenting dietary fibre – which help fuel the lining cells (shoring up the wall). These short-chain fatty acids also ‘talk’ to our immune cells, making sure our immune system doesn’t get too jumpy and start reacting to everything.

Why mercenaries? Well we do need to feed them dietary fibre. If we don’t they might start to rebel – munching on the mucus layer in lieu of a decent meal, and some of them might get a bit rowdy….  Bacterial imbalance can lead to inflammation and immune activation (think IBS) – so ignore these guys at your peril.

Putting it into practice

So in short – by eating fruit, veg and wholegrains for dietary fibre, as well as sources of protein & healthy fats to help repair cells, making sure we’re getting enough sunlight (or often times supplementing vitamin D if we live in the UK), avoiding food additives, alcohol, unnecessary medications, harsh cleaning products, and getting enough sleep we can help patch that ‘bubble’ keeping us apart from the bacteria and viruses we’d rather not let in to our systems. I appreciate however that all of this is really rather more easily said than done.

If you’d like to spend six weeks putting some of these things into practice – in bite size chunks to help you create new habits – then there are still a few days to sign up for my Winter Wellness course, starting on 7 November. More details are available at

1 Comment

  1. Sue Taylor on November 5, 2021 at 4:48 pm

    Great analogy, helps us understand how our body works. Thank you

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