The link between your immune system and your gut

I was recently approach by a man who wanted a colonic as he felt his immune system was low and he had heard that colonics might help. I had studied the link between the colon and the immune system when I trained as a colon hydrotherapist – but felt a refresher would be a good move!

…and this is what I found…

Your gut health and immune system are inextricably linked.  The obvious link between our gut and our immune system is that our food is ingested and processed by the gastrointestinal tract – our gut.  Just think of how many possibly rogue bacteria could get into our bodies as we eat our food – so our gut definitely wants to be on fighting form if we are not to fall prey to one of them! I say bacteria – but as we eat we expose ourselves to much more: bacteria, protozoa, fungi, viruses and toxic substances. And, of course, most of our gut is all about absorption – absorbing the nutrients from our food – we are designed to take things in through the gut  – and into our blood stream,  and thence to every cell in the body – which is great if the only things we ingest are 100% good for us – but unfortunately it is not as simple as that!

The sense that our gut is one of our first lines of defence is born out by the huge amount of immune cells that reside within it – and most of the immune cells are mucosal-associated lymphoid tissue (MALT).

Basically lymph flows round our body – in a similar way to blood and the circulation system – but lymph is all about keeping us safe from disease and infection. As the lymph flows round it goes through filtering systems made up of lymphoid tissues (MALT) – where the body  releases specific white blood cells known as T-cells and B-cells to defend us from disease.

Part of this filtering system (MALT) is housed within the gut and so is called gut-associated lymphoid tissue (GALT). It is estimated that 70-80% of lymphoid tissue resides in the gut – which in simple terms means:

70-80% of your immune system is housed in your gut.

Thus anything we can do to support it must make a significant contribution to how healthy we are :)

It is estimated that over 500 microbial species live in the human gut, contributing some two pounds (about one kilogram) to the body’s overall weight. It is estimated that over 90% of exposure to microorganisms occurs within the gut. Many of these bacteria (known as ‘commensals’) are a perfectly normal part of the gut population and do not cause disease – in fact they often perform some very useful roles such as aiding in the digestion of food.

We also know that a healthy population of commensals in the gut can help to prevent colonisation by harmful bacteria – by crowding them out and not allowing them take hold – thus complementing action of the GALT.  Certain commensals have even developed particular substances, called colicins, that neutralise other bacteria. Due to certain differences in the way commensal ‘behave’, compared to disease-causing species, it seems that the immune system is able to tell the difference between the two.

Evidence for the importance of commensal bacteria is found when oral antibiotics are taken by people to counter harmful bacterial infections. These can also drastically reduce the population of commensal bacteria in the gut. Although the population grows back again, it has been noted that the gut is temporarily more vulnerable to infection with harmful bacteria, due to the breaking of the ‘commensal barrier’.

It seems that in the gut, as in other aspects of life, it pays to cultivate a healthy group of friends to protect you from your enemies…

So… three things we can do to support our gut and its role in our immune system are:

1)      Eat healthy food – both to provide nutrients for our body – AND – nutrients for the bacteria in our colon. Yes you heard me right! We need to make sure we not only feed ourselves well – but the commensal bacteria inside us.

2)      Take a good quality probiotic – and I’m not talking about yoghurt drinks full of sugar!

and lastly:

3)      Every now and again – have a good clear out – have a colonic – get rid of the harmful bacteria that feed off the faecal matter in your colon and then let the commensal bacteria – many of whom will remain unaffected in the mucous lining of the colon – recolonise the gut and boosting your immune system :)

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Emily MumfordView all posts by Emily Mumford