“The immune system is the most interesting organ in the body”

Michael Kinch PhD.

As part of the gut and brain series, we will look at the roles they play in our health, this article will primarily look at how the gut links in with the immune system. There is an ever-increasing amount of research into the gut and this is beginning to identify that a large part of our immune system exists in the gut itself, making it a critical part of our defences. In previous articles, we have talked about supplementation to support immune function, but this article will expand on that some more.

The Gut and Immunity

The gut is a large and vital component of our immune system, it is an active working barrier to prevent toxins and bacteria (termed ‘antigens’) passing into the body. The things we ingest like food, water and even the air we breathe will all carry some bacteria or toxins with them into the body. 

The gut is a line of defence which is only 1 cell layer in thickness but is very active and effective at preventing antigens entering the body. The gut has a mucus layer which is able to trap bacteria and microbes in it, and also secretes substances which can also trap and fight these foreign particles. 

Taking care of your gut health is not only good for symptoms like bloating and gas but is supportive of the immune system too. 

Exercise and Immunity

There is also a link between exercise activity and immunity, which is termed as the J shaped curve. In quite simple terms this states that too little and too much exercise reduces our ability to fight off potential infections (2), so we need a moderate amount of exercise in order to improve our immunity as best possible. 

If we do exercise in extreme amounts it needs to be then followed by a period of focussed rest and recovery to let the immune system return to a normal operating level. Ideally, we should stay training consistently in moderate amounts to maximise our health.

Supporting your Gut and Immunity

Since bacteria live in your gut it is good to ensure there is a diverse range of bacteria so they can perform their individual functions. To diversify your gut bacteria it is good to rotate foods, eat fermented foods and take immune-supporting vitamins and mineral supplements.

Rotating your foods simply means that you don’t eat the same food on 2 consecutive days, so consider alternating days of white meats with days of red meats, or alternate leafy greens with cruciferous vegetables, or fish with poultry. Also including fermented foods such as sauerkraut can be beneficial to gut bacteria. 

Probiotics could be another option, these contain various strains of bacteria which can help with digestion, inflammation and promoting good bacteria in the gut. These bacteria can also fight off potential harmful substances to the body. Consider a probiotic to help support your gut.

There are some vitamins and minerals which play a key role within immunity and any deficiencies of these could be holding back your immune function. Vitamin C and Vitamin D are both needed to regulate the activity of the cells of the immune system and both are good antioxidants. While vitamin E and Zinc are also strong antioxidants.

A good multivitamin should be considered and especially one with a good antioxidant profile. HPH Bio Avail Multi Phytonutrient Multivitamin has a good quantity of numerous antioxidants which could be of benefit for your immune function and reducing toxicity.


The gut is integral to our immunity, and supporting the gut can help your immune system to operate better. While supplements cannot prevent illness or disease, they can help get your body the things it needs (vitamins, minerals, good bacteria, etc…) to be in the best possible position.


We’re always here to help. If you have any questions or would like advice about supplements, nutrition, or training, please book in for a consultation.


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  1. Immunity in the Gut
  2. J Shaped Curve 
  3. The Gut: Where Bacteria and Immune System Meet