As with foods and pollen, our own body cells also bear antigens (known as self antigens).

A further function of the regulatory arm of the immune system is to recognize self antigens and ensure that they are not attacked.  To do this the immune system must be programmed with data, enabling it to recognize self antigens and ensure that they are not attacked.

If we are not sufficiently ”programmed”, by ongoing exposure to Old Friends microbes, the immune system may fail to recognise self antigens as harmless and attack them.  It is this “attack” which triggers autoimmune diseases such as Multiple Sclerosis, Inflammatory Bowel Disorder etc.