The Immune System
The immune system protects us from external threats - infections and toxins.
Cells of the immune system are found throughout the body but around 70% are in
the gut. They fight invaders by secreting toxic chemicals or engulfing them. Activity of the immune system
generates inflammation.
The immune system is capable of evolving thoughout our lifetime. Exposure to a
range of foreign substances and micro-organisms (especially bacteria inhabiting
the gut) is vital to its healthy development. The immune system must learn to
differentiate between helpful, harmless and toxic substances and life forms.
Immune Imbalance
Immune imbalance can manifest as:
- allergy - the immune system responds inappropriately to harmless substances such
as pollen.
- autoimmune disease - the immune system mistakenly attacks the body's own cells.
Examples are rheumatoid arthritis and type I diabetes.
- susceptibility to infection - a weakened immune system cannot fight off
infections.
Psychoneuroimmunology
Immune cells communicate with each other via messenger molecules called
cytokines. Immune cells can also respond to hormones, and nerve signals. In
turn, the brain and nervous system (and thus how we feel and act) are influenced
by immune cell activity.