Key Points

• IgA is a binding molecule that neutralizes toxins without eliciting an inflammatory immune response.
• The diversity and expression of IgA is dependant on the microbiome.
  • The microbiome activates and stimulates the immune cells to produce IgA through cross talk with the mucosa layer via pattern recognition receptors.
  • Pattern recognition receptors read patterns on structures of viruses, bacteria (including commensal bacteria), food particles, antigens. When reading these patterns, the mucosa layer secretes more IgA to neutralize these compounds. This is called oral tolerance, and losing this functionality via a dysbiotic gut causes sensitivities in foods and a dysfunctional/inflammatory gut.
    • If you don't have enough IgA secreted in your gut, your body replaces it with IgE which is pro-inflammatory and can cause allergic reactions and activate mast cells and so on via the release of histamines.
• Bad gram-negative bacteria releases LPS which is an inflammatory fat-soluble toxin.
  • LPS is carried through the body via our bodies emulsification process, made worse by a high-fat diet because the body will produce more emulsifiers when fat is detected in the diet.