Special immune cells form part of the defence system in the intestine. They react to foreign substances and trigger an immune response. They can be activated by feeding them special bacteria. The bacteria have a training function for the immune system in the intestine. They do not trigger diseases, but stimulate immune cells to produce antibodies. The blood and lymphatic system conveys these antibodies to the mucous membranes of other organs, where the antibodies from the defence cells support the immune system as the first line of defence against unwanted pathogens.
For more on the sinusitis and bronchitis indications, see Sinusitis and Bronchitis.