Bacteria and Their Relationship to Allergic Diseases

Overview

From the beginning of life, human immune system is affected by interactions with different microorganisms.Immediately after the birth bacteria colonize mucous tissues and namely the gastrointestinal tract, which wasantenatally sterile. Bacteria are involved in allergic inflammation by two different ways. They can either initiate theallergic response or they can diminish it. To the negative factors, which can trigger the allergic response belongsuperantigens, namely the bacterial enterotoxins. Positive factors include mycobacterial antigens, intestinal microflora,pathogen-associated molecular patterns and CpG motives that belong to components of the bacterial genomeDNA. The effect of lipopolysaccharide from gram-negative bacteria on the development of allergic inflammation istwo faced. Lipopolysaccharide has a protective role when the infection precedes the contact with allergen for a longtime. Short period between the infection and allergen exposition leads in a sensitized person to the provocation ofallergic disease. These and other factors are important in relation to the so-called hygiene hypothesis where the Tregulatory lymphocytes seem to play the key role in the balance between Th1 and Th2 lymphocytes.

Key words:
allergy, bacteria, asthma, atopic dermatitis.