Probiotics AND Allergy Primary prevention of asthma and allergy by supplementation of probiotics in early life

The date of the original protocol was January 2004 2 SUMMARY Background. Atopic diseases are increasing in countries with a Western lifestyle. The hygiene hypothesis states that the increase in atopic disease could be due to reduced exposure to microbial antigens in early in life. In search of new preventive therapies for atopic disease, exposure of pregnant women with previous or recent atopic disease, and their offspring to probiotics has been suggested. Probiotics are mono or mixed cultures of microbes which, when applied to animal or man, can beneficially affect the host, among others by inducing an immune response. Probiotics are generally accepted to be safe in children. Probiotics have shown to be effective in primary prevention of atopic disease in high-risk neonates in one study so far. However, it is still unclear by what mechanism probiotics work and which is the most immunopotent (combinations of) probiotic(s). It is likely that antigen-presenting cells (APC's) are involved, since these cells are important in the first line of defence in the gastrointestinal tract. It can be imagined that the immune response is the result of the interplay between probiotics and APC's. In particular, the match between pathogen-associated molecular patterns (PAMP's) on probiotics and their counterparts on APC's, the pathogen-recognition-receptors (PRR's) (like for instance Toll-like receptors) is decisive in this aspect.