Abstract

The human intestinal microflora may be considered as a post-natally acquired organ composed of a large diversity ofbacteria with different functions on human health. Probiotics are live microorganisms which, when administered in adequateamounts, confer a health benefit on the host. Probiotics are widely used to rebalance microbiota composition, thus improvinggut functionality and immune system responses. However, only few data on the specific immunologic pathways are currentlyavailable. This study showed that Bifidobacterium breve BR03 (DSM 16604) is able to induce a relevant increase of helperT lymphocytes and the secretion of Th2 cytokines (IL-10 and IL-4). This strain demonstrates a strong anti-inflammatory propertythrough the shift of Th1/Th2 balance towards a Th2 response and could therefore be beneficial in irritable bowel diseases.