2010 年 59 巻 1 号 p. 49-57
The number of pet animals having type I allergic symptoms have increased under a change of breeding environments. The type I allergic disease is mainly discussed to be associable to a skewed T helper type 1 (Th1)/T helper type 2 (Th2) cell balance. In recent years, some investigators demonstrated that numerous lactic acid bacteria and their cellular components reduce allergic symptoms via not only shifting the Th1/Th2 balance from a Th2-dominant state to a Th1-dominant state but also inducing of regulatory T cells. On the other hand, lactic acid bacteria and their cell components are found to modulate immune responses via pattern recognition receptors (PRRs) such as Toll-like receptor (TLR) and nucleotide-binding oligomerization domain (NOD). In our studies, it was suggested that Lactobacillus crispatus KT-11 strain reduced allergic symptoms in NC/Nga mice by the adjustment of Th1 and Th2 balance via TLR2, NOD1 and NOD2. It is known that PRRs express on intestinal tract in dogs and cats. Thus, it is expected that lactic acid bacteria may be a pet food materials for a reduction of allergic symptoms.