Fuller (1989) defined the term probiotic as ‘a live
microbial feed supplement which beneficially affects the
host animal by improving its intestinal microbial balance’.
The definition of probiotic has broadened over the years
as knowledge of the symbiotic interactions between
microbes and host animals has increased (Salminen et al.
1999, 2006). Most current probiotics, which can colonize
in the human intestine, are lactic acid bacteria, particularly
Lactobacillus spp. and Bifidobacterium spp. Emerging
evidence from recent clinical and animal studies supports
the notion that probiotic lactobacilli, especially some
selected strains, can modify host innate and acquired
immune responses by which they can protect against
respiratory infections (Hori et al. 2002). This study aimed
to evaluate potent protective effects of orally administered
Lactobacillus rhamnosus GG (LGG) and Lactobacillus
gasseri TMC0356 (TMC0356) using an Flu infection
mouse model.