Probiotics have been associated with gut health. However, during the last decade several investigators have also suggested the use of probiotics for oral health purposes. Recently, it was shown that long-term consumption of milk containing Lactobacillus rhamnosus GG (LGG) caused a significant reduction in caries risk in day-care children [7]. And short-term consumption of fruit yogurt containing bifidobacteria cause a statistically significant reduction of salivary mutans streptococci in orthodontic patient with fixed appliances during consumption of yoghurt [8], the key reduction of salivary mutans streptococci in orthodontic patients during daily consumption of yoghurt containing probiotic bacteria such as strains of lactobacilli or bifidobacteria can occupy a space in a biofilm that otherwise would be colonized by a pathogen. However, L. rhamnosus GG and two different L. reuteri strains have been reported to colonize the oral cavity of 48–100% of volunteers consuming products containing them. After the 14-day trial period, the occurrence of LGG in the oral cavity decreased gradually, indicating that no permanent colonization had occurred and that the oral persistence of LGG was only temporary [9, 10]. It may cause not potential strains for specific oral ecology. For these reason, should be find potentially probiotic microbial strains for specific oral ecology. Lactobacillus paracasei SD1 is a normal flora that isolated from caries-free children, the advantage of this strain includes 1) growth inhibition of pathogenic strains; S. mutans and S. sobrinus 2) less acidic produce than the other strains and 3) ability to adherence oral epithelial cells. Thus, this strain may be useful for a potentially probiotic microbial strain for oral cavity.