The level of beta defensin-2 in saliva and its expression in parotid gland epithelial cells after probiotic (Lactobacillus reuteri) induction to inhibit Streptococcus mutans in caries

OBJECTIVE: The aim of this study was to prove that administrating L. reuteri probiotics can increase the level of BD-2 saliva and BD-2 expression in the epithelial parotid glands of Wistar rats. MATERIALS AND METHODS: Experimental design in this study was randomized control group post test only. Twenty-four white male Rattus norvegicus Wistar strain rats were divided into four groups. The negative control group included rats not induced by S. mutans whereas the positive control group included rats induced by S. mutans. The two treatment groups are as follows: treatment 1 (T1), the group that is induced for 14 days by L. reuteri and 7 days by S. mutans and treatment 2 (T2), the group which is induced simultaneously by S. mutans and L. reuteri for 14 days. L. reuteri culture at a concentration of 108 colony-forming unit/ml and S. mutans culture at a concentration of 1010 are induced in the oral cavity of the Wistar rats. The Elisa technique is used to examine the salivary level of BD-2, whereas the immunohistochemical technique is used to examine the BD-2 expression in the epithelial salivary glands. RESULTS: The study shows the increasing levels of BD-2 and BD-2 expression in the epithelial parotid glands after the administration of L. reuteri probiotics. Besides, there is a relationship between the increasing expression of BD-2 in the epithelial parotid glands with the decreasing amount of S. mutans. CONCLUSION: Giving L. reuteri probiotic scan increases the level of saliva of BD-2 and the expression of BD-2 in the parotid glands.