Dental caries is a bacterial, transmissible and multifactorial disease causing demineralization of enamel. One group of the products which is studied several times as an effective factor on cariogenic bacteria are “probiotic products”. The aim of this study was to evaluate the effect of probiotic yogurt on the survival of streptococcus mutans.
Methods:
In this experimental double blind study two kinds of yogurts were compared according to their effect on survival of streptococcus mutans: 1) Non-probiotic yogurt and 2) Probiotic yogurt (containing Bifidobacterium lactis, Lactobacillus delbrueckii, Lactobacillus acidophlus). Three tests were done on each yogurt sample; while the Co-culture test evaluated the net effect of each bacteria on the Streptococcus mutans (ATCC35668), in the Disc diffusion method the effect of extract of probiotic bacteria was investigated. Finally, in the Diffusion Well method, the Streptococcus mutans was cultured in its special culture area and two 10mm hole were punched on the area. Each of the mentioned tests was repeated three times. Data were analyzed by Kruskal-Wallis test at alpha 0.05.
Results:
The results of this study revealed that the probiotic bacteria existing in the probiotic yogurt could have a negative effect on the growth of streptococcus mutans (p<0.05) and decrease its number. This effect was significant after 24 hours (p<0.05).
Conclusions:
Consumption of probiotic yogurt can decrease the number of streptococcus mutans. More studies need to be done regarding the time and frequency of consumption of these products to see if they have caries prevention effect.