The effect of five probiotic lactobacilli strains on the growth and biofilm formation of Streptococcus mutans

ObjectiveTo compare the effects of five probiotic lactobacilli strains on the growth and biofilm formation of Streptococcus mutans (MS). Materials and MethodsFive probiotic lactobacilli bacteria (LB), Lactobacillus casei Shirota, Lactobacillus caseiLC01, Lactobacillus plantarumST-III, Lactobacillus paracasei Lpc-37, and Lactobacillus rhamnosusHN001, were used as test strains effecting on the Streptococci strain S.mutansUA159 in this study. The effect of LB strains and their supernatants on the viability of the MS was evaluated. Then, the effect of LB strains on the growth of MS biofilm formation was observed by fluorescence microscope. ResultsAll of the LB strains inhibited the growth of MS at concentrations of 1x10(8) and 3x10(8)CFUml(-1) (P<0.05). Untreated (without pH adjustment and ultrafiltration) LB supernatants from all of the LB strains inhibited the growth of MS (P<0.05) as well. After pH adjustment and ultrafiltration (treated), only supernatants from L.casei Shirota and L.rhamnosus HN001 inhibited the growth of MS (P<0.05). MS biofilm formation was also inhibited by all untreated supernatants and by the treated supernatants of L.casei Shirota and L.rhamnosus HN001 (P<0.05). ConclusionAll five probiotic lactobacilli strains inhibited the growth and biofilm formation of MS, likely through the production of an acid environment, bacteriocin-like poly peptides, or both, and the effects on MS were dependent on the LB strains used.