Efficiency of metabolism of sugar alcohols governs its probiotic effect against cariogenic .

is a Gram-positive probiotic bacterium that successfully colonises plant roots due to its ability to utilise various sugars. The vast probiotic potential of has been recently demonstrated in numerous host organisms under different environmental conditions. We examined the probiotic potential of against the pathogenic bacterium , which is involved in various oral disorders due to its robust biofilm-forming capability. cells attenuated biofilm formation by during their dual growth in the presence of sugar alcohols. Transcription of genes encoding key enzymes in the metabolism of sugar alcohols by were highly induced. Moreover, growth-curve analysis suggested that is more efficient at early utilising sugar alcohols than , as supported by the bacterial metabolic activity rates. Similarly, a comparison of secondary metabolites of mono and mixed cultures of and indicated that is more active metabolically in the dual culture. Finally, knock-out mutations of the genes encoding key enzymes in the central metabolic pathway significantly reduced ' ability to mitigate biofilm formation by . We conclude that effective metabolism of sugar alcohols by reinforces the probiotic potential of this bacterium against pathogenic species such as .