Oral bifidobacteria: Caries-associated bacteria in older adults

Bifidobacteria are aciduric bacteria that might play a role in the caries process. to test the hypothesis that bifidobacteria behave as caries-associated organisms,as predicted by the ecological plaque hypothesis,we determined salivary levels of bifidobacteria and caries-associated organisms for 156 older adults. salivary levels of bifidobacteria,mutans streptococci,lactobacilli,and yeasts were correlated with each other (p < 0.001),negatively correlated with salivary flow rate (p < 0.001),and positively correlated with plaque index (p < 0.05). salivary bifidobacteria levels were positively associated with the number of filled (p < 0.001) and decayed (p = 0.036) tooth surfaces and negatively associated with number of teeth (p < 0.001) and salivary flow rate (p = 0.049). in regression analyses,caries experience was significantly associated with only salivary bifidobacteria (p < 0.001) and yeast (p < 0.001) levels and the individuals age (p = 0.021). bifidobacteria should be regarded as caries-associated organisms whose role in the caries process and as markers of caries risk requires further investigation. © international & american associations for dental research.