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Open Access Research article

Effects of Lactobacillus salivarius-containing tablets on caries risk factors: a randomized open-label clinical trial

Tetsuyo Nishihara, Nao Suzuki*, Masahiro Yoneda and Takao Hirofuji

Author Affiliations

Section of General Dentistry, Department of General Dentistry, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka, 801-0193, Japan

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BMC Oral Health 2014, 14:110  doi:10.1186/1472-6831-14-110

Published: 2 September 2014

Abstract

Background

To evaluate the effects of the lactic acid bacterium Lactobacillus salivarius on caries risk factors.

Methods

The study was performed in 64 healthy volunteers to evaluate the effects of L. salivarius-containing tablets on caries risk factors. The participants were divided randomly into four groups, and took tablets containing L. salivarius WB21, L. salivarius TI 2711, Ovalgen® DC (antibody against glucosyltransferase from Streptococcus mutans), or xylitol. Levels of mutans streptococci and lactobacilli, amount of salivary flow, salivary pH, and salivary buffering capacity were assessed before and after taking the tablets. Subsequently, a short-term administration trial using L. salivarius WB21-containing tablets was performed in eight healthy volunteers. The participants took L. salivarius WB21-containing tablets (2.0 × 109 colony forming units/day) for 2 weeks, and the numbers of mutans streptococci in saliva were counted.

Results

The levels of mutans streptococci seemed to decrease in the L. salivarius WB21, TI 2711, and Ovalgen® DC groups compared to the xylitol group, with no significant differences between the groups. Lactobacilli levels significantly increased in the L. salivarius WB21 and TI 2711 groups compared to the other groups. Concerning salivary flow and salivary pH, no significant differences were observed between the groups. The salivary buffering capacity significantly increased in the L. salivarius TI 2711 group (P = 0.003) and Ovalgen® DC group (P = 0.002) compared to the xylitol group. The short-term administration trial showed that the L. salivarius WB21-containing tablets significantly decreased the number of mutans streptococci (P = 0.039).

Conclusion

L. salivarius-containing tablets were suggested to increase resistance to caries risk factors.

Trial registration

UMIN000013160 (registration date: February 14, 2014).

Keywords:
Caries risk factor; Lactobacillus salivarius; Mutans streptococci; Oral environment; Probiotics