Human lactoferrin protects against Streptococcus mutans ‐induced caries in mice

Objectives The objective of this study is to evaluate the importance of human lactoferrin ( hLF ) in an experimental caries induced by Streptococcus mutans in a lactoferrin‐knockout ( LFKO −/− ) mouse model compared with C576J/ BL wild‐type ( WT ) mice. Materials and Methods The WT and LFKO −/− mice were infected with S. mutans (1 × 10 8  cells) and/or sham infection. Furthermore, the effect of hLF administration was evaluated in LFKO −/− mice infected with S. mutans . Mice were assessed for colonization, salivary pH , and caries development. Results The results showed that the lactoferrin‐knockout infected ( LFKO −/− I) mice had significantly higher colonization with S. mutans ( P  = 0.02), lower salivary pH ( P  = 0.01), and more carious lesions ( P  = 0.01) when compared to wild‐type infected ( WTI ) mice. In addition, the administration of hLF did not show any evidence of S. mutans colonization as well as carious lesions ( P  = 0.001) in LFKO −/− I mice when compared to untreated LFKO −/− I mice. Conclusion These results show that endogenous LF protects against S. mutans ‐induced caries and that exogenous hLF can exert a protective effect against caries development.