Effect of Lactoferrin on Oral Biofilm Formation

Lactoferrin Lf, an iron-binding salivary glycoprotein, plays an important role in human innate defense against local mucosal infection. We hypothesized that Lf interferes with initial oral bacterial attachment to surfaces by iron sequestration, so inhibiting subsequent biofilm formation. The objective was to investigate the effect of Lf on the early stages of single-species and multispecies oral biofilm development. Streptococcus gordonii Sg, Streptococcus mutans, Fusobacterium nucleatum Fn and Porphyromonas gingivalis Pg were used in this study. Glass disks of a two-track flow cell coated with flowing artificial saliva with and without Lf were used for studying bacterial attachment 3 h, 37C. The effects of Beta-lactoglobulin, 2,2-dipyridyl, an iron chelator, and FeCl3 on attachment were also examined. Results Lf inhibited the initial attachment of Sg 50.3, P 0.05 but not that of Fn and Pg. The attachment of biofilm containing SgFn or SgPg was significantly reduced by 48.7 and 62.1, P 0.05 in the presence of Lf. Beta-Lactoglobulin did not affect the attachment of Sg. 2,2-dipyridyl reduced attachment of Sg by 53.87. No reduction in attachment was noted in Sg pretreated with Lf 100 microgrammegaliter and FeCl3 20-200 micrometer. In conclusion, Lf suppresses initial attachment of Sg and Sg coaggregates by iron sequestration, which may lead to subsequent inhibition of oral biofilm development.