Effects of Human Milk on Adhesion of <i>Streptococcus mutans </i>to Saliva-Coated Hydroxyapatite in vitro

Abstract

Adhesion of bacteria to pellicle-coated tooth surfaces is the first step in biofilm formation on teeth. The aim of this study was to explore whether human milk prevents or promotes adhesion of cariogenic <i>Streptococcus mutans </i>to saliva-coated hydroxyapatite (HA) using an in vitromodel system. <i>S. mutans</i> binding to HA coated with human parotid saliva (s-HA) or human milk was studied, in addition to binding inhibition to s-HA by human milk. <i>S. mutans </i>did not bind to HA coated with milk. <i>S. mutans </i>binding to s-HA was inhibited by milk from 15 (71 %) of 21 women, whereas milk from the remaining 6 mothers enhanced binding of <i>S. mutans</i> to s-HA. Inhibition of <i>S. mutans</i> binding correlated with bacterial binding to s-HA (r = 0.76). Human milk does not mediate adhesion of <i>S. mutans</i> to HA in vitro<i>,</i> but affects adhesion in an individually varying fashion. Phenotypic variations in milk and saliva glycosylation may explain the inhibitory capacity and possibly affect susceptibility to colonization by <i>S. mutans</i> in childhood.