Investigation of the role of human breast milk in caries development

The objective of this study was to determine the caries-related risk associated with human breast milk (HBM).

First, the plaque pH of 18 children (12-24 months) was monitored before and after a five-minute feeding with HBM to determine the pH drop and minimum pH obtained. Second, Streptococcus sobrinus 6715 was cultured for 3 hr in HBM, and the increase in the number of colony forming units (cfus) and the culture pH was measured. Third, HBM was incubated for 24 hr with powdered enamel to determine the solubility of mineral in the absence of bacteria. Fourth, HBM was mixed with acid to determine the buffering capabilities. Finally, enamel windows were created on extracted premolar crowns (N = 33) that were colonized with Mutans Streptococci and incubated with HBM. Caries was assessed visually and radiographically for 12 weeks.

One- and two-way ANOVAs of these five assays demonstrated that HBM did not cause a significant drop in plaque pH when compared to rinsing with water; HBM supported moderate bacterial growth; calcium and phosphate were actually deposited onto enamel powder after incubation with HBM; the buffer capacity of HBM was very poor; and HBM alone did not cause enamel decalcification even after 12 weeks exposure. However, when supplemented with 10% sucrose, HBM caused dentinal caries in 3.2 weeks.

It is concluded that human breast milk is not cariogenic.