Abstract

It has been suggested that the ingestion of probiotic lactobacilli supplements could decrease levels of mutans streptococci. Previous studies have found that oral colonization of probiotic lactobacilli occurs only transiently with use, although it has been hypothesized that, if the probiotics are introduced earlier in life, rather than when the microbiota is established, it may prevent or delay mutans streptococci colonization. The aim of this investigation was to determine the long-term effects of a cereal supplemented with Lactobacillus paracasei F19 (LF19) given to infants during weaning on caries experience when the children were 3, 6 and 9-years-old. This study was a nine-year follow-up to a double-blind randomized controlled trial carried out in Sweden from 2000 to 2003. In the original trial, participants (n=179) were randomized to have a daily intake of cereal from 4 to 13-months-old, which in the intervention group was supplemented with LF19. In total, 56 children from the probiotic group and 62 children from the placebo group participated in the follow-up study. Caries diagnosis at 9-years-old was based on a clinical and radiographic assessment, although at 3 and 6-years-old caries experience was determined retrospectively from public health dental records. The study population had an overall low caries incidence. The key findings were that there was no statistically significant difference (p>0.05) in caries experience at 3, 6 or 9-years-old between the probiotic and the control group. Additionally, there were no differences in the levels of mutans streptococci or lactobacilli between the two groups, and LF19 could not be detected in the saliva of participants, suggesting that colonization is not permanent.