Administration of Bifidobacterium animalis subsp. lactis BB-12 in early childhood: a post-trial effect on caries occurrence at four years of age

Probiotic bifidobacteria are widely used in the prevention of childhood diseases. These bacteria are also associated with caries occurrence. The present secondary analysis in a low-caries population evaluated the effect of early administration of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on caries occurrence and identified markers of dental decay in early childhood. In the original randomized, double-blind, placebo-controlled study (NCT00638677, http://www.clinicaltrials.gov), infants (n = 106) received BB-12, xylitol or sorbitol tablets from the age of 1-2 months to 2 years with a slow-release pacifier or a spoon (daily dose of BB-12 10(10) colony-forming units, polyol 200-600 mg). The present data were collected using clinical examinations and questionnaires at the age of 4 years. The occurrence of dental caries was assessed using the International Caries Detection and Assessment System. Oral hygiene status and mutans streptococci (MS) levels were also determined. No differences were detected between the study groups in the occurrence of enamel caries (p = 0.268) or obvious dentinal caries (p = 0.201). The occurrence of caries was associated with daily consumption of sweet drinks (p = 0.028), visible plaque observed (p = 0.002) and MS detected in the dental plaque (p = 0.002). Administration of BB-12 in infancy does not seem to increase or decrease the occurrence of caries by 4 years of age in a low-caries population.