Salivary mutans streptococci levels after supplementation with Lactobacillus reuteri
A prospective, randomised, placebo-controlled study with the aim to investigate the effect on mutans streptococci and lactobacilli of a probiotic delivered by two non-dairy delivery systems.
The study included 120 young adults (21-24 years) with overall good health, including the oral cavity status. The study used parallel arms where the subjects were randomly assigned to four equally sized groups (n=30): group A drank 200 ml of water through a prepared straw containing Lactobacillus reuteri once daily for 3 weeks, while group B took 200 ml of water through a placebo straw during the same period. Group C was given one tablet containing the same probiotic once daily for 3 weeks, while group D received placebo tablets without bacteria. Salivary mutans streptococci and lactobacilli were enumerated with chair-side kits at baseline and 1 day after the final ingestion.
A statistically significant reduction of the mutans streptococci levels was recorded after ingestion of the probiotic bacteria via the straw and the tablet, compared to the placebo controls. A similar but non-significant trend was seen for lactobacilli.
Conclusion: A short-term daily ingestion of Lactobacillus reuteri delivered by drinking straw or tablets reduced the levels of salivary mutans streptococci in young adults.