The role of probiotic bacteria in managing periodontal disease: a systematic review

Dental plaque forms naturally on teeth and is of benefit to the host by helping to prevent colonization by exogenous species. The bacterial composition of plaque remains relatively stable despite regular exposure to minor environmental perturbations. This stability (microbial homeostasis) is due in part to a dynamic balance of both synergistic and antagonistic microbial interactions. However, homeostasis can break down, leading to shifts in the balance of the microflora, thereby predisposing sites to disease. For example, the frequent exposure of plaque to low pH leads to inhibition of acid-sensitive species and the selection of organisms with an aciduric physiology, such as mutans streptococci and lactobacilli. Similarly, plaque accumulation around the gingival margin leads to an inflammatory host response and an increased flow of gingival crevicular fluid. The subgingival microflora shifts from being mainly Gram-positive to being comprised of increased levels of obligately anaerobic, asaccharolytic Gram-negative organisms. It is proposed that disease can be prevented or treated not only by targeting the putative pathogens but also by interfering with the processes that drive the breakdown in homeostasis. Thus, the rate of acid production following sugar intake could be reduced by fluoride, alternative sweeteners, and low concentrations of antimicrobial agents, while oxygenating or redox agents could raise the Eh of periodontal pockets and prevent the growth and metabolism of obligately anaerobic species. These views have been incorporated into a modified hypothesis (the "ecological plaque hypothesis") to explain the relationship between the plaque microflora and the host in health and disease, and to identify new strategies for disease prevention.

Teughels W, Durukan A, Ozcelik O, Pauwels M, Quirynen M, Haytac MC. Clinical and microbiological effects of Lactobacillus reuteri probiotics in the treatment of chronic periodontitis: a randomized placebo-controlled study. J Clin Periodontol 2013; 40: 1025–1035. doi: 10.1111/jcpe.12155. AimThe aim of this randomized placebo-controlled clinical trial was to evaluate the effects of Lactobacillus reuteri-containing probiotic lozenges as an adjunct to scaling and root planing (SRP). Material and MethodsThirty chronic periodontitis patients were recruited and monitored clinically and microbiologically at baseline, 3, 6, 9 and 12 weeks after therapy. All patients received one-stage full-mouth disinfection and randomly assigned over a test (SRP + probiotic, n = 15) or control (SRP + placebo, n = 15) group. The lozenges were used two times a day for 12 weeks. ResultsAt week 12, all clinical parameters were significantly reduced in both groups, while there was significantly more pocket depth reduction (p < 0.05) and attachment gain (p < 0.05) in moderate and deep pockets; more Porphyromonas gingivalis reduction was observed in the SRP + probiotic group. ConclusionsThe results indicate that oral administration of L. reuteri lozenges could be a useful adjunct to SRP in chronic periodontitis.