Interactions between Lactobacillus rhamnosus GG and oral micro-organisms in an in vitro biofilm model. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Jiang, Qingru; Stamatova, Iva; Kainulainen, Veera; Korpela, Riitta; Meurman, Jukka
• Is Part Of: BMC microbiology. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 11
• Publication Date: 2016-12
• Subjects: Probiotics -- Biofilm -- Oral pathogen -- Oral health; Microbiology -- Periodicals; 579.05
• DOI: 10.1186/s12866-016-0759-7
• Languages: English
• ISSNs: 1471-2180

Abstract

Abstract Background Probiotics have shown favourable properties in maintaining oral health. By interacting with oral microbial communities, these species could contribute to healthier microbial equilibrium. This study aimed to investigate in vitro the ability of probioticLactobacillus rhamnosus GG (L.GG) to integrate in oral biofilm and affect its species composition. Five oral strains, Streptococcus mutans, Streptococcus sanguinis, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum andCandida albicans were involved. The group setup included 6 mono-species groups, 3 dual-species groups (L.GG + S. mutans /S. sanguinis /C. albicans ), and 4 multi-species groups (4/5 species and 4/5 species + L.GG, 4 species were all the tested strains exceptS. mutans ). Cell suspensions of six strains were pooled according to the group setup. Biofilms were grown on saliva-coated hydroxyapatite (HA) discs at 37 °C in anaerobic conditions for 64.5 h. Biofilm medium was added and refreshed at 0, 16.5, and 40.5 h. The pH of spent media was measured. Viable cells of the 16.5 h and 64.5 h biofilms were counted. 64.5 h biofilms were stained and scanned with confocal laser scanning microscopy. Results Our results showed that L.GG andS. mutans demonstrated stronger adhesion ability than the other strains to saliva-coated HA discs. L.GG, C. albicans, S. mutans andF. nucleatum, with poor ability to grow in mono-species biofilms demonstrated better abilities of adhesion and reproduction in dual- and/or multi-species biofilms. L.GG slightly suppressed the growth ofC. albicans in all groups, markedly weakened the growth ofS. sanguinis andF. nucleatum in 4sp + L.GG group, and slightly reduced the adhesion ofS. mutans in L.GG+S. mutans group. Conclusions To conclude, in this in vitro model L.GG successfully integrated in all oral biofilms, and reduced the counts ofS. sanguinis andC. albicans and lowered the biofilm-forming ability ofF. nucleatum, but only slightly reduced the adhesion ofS. mutans. C. albicans significantly promoted the growth of L.GG.