IADR Abstract Archives
Cariogenic Biofilm Interventions Using Probiotic Lactic Acid Bacteria and Fluoride
Objectives: The use of probiotics for treatment of oral-dysbiosis associated dental caries is the focus of several clinical trials with mixed results. Multiple studies report reduction in cariogenicity through direct or indirect assessment. Controversially, many probiotics trialled are lactic acid bacteria, and raise concerns that acid production by the probiotic may negate beneficial impact on oral biofilm properties. This study investigates biofilm quantity and pH balance of saliva-derived (SD) mixed species microbial biofilms amended with lactic acid bacteria and fluoride.
Methods: SD microbial biofilms were cultured over 48 hours in microtiter plates, using combined participant/artificial saliva supplemented with 2% sucrose. Treatments included fluoride at 0 and 10µg/ml and the following inocula: 1) SD consortia only (n=10); 2) SD consortia with Lactobacillus rhamnosus LB21 (n=4); 3) SD consortia with Limosilactocbacillus reuteri DSM17938 (n=4); 4) SD consortia with Lactococcus lactis BerridgeX13 (n=4). Biofilm quantity was measured using crystal violet assay. Planktonic cells were aspirated and artificial saliva medium refreshed before an additional 24-hour culture period, spent media was measured using pH microprobe.
Results: Co-culture of SD consortia with Lactobacillus rhamnosus (2.35 ± 0.29) or Lactobacillus reuteri (2.545±0.13) increased biofilm quantity, as compared to SD consortia alone (2.110±0.59). Presence of Lactococcus lactis had little impact on biofilm quantity (2.186±0.85). Elevated pH was evident when SD consortia was co-cultured with Lactobacillus rhamnosus (4.22±0.25); Limosilactocbacillus reuteri had no effect on pH (4.06±0.16); and Lactococcus lactis led to reduced pH (3.79±0.02), in comparison to SD consortia alone (3.97±0.17). There was a trend of increased pH when SD consortia cultured in presence of fluoride regardless of addition of probiotic.
Conclusions: Lactic acid producing probiotic strains increased the quantity of oral biofilm and modulated pH of biofilms with specific effects contingent upon species/strains applied. Addition of 10ppm fluoride led to pH increase regardless of the addition of probiotic.
Methods: SD microbial biofilms were cultured over 48 hours in microtiter plates, using combined participant/artificial saliva supplemented with 2% sucrose. Treatments included fluoride at 0 and 10µg/ml and the following inocula: 1) SD consortia only (n=10); 2) SD consortia with Lactobacillus rhamnosus LB21 (n=4); 3) SD consortia with Limosilactocbacillus reuteri DSM17938 (n=4); 4) SD consortia with Lactococcus lactis BerridgeX13 (n=4). Biofilm quantity was measured using crystal violet assay. Planktonic cells were aspirated and artificial saliva medium refreshed before an additional 24-hour culture period, spent media was measured using pH microprobe.
Results: Co-culture of SD consortia with Lactobacillus rhamnosus (2.35 ± 0.29) or Lactobacillus reuteri (2.545±0.13) increased biofilm quantity, as compared to SD consortia alone (2.110±0.59). Presence of Lactococcus lactis had little impact on biofilm quantity (2.186±0.85). Elevated pH was evident when SD consortia was co-cultured with Lactobacillus rhamnosus (4.22±0.25); Limosilactocbacillus reuteri had no effect on pH (4.06±0.16); and Lactococcus lactis led to reduced pH (3.79±0.02), in comparison to SD consortia alone (3.97±0.17). There was a trend of increased pH when SD consortia cultured in presence of fluoride regardless of addition of probiotic.
Conclusions: Lactic acid producing probiotic strains increased the quantity of oral biofilm and modulated pH of biofilms with specific effects contingent upon species/strains applied. Addition of 10ppm fluoride led to pH increase regardless of the addition of probiotic.