Influence of sucrose and xylitol on an early Streptococcus mutans biofilm in a dental simulator.
OBJECTIVE
In vitro methods to study dental biofilms are useful in finding ways to support a healthy microbial balance in the oral cavity. The effects of sucrose, xylitol, and their combination on three strains of Streptococcus mutans and one strain of Streptococcus sobrinus were studied using a dental simulator.


METHODS
A simulator was used to mimic the oral cavity environment. It provided a continuous-flow system using artificial saliva (AS), constant temperature, mixing, and hydroxyapatite (HA) surface in which the influence of xylitol was studied. The quantities of planktonic and adhered bacteria were measured by real-time qPCR.


RESULTS
Compared against the untreated AS, adding 1% sucrose increased the bacterial colonization of HA (p<0.0001) whereas 2% xylitol decreased it (p<0.05), with the exception of clinical S. mutans isolate 117. The combination of xylitol and sucrose decreased the bacterial quantities within the AS and the colonization on the HA by clinical S. mutans isolate 2366 was reduced (p<0.05). Increasing the concentration (2%-5%) of xylitol caused a reduction in bacterial counts even in the presence of sucrose.


CONCLUSIONS
The continuous-culture biofilm model showed that within a young biofilm, sucrose significantly promotes whereas xylitol reduces bacterial colonization and proliferation. The results indicate that xylitol affects the ability of certain S. mutans strains to adhere to the HA. Clinical studies have also shown that xylitol consumption decreases caries incidence and reduces the amount of plaque. This study contributes to the understanding of the mechanism behind these clinical observations.
DuPont Nutrition and Health, Global Health and Nutrition Science, Danisco Sweeteners Oy, 02460 Kantvik, Finland. Electronic address: krista.salli@dupont.com.
K M
KM
Salli
DuPont Nutrition and Health, Global Health and Nutrition Science, Danisco Sweeteners Oy, 02460 Kantvik, Finland. Electronic address: sofia.forssten@dupont.com.
S D
SD
Forssten
DuPont Nutrition and Health, Global Health and Nutrition Science, Danisco Sweeteners Oy, 02460 Kantvik, Finland. Electronic address: sampo.lahtinen@dupont.com.
S J
SJ
Lahtinen
DuPont Nutrition and Health, Global Health and Nutrition Science, Danisco Sweeteners Oy, 02460 Kantvik, Finland. Electronic address: arthur.ouwehand@dupont.com.
A C
AC
Ouwehand
D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D003731:Dental Caries / Q000382:microbiology; D003773:Dental Plaque; D050296:Microbial Viability / Q000187:drug effects; D009055:Mouth / Q000382:microbiology; D060888:Real-Time Polymerase Chain Reaction; D012464:Saliva, Artificial / Q000737:chemistry; D013295:Streptococcus mutans / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D016986:Streptococcus sobrinus / Q000187:drug effects / Q000235:genetics; D013395:Sucrose / Q000494:pharmacology*; D013499:Surface Properties; D013549:Sweetening Agents / Q000494:pharmacology; D014993:Xylitol / Q000494:pharmacology*
D012464:Saliva, Artificial; D013549:Sweetening Agents; D013395:Sucrose; D014993:Xylitol
Artificial saliva; Biofilm model; Mutans streptococci; Xylitol; in vitro