The caries-preventive effects of arginine have been attributed to its impact on biofilm composition and pH.Recent in vitro studies suggest that arginine also affects the production of biofilm matrix components that co...The caries-preventive effects of arginine have been attributed to its impact on biofilm composition and pH.Recent in vitro studies suggest that arginine also affects the production of biofilm matrix components that contribute to virulence,but this mechanism has not been investigated clinically.This randomized,placebo-controlled,triple-blind,split-mouth in situ trial assessed arginine's impact on the microbial composition,matrix architecture,and microscale pH of biofilms from caries-active patients(N=10).We also examined whether individual differences in the pH response to arginine were related to biofilm composition and matrix structure.Biofilms were grown for four days on carriers attached to intraoral splints.Three times daily,the biofilms were treated extraorally with sucrose(5 min),followed by arginine or placebo(30 min),in a split-mouth design.After growth,the microscale biofilm p H response to sucrose was monitored by pH ratiometry.Microbial biofilm composition and carbohydrate matrix architecture were analyzed by 16S rRNA gene sequencing and fluorescence lectin-binding analysis,respectively.Arginine treatment significantly mitigated sucrose-induced pH drops,reduced total carbohydrate matrix production,and altered the spatial distribution of fucoseand galactose-containing carbohydrates.Both arginine-and placebo-treated biofilms were dominated by streptococci and Veillonella spp.Paired analyses showed a significant reduction in mitis/oralis group streptococci and a non-significant increase in several arginine metabolizers in arginine-treated biofilms.Individual pH responses were not significantly associated with the abundance of specific bacterial taxa or carbohydrate matrix components.In conclusion,arginine reduced the virulence of biofilms from caries-active patients through multiple mechanisms,including suppressing matrix carbohydrate production.展开更多
Objective: To compare oral hygiene practices, education and social background, food intake and oral malodor of Algerian adults suffering from dental caries with normal controls, and to determine and compare the bacter...Objective: To compare oral hygiene practices, education and social background, food intake and oral malodor of Algerian adults suffering from dental caries with normal controls, and to determine and compare the bacterial composition of the supragingival plaques from the above-mentioned groups.Methods: Participants completed a questionnaire and were clinically examined for dental caries using decayed, missing and filled teeth index according to the criteria laid down by the World Health Organization. Supragingival plaque samples were collected from 50 caries-free adults(CF) and 50 caries-active adults(CA). Standard procedures of culture and identification of aerobic and anaerobic bacteria were used. Data were analyzed using Chi-square test.Results: A total of 117 bacterial strains were isolated from supragingival plaques in CF group subjects, 76(64.96%) of them belonged to 9 aerobic genera, and 41(35.04%) to 9anaerobic genera(P < 0.05). While in the second group, 199 strains were isolated, 119(59.80%) of the strains belonged to 10 aerobic genera and 80(40.20%) to 10 anaerobic bacteria(P < 0.05). Streptococcus mutans, Enterococcus faecium, Aerococcus viridans,Actinomyces meyeri, Lactobacillus acidophilus and Eubacterium limosum showed a significantly higher prevalence in the CA group(P < 0.05). The findings revealed that CA group had a high sugar intake(80%). A significantly higher frequency of tooth brushing(P < 0.000) and a significantly less self-reported oral malodor(P < 0.000) and tooth pain(P < 0.000) were found in CF group, while there was no association of socioeconomic levels and intake of meal snacks with dental caries.Conclusions: This study confirms the association of some aciduric bacteria with caries formation, and a direct association of sugar intake and cultural level with dental caries.Furthermore, oral hygiene practices minimize the prevalence of tooth decay.展开更多
基金supported by the Faculty of Health,Aarhus University,Denmark。
文摘The caries-preventive effects of arginine have been attributed to its impact on biofilm composition and pH.Recent in vitro studies suggest that arginine also affects the production of biofilm matrix components that contribute to virulence,but this mechanism has not been investigated clinically.This randomized,placebo-controlled,triple-blind,split-mouth in situ trial assessed arginine's impact on the microbial composition,matrix architecture,and microscale pH of biofilms from caries-active patients(N=10).We also examined whether individual differences in the pH response to arginine were related to biofilm composition and matrix structure.Biofilms were grown for four days on carriers attached to intraoral splints.Three times daily,the biofilms were treated extraorally with sucrose(5 min),followed by arginine or placebo(30 min),in a split-mouth design.After growth,the microscale biofilm p H response to sucrose was monitored by pH ratiometry.Microbial biofilm composition and carbohydrate matrix architecture were analyzed by 16S rRNA gene sequencing and fluorescence lectin-binding analysis,respectively.Arginine treatment significantly mitigated sucrose-induced pH drops,reduced total carbohydrate matrix production,and altered the spatial distribution of fucoseand galactose-containing carbohydrates.Both arginine-and placebo-treated biofilms were dominated by streptococci and Veillonella spp.Paired analyses showed a significant reduction in mitis/oralis group streptococci and a non-significant increase in several arginine metabolizers in arginine-treated biofilms.Individual pH responses were not significantly associated with the abundance of specific bacterial taxa or carbohydrate matrix components.In conclusion,arginine reduced the virulence of biofilms from caries-active patients through multiple mechanisms,including suppressing matrix carbohydrate production.
基金Supported by the National Committee of Research Program and Assessment(Cnepru-code I02020130110)
文摘Objective: To compare oral hygiene practices, education and social background, food intake and oral malodor of Algerian adults suffering from dental caries with normal controls, and to determine and compare the bacterial composition of the supragingival plaques from the above-mentioned groups.Methods: Participants completed a questionnaire and were clinically examined for dental caries using decayed, missing and filled teeth index according to the criteria laid down by the World Health Organization. Supragingival plaque samples were collected from 50 caries-free adults(CF) and 50 caries-active adults(CA). Standard procedures of culture and identification of aerobic and anaerobic bacteria were used. Data were analyzed using Chi-square test.Results: A total of 117 bacterial strains were isolated from supragingival plaques in CF group subjects, 76(64.96%) of them belonged to 9 aerobic genera, and 41(35.04%) to 9anaerobic genera(P < 0.05). While in the second group, 199 strains were isolated, 119(59.80%) of the strains belonged to 10 aerobic genera and 80(40.20%) to 10 anaerobic bacteria(P < 0.05). Streptococcus mutans, Enterococcus faecium, Aerococcus viridans,Actinomyces meyeri, Lactobacillus acidophilus and Eubacterium limosum showed a significantly higher prevalence in the CA group(P < 0.05). The findings revealed that CA group had a high sugar intake(80%). A significantly higher frequency of tooth brushing(P < 0.000) and a significantly less self-reported oral malodor(P < 0.000) and tooth pain(P < 0.000) were found in CF group, while there was no association of socioeconomic levels and intake of meal snacks with dental caries.Conclusions: This study confirms the association of some aciduric bacteria with caries formation, and a direct association of sugar intake and cultural level with dental caries.Furthermore, oral hygiene practices minimize the prevalence of tooth decay.
