The oral microbiome in oral lichen planus during a 1-year randomized clinical trial.

BACKGROUND: Several recent studies have investigated the oral bacteriome in oral lichen planus (OLP), but longitudinal changes in microbiome have not been investigated. OBJECTIVE: To study the bacteriome and mycobiome in OLP over a 1-year period and the impact of topical treatment. MATERIAL AND METHODS: Samples from 22 symptomatic OLP patients from a double-blinded, randomized intervention study were collected over a 1-year course at five visits. Bacterial and fungal abundances were investigated through lesional cytobrush (CB) and full mouthwash (MW). Initially, all patients received conventional (antimycotic or steroid) and probiotic or placebo treatment. RESULTS: The microbial composition differed between the MW and CB samples. During the study period, the microbial composition was individual, with pronounced variability between visits. Patients grouped according to initial conventional treatment. During the study period, unidirectional change in the bacteriome was seen in the antimycotic group, whereas the mycobiome was stable. Malassezia restricta was the most abundant fungus. CONCLUSIONS: The microbial composition of MW and CB differs in OLP. CB composition is less influenced by conventional and probiotic intervention. Initial antimycotic treatment influenced the bacteriome during the 1-year period. How the oral microbiome in health and disease is influenced by individual variability of fungi and bacteria, and Malassezia needs further investigation.

Prevention of caries with probiotic bacteria during early childhood. Promising but inconsistent findings.

PURPOSE: This review summarized the available literature on the prevention of childhood caries through biofilm engineering with probiotic bacteria in early childhood. METHODS: Three databases (PubMed, Cochrane Library and Trip) were searched through January, 2016 for randomized controlled trials published in English. Out of 144 abstracts, seven studies fulfilled the predetermined inclusion criteria and were quality assessed with respect to risk of bias independently by two examiners. Due to the paucity and heterogeneity, a narrative synthesis was performed. The effect size was estimated from the caries prevalence and expressed as prevented fraction and number needed to treat. RESULTS: Probiotic supplements were better than placebo in preventing early childhood caries in all seven studies although the difference was statistically significant in only four of them. The prevented fraction ranged from 11% to 61% with a median of 48%. However, the quality of the evidence was low or very low and further translational research is needed to investigate this preventive approach in the clinic.

Lactobacillus reuteri supplements do not affect salivary IgA or cytokine levels in healthy subjects: A randomized, double-blind, placebo-controlled, cross-over trial.

OBJECTIVES: To evaluate the effect of daily ingestion of probiotic lactobacilli on the levels of secretory IgA (sIgA) and selected cytokines in whole saliva of healthy young adults. MATERIALS AND METHODS: The study group consisted of 47 healthy adults (18-32 years) who volunteered for a randomized, double-blind, placebo-controlled, cross-over trial after informed consent. During intervention, the subjects ingested two lozenges per day containing two strains of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) or placebo lozenges. The intervention and wash-out periods were 3 weeks. Saliva samples were collected at baseline, immediately after each intervention period and 3 weeks post-intervention. ELISA was used to measure sIgA and luminex technology was used to measure the interleukins (IL)-1ß, IL-6, IL-8 and IL-10. For statistical analyses a mixed ANOVA model was employed to calculate changes in the salivary outcome variables. RESULTS: Forty-one subjects completed the study and reported a good compliance. No significant differences in the concentrations of salivary sIgA or cytokines were recorded between the L. reuteri and placebo interventions or between baseline and 3 weeks post-intervention levels. No side- or adverse effects were reported. CONCLUSIONS: Supplementation with two strains of the probiotic L. reuteri did not affect sIgA or cytokine levels in whole saliva in healthy young adults. The results thereby indicate that daily oral supplementation with L. reuteri do not seem to modulate the salivary oral immune response in healthy young subjects (ClinicalTrials.gov NCT02017886).

The effect of a lozenge combining prebiotic arginine and probiotics on caries increment in children during 10-12 months, a randomized clinical trial.

OBJECTIVES: To investigate the effect of daily use of a lozenge containing arginine and probiotics for 10-12 months on caries increment, gingivitis- and plaque occurrence in children aged 5-9 years. METHODS: In this placebo-controlled, double-blinded, parallel-grouped randomized clinical trial, 343 children were randomly assigned to one of the study arms (1:1). The intervention group (n = 172) received a lozenge containing Lacticaseibacillus rhamnosus, LGG® (DSM33156), Lactobacillus paracasei subsp. paracasei, L. CASEI 431® (DSM33451) and prebiotic (arginine 2%). The placebo group (n = 171) received an identical lozenge without arginine or probiotics. Primary canines and molars, and permanent first molars were examined clinically (d/D= ICDAS1-6) and radiographically (d/D = R1-6) at baseline and follow-up. Missing (m/M), sealed (s/S), and filled (f/F) surfaces (-s/-S) in both dentitions were also included. Utilizing clinical and radiographic scorings, caries experience was classified as dICDAS1-6msf-s (primary teeth), DICDAS1-6MSF-S (permanent teeth), d/DICDAS1-6 m/M-s/S-f/F-s/S (mixed dentition). A weighted and an unweighted score system was applied. RESULTS: The study was completed by 288 children. The dropout rate was 15%. The increase in ∆mean dICDAS3-6msf-s and ∆mean d/DICDAS3-6m/M-s/S-f/F-s/S was lower in the intervention group (p = 0.007). No differences were found for gingivitis- and plaque occurrence. No product-related side effects were reported. This study followed ICH-GCP including external monitoring. CONCLUSION: Daily consumption of a lozenge containing prebiotic arginine and two strains of probiotics showed safe use and statistically significantly reduction in caries incrementbut no effect on the mean plaque or gingivitis occurrence in children. The use of a lozenge with arginine and probiotics combined has a promising potential as a supplementary tool for future management of caries. www. CLINICALTRIALS: gov (NCT03928587). CLINICAL SIGNIFICANCE: The combination of prebiotic arginine and probiotics shows clinical potential as a supplementary approach to toothbrushing with fluoride toothpaste in managing caries increment in children. A new era in the management of caries may be emerging.

Co-aggregation and growth inhibition of probiotic lactobacilli and clinical isolates of mutans streptococci: an in vitro study.

OBJECTIVE: Co-aggregation and growth inhibition abilities of probiotic bacteria may play a key role in their interference with the oral biofilm. The aim was to investigate the in vitro ability of selected commercial probiotic lactobacilli to co-aggregate and inhibit growth of oral mutans steptococci isolated from adults with contrasting levels of caries. MATERIALS AND METHODS: Mutans streptococci (MS) strains were isolated from caries-free (n = 3) and caries-susceptible (n = 5) young adults and processed with eight commercial probiotic lactobacilli strains. One laboratory reference strain (S. mutans Ingbritt) was selected as control. Co-aggregation was determined spectrophotometrically and growth inhibition was assessed with the agar overlay technique. RESULTS: All probiotic lactobacilli showed an ability to co-aggregate with the isolated MS strains. Statistically significant differences (p < 0.05) were found between strains from different individuals when compared with the reference strain. The selected lactobacilli inhibited MS growth, but the ability varied between the strains and was clearly related to pH. No differences were observed between the different MS strains from caries-free and caries-susceptible individuals. CONCLUSIONS: The selected lactobacilli displayed co-aggregation activity and inhibited growth of clinical mutans streptococci. The growth inhibition was strain-specific and dependent on pH and cell concentration. The findings indicate that the outcome of lactobacilli-derived probiotic therapy might vary between individuals and depend on the specific strain used.

Probiotic Lactobacillus reuteri has antifungal effects on oral Candida species in vitro.

Background: An alternative approach for managing Candida infections in the oral cavity by modulating the oral microbiota with probiotic bacteria has been proposed. Objective: The aim was to investigate the antifungal potential of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) against six oral Candida species (C. albicans, C. glabrata, C. krusei, C. tropicalis, C. dubliniensis, and C. parapsilosis). Design: The lactobacilli were tested for their ability to co-aggregate with and inhibit the growth of the yeasts assessed by spectrophotometry and the agar overlay inhibition assay. Additionally, the pH was evaluated with microsensors, and the production of hydrogen peroxide (H2O2) by the lactobacilli was verified. Results: Both L. reuteri strains showed co-aggregation abilities with the yeasts. The lactobacilli almost completely inhibited the growth of C. albicans and C. parapsilosis, but did not affect C. krusei. Statistically significant differences in co-aggregation and growth inhibition capacities between the two L. reuteri strains were observed (p<0.001). The pH measurements suggested that C. krusei can resist the acids produced by the lactobacilli. Conclusions:L. reuteri exhibited antifungal properties against five of the six most common oral Candida species. Further, the results reconfirms that the probiotic capacity of L. reuteri is strain specific.

Detection of non-cavitated occlusal caries with impedance spectroscopy and laser fluorescence: an in vitro study.

OBJECTIVE: To evaluate the performance of an impedance spectroscopy technology for detecting non-cavitated occlusal caries lesions in permanent teeth in vitro. The method was compared with a commonly used laser fluorescence device and validated against histology. MATERIAL AND METHODOLOGY: A non-cavitated sample of 100 extracted posterior teeth was randomly selected and assessed for caries on enamel and dentin level with aid of CarioScan PRO (ACIS) and DIAGNOdent pen (LF pen) by three examiners. After the measurements, the extension of the lesion was histologically determined as gold standard. Sensitivity, specificity, accuracy and receiver-operating curves were calculated. Intra- and inter-examiner reproducibility was expressed by intra class correlation coefficients. RESULTS: The histological caries prevalence was 99% and 41% exhibited dentin caries. The ACIS technique displayed high specificities but almost negligible sensitivities at readings >50. A similar pattern was noted for the LF pen at readings >30. The intra- and inter-examiner reproducibility varied between 0.47 and 0.98 and the values were generally lower for the ACIS technique than for the LF pen. The inter-examiner agreement reached excellent levels with both methods. CONCLUSIONS: In vitro,the ACIS technique showed a low ability to disclose occlusal caries lesions in the enamel and/or dentin of non-cavitated permanent molars. However, further in vivo studies of permanent occlusal surfaces are needed to mirror the clinical situation.