Effect of long-term consumption of milk supplemented with probiotic lactobacilli and fluoride on dental caries and general health in preschool children: a cluster-randomized study

Strategies and mechanisms targeting Enterococcus faecalis biofilms associated with endodontic infections: a comprehensive review

Enterococcus faecalis is one of the main microorganisms that infects root canals, ranking among the most prevalent microorganisms associated with endodontic treatment failure. Given its pervasive presence in persistent endodontic infections, the successful elimination of Enterococcus faecalis is crucial for effective endodontic treatment and retreatment. Furthermore, Enterococcus faecalis can form biofilms - defense structures that microbes use to fight environmental threats. These biofilms confer resistance against host immune system attacks and antibiotic interventions. Consequently, the presence of biofilms poses a significant challenge in the complete eradication of Enterococcus faecalis and its associated disease. In response, numerous scholars have discovered promising outcomes in addressing Enterococcus faecalis biofilms within root canals and undertaken endeavors to explore more efficacious approaches in combating these biofilms. This study provides a comprehensive review of strategies and mechanisms for the removal of Enterococcus faecalis biofilms.

Probiotics-containing beverages and dental caries: A systematic review and meta-analysis

The aim was to evaluate the effect of probiotics-containing beverages on dental caries development by a systematic review and meta-analysis (PROSPERO CRD42021258010). PubMed, Embase, and Web of Science databases were assessed (up to October 2023) for randomized placebo-controlled trials that evaluated the consumption of probiotics-containing beverages having dental caries as endpoint. Risk of bias assessment (Cochrane Handbook) was performed for all studies. Risk ratio (RR), standardized mean difference (SMD) and 95% confidence interval (CI), were calculated for caries prevalence and caries increment, respectively. Meta-analysis was performed. Qualitative analysis of more than 2000 individuals aged from 1 to 84 years (9 studies) showed inconsistent effects of these probiotics-containing beverages. Synthesis of more than 1000 children and adolescents did not demonstrate a statistically significant difference in the proportion of individuals with cavitated lesions (RR 0.60 [95 % CI 0.34 to 1.08]; n = 2), but a significantly smaller increment of both cavitated and non-cavitated carious lesions (SMD -0.23 [95 % CI -0.39 to -0.08]; n = 4) was related to the consumption of probiotics-containing beverages. Certainty of evidence for caries prevalence and caries increment were moderate and low, respectively. Current evidence is not substantial to strengthen the impact of these beverages on caries development.

Anti-caries Streptococcus spp.: A potential preventive tool for special needs patients

INTRODUCTION

Probiotics are living microorganisms that act on the host-microbiome interface to restore the microbiota's physiological homeostasis. Numerous probiotics have been marketed with inhibitory activity against Streptococcus mutans and consequently with a potential anti-caries effect, mainly of the genera Lactobacillus and Bifidobacterium, whose main disadvantage is their limited ability to settle in the oral cavity.

METHODS

This narrative review describes the main Streptococcus spp. with probiotic anti-Streptococcus mutans activity, whose substantivity is greater than that of Lactobacillus spp. and consequently with anti-caries potentiality. We performed a literature review in the PubMed, Science Direct and Google Scholar databases of articles published in English (without time restriction) related to caries and probiotics.

RESULTS

The potential identified anti-caries probiotics included Streptococcus spp. A12, Streptococcus oralis (AJ3), Streptococcus oligofermentans, Streptococcus salivarius (K12, M18, JH, LAB813, 24SMB), Streptococcus spp. with arginolytic activity (S. sanguinis, S. gordonii, S. ratti, S. parasanguinis, S. intermedius, S. australis, and S. cristatus), Streptococcus rattus (JH145), Streptococcus dentisani and Streptococcus downii.

CONCLUSIONS

The possibility of using these Streptococcus spp. as probiotics that inhibit the growth of dental plaque and the development of carious lesions represents a potential tool of particular interest for individuals with physical or intellectual disabilities that impede the routine and effective application of mechanical dental plaque removal techniques.

Manipulating the diseased oral microbiome: the power of probiotics and prebiotics

Dental caries and periodontal disease are amongst the most prevalent global disorders. Their aetiology is rooted in microbial activity within the oral cavity, through the generation of detrimental metabolites and the instigation of potentially adverse host immune responses. Due to the increasing threat of antimicrobial resistance, alternative approaches to readdress the balance are necessary. Advances in sequencing technologies have established relationships between disease and oral dysbiosis, and commercial enterprises seek to identify probiotic and prebiotic formulations to tackle preventable oral disorders through colonisation with, or promotion of, beneficial microbes. It is the metabolic characteristics and immunomodulatory capabilities of resident species which underlie health status. Research emphasis on the metabolic environment of the oral cavity has elucidated relationships between commensal and pathogenic organisms, for example, the sequential metabolism of fermentable carbohydrates deemed central to acid production in cariogenicity. Therefore, a focus on the preservation of an ecological homeostasis in the oral environment may be the most appropriate approach to health conservation. In this review we discuss an ecological approach to the maintenance of a healthy oral environment and debate the potential use of probiotic and prebiotic supplementation, specifically targeted at sustaining oral niches to preserve the delicately balanced microbiome.

Efficacy and Safety of Probiotics for Dental Caries in Preschool Children: A Systematic Review and Meta-analysis

Background

Early childhood caries is one of the most serious and high-priced oral health conditions among young children. With advancing dental sciences, the focus of dental caries treatment is shifted from restorative procedures to preventive measures, and a modality grabbing attention is probiotics. Probiotics exert their effects in many ways as chemical inhibition of pathogenic bacteria and stimulation of the immune response through the production of immunoglobulin A and many more.

Objective

This systematic review aims to explore the efficacy and safety of probiotics in dental caries in preschool children.

Methodology

The study was registered in the PROSPERO International Prospective Register of Systematic Reviews (registration number: CRD42020159058). The search was done for randomized control trials in electronic databases such as Cochrane, PubMed, ClinicalTrials.gov, Medline, and Embase. It has further included manual searches of journals, conference abstracts, and books. Three reviewers done the selection of the study as per the criteria and also did the risk of bias assessment independently and wherever required, a fourth reviewer resolved the discrepancy in case of disagreement.

Results

The nine randomized control trials were included in the study, and the pooled analysis revealed probiotics as an effective intervention in preschool children with dental caries.

Conclusion

The results about the efficacy of probiotics in the prevention of dental caries are very encouraging, though the level of evidence is still inadequate.

Modulation of Gut Microbiome as a Therapeutic Modality for Auditory Disorders

The gut microbiome has been shown to play a pivotal role in health and disease. Recently, there has been increased interest within the auditory community to explore the role of the gut microbiome in the auditory system and its implications for hearing disorders such as sensorineural hearing loss (SNHL), otitis media, and tinnitus. Studies have suggested that modulating the gut microbiome using probiotics as well as with diets high in monounsaturated and omega-3 fatty acids is associated with a reduction in inflammation prevalence in auditory disorders. This review aims to evaluate the current literature on modulation of the gut microbiome and its effects on otological conditions. The probiotic conversion of nondigestible carbohydrates into short-chain fatty acids has been shown to provide benefits for improving hearing by maintaining an adequate vascular supply. For acute and secretory otitis media, studies have shown that a combination therapy of probiotics with a decreased dose of antibiotics yields better clinical outcomes than aggressive antibiotic treatment alone. Gut microbiome modulation also alters neurotransmitter levels and reduces neuroinflammation, which may provide benefits for tinnitus by preventing increased neuronal activity. Further studies are warranted to evaluate the efficacy of probiotics, natural health products, and micronutrients on auditory disorders, paving the way to develop novel interventions.

The efficacy of combined arginine and probiotics as an add-on to 1450 ppm fluoride toothpaste to prevent and control dental caries in children - A randomized controlled trial

OBJECTIVES

To determine how daily consumption of a lozenge combining arginine and two probiotic strains affects the Relative Risk Reduction (RRR) in children regarding dental caries transitions and lesion activity at tooth surface level during 10-12 months.

METHODS

A total of 21,888 tooth surfaces in 288 children were examined. The intervention group (n = 141) received a lozenge containing 2% arginine, Lacticaseibacillus rhamnosus, LGG® (DSM33156), and Lactobacillus paracasei subsp. paracasei, L. CASEI 431® (DSM33451). The placebo group (n = 147) received a placebo lozenge. Both groups received 1,450 ppm F- toothpaste. Primary canines, molars, and first permanent molars were examined clinically (ICDAS0-6) and radiographically (R0-6) at baseline and follow-up. Sealed, filled, and missing surfaces were also included. Caries activity was computed as a sum of each caries lesion's location, color, texture, cavitation, and gingival bleeding. RRRs were computed with cluster effect on surface level. ICH-GCP was followed, including external monitoring.

RESULTS

A total of 19,950 surfaces were analyzed after excluding 1,938 tooth surfaces. No statistically significant differences were found between the groups. The RRRs showed less caries progression (13.6%, p = 0.20), more regression (0.3%, p = 0.44), and fewer active caries lesions (15.3%, p = 0.15) in the intervention group.

CONCLUSION

Daily consumption of a lozenge combining arginine and probiotics for 10-12 months given to 5-9-years-old children characterized being with low caries risk demonstrated a marked, though not statistically significant RRR for caries progression, regression, and number of active lesions in the intervention group compared to the placebo-group.

CLINICALTRIALS

gov (NCT03928587).

CLINICAL SIGNIFICANCE

Since all the RRRs were in favor of the intervention group and the PF of combined arginine and probiotics is high (81.6%) compared to fluoride toothpaste (24.9%) and arginine-fluoride toothpaste alone (19.6%) the combined pre-and probiotics approach may be a future additional tool regarding caries prevention and control.

Can acid produced from probiotic bacteria alter the surface roughness, microhardness, and elemental composition of enamel? An in vitro study

Probiotics are live microorganisms that upon administration in adequate amounts provide various health benefits to the host. Probiotics are "lactic acid-producing bacteria" as they release large amounts of organic acids, particularly lactic acids, in their surrounding environment. Although the acids produced by probiotics are beneficial for gastrointestinal and vaginal health, the acidogenic nature of probiotics has raised concerns among dental professionals, especially concerning their effect on the enamel and dentin. Previous studies have found that probiotics can lower the pH of the saliva and cause essential elements like Calcium and Phosphorus to leach from the enamel. This can alter the surface topography of enamel and increase the risk of enamel defects. Studies have also noted that probiotic bacteria can replace cariogenic bacteria and lower the risk of tooth decay. However, the effect of acid produced by probiotics on the enamel surface remains unclear. Hence, the present study aims to evaluate the effect of probiotics on the surface roughness, microhardness, and elemental composition of enamel compared to 0.1 M Lactic acid (demineralizing agent). Twenty enamel sections were randomly divided into groups and subjected to a pH cycling model using a probiotic suspension and 0.1 M lactic acid. The changes in the surface roughness, microhardness, surface morphology, and elemental composition of the enamel with regard to Carbon, Oxygen, Sodium, Hydrogen, Magnesium, Phosphorus, Fluoride, Chlorine, and Calcium of the enamel were evaluated before and after the emersion in both the groups. The results showed a significant increase in the mean surface roughness in the probiotic group before and after the exposure. The microhardness of the enamel decreased along with altered arrangement of the enamel prisms, increased striations, scratch marks, and pitting after exposure to the probiotic group. A decrease in the atomic/weight% for Calcium, Phosphorous, Fluoride, Aluminium, and Oxygen and an increase in the weight/atomic% for Carbon, Nitrogen, and Sodium were noted compared to the baseline in the probiotic solution. The results in the probiotic group were comparable to the 0.1 M lactic acids. The pH changed from 5.78 to 3.06 at the end of 24 h in the probiotic group. Based on these findings, we conclude that exposure to probiotics can affect microhardness and surface roughness and cause leaching of essential elements like Calcium and Phosphorous from the enamel.

A comprehensive review of the application of probiotics and postbiotics in oral health

Oral diseases are among the most common diseases around the world that people usually suffer from during their lifetime. Tooth decay is a multifactorial disease, and the composition of oral microbiota is a critical factor in its development. Also, Streptococcus mutans is considered the most important caries-causing species. It is expected that probiotics, as they adjust the intestinal microbiota and reduce the number of pathogenic bacteria in the human intestine, can exert their health-giving effects, especially the anti-pathogenic effect, in the oral cavity, which is part of the human gastrointestinal tract. Therefore, numerous in vitro and in vivo studies have been conducted on the role of probiotics in the prevention of tooth decay. In this review, while investigating the effect of different strains of probiotics Lactobacillus and Bifidobacteria on oral diseases, including dental caries, candida yeast infections, periodontal diseases, and halitosis, we have also discussed postbiotics as novel non-living biological compounds derived from probiotics.

Using probiotics in paediatric populations

This statement defines probiotics and reviews the most recent literature on their use in paediatrics. Many studies have examined the potential benefit of probiotics, but significant variation in the strains and doses of probiotics used, the patient populations studied, and in study design, have led to heterogeneous results. Present evidence suggests that probiotics can decrease mortality and lower incidence of necrotizing enterocolitis in preterm and low birth weight neonates. Probiotics may also be beneficial in reducing feeding intolerance. In infants, probiotics may be considered to reduce symptoms of colic. In older children, probiotics can be considered to prevent antibiotic-associated diarrhea and Clostridium difficile -associated diarrhea. Probiotic supplements used in conjunction with standard therapy can help with Helicobacter pylori eradication and decrease the side effects of treatment. Lactobacillus species can be considered to treat irritable bowel syndrome. Probiotics can also be considered to help prevent atopic dermatitis and eczema. To optimize paediatric policy and practice, large, quality studies are needed to determine what types and combinations of probiotics are most efficacious.

L’utilisation des probiotiques dans la population pédiatrique

Le présent document de principes définit les probiotiques et fournit une analyse des publications scientifiques les plus récentes sur leur utilisation en pédiatrie. De nombreuses études ont évalué les avantages potentiels des probiotiques, mais en raison des variations importantes dans les souches et les doses utilisées, des populations de patients étudiées et des méthodologies privilégiées, les résultats sont hétérogènes. Selon les données probantes à jour, les probiotiques peuvent réduire le taux de mortalité et l’incidence d’entérocolite nécrosante chez les nouveau-nés prématurés et de petit poids à la naissance. Ils peuvent également être bénéfiques pour réduire l’intolérance alimentaire. Chez les nourrissons, on peut envisager de les utiliser pour limiter les symptômes de coliques, et chez les enfants plus âgés, pour prévenir la diarrhée associée aux antibiotiques ou au Clostridium difficile . Les suppléments de probiotiques utilisés conjointement avec un traitement standard peuvent contribuer à éradiquer l’Helicobacter pylori et à atténuer les effets secondaires du traitement. On peut envisager d’utiliser des espèces de Lactobacillus pour traiter le syndrome du côlon irritable ou de recourir à des probiotiques pour contribuer à prévenir la dermatite atopique et l’eczéma. Afin d’optimiser les politiques et les pratiques en pédiatrie, de vastes études de qualité devront être réalisées pour déterminer les types et les combinaisons de probiotiques les plus efficaces.

Effect of a Short-Term Intervention with Lactobacillus salivarius Probiotic on Early Childhood Caries-An Open Label Randomized Controlled Trial

ECC is a significant therapeutic and social problem and a global burden on public health. The aim of this clinical trial was to test whether a 2-week daily consumption of chewing tablets containing thermally inactivated L. salivarius reduces the 12-month caries increment compared to the control group. The investigation was a single-center, randomized, controlled open-label, blinded end-point evaluation trial in two parallel groups. At baseline, 140 generally healthy children between 3 and 6 years of age with or without ECC were randomly assigned to the probiotic test group (n = 70) or to the treatment as the usual control group (n = 70). The primary outcome measure was the 1-year increment in caries incidence and prevalence. Secondary endpoints assessed were the initial, cavitated and obvious dentinal caries increment as well as the measurement of dental plaque accumulation, as an indicator of the ECC risk. Data were collected through the clinical assessment of the children's caries (dmft and ICDAS II) and oral hygiene status (DI-S of OHI-S index). Caries incidence and prevalence were statistically significantly lower in the probiotic group versus the control group (p < 0.001 and p = 0.0075). The initial and final mean OHI-S scores in the probiotic group did not show any significant differences. In conclusion, the regular short-term intake of probiotics may reduce caries development. Our findings suggest that self-administered probiotic therapy may provide a good complement to increase the effectiveness of individual preventive home care in preschool children. This is the first clinical study evaluating the effect of a short-term probiotic intervention on reducing early childhood caries with 12 months of follow-up.

Complementary/Integrative Medicine for Pediatric Otitis Media

Complementary/integrative medicine can be used in treating otitis media, especially during the watchful waiting phase. Elimination of risk factors can be important. Products such as echinacea, xylitol, and probiotics may help in prevention. Herbal eardrop formulations can relieve symptoms in some patients. Other modalities such as homeopathy can lead to faster relief of symptoms in combination with conventional therapy. Chinese, Japanese, and other forms of traditional medicine have varying formulations with unclear safety, but initial results are promising. Most studies are limited by methodological failures and small sample sizes, emphasizing the need for continued research in this area.

A Scopus-Based Bibliometric Analysis of Global Research Contributions on Milk Fluoridation

Fluoridated-milk schemes have been developed and implemented in many countries to prevent dental caries. This study aimed to evaluate the impact/influence of scientific publications, researchers, and institutions conducting research on milk fluoridation; to explore the international and inter-institutional collaboration and illustrate scientific output trends; and to pinpoint research hotspots in milk fluoridation research. This bibliometric analysis of original research articles on milk fluoridation includes all of the original articles published in peer-reviewed journals systematically extracted from the SCOPUS database. In total, 108 articles were included in this study, with a total of 11,789 citations. A majority (67.6%) of these articles were in the subject area of ‘dentistry’, 22.2% externally funded, 14.8% published in the journal, Caries Research, 7.4% authored/co-authored by Twetman S, 6.5% by authors from Universidad de Chile, and the UK had the highest output (24.1%). The network visualizations showed that those countries with current/past histories of implemented milk fluoridation programs were interconnected on the network visualization map, and they were predominantly the hotspots for original research on milk fluoridation. This study also identified inequalities in research outputs on the topic. With the current enormous global burden of dental caries in children, particularly in low- and middle-income countries, there is an urgent need for greater and more equitable funding of milk fluoridation research globally.

Effectiveness of the Lorodent Probiotic Lozenge in Reducing Plaque and Streptococcus mutans Levels in Orthodontic Patients: A Double-Blind Randomized Control Trial

Orthodontic patients are at a significant risk for oral diseases due to increased plaque accumulation and oral bacterial dysbiosis. We aimed to determine the efficacy of the commercially available Lorodent Probiotic Complex at reducing plaque accumulation and Streptococcus mutans bacterial levels in adolescent orthodontic patients. Sixty adolescents undergoing fixed orthodontic treatment for a minimum of 6 months were recruited in a randomized, double-blind, parallel-group, placebo-controlled trial. They received either Lorodent probiotic lozenge (intervention, n = 30) or placebo lozenge (control, n = 30) orally every day for a 28-day administration period. Participants were assessed at four appointments (T1–T4) over a total of 56 days. Compliance and lozenge satisfaction were monitored. Saliva samples and supragingival plaques were collected for evaluation of S. mutans levels. Clinical assessment using a Plaque Index (PI) was used. Compliance with lozenge intake of all participants was over 90%. There was no significant change in the PI and composite PI scores in both placebo and probiotic groups at each time frame (all p &gt; 0.05) or the relative S. mutans DNA levels in the saliva and plaque between the probiotic and placebo groups. The findings of high compliance and satisfaction with the probiotic lozenges combined with the study's rigorous design offer a baseline for subsequent testing of further potential probiotics (of varying formulations, concentrations), especially in adolescents.

Evaluation of the efficacy of plaque reduction and gingival health among 6-12 years old school children before and after a short term daily intake of probiotic lozenge - A comparative study

CONTEXT

Probiotics are defined as live microorganisms which when delivered in adequate amounts provides health benefit in the host. Dietary supplements like lozenge seem to be the easy and acceptable vehicle for ingestion of probiotics in young children.

AIM

To assess the efficacy of probiotics in plaque reduction and gingival health among 6-12 years school children before and after short term daily intake of Probiotic lozenge.

SETTINGS AND DESIGN

This Comparative study was conducted among 60 children in the age group 6-12 years. Thirty children in experimental group; who were given lozenge containing probiotic bacteria twice daily, one in the morning and another in the evening after brushing for one month. The placebo lozenge group also followed the same protocol.

STATISTICAL ANALYSIS USED

SPSS version 21.

RESULTS

The Probiotic lozenge group was found to have statistically significant reduction in plaque scores when compared to that of the placebo group with P < 0.001 and there was also a significant improvement in gingival health.

CONCLUSION

An effective reduction in plaque accumulation and gingival inflammation was found with the use of probiotic lozenges and hence proved the therapeutic value of the same.

Efficacy of Probiotic, Chlorhexidine, and Sodium Fluoride Mouthrinses on Mutans Streptococci in 8- to 12-Year-Old Children: A Crossover Randomized Trial

INTRODUCTION

The oral cavity is home to a diverse and distinct microbiome. While the role of oral bacteria in cariogenic and other dental diseases is irrefutable, their beneficial effects in the form of probiotics (PB) has been less studied, especially pertaining to oral diseases in children. This study compares the efficacy of a PB mouthrinse with 0.12% chlorhexidine (CHX) and 0.05% sodium fluoride (NaF) mouthrinse on the colony counts of mutans streptococci (MS) in children.

METHODS

A triple-blind crossover randomized trial between interventional groups was planned. Fifty-one children between 8 to 12 years of age were divided into three groups (I, II, and III) and were exposed to all three mouthrinses (A, B, and C) by randomized allocation for a period of two weeks with an inter-phase washout period of four weeks. Pre- and post-interventional MS counts (CFU/mL) were assessed, and the mean change was analysed using the t test (intragroup) and ANOVA (intergroup and crossover).

RESULTS

The mean changes in the colony counts obtained with the use of PB, CHX, and NaF mouthrinses were -1.0223 (-1.2201 to -0.8246), -0.9564 (-1.1503 to -0.7626), and -0.9511 (-1.1554 to -0.7467), respectively, which were statistically significant (p < 0.0001). However, the intergroup comparison for the mean change in colony counts revealed no statistically significant differences (p > 0.05).

CONCLUSION

The study concluded that the PB mouthrinse was equally efficacious as compared to CHX and NaF mouthrinses against MS in 8- to 12-year-old children. However, further studies are recommended to strengthen the evidence.

Probiotics, Prebiotics, Synbiotics and Dental Caries. New Perspectives, Suggestions, and Patient Coaching Approach for a Cavity-Free Mouth

Probiotic therapy forms a new strategy for dental caries prevention. Probiotic microorganisms possess the ability to displace cariogenic microorganisms and colonize the oral cavity. They can produce various antimicrobial substances such as bacteriocins, bacteriocin-like peptides, lactic acid, and hydrogen peroxide. Dairy products may be ideal for probiotic administration in dental patients. Many other means have been proposed, primarily for those allergic to dairy components, such as capsules, liquid form, tablets, drops, lozenges, sweetened cakes, and ice creams. The last two forms can be used in a coaching approach for children and elderly patients who find it difficult to avoid sugary beverages in their daily routine and benefit from the suggestion of easy, cheap, and common forms of delicacies. In caries prevention, the concept of the effector strain is already considered an integral part of the contemporary caries cure or prevention strategy in adults. Adults, though, seem not to be favored as much as children at early ages by using probiotics primarily due to their oral microbiome’s stability. In this non-systematic review we describe the modes of action of probiotics, their use in the cariology field, their clinical potential, and propose options to prevent caries through a patient coaching approach for the daily dental practice.

A Review of the Role of Probiotic Supplementation in Dental Caries

Dental diseases are among the common health issues experienced around the world. Dental caries is one of the most predominant oral diseases worldwide. Major factors associated with caries development include poor oral hygiene, the content of specific carbohydrates in the diet, dental biofilm formation, the cariogenic microbial load, reduction in salivary flow, insufficient fluoride exposure, gingival recession, genetic factors, and lack of personal attention to one's dental health. Several preventive measures have been implemented to reduce the risk of the development of caries. Probiotics are live microbes that when administered in suitable amounts confer health benefits on the host; they are recognized as potential adjunct therapeutic agents for several diseases. The present manuscript summarizes recent findings on the role of probiotics in dental caries prevention and the possible mechanisms of probiotic effects. Review of the literature indicates the regular consumption of probiotic products significantly reduced the risk of caries by inhibiting cariogenic bacteria and enriching commensal microbes in the oral cavity. Buffering the salivary pH, production of bacteriocin and enzymes (dextranase, mutanase, and urease), the capacity of competing for the adhesion and colonization on tooth surfaces are the possible mechanisms behind the beneficial effect of probiotics. Further studies are necessary to address the efficacy of long-term probiotic supplementation on the control of dental diseases and the influence of childhood probiotic supplementation on the risk of caries development.

Can probiotic supplements prevent early childhood caries? A systematic review and meta-analysis

The aim of this study was to explore the preventive effect of probiotic supplements on the development of early childhood caries (ECC). We searched the PubMed, Google Scholar and Cochrane databases up to January 15, 2021. The authors screened the hits independently for relevance, extracted outcome data and assessed the risk of bias. We performed a random effects meta-analysis to pool and compare the incidence of ECC in children assigned to test or placebo groups, respectively. The authors included nine randomised controlled trials published between 2001 and 2021, involving 2,363 preschool children. We assessed two publications with a moderate risk of bias and seven with high risk of bias. The median caries incidence in the probiotic test groups was 8.5% compared with 17.5% in the placebo groups and this difference was statistically significant (P<0.001). A pooled random effects meta-analysis on caries incidence on subject level showed a small but statistically significant risk difference in favour of the probiotic intervention (-0.05, 95% confidence interval (CI) -0.10, -0.00; P<0.05). The mean difference in caries increment on tooth/surface level was -0.57, (95% CI -0.91, -0.23; P<0.01). In conclusion, we demonstrated a small but statistically significant preventive effect of probiotic supplements on ECC. However, the certainty of this finding was low due to the risk of bias, heterogeneity and inconsistencies across the studies. Further long-term randomised controlled trials with low risk of bias are required in order to answer the research question with a higher certainty.

Effect of probiotics on gingival inflammation and oral microbiota: A meta-analysis

To evaluate the effect of probiotics on gingival inflammation and oral microbiota in patients suffering from plaque-induced gingivitis. PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE were electronically searched until December 2020. The quality of included studies was assessed with the Cochrane Collaboration's Risk of Bias tool. The differences were expressed as weighted mean differences (WMD) and 95% of confidence interval (95% CI). I² test was performed to evaluate the heterogeneity of the studies. All analyses were performed using Review Manager (version 5.3). Eleven randomized and controlled trials were included, enrolling 554 patients. All comparisons displayed that oral probiotics had no significant improvement in the Gingival Index (GI), Plaque Index (PI), and bleeding on probing (BOP) of patients with plaque-induced gingivitis. In terms of microecology, no significant difference in the volumes of gingival crevicular fluid (GCF), the concentration of IL-1β, and the counts of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and Fusobacterium nucleatum (Fn) were found between the probiotic group and the placebo group. There exists no clear evidence that oral probiotics have positive effect on gingival inflammation and oral microecological environment of patients with plaque-induced gingivitis.

Review of probiotic use in otolaryngology

OBJECTIVE

Probiotics have garnered considerable attention as an intervention for various conditions common to otolaryngology. The purpose of this review is to evaluate the current literature to offer recommendations about the safety and efficacy of probiotic management in otolaryngologic conditions.

STUDY DESIGN

Narrative review.

METHODS

PubMed and Google Scholar were queried using pertinent keywords to retrieve relevant studies with particular focus in the recent 5 years. All abstracts were assessed and studies, reviews and meta-analyses achieving evaluation of probiotic therapies or characterization of microbiome changes were included for further review. Studies were categorized by condition or anatomic region across various subspecialties. Key data parameters were extracted and evaluated across studies and treatment types.

RESULTS

Strong evidence exists for the use probiotic agents to improve symptoms for allergic rhinitis, chronic rhinosinusitis and certain dental conditions. Despite promising results, further investigation is needed to evaluate and optimize probiotic delivery for mitigating otitis media, oropharyngeal inflammation and upper respiratory tract infections. Preclinical studies suggest that probiotics may potentially offer benefit for voice prosthesis maintenance, wound healing and mitigation of oral dysplasia.

CONCLUSION

Probiotic therapies may offer clinical benefit in a variety of contexts within the field of otolaryngology, especially for short-term relief of certain inflammatory conditions of the oral cavity, auditory and nasal cavities. Further investigation is warranted for evaluation of long-term outcomes and pathogenic deterrence.

Can Probiotics Emerge as Effective Therapeutic Agents in Apical Periodontitis? A Review

Apical periodontitis (AP) is a biofilm-associated disease initiated by the invasion of dental pulp by microorganisms from the oral cavity. Eradication of intracanal microbial infection is an important goal of endodontic treatment, and this is typically accomplished by mechanical instrumentation and application of sodium hypochlorite and chlorhexidine. However, these agents are tissue-irritating at higher concentrations and cytotoxic. Certain probiotics have been found effective in controlling marginal periodontitis, as evidenced by reduction of pathogenic bacterial loads, gains in clinical attachment levels, and reduced bleeding on probing. In vitro studies have shown inhibitory activity of some probiotics against endodontic pathogens. Similarly, in vivo studies in rats have demonstrated a positive immuno-modulatory role of probiotics in AP, as manifested by decreased levels of proinflammatory markers and increased levels of anti-inflammatory markers. A role for probiotics in effecting a reduction of bone resorption has also been reported. This review provides an outline of current research into the probiotic management of AP, with a focus on understanding the mechanisms of their direct antagonistic activity against target pathogens and of their beneficial modulation of the immune system.

Efficacy of Probiotic Milk for Caries Regression in Preschool Children: A Multicenter Randomized Controlled Trial

This multicenter double-blind randomized controlled trial aimed to determine the efficacy of daily or triweekly consumption of reconstituted milk powder, containing <i>Lactobacillus paracasei</i>SD1, in preschool children for caries prevention. A 6-month intervention was conducted in 487 children (aged 37.6 ± 9.2 months) with ≤4 decayed teeth from 8 childcare centers. Using stratified block randomization, participants were randomly allocated into 3 groups, comprising: (1) daily probiotic, receiving probiotic milk once daily, (2) triweekly probiotic, randomly receiving probiotic milk 3 days a week and the placebo milk for the remaining 4 days, and (3) placebo, receiving milk without probiotics. Each tooth surface was assessed for caries status using the modified Nyvad criteria at baseline (T0), 6 (T6) and 12 (T12) months after T0. Study outcomes were caries transition, including caries progression and regression during the T0–T6, T6–T12 and T0–T12 periods. Negative binomial regression with a generalized linear model was used to estimate the caries outcomes, which were reported as incidence rate ratios (IRRs) and 95% confidence intervals (CIs). At baseline, caries prevalence and mean decayed surfaces were 81.9% and 7.29 ± 7.60, respectively. Three groups were balanced at baseline with an overall dropout rate of 25.2%. After adjusting for age, sex, and the number of noncavitated and cavitated caries at baseline, a decreased caries risk during T0–T6 was shown in both the daily and triweekly probiotic groups (adjusted IRR 0.83, 95% CI 0.72–0.96 in both groups) and during T0–T12 (adjusted IRR 0.84, 95% CI 0.76–0.94, and adjusted IRR 0.86, 95% CI 0.76–0.96, respectively) compared to the placebo group. In contrast, significantly increased regressive surfaces were demonstrated during T0–T6 by adjusted IRR 1.76 (95% CI 1.25–2.48) and 2.01 (95% CI 1.42–2.85) and during T0–T12 by adjusted IRR 1.98 (95% CI 1.50–2.61) and 1.92 (95% CI 1.45–2.55) for the daily and triweekly groups, respectively. In conclusion, probiotic milk consumption either daily or triweekly can modestly prevent new caries, but considerably reverse carious lesions, suggesting that a daily or triweekly dose interval is sufficient to reverse carious lesions.

Influence of Probiotics on the Salivary Microflora Oral Streptococci and Their Integration into Oral Biofilm

Probiotics’ ability to integrate into dental biofilms is not yet clarified. The aim of this trial was to detect probiotic bacteria from probiotic products in dental biofilm and saliva during and after intake. In this parallel, randomized clinical trial, 39 subjects wore customized appliances to build up intra-oral biofilms (72-h periods). The trial was divided into screening (S) to determine baseline biofilm flora, intervention (I), and wash out (WO). During I (28 days), subjects consumed a product containing (a) Enterococcus faecalis (b) Lactobacilluscasei, or (c) Lactobacillus rhamnosus GG. Probiotic bacteria and Streptococci spp. were detected in the biofilms and saliva of the 35 subjects that were included in the analysis. During I and WO, the ratio of probiotics in the biofilm was very low compared to total bacterial load, while saliva had slightly but not significantly higher values. No significant changes of probiotic bacteria (p > 0.05) were found at any visit during I or WO. The proportion of streptococci was significantly reduced (p < 0.05) during I and even lower in WO, compared to S. Probiotic bacteria could neither integrate nor persist in dental biofilm and saliva but did influence the growth of streptococci in biofilm and saliva.

Effect of a novel synbiotic on Streptococcus mutans

We examined the effect of L-arginine - (i) on the growth of L. rhamnosus GG (LrG) and (ii) combined LrG synbiotic on the growth of cariogenic S. mutans. Viability of LrG was assessed using MTT/XTT assays, confocal imaging with ADS activity measurement. The effect of L-arginine (0.5%/1%/2%) (2×/24 h) with LrG on S. mutans was evaluated by measuring the colony forming units, biofilm biomass, real-time qPCR and confocal imaging. The pH of the spent media was measured immediately and 24 h post-treatment with assessment of lactic acid. The LrG viability was highest with 2% L-arginine (p < 0.001). Confocal imaging showed that 2% L-arginine increased biofilm thickness of LrG. The 2% L-arginine and LrG synbiotic significantly inhibited the growth of S. mutans (p < 0.001) reducing the viable counts (p = 0.002) and biofilm biomass (p < 0.001). The pH of spent media was the highest when treated with 2% L-arginine and LrG synbiotic (p < 0.001) with no difference between post-treatment and 24 h post-treatment (p > 0.05). Conversely, the 2% L-arginine and LrG synbiotic showed the lowest lactic acid production (p < 0.001). This study demonstrated that L-arginine enhanced the growth of LrG. The 2% L-arginine and LrG synbiotic synergistically inhibits the growth of S. mutans with significant potential to develop as an anti-caries regimen.

Guidelines on the use of fluoride for caries prevention in children: an updated EAPD policy document

AIM

To update the exisitng European Academy of Paediatric Dentistry (EAPD) 2009 fluoride guidelines.

METHODS

Experts met in Athens, Greece duirng November 2018 for the following groups: I Fluoride toothpastes, II Fluoride gels, rinses and varnishes, III Fluoridated milk, fluoridated salt, tablets/lozenges and drops, IV Water fluoridation. Systematic reviews and meta-analyses were reviewed and discussed for each of the groups. The GRADE system was used to assess the quality of evidence which was judged as HIGH, MODERATE, LOW or VERY LOW based on the assessment of eight criteria which can influence the confidence of the results. Following the quality assessment, GRADE was then used to indicate the strength of recommendation for each fluoride agent as STRONG or WEAK/CONDITIONAL.

RESULTS

Parents must be strongly advised to apply an age-related amount of toothpaste and assist/supervise tooth brushing until at least 7 years of age. The EAPD strongly endorses the daily use of fluoride as a major part of any comprehensive programme for the prevention and control of dental caries in children. Regardless of the type of programme, community or individually based, the use of fluoride must be balanced between the estimation of caries-risk and the possible risks of adverse effects of the fluorides. Fluoride use is considered safe when the manufacturer's instructions are followed. Preventive programmes should be re-evaluated at regular intervals and adapted to a patient's or population's needs and risks.

CONCLUSIONS

For the majority of European Countries, the EAPD recommends the appropriate use of fluoride toothpaste in conjunction with good oral hygiene to be the basic fluoride regimen.

Probiotics for preventing acute otitis media in children

BACKGROUND

Acute otitis media (AOM), or acute middle ear infection, is one of the most frequently occurring childhood diseases, and the most common reason given for prescribing antibiotics in this age group. Guidelines often recommend antibiotics as first-line treatment for severe AOM. However, antibiotics also lead to antibiotic resistance, so preventing episodes of AOM is an urgent priority.

OBJECTIVES

To assess the effects of probiotics to prevent the occurrence and reduce the severity of acute otitis media in children.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, and three other databases (October 2018), two trial registers (October 2018), and conducted a backwards and forwards citation analysis (August 2018). We did not apply any language, publication date, or publication status restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of children (aged up to 18 years), comparing probiotics with placebo, usual care, or no probiotic.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of trials for inclusion and risk of bias of the included trials, and extracted data using pre-piloted data extraction forms. We analysed dichotomous data as either risk ratio (RR) or odds ratios (OR) and continuous data as mean differences (MD).

MAIN RESULTS

We included 17 RCTs involving 3488 children, of which 16 RCTs were included in the meta-analyses. Of the 16 RCTs that reported the mean age of children, mean age overall was 2.4 years; in 4 RCTs the mean age of children participating in the trial was less than 1 year old; in 2 RCTs the mean age was between 1 and 2 years old; and in 10 RCTs the mean age was older than 2 years. Probiotic strains evaluated by the trials varied, with 11 of the included RCTs evaluating Lactobacillus-containing probiotics, and six RCTs evaluating Streptococcus-containing probiotics.The proportion of children (i.e. the number of children in each group) experiencing one or more episodes of AOM during the treatment was lower for those taking probiotics (RR 0.77, 95% confidence interval (CI) 0.63 to 0.93; 16 trials; 2961 participants; number needed to treat for an additional beneficial outcome (NNTB) = 10; moderate-certainty evidence).Post hoc subgroup analysis found that among children not prone to otitis media, a lower proportion of children receiving probiotics experienced AOM (RR 0.64, 95% CI 0.49 to 0.84; 11 trials; 2227 participants; NNTB = 9; moderate-certainty evidence). However, among children who were otitis prone, there was no difference between probiotic and comparator groups (RR 0.97, 95% CI 0.85 to 1.11; 5 trials; 734 participants; high-certainty evidence). The test for subgroup differences was significant (P = 0.007).None of the included trials reported on the severity of AOM.The proportion of children experiencing adverse events did not differ between the probiotic and comparator groups (OR 1.54, 95% CI 0.60 to 3.94; 4 trials; 395 participants; low-certainty evidence).Probiotics decreased the proportion of children taking antibiotics for any infection (RR 0.66, 95% CI 0.51 to 0.86; 8 trials; 1768 participants; NNTB = 8; moderate-certainty evidence). Test for subgroup differences (use of antibiotic specifically for AOM, use of antibiotic for infections other than AOM) was not significant.There was no difference in the mean number of school days lost (MD -0.95, 95% CI -2.47 to 0.57; 5 trials; 1280 participants; moderate-certainty evidence). There was no difference between groups in the level of compliance in taking the intervention (RR 1.02, 95% CI 0.99 to 1.05; 5 trials; 990 participants).Probiotics decreased the proportion of children having other infections (RR 0.75, 95% CI 0.65 to 0.87; 11 trials; 3610 participants; NNTB = 12; moderate-certainty evidence). Test for subgroup differences (acute respiratory infections, gastrointestinal infections) was not significant.Probiotic strains trialled and their dose, frequency, and duration of administration varied considerably across studies, which likely contributed to the substantial levels of heterogeneity. Sensitivity testing of funnel plots did not reveal publication bias.

AUTHORS' CONCLUSIONS

Probiotics may prevent AOM in children not prone to AOM, but the inconsistency of the subgroup analyses suggests caution in interpreting these results. Probiotics decreased the proportion of children taking antibiotics for any infection. The proportion of children experiencing adverse events did not differ between the probiotic and comparator groups. The optimal strain, duration, frequency, and timing of probiotic administration still needs to be established.

In vitro evaluation of probiotic strains for lactic acid production

Background

The growing interest on usage of probiotic lactobacilli in maintaining oral health has posed number of questions on its probable side effects. One such consideration could be an increased acid production in dental plaque, in turn leading to dental caries. Thus, the aim of this study was to comparatively evaluate the lactic acid producing ability of L. acidophilus and L. plantarum with and without dental plaque.

Material and Methods

The study consisted of five groups: 3 control groups (Supragingival plaque, L. acidophilus and L. plantarum) and 2 test groups (Supragingival plaque with L. acidophilus and Supragingival plaque with L. plantarum). 26 samples for each group were collected and their baseline spectrophotometric values were recorded. The acid production was initiated by adding 25?l fructose (10%) and stopped by centrifugation for 2 min. The concentration of the lactic acid produced was determined with the aid of COBAS INTEGRA 400 plus.

Results

On comparison of Lactic Acid estimation in mg/dl, the mean values of Plaque group was the highest followed by Plaque +L acidophilus, Plaque +L plantarum, L acidophilus and least in L plantarum. The posthoc analysis shows that the comparison of Group 1 (Plaque) and Group 2 (Plaque +L acidophilus) is statistically Significant results between all the groups except between the Plaque +L acidophilus and Plaque +L plantarum group.

Conclusions

The lactic acid producing ability of pure suspensions of L.acidophilus and L.plantarum and the lactic acid producing efficiency becomes more when they are added to the supragingival plaque. Key words:Probiotic, lactic Acid, plaque.

Critical Appraisal of Oral Pre- and Probiotics for Caries Prevention and Care

In recent years, the concept of preventing caries-related microbial dysbiosis by enhancing the growth and survival of health-associated oral microbiota has emerged. In this article, the current evidence for the role of oral pre- and probiotics in caries prevention and caries management is discussed. Prebiotics are defined as "substrates that are selectively utilized by host microorganisms conferring a health benefit." With regard to caries, this would include alkali-generating substances such as urea and arginine, which are metabolized by some oral bacteria, resulting in ammonia production and increase in pH. While there is no evidence that urea added to chewing gums or mouth rinses significantly contributes to caries inhibition, multiple studies have shown that arginine in consumer products can exert an inhibitory effect on the caries process. Probiotics are "live microorganisms which when administrated in adequate amounts confer a health benefit on the host." Clinical trials have suggested that school-based programs with milk supplemented with probiotics and probiotic lozenges can reduce caries development in preschool children and in schoolchildren with high caries risk. Due to issues with research ethics (prebiotics) and risk of bias (prebiotics, probiotics), the confidence in the effect estimate is however limited. Further long-term clinical studies are needed with orally derived probiotic candidates, including the health-economic perspectives. In particular, the development and evaluation of oral synbiotic products, containing both prebiotics and a probiotic, would be of interest in the future management of dental caries.

Probiotics in the treatment of otitis media. The past, the present and the future

Otitis media (OM) is one of the most common infectious diseases in children and the leading cause for medical consultations and antibiotic prescription in this population. The burden of disease associated with OM is greater in developing nations and indigenous populations where the associated hearing loss contributes to poor education and employment outcomes. Current treatment and prevention is largely focused on vaccination and antibiotics. However, rates of OM, particularly in indigenous populations, remain high. With growing concerns regarding antibiotic resistance and antibiotic-associated complications, an alternative, more effective treatment is required. Administration of probiotics, both locally and systemically have been investigated for their ability to treat and prevent OM in children. This review explores the theoretical bases of probiotics, successful application of probiotics in medicine, and their use in the treatment and prevention of OM. We conclude that local administration of niche-specific probiotic bacteria that demonstrates the ability to inhibit the growth of otopathogens in vitro shows promise in the prevention and treatment of OM and warrants further investigation.

Probiotics and carriage of Streptococcus pneumoniae serotypes in Danish children, a double-blind randomized controlled trial

This study examined the carriage of Streptococcus pneumoniae in healthy Danish children aged 8–19 months and assessed the effect of the probiotics Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis on the pneumococcal carriage during daycare enrolment. Potential risk factors of pneumococcal carriage were analysed and the carriage study was compared with registered invasive pneumococcal disease (IPD) data. This study is a part of the ProbiComp study, which was a double-blind, randomized controlled trial, including 290 children allocated to probiotics or placebo for 6 months and recruited during two autumn seasons (2014/2015). Pneumococci were identified by optochin sensitivity, bile solubility, α-hemolysis and/or capsular reaction. Serotyping was performed by latex agglutination kit and Quellung reaction. The carriage rate of S. pneumoniae was 26.0% at baseline and 67.4% at the end of intervention. No significant difference was observed between the placebo group and the probiotics group (p = 0.508). Children aged 8–19 months were carriers of non-pneumococcal vaccine serotypes causing IPD in children aged 0–4 years. However, serotypes causing most IPD cases in Danish elderly were either not found or found with low prevalence suggesting that children are not the main reservoir of those serotypes and other age groups need to be considered as carriers.

Are dairy products containing probiotics beneficial for oral health? A systematic review and meta-analysis

OBJECTIVES

To evaluate the effect of probiotic containing in dairy products on oral and salivary parameters.

MATERIAL AND METHODS

Electronic searches were performed based on the PICO criteria. Randomized controlled trials in adults/children (P) in which dairy products containing probiotics (I) were compared to controls (C) for establishment of oral health (O) were included. Risk of bias and data extraction were performed. The meta-analysis evaluated the influence of probiotics on Streptococcus mutans (SM), Lactobacillus spp. (LB), and yeast counts, plaque index, and salivary pH. Random or fixed effect models were used, and heterogeneity was tested.

RESULTS

Thirty-two studies were included in the qualitative synthesis, and 24 in the meta-analysis. For dichotomous results, individuals who consumed probiotics exhibited decreased scores in SM concentrations (RD 0.15 [0.02, 0.28] p = 0.03, I² = 70%), but no change was observed for LB (RD 0.10 [- 0.03, 0.23] p = 0.13, I² = 94%), or yeast levels (RD 0.05 [- 0.02, 0.12] p = 0.7, I² = 48%). For continuous analysis, both probiotic and control groups presented similar results for SM and LB (MD - 0.55 [- 1.16, 0.07] p = 0.08, I² = 62%, and RD 0.10 [- 0.03, 0.23] p = 0.13, I² = 94%, respectively). The consumption of probiotics increased salivary pH (MD 0.20 [0.04, 0.35] p = 0.01, I² = 46%) and plaque index (MD 0.38 [0.11, 0.65] p = 0.005, I² = 0%). The probiotic milk reduced SM (MD - 0.59 [- 0.96, - 0.22] p = 0.002, I² = 0%), and the probiotic yogurt decreased LB counts (RD 0.35 [0.19, 0.51] p < 0.0001, I² = 0%).

CONCLUSIONS

In general, dairy probiotics were effective in reducing SM, increasing salivary pH, and promoting a higher plaque index. Liquid matrices, such as milk and yogurt, seem to be more effective in reducing SM and LB levels.

CLINICAL RELEVANCE

Consumption of dairy products containing probiotics could be a supporting method in caries prevention.

Reducing mutans streptococci and caries development by Lactobacillus paracasei SD1 in preschool children: a randomized placebo-controlled trial

OBJECTIVE

To examine a reducing effect of Lactobacillus paracasei SD1 on MS and caries in preschool children.

MATERIALS AND METHODS

A total of 124 children, aged 1.5-5 years old, participated and were randomly assigned to the probiotic or control group. The probiotic group received L. paracasei SD1-milk and the control group received standard-milk once daily for 3 months. MS/lactobacilli were enumerated and the caries score was examined. Association between probiotic consumption and bacterial level, or caries progression was assessed by a multivariate logistic regression. This study was registered at the Thai-Clinical-Trials-Registry (TCTR20140903001).

RESULTS

Probiotic was found to be a factor associated with the MS level. Children in the probiotic group had a significantly lower risk of an increase in the MS level than in the control group after receiving the probiotic milk at 3- and 4-months with p < .001 and p = .040, respectively. Probiotic significantly reduced the risk for caries compared to the control group (p = .016). There were no adverse effects or non-compliance reported in either group.

CONCLUSIONS

Consumption of milk powder containing L. paracasei SD1 resulted in a reduction of both salivary MS and delayed new caries development, and the strain is safe for use in young children. Results suggest that L. paracasei SD1 may be an alternative way for caries prevention in young children.

Antimicrobial and anti-biofilm activities of Lactobacillus kefiranofaciens DD2 against oral pathogens

Background: Streptococcus mutans and Streptococcus sobrinus are major causative bacterial pathogens of dental caries. Objective: We investigated the applicability of three Lactobacillus strains (L. kefiranofaciens DD2, DD5, and DD6) isolated from kefir and three commercial Lactobacillus strains (L. plantarum ATCC 10,012, L. johnsonii JCM 1022, and L. rhamnosus ATCC 7469) as potential oral probiotics with respect to their survivability in an experimental oral environment, antimicrobial activity, and anti-biofilm formation activity against S. mutans and S. sobrinus. Results: Strains DD2, ATCC 10012, ATCC 7469, and JCM 1022 had the best oral survivability, including aerotolerance and enzymatic resistance, and inhibited the growth and biofilm formation of S. mutans and S. sobrinus. In particular, DD2 suppressed all three classes of biofilm formation-associated genes: those associated with carbohydrate metabolism and those encoding regulatory biofilm and adhesion proteins. Conclusions: These results indicate that the novel kefir isolate L. kefiranofaciens DD2 effectively and directly inhibits S. mutans and S. sobrinus.

Effects of a food enriched with probiotics on Streptococcus mutans and Lactobacillus spp. salivary counts in preschool children: a cluster randomized trial

Probiotics have provided benefits to general health, but they are still insufficient to dental health.

A microbiome case-control study of recurrent acute otitis media identified potentially protective bacterial genera

Background

Recurrent acute otitis media (rAOM, recurrent ear infection) is a common childhood disease caused by bacteria termed otopathogens, for which current treatments have limited effectiveness. Generic probiotic therapies have shown promise, but seem to lack specificity. We hypothesised that healthy children with no history of AOM carry protective commensal bacteria that could be translated into a specific probiotic therapy to break the cycle of re-infection. We characterised the nasopharyngeal microbiome of these children (controls) in comparison to children with rAOM (cases) to identify potentially protective bacteria. As some children with rAOM do not appear to carry any of the known otopathogens, we also hypothesised that characterisation of the middle ear microbiome could identify novel otopathogens, which may also guide the development of more effective therapies.

Results

Middle ear fluids, middle ear rinses and ear canal swabs from the cases and nasopharyngeal swabs from both groups underwent 16S rRNA gene sequencing. The nasopharyngeal microbiomes of cases and controls were distinct. We observed a significantly higher abundance of Corynebacterium and Dolosigranulum in the nasopharynx of controls. Alloiococcus, Staphylococcus and Turicella were abundant in the middle ear and ear canal of cases, but were uncommon in the nasopharynx of both groups. Gemella and Neisseria were characteristic of the case nasopharynx, but were not prevalent in the middle ear.

Conclusions

Corynebacterium and Dolosigranulum are characteristic of a healthy nasopharyngeal microbiome. Alloiococcus, Staphylococcus and Turicella are possible novel otopathogens, though their rarity in the nasopharynx and prevalence in the ear canal means that their role as normal aural flora cannot be ruled out. Gemella and Neisseria are unlikely to be novel otopathogens as they do not appear to colonise the middle ear in children with rAOM.

Electronic supplementary material

The online version of this article (10.1186/s12866-018-1154-3) contains supplementary material, which is available to authorized users.

Human oral microbiota and its modulation for oral health

The oral microbiome is an important part of the human microbiome. The oral cavity contains several significantly different niches with distinct microbial communities. A wide range of microorganisms inhabit the human oral cavity, including bacteria, fungi, viruses, archaea and protozoa. These microorganisms form a complex ecological community that influences oral and systemic health. The most prevalent oral diseases, dental caries and periodontal diseases, are microbiota-associated diseases. Moreover, increasing evidences have supported that many systemic diseases are associated with disturbances in the oral ecosystem, such as diabetes, cardiovascular diseases and tumors. The current control of dental plaque-related diseases is nonspecific and is centered on the removal of plaque by mechanical means. Due to this realization about the oral microbiome, several new methods based on the modulation of the microbiome that aim at maintaining and reestablishing a healthy oral ecosystem have been developed.

Ecological Approaches to Dental Caries Prevention: Paradigm Shift or Shibboleth?

Contemporary paradigms of dental caries aetiology focus on the ecology of the dental plaque biofilm and how local environmental factors can modulate this to cause disease. The crucial role that a healthy oral microbiome plays in preventing caries and promoting oral health is also being increasingly recognized. Based on these concepts, several ecological preventive approaches have been developed that could potentially broaden the arsenal of currently available caries-preventive measures. Many of these ecological approaches aim for long-term caries control by either disrupting cariogenic virulence factors without affecting bacterial viability, or include measures that can enhance the growth of health-associated, microbially diverse communities in the oral microbiome. This paper argues for the need to develop ecological preventive measures that go beyond conventional caries-preventive methods, and discusses whether these ecological approaches can be effective in reducing the severity of caries by promoting stable, health-associated oral biofilm communities.

Effect of tablets containing probiotic candidate strains on gingival inflammation and composition of the salivary microbiome: a randomised controlled trial

The aim of the study was to investigate clinical and microbial effects of probiotic candidate strains in patients with moderate gingivitis. The null hypothesis was that the clinical measurements with treatment would not differ from placebo. 47 adult patients were enrolled in a randomised placebo-controlled trial with a 4-week intervention of tablets containing a mix of Lactobacillus rhamnosus PB01, DSM 14869 and Lactobacillus curvatus EB10, DSM 32307 or placebo. Clinical examinations and samplings were done at baseline and after 2, 4 and 6 weeks. The clinical endpoints were general bleeding on probing (BOP), general plaque index (PI) and flow of gingival crevicular fluid (GCF). In addition, the concentration of selected cytokines (interleukin (IL)-1β, IL-6, IL-8, IL-10, tumour necrosis factor alpha (TNF-α)) in GCF was determined with multiplex immunoassays. The profiles of the salivary microbiome were analysed with Next Generation Sequencing (NGS) and qPCR. In contrast to the placebo group, there was a significant reduction in BOP and amount of GCF (P<0.05) after 4 weeks in the probiotic test group when compared with baseline. The general PI was less affected although there was a tendency of decreased plaque levels in the probiotic group (P=0.05-0.09). The cytokines were unaffected by the intervention as well as the salivary microbiome. The Shannon index showed no significant differences between the groups or alterations over time. The occurrence of both probiotic strains increased in saliva of the test subjects during the intervention but returned to baseline levels within 2 weeks. Although a marked improvement in gingival health was recorded in the probiotic group, the null hypothesis could not be rejected.

Quantification of carious pathogens in the interdental microbiota of young caries-free adults

Background

The majority of caries lesions in adults occur on the proximal tooth surfaces of the posterior teeth. A comprehensive study of the composition of the oral microbiota is fundamental for a better understanding of the etiology of interdental caries.

Methods

Twenty-five caries-free subjects (20–35 years old) were enrolled in the study. The interdental biofilm of four interdental sites were collected. The real-time polymerase chain reaction (PCR) methodology were used to quantify (i) the following bacteria: Streptococcus spp., Streptococcus mutans, Lactobacillus spp., Enterococcus spp., and Enterococcus faecalis; (ii) the fungus Candida albicans; and (iii) total bacteria.

Results

Streptococcus spp. was the most abundant species, followed by Lactobacillus spp. and Enterococcus spp. Streptococcus spp. and Lactobacillus spp. were detected at all tested sites and Enterococcus spp. at 99% of sites. S. mutans was detected at only 28% of the tested sites and C. albicans was detected at 11% of sites. E. faecalis was never detected. In 54.5% of the biofilm inhabited by C. albicans, S. mutans was present. Moreover, 28% of the ID sites co-expressed S. mutans and Lactobacillus spp. The studied pathogens were organized into two correlated groups of species. Strikingly, the fungus C. albicans and the bacteria Enterococcus spp. cluster together, whereas Streptococcus spp., S. mutans and Lactobacillus spp. form one distinct cluster.

Conclusion

The interdental biofilm of young caries-free adults is comprised of pathogens that are able to induce interproximal caries. That several of these pathogens are implicated in heart disease or other systemic diseases is an argument for the disruption of interdental biofilms using daily oral hygiene.

Health-Associated Niche Inhabitants as Oral Probiotics: The Case of Streptococcus dentisani

Oral diseases, including dental caries and periodontitis, are among the most prevalent diseases worldwide and develop as a consequence of a microbial dysbiosis. Several bacterial strains are being tested as potential oral health-promoting organisms, but usually they are species isolated from niches other than the site where they must exert its probiotic action, typically from fecal samples. We hypothesize that oral inhabitants associated to health conditions will be more effective than traditional, gut-associated probiotic species in key aspects such as colonization of the oral site where disease takes place or the possession of oral health promoting functions, as well as more practical issues like safety and toxicity, and establishing proper doses for administration. As an example of these active colonizers, we describe the case of Streptococcus dentisani, a new streptococcal species isolated from dental plaque of caries-free individuals. We have detected it in 98% of dental plaque samples from healthy individuals and, as expected, it does not produce any toxic secondary metabolite and does not survive a simulated stomach digestion, preventing potential secondary effects. Besides, this species has a double probiotic action, as it inhibits the growth of major oral pathogens through the production of bacteriocins, and also buffers acidic pH (the primary cause of dental caries) through an arginolytic pathway. We propose the use of S. dentisani as a promising probiotic against tooth decay.

Inhibition of Streptococcus mutans Growth and Biofilm Formation by Probiotics in vitro

To exert anticaries effects, probiotics are described to inhibit growth and biofilm formation of cariogenic bacteria such as Streptococcus mutans (SM). We screened 8 probiotics and assessed how SM growth or biofilm formation inhibition affects cariogenicity of probiotic-SM mixed-species biofilms in vitro. Growth inhibition was assessed by cocultivating probiotics and 2 SM strains (ATCC 20532/25175) on agar. Probiotics were either precultured before SM cultivation (exclusion), or SM precultured prior to probiotic cultivation (displacement). Inhibition of SM culture growth was assessed visually. Inhibition of SM biofilm formation on bovine enamel was assessed using a continuous-flow short-term biofilm model, again in exclusion or displacement mode. The cariogenicity of mixed-species biofilms of SM with the most promising growth and biofilm formation inhibiting probiotic strains was assessed using an artificial mouth model, and enamel mineral loss (ΔZ) was measured microradiographically. We found limited differences in SM growth inhibition in exclusion versus displacement mode, and in inhibition of SM 20532 versus 25175. Results were therefore pooled. Lactobacillus acidophilus LA-5 inhibited significantly more SM culture growth than most other probiotics. L. casei LC-11 inhibited SM biofilm formation similarly to other alternatives but showed the highest retention of probiotics in the biofilms (p < 0.05). Mineral loss from SM monospecies biofilms (ΔZ = 9,772, 25th/75th percentiles: 6,277/13,558 vol% × µm) was significantly lower than from mixed-species SM × LA-5 biofilms (ΔZ = 24,578, 25th/75th percentiles: 19,081/28,768 vol% × µm; p < 0.01) but significantly higher than from SM × LC-11 biofilms (ΔZ = 4,835, 25th/75th percentiles: 263/7,865 vol% × µm; p < 0.05). Probiotics inhibiting SM culture growth do not necessarily reduce the cariogenicity of SM-probiotic biofilms. Nevertheless, SM biofilm formation inhibition may be relevant in the reduction of cariogenicity.

Oral microflora in preschool children attending a fluoride varnish program: a cross-sectional study

Background

To compare the oral microflora in preschool children attending a fluoride varnish program with a reference group receiving a standard oral health program without fluoride varnish applications. A second aim was to relate the microbial composition to the caries prevalence.

Methods

Five hundred seven 3-year-old children were enrolled from a cohort of 3403 preschool children taking part in a community based oral health project. Two hundred sixty-three of them had attended caries-preventive program with semi-annual applications of a fluoride varnish since the age of 1 year (test group) while 237 had received standard preventive care (reference group). Oral samples were collected with a sterile swab and analysed with checkerboard DNA-DNA hybridization using 12 pre-determined bacterial probes. Caries and background data were collected from clinical examinations and questionnaires.

Results

Gram-positive streptococci (S. intermedius, S. salivarius, S. oralis) were most frequently detected and displayed the highest counts in both groups. There were no significant differences between the groups concerning prevalence of any of the selected bacterial strains except for S. oralis that occurred less frequently in the reference group. In children with caries, V. parvula were significantly more common (p < 0.05) while strains of Lactobacillus, Bifidobacterium and Neisseria were more prevalent among the caries-free children (p < 0.05).

Conclusions

A 2-year community program with semi-annual fluoride varnish applications did not seem to significantly influence the oral microflora in preschool children.

Trial registration

www.controlled-trials.com (ISRCTN35086887) 20131216 ‘retrospectively registered’.

Randomized controlled trial of juzen-taiho-to in children with recurrent acute otitis media

OBJECTIVE

Recurrent acute otitis media (AOM) in young children is rapidly increasing worldwide. Repeated antibiotic use leads to antibiotic-resistant pathogen development. Complementary and alternative medicine approaches have been suggested as a supplemental treatment option to conventional antimicrobial medicine. This randomized, parallel-group, open-label, non-herbal medicine controlled trial assessed the efficacy of a traditional Japanese herbal medicine, juzen-taiho-to (JTT) for AOM prevention in otitis-prone children.

METHODS

Children prone to recurrent AOM aged 6-48 months were recruited from 26 otolaryngology clinics in Japan and received conventional AOM treatment based on Japanese guidelines with or without 2 daily oral doses of JTT (0.10-0.25g/kg/day). The mean number of AOM episodes, coryza episodes, and duration of total antibiotic administration per month were compared during 3-month intervention.

RESULTS

At least one episode of AOM was diagnosed in 71% of JTT-group and 92% of control participants during follow-up. JTT administration reduced the frequency of AOM episodes by 57% compared with children who received conventional treatment alone (0.61±0.54 vs. 1.07±0.72 AOM instances/month; P=0.005) and also significantly decreased number of coryza episodes (P=0.015) and total antibiotic administration (P=0.024).

CONCLUSIONS

This is the first report of recurrent AOM prevention by herbal medication. JTT appears to effectively prevent recurrent AOM in children. Subsequent double-blind studies are needed to confirm the beneficial effects of JTT on recurrent AOM and upper respiratory tract infections.