The caries preventive effect of 1-year use of low-dose xylitol chewing gum. A randomized placebo-controlled clinical trial in high-caries-risk adults

The food additive xylitol enhances the butyrate formation by the child gut microbiota developed in a dynamic colonic simulator

The gut microbiota should be included in the scientific processes of risk assessment of food additives. Xylitol is a sweetener that shows low digestibility and intestinal absorption, implying that a high proportion of consumed xylitol could reach the colonic microbiota. The present study has evaluated the dose-dependent effects of xylitol intake on the composition and the metabolic activity of the child gut-microbiota. The study was conducted in a dynamic simulator of the colonic microbiota (BFBL Gut Simulator) inoculated with a child pooled faecal sample and supplemented three times per day, for 7 days, with increasing xylitol concentrations (1 g/L, 3 g/L and 5 g/L). Sequencing of 16S rRNA gene amplicons and group-specific quantitative PCR indicated a xylitol dose-response effect on the abundance of Lachnospiraceae, particularly the genera Blautia, Anaerostipes and Roseburia. The microbial changes observed with xylitol corresponded with a dose-dependant effect on the butyrate concentration that, in parallel, favoured an increase in epithelial integrity of Caco-2 cells. The study represents a detailed observation of the bacterial taxa that are the main contributors to the metabolism of xylitol by the child gut microbiota and the results could be relevant in the risk assessment re-evaluation of xylitol as a sweetener.

How probiotics, prebiotics, synbiotics, and postbiotics prevent dental caries: an oral microbiota perspective

Dental caries, a highly prevalent oral disease, impacts a significant portion of the global population. Conventional approaches that indiscriminately eradicate microbes disrupt the natural equilibrium of the oral microbiota. In contrast, biointervention strategies aim to restore this balance by introducing beneficial microorganisms or inhibiting cariogenic ones. Over the past three decades, microbial preparations have garnered considerable attention in dental research for the prevention and treatment of dental caries. However, unlike related pathologies in the gastrointestinal, vaginal, and respiratory tracts, dental caries occurs on hard tissues such as tooth enamel and is closely associated with localized acid overproduction facilitated by cariogenic biofilms. Therefore, it is insufficient to rely solely on previous mechanisms to delineate the role of microbial preparations in the oral cavity. A more comprehensive perspective should involve considering the concepts of cariogenic biofilms. This review elucidates the latest research progress, mechanisms of action, challenges, and future research directions regarding probiotics, prebiotics, synbiotics, and postbiotics for the prevention and treatment of dental caries, taking into account the unique pathogenic mechanisms of dental caries. With an enhanced understanding of oral microbiota, personalized microbial therapy will emerge as a critical future research trend.

Chronic graft-versus-host disease. Part II: Disease activity grading and therapeutic management

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 Federal Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of cGVHD. Part II discusses disease grading and therapeutic management.

A concise review of chewing gum as an anti-cariogenic agent

Chewing gum has been endorsed as a caries preventive agent by the FDI World Dental Federation, the American Dental Association, and the European Food Safety Authority. This review discusses the mechanism and provides an update of the use of chewing gum for caries prevention. Chewing gum typically consists of a water-insoluble gum base, water-soluble added ingredients, and active ingredients. It can be classified as sugar-containing or sugar-free, as well as nonmedicated or medicated. Chewing gum prevents dental caries through a range of mechanisms, including the clearance of the oral cavity, neutralization of oral acidity, inhibition of cariogenic bacterial growth, remineralization of enamel, and reduction of appetite. Recent clinical studies have evaluated the efficacy of sugar-free chewing gum for caries prevention, with most demonstrating positive results, although some studies have reported contradictory outcomes. To achieve optimal caries prevention, it is generally recommended that individuals chew sugar-free gum for five minutes after meals, three times daily.

Study protocol for a randomized clinical trial to evaluate the effect of the use of Xylitol gum in the prevention of caries lesions in children living in Ladakh-the Caries Prevention Xylitol in Children (CaPreXCh) trial

Background

Xylitol use is reported to be able to reduce dental plaque amount and cariogenic bacteria and, as a consequence, the caries increment. Only few data on the oral health of Ladakh’s population are available. The aim of the present protocol will be to record the caries prevalence of primary and permanent molars of schoolchildren living in Ladakh and to implement a school-based Xylitol programme, named the Caries Prevention Xylitol in Children (CaPreXCh) trial, using chewing gums.

Methods

The protocol is designed as a triple-blind randomized, controlled, parallel-group clinical trial in children aged 5–14 years. The study should have been carried out from August 2021 to August 2024 in Zanskar Valley (Ladakh), but the COVID-19 pandemic does not allow today to make predictions on the exact start. Participants will be randomly allocated into two groups: subjects who will receive a chewing gum with Xylitol (70% w/v) as only sweetener, and those who will receive a sugared chewing gum containing Maltitol (23% w/v). The subjects will be instructed to chew a total of 6 pellets for 5 min divided into 3 intakes a day (2 in the morning, 2 after the midday meal and 2 in the afternoon) for one school year. Clinical examination will comprise an oral examination in which caries index (ICDAS scores), bleeding on probing and plaque pH evaluation after sucrose challenge will be recorded at baseline (t₀); the clinical examination will be repeated after 12 months since the beginning of the chewing gum administration period (t₁), after another 12-month period (t₂) and finally after further 12 months (t₃) (24 months from the end of the chewing gum use). The primary outcome will be the caries increment measured both at enamel and dentinal levels on primary and permanent molars. Data analysis will be conducted through Kaplan-Meyer graphs to evaluate caries increment. A comparison of the methods will be carried out with Cox regression with shared frailty. The net caries increment for initial, moderate and severe caries levels, using ICDAS (Δ-initial, Δ-moderate and Δ-severe), will be calculated.

Discussion

This trial will be the first trial conducted in India assessing the efficacy of a school-based caries preventive programme through the use of chewing gum containing only Xylitol as a sweetener. The findings could help strengthen the evidence for the efficacy of Xylitol use in community-based caries prevention programmes in children.

Trial registration

Clinical trials.govNCT04420780. Registered on June 9, 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05828-y.

Effect of Xylitol Chewing Gum on Presence of Streptococcus mutans in Saliva

BACKGROUND: Oral disease ranks third among the most serious diseases in the world, after cancer and cardiovascular disease. Vietnamese population has suffered from various dental and oral diseases, of which the most common have been identified to be cavities and inflammation around the teeth. AIM: The aim of the study was to evaluate the effectiveness of using xylitol gum on the status of Strepptococus mutans bacteria in saliva. METHODS: The study design was an uncontrolled clinical study conducted at the Hanvinco Texture Factory (Hanoi). Two hundred and fifty-four subjects between the ages of 18 and 63 were included in the clinical trial. These subjects brushed their teeth for 2 weeks before providing a saliva sample for S. mutans. The 80 subjects with the highest number of salivary S. mutans were recruited for the further analysis (at least 104 CFU/ml). After each clinical intervention, participant chewed Lotte xylitol gum after each meal, two capsules each time and 1 time in the evening (total 4 times/day), continuously for 4 weeks. Saliva samples were quantified for S. mutans by real-time PCR method. RESULTS: Quantitative analysis of S. mutans bacteria in saliva of 254 subjects showed that 19.7% had S. mutans detected within 105 CFU/ml of saliva. These result shows that nearly 20% of the subjects examined have a high risk of tooth decay. After continuous use of xylitol chewing gum 4 times a day for 4 weeks by 80 subjects, it showed a decrease in the number of S. mutans in the saliva of participants, and the difference was statistically significant. CONCLUSIONS: The use of xylitol chewing gum taken 4 times/day is effective in reducing the number of S. mutans bacteria in saliva when combined with brushing your teeth.

pH-Responsive Hybrid Nanoparticles for Imaging Spatiotemporal pH Changes in Biofilm-Dentin Microenvironments

Engineering highly sensitive nanomaterials to monitor spatiotemporal pH changes has rather broad applications in studying various biological systems. Intraoral/biofilm-tooth pH is the single parameter that has demonstrated accurate assessment of dental caries risk, reflecting the summative integrated outcome of the complicated interactions between three etiological factors, namely, microorganisms/biofilm, diet/carbohydrates, and tooth/saliva/host. However, there is little to no technology/system capable of accurately probing simultaneously both the micro-pH profiles in dentin tissues and acidogenic oral biofilms and examining the pathophysiologic acid attacks with high spatial/temporal resolution. Therefore, a highly sensitive pH-responsive hybrid nanoparticle (pH-NP) is developed and coupled with an ex vivo tooth-biofilm caries model to simulate and study the key cariogenic determinants/steps. The pH-NP emits two distinct fluorescences with mutually inversely proportional intensities that vary accordingly to the proximity pH and with a ratiometric output sensitivity of 13.4-fold across a broad clinically relevant pH range of 3.0-8.0. Using [H⁺], in addition to pH, to calculate the "area-under-curve" corroborates the "minimum-pH" in semiquantifying the demineralizing potential in each biofilm-dentin zones/depth. The data mechanistically elucidates a two-pronged cariogenic effect of a popular-acidic-sweet-drink, in inundating the biofilm/tooth-system with H⁺ ions from both the drink and the metabolic byproducts of the biofilm.

The Current Strategies in Controlling Oral Diseases by Herbal and Chemical Materials

Dental plaque is a biofilm composed of complex microbial communities. It is the main cause of major dental diseases such as caries and periodontal diseases. In a healthy state, there is a delicate balance between the dental biofilm and host tissues. Nevertheless, due to the oral cavity changes, this biofilm can become pathogenic. The pathogenic biofilm shifts the balance from demineralization-remineralization to demineralization and results in dental caries. Dentists should consider caries as a result of biological processes of dental plaque and seek treatments for the etiologic factors, not merely look for the treatment of the outcome caused by biofilm, i.e., dental caries. Caries prevention strategies can be classified into three groups based on the role and responsibility of the individuals doing them: (1) community-based strategy, (2) dental professionals-based strategy, and (3) individual-based strategy. The community-based methods include fluoridation of water, salt, and milk. The dental professionals-based methods include professional tooth cleaning and use of varnish, fluoride gel and foam, fissure sealant, and antimicrobial agents. The individual-based (self-care) methods include the use of fluoride toothpaste, fluoride supplements, fluoride mouthwashes, fluoride gels, chlorhexidine gels and mouthwashes, slow-release fluoride devices, oral hygiene, diet control, and noncariogenic sweeteners such as xylitol. This study aimed to study the research in the recent five years (2015–2020) to identify the characteristics of dental biofilm and its role in dental caries and explore the employed approaches to prevent the related infections.

Inhibition of Streptococcus mutans biofilm formation by strategies targeting the metabolism of exopolysaccharides

Dental caries is one of the most prevalent and costly biofilm-associated infectious diseases affecting most of the world's population. In particular, dental caries is driven by dysbiosis of the dental biofilm adherent to the enamel surface. Specific types of acid-producing bacteria, especially Streptococcus mutans, colonize the dental surface and cause damage to the hard tooth structure in the presence of fermentable carbohydrates. Streptococcus mutans has been established as the major cariogenic pathogen responsible for human dental caries, with a high ability to form biofilms. The exopolysaccharide (EPS) matrix, mainly contributed by S. mutans, has been considered as a virulence determinant of cariogenic biofilm. As EPS is an important virulence factor, targeting EPS metabolism could be useful in preventing cariogenic biofilm formation. This review summarizes plausible strategies targeting S. mutans biofilms by degrading EPS structure, inhibiting EPS production, and disturbing the EPS metabolism-related gene expression and regulatory systems.

Effects of xylitol and erythritol consumption on mutans streptococci and the oral microbiota: a systematic review

OBJECTIVE

A systematic review of published data was conducted with the aim of assessing effects of xylitol and erythritol consumption on levels of mutans streptococci (MS) and the oral microbiota.

MATERIALS AND METHODS

Electronic and hand searches were performed to find clinical microbiological studies concerning the consumption of xylitol and erythritol chewing gum or candies, and published between 2000 and 2019. Prospective randomized controlled clinical trials conducted in healthy subjects were included in the review.

RESULTS

The initial search identified 561 xylitol and 83 erythritol studies. After applying inclusion and exclusion criteria, 21 xylitol studies and one erythritol study were reviewed. The review identified nine xylitol studies with a fair or high quality, four conducted in children and five in adults, all demonstrating a decrease in MS levels in association with habitual consumption of xylitol. The three microbiota studies employing multispecies probe approaches revealed no effects for xylitol on the microbiota. The only erythritol study fulfilling the inclusion criteria showed no consistent effects on MS levels.

CONCLUSIONS

Xylitol consumption is likely to decrease MS counts but it may not change the overall microbiota. Xylitol shows thus properties of an oral prebiotic. More studies are needed to demonstrate the effects of erythritol on MS.

Effect of xylitol tablets with and without red propolis on salivary parameters, dental biofilm and sensory acceptability of adolescents: a randomized crossover clinical trial

The effect of xylitol tablets with (XPT) and without (XT) red propolis on salivary parameters, dental biofilm and acceptability of adolescents was evaluated through a blinded randomized crossover clinical trial. Healthy volunteers were allocated in the XPT and XT groups with a 30-day washout period for consumption of two tablets/dayfor seven days. An increase in salivary parameters was only observed immediately after tablet consumption, without differences between XPT and XT. The results for total microorganisms were similar, but XT was better in controlling Streptococcus spp. Rothia dentocariosa and Streptococcus salivarius were the most frequent in the biofilm and saliva, respectively. XPT and XT showed similar acceptability, with the highest purchase intention for XT. Although propolis did not enhance the properties of XT, further studies testing different protocols and follow-up are necessary; XT controlled Streptococcus spp. in biofilms, which demonstrate its potential for clinical application.

Dental management of patients with substance use disorder

Substance use disorder (SUD) is a relapsing brain disorder characterized by compulsion and chronicity. SUD has detrimental effects on oral health. Drugs and alcohol negatively impact oral health by inducing a myriad of orofacial conditions including xerostomia, dental caries, periodontal disease, bruxism, pre-cancer and cancer, to name a few. Limited recommendations are available for dental professionals on how best to manage patients afflicted with SUD. The aim of this article is to review the oral health consequences of alcohol and commonly abused drugs to provide guidelines for the public health community and dental professionals. The United Nations estimates that a quarter billion people, representing five per cent of the global adult population, used drugs at least once in 2015. Developing public health interventions that include the participation of dental professionals and access to dental services for persons afflicted with SUD could play a critical role in improving their quality of life, their recovery, and their reintroduction into society.

Teeth: Small but Mighty and Mighty Important. A Comprehensive Review of Children's Dental Health for Primary Care Clinicians

Healthy teeth allow us to eat and stay well-nourished. Although primary care clinicians receive limited training about teeth, given the common nature of dental problems, it is important that they understand and recognize normal and abnormal dental conditions and can implement primary and secondary prevention of dental conditions in their practice. PubMed has been used to search the scientific literature for evidence on the following topics: normal dental development, dental abnormalities, malocclusion, teething, dental caries and related epidemiology and prevention, fluoride, dental injury and its management and prevention; and identification, prevention and treatment of gingivitis and periodontal disease. Literature review relied on randomized controlled trials, meta-analyses, systematic reviews, and Cochrane reviews when relevant and available. Other sources of evidence included cohort and case-control studies. Consensus statements and expert opinion were used when there was a paucity of high-quality research studies. The literature has been synthesized on these topics to make them relevant to pediatric primary care clinicians, and as available, the strength of evidence has been characterized when making clinical recommendations.

Oral and Systemic Effects of Xylitol Consumption

Recent results of randomized trials testing the efficacy of xylitol in caries prevention have been conflicting. This narrative review reveals the sources of discrepancy. The following databases were searched for the terms "xylitol" or "artificial sweeteners" restricted to the English language: PubMed, Web of Science, Evidenced-Based Medicine, Scopus, and the Cochrane database. In a separate search, the terms "dental caries" or "cariogenicity" or "glucosyltransferase" or "low glycemic" or "low insulinemic" or "dysbiosis" or "gut microbiome" were used and then combined. In section I, findings regarding the role of xylitol in dental caries prevention, the appropriateness of research methods, and the causes for potential biases are summarized. In section II, the systemic effects of xylitol on gut microbiota as well as low-glycemic/insulinogenic systemic effects are evaluated and summarized. The substitution of a carbonyl group with an alcohol radical in xylitol hinders its absorption and slowly releases sugar into the bloodstream. This quality of xylitol is beneficial for diabetic patients to maintain a constant glucose level. Although this quality of xylitol has been proven in in vitro and animal studies, it has yet to be proven in humans. Paradoxically, recent animal studies reported hyperglycemia and intestinal dysbiosis with artificial sweetener consumption. Upon careful inspection of evidence, it was revealed that these reports may be due to misinterpretation of original references or flaws in study methodology. Any systemic benefits of xylitol intake must be weighed in consideration with the well-established adverse gastrointestinal consequences. The contribution of xylitol to gut dysbiosis that may affect systemic immunity warrants further research.