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

Real-time acid production and extracellular matrix formation in mature biofilms of three Streptococcus mutans strains with special reference to xylitol

Background

Acidogenicity and production of an extracellular matrix (ECM) are important virulence factors for the dental caries-associated bacteria, such as Streptococcus mutans, that live in biofilms on tooth surface. The ECM protects the bacteria from the flushing and buffering effects of saliva resulting in highly acidic microenvironments inside the biofilm.

Materials and methods

In this in vitro study, we applied real-time assays to follow biofilm formation and pH decrease in a growth medium and saliva by three S. mutans strains, as well as acid neutralization inside the mature biofilm. Results were compared with the biofilm composition. Effects of a non-fermentable polyol, xylitol, on acid production and acid neutralization in mature biofilms were evaluated by real-time pH measurements and confocal microscopy.

Results

Combination of real-time pH measurements with biofilm accumulation assays revealed growth media dependent differences in the pH decrease and biofilm accumulation, as well as strain differences in acid production and biofilm formation but not in the buffer diffusion through ECM. The presence of xylitol reduced the pH drop during biofilm formation of all strains. In addition, with strain Ingbritt xylitol reduced the amount of ECM in biofilm, which increased the rate of acid neutralization inside the biofilm after buffer exposure.

Conclusion

Our results stress the importance of biofilm matrix in creating the acidic environment inside a S. mutans biofilm, especially in the presence of saliva. In addition, our results suggest a novel mechanism of xylitol action. The observed increase in the permeability of the S. mutans ECM after xylitol exposure may allow acid-neutralizing saliva to reach deeper layer of the biofilms and thus, in part, explain previous clinical observations of reduced plaque acidogenicity after frequent xylitol use.

Bibliometric Analysis of Clinical Trials on the Effect of Sugar Alcohol Consumption on Oral Health: Trends, Insights, and Future Directions (1967-2024)

In recent years, the quest for healthier alternatives to sugar has led to the widespread use of sugar alcohol in various food and beverage products. Sugar alcohols, such as xylitol, sorbitol, and erythritol, are popular substitutes due to their sweet taste and lower calorie content than sucrose. Beyond their role in calorie reduction, sugar alcohols have garnered attention for their potential impact on oral health. The bibliometric analysis of clinical trials on sugar alcohol and oral health in PubMed reveals a dynamic and multifaceted research landscape shaped by various factors. Fluctuations in publication rates over time suggest influences such as shifts in research interests, technological advancements, regulatory changes, and evolving consumer behaviors. Key authors like Makinen KK, Makinen PL, and Soderling E emerge as prolific contributors with collaborative solid networks within the research community. The University of Turku in Finland has been identified as the highest contributing university, while Caries Research is the most contributing journal based on the number of clinical trials published. The country-wise analysis highlights Italy and the United States as substantial contributors, with diverse trajectories of research activity observed across nations. The subject-specific words with the highest cooccurrence are xylitol, dental caries, chewing gum, Streptococcus mutans, and saliva. Thematic analysis dives deep into how sugar alcohols relate to oral health, using different methods to study their effectiveness, safety, and how they affect the oral microbiome. The analysis of topic trends indicates ongoing exploration of sorbitol and xylitol, with an increasing emphasis on the potential advantages of xylitol. Additionally, there is notable attention on cariostatic agents, strategies for dental caries prevention, and the emergence of novel research domains like probiotics and erythritol, showcasing the dynamic evolution of oral health research focuses and developments. Overall, this analysis provides valuable insights into the distribution and trends of clinical trial publications, contributing to a nuanced understanding of the research landscape in sugar alcohol and oral health.

The effect of xylitol chewing gums and candies on caries occurrence in children: a systematic review with special reference to caries level at study baseline

PURPOSE

A systematic review of published data was carried out to assess the caries-preventive effects of xylitol chewing gums and candies in children.

METHODS

Electronic and hand searches were performed to find clinical studies on the effects of xylitol chewing gums and candies on dental caries in children (≤ 18 years). Prospective randomised or controlled clinical trials published before 2023 were included in the review.

RESULTS

The initial search identified 365 titles to be evaluated. After applying inclusion and exclusion criteria, 15 articles with either fair or low quality were reviewed. Nine articles studied chewing gums, five candies, and one both of them. In the ten evaluated xylitol chewing gum studies xylitol consumption significantly reduced caries occurrence when compared with no treatment or a placebo polyol gum. The effect was clinically significant in studies with high or moderate caries level at study baseline. The results also suggested that the caries-reducing effect of xylitol gums may differ from sorbitol/polyol gums. In five of the six heterogenous xylitol candy studies, no caries-reducing effect was found independent of caries level. In addition to caries level, also the daily xylitol dose was a confounding factor.

CONCLUSION

The present findings suggest that the caries-reducing effect of adding xylitol chewing gum to the daily diet has been well demonstrated in children and adolescents with high or moderate caries level at study baseline. Xylitol gum use could benefit subjects with active incipient caries lesions on smooth tooth surfaces.

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.

Inhibitory effects of Stevioside on Streptococcus mutans and Candida albicans dual-species biofilm

Introduction

Streptococcus mutans is the most prevalent biofilm-forming pathogen in dental caries, while Candida albicans is often detected in the presence of S. mutans.

Methods

We aimed to evaluate the anti-caries effect of stevioside in medium trypticase soy broth (TSB) with or without sucrose supplementation compared with the same sweetness sucrose and xylitol in a dual-species model of S. mutans and C. albicans, based on planktonic growth, crystal violet assay, acid production, biofilm structural imaging, confocal laser scanning microscopy, and RNA sequencing.

Results

Our results showed that compared with sucrose, stevioside significantly inhibited planktonic growth and acid production, changed the structure of the mixed biofilm, and reduced the viability of biofilm and the production of extracellular polysaccharides in dual-species biofilm. Through RNA-seq, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway impact analysis showed that stevioside decreased sucrose metabolism and increased galactose and intracellular polysaccharide metabolism in S. mutans, and decreased genes related to GPI-modified proteins and secreted aspartyl proteinase (SAP) family in C. albicans. In contrast to xylitol, stevioside also inhibited the transformation of fungal morphology of C. albicans, which did not form mycelia and thus had reduced pathogenicity. Stevioside revealed a superior suppression of dual-species biofilm formation compared to sucrose and a similar anti-caries effect with xylitol. However, sucrose supplementation diminished the suppression of stevioside on S. mutans and C. albicans.

Conclusions

Our study is the first to confirm that stevioside has anticariogenic effects on S. mutans and C. albicans in a dual-species biofilm. As a substitute for sucrose, it may help reduce the risk of developing dental caries.

Effects of sugar-free polyol chewing gums on gingival inflammation: a systematic review

OBJECTIVES

A systematic review of published data was conducted with the aim of assessing the effects of sugar-free polyol chewing gums on gingival inflammation.

MATERIALS AND METHODS

Electronic and hand searches were performed to find clinical studies concerning the effects of sugar-free chewing gums on gingival scores. Prospective randomized controlled clinical trials published between 1971 and 2021 were included in the review.

RESULTS

The initial search identified 46 erythritol, 102 xylitol, 23 sorbitol, and nine maltitol chewing gum articles. After applying inclusion and exclusion criteria, seven xylitol chewing gum studies, one sorbitol, and one maltitol chewing gum study with either high or fair quality were reviewed. In five out of the seven xylitol studies, xylitol gum decreased gingival scores. In two studies, xylitol decreased gingival scores compared to a polyol gum, and in three studies compared to no gum/gum base. As for sorbitol and maltitol, only sorbitol gum chewing showed a small decrease in gingival scores compared to the controls.

CONCLUSIONS

Habitual xylitol gum chewing may reduce gingival inflammation. The low number of studies and their heterogeneity provide clear indications that the effects of sugar-free polyol chewing gums on gingival inflammation need further, well-controlled studies.

CLINICAL RELEVANCE

Sugar-free chewing gums, especially xylitol gum, may function as adjuncts to toothbrushing for reducing gingival inflammation, but the evidence so far is inconclusive.

Dvorak C, Den Besten P. Dental caries as a risk factor for bacterial blood stream infection (BSI) in children undergoing hematopoietic cell transplantation (HCT)

Background

Hematopoietic cell transplantation (HCT) is a potentially curative therapy for a wide range of pediatric malignant and nonmalignant diseases. However, complications, including blood stream infection (BSI) remain a major cause of morbidity and mortality. While certain bacteria that are abundant in the oral microbiome, such as S. mitis, can cause BSI, the role of the oral microbial community in the etiology of BSI is not well understood. The finding that the use of xylitol wipes, which specifically targets the cariogenic bacteria S. mutans is associated with reduced BSI in pediatric patients, lead us to investigate dental caries as a risk factor for BSI.

Methods

A total of 41 pediatric patients admitted for allogenic or autologous HCT, age 8 months to 25 years, were enrolled. Subjects with high dental caries risk were identified as those who had dental restorations completed within 2 months of admission for transplant, or who had untreated decay. Fisher's exact test was used to determine if there was a significant association between caries risk and BSI. Dental plaque and saliva were collected on a cotton swab from a subset of four high caries risk (HCR) and four low caries risk (LCR) children following pretransplant conditioning. 16SrRNA sequencing was used to compare the microbiome of HCR and LCR subjects and to identify microbes that were significantly different between the two groups.

Results

There was a statistically significant association between caries risk and BSI (p < 0.035) (Fisher's exact test). Multivariate logistic regression analysis showed children in the high dental caries risk group were 21 times more likely to have BSI, with no significant effect of age or mucositis severity. HCR subjects showed significantly reduced microbial alpha diversity as compared to LCR subjects. LEfse metagenomic analyses, showed the oral microbiome in HCR children enriched in order Lactobacillales. This order includes Streptococcus and Lactobacillus, both which contain bacteria primarily associated with dental caries.

Discussion

These findings support the possibility that the cariogenic microbiome can enhance the risk of BSI in pediatric populations. Future metagenomic analyses to measure microbial differences at, before, and after conditioning related to caries risk, may further unravel the complex relationship between the oral microbiome, and whether it affects health outcomes such as BSI.

Biochemical characterization of a novel acidophilic β-xylanase from Trichoderma asperellum ND-1 and its synergistic hydrolysis of beechwood xylan

Acidophilic β-xylanases have attracted considerable attention due to their excellent activity under extreme acidic environments and potential industrial utilizations. In this study, a novel β-xylanase gene (Xyl11) of glycoside hydrolase family 11, was cloned from Trichoderma asperellum ND-1 and efficiently expressed in Pichia pastoris (a 2.0-fold increase). Xyl11 displayed a maximum activity of 121.99 U/ml at pH 3.0 and 50°C, and exhibited strict substrate specificity toward beechwood xylan (K_m = 9.06 mg/ml, V_max = 608.65 μmol/min/mg). The Xyl11 retained over 80% activity at pH 2.0–5.0 after pretreatment at 4°C for 1 h. Analysis of the hydrolytic pattern revealed that Xyl11 could rapidly convert xylan to xylobiose via hydrolysis activity as well as transglycosylation. Moreover, the results of site-directed mutagenesis suggested that the Xyl11 residues, Glu¹²⁷, Glu¹⁶⁴, and Glu²¹⁶, are essential catalytic sites, with Asp¹³⁸ having an auxiliary function. Additionally, a high degree of synergy (15.02) was observed when Xyl11 was used in association with commercial β-xylosidase. This study provided a novel acidophilic β-xylanase that exhibits excellent characteristics and can, therefore, be considered a suitable candidate for extensive applications, especially in food and animal feed industries.

Effect of chewing gum containing Xylitol and blackberry powder on oral bacteria: A randomized controlled crossover trial

OBJECTIVE

The aim was to determine the effect of chewing gum containing xylitol and freeze-dried blackberry powder on oral bacteria.

DESIGN

This was a randomized, controlled, cross-over study (RCT #: NCT05133557). Fifty participants chewed gum over an 8 h period, four times for 20 min at 2-hour intervals, containing 700 mg xylitol (CG) with or without 50 mg blackberry powder (BG), while wearing a stent containing a sterile enamel chip. After a 1 week washout, participants chewed gum from the other group following the same protocol. The primary outcome was the amount of nine oral bacteria in saliva as determined by quantitative PCR. The secondary outcome was bacteria formed on enamel chips.

RESULTS

Chewing BG for four twenty-minute intervals reduced mean total bacteria load and the relative abundance of six of the nine bacteria studied in saliva (p < 0.05). In comparison, only four bacteria were reduced in abundance in the CG group. After gum chewing and regardless of group, S. sanguinis and A. naeslundii were the predominant bacteria adherent to enamel, with S. mutans representing < 1 % of the total bacteria on enamel.

CONCLUSION

Bacterial loads in saliva were rapidly, differentially, and significantly reduced after one day of chewing BG.

Research progress on extraction technology and biomedical function of natural sugar substitutes

Improved human material living standards have resulted in a continuous increase in the rate of obesity caused by excessive sugar intake. Consequently, the number of diabetic patients has skyrocketed, not only resulting in a global health problem but also causing huge medical pressure on the government. Limiting sugar intake is a serious problem in many countries worldwide. To this end, the market for sugar substitute products, such as artificial sweeteners and natural sugar substitutes (NSS), has begun to rapidly grow. In contrast to controversial artificial sweeteners, NSS, which are linked to health concepts, have received particular attention. This review focuses on the extraction technology and biomedical function of NSS, with a view of generating insights to improve extraction for its large-scale application. Further, we highlight research progress in the use of NSS as food for special medical purpose (FSMP) for patients.

Obesity influences composition of salivary and fecal microbiota and impacts the interactions between bacterial taxa

Obesity is an increasing global health concern and is associated with a broad range of morbidities. The gut microbiota are increasingly recognized as important contributors to obesity and cardiometabolic health. This study aimed to characterize oral and gut microbial communities, and evaluate host: microbiota interactions between clinical obesity classifications. We performed 16S rRNA sequencing on fecal and salivary samples, global metabolomics profiling on plasma and stool samples, and dietary profiling in 135 healthy individuals. We grouped individuals by obesity status, based on body mass index (BMI), including lean (BMI 18-124.9), overweight (BMI 25-29.9), or obese (BMI ≥30). We analyzed differences in microbiome composition, community inter-relationships, and predicted microbial function by obesity status. We found that salivary bacterial communities of lean and obese individuals were compositionally and phylogenetically distinct. An increase in obesity status was positively associated with strong correlations between bacterial taxa, particularly with bacterial groups implicated in metabolic disorders including Fretibacterium, and Tannerella. Consumption of sweeteners, especially xylitol, significantly influenced compositional and phylogenetic diversities of salivary and fecal bacterial communities. In addition, obesity groups exhibited differences in predicted bacterial metabolic activity, which was correlated with host's metabolite concentrations. Overall, obesity was associated with distinct changes in bacterial community dynamics, particularly in saliva. Consideration of microbiome community structure and inclusion of salivary samples may improve our ability to understand pathways linking microbiota to obesity and cardiometabolic disease.

Effects of xylitol chewing gum and candies on the accumulation of dental plaque: a systematic review

OBJECTIVES

A systematic review of published data was conducted with the aim of assessing the effects of xylitol consumption on the amount of dental plaque.

MATERIALS AND METHODS

Electronic and hand searches were performed to find clinical studies concerning the effects of xylitol chewing gum or candies on dental plaque. Prospective randomized controlled clinical trials published between 1971 and 2020 conducted in healthy subjects were included in the review.

RESULTS

The initial search identified 424 xylitol articles. After applying inclusion and exclusion criteria, altogether 14 articles (16 studies) were reviewed. The review identified 12 of the total of 14 xylitol chewing gum studies as having fair or high quality. In 13 of the 14 chewing gum studies, xylitol gum decreased plaque accumulation. In six studies, xylitol gum chewing decreased plaque compared to sorbitol gum, and in three studies compared to gum base/no gum. In three fair-quality studies conducted with xylitol candies, plaque accumulation did not change.

CONCLUSIONS

Habitual xylitol gum chewing appears to show plaque-reducing effects that differ from those of sorbitol gum. This suggests specific effects for xylitol on plaque accumulation. Xylitol candies appear not to decrease plaque. The heterogeneity of the studies warrants further research. Clinical relevance Habitual xylitol gum chewing is likely to decrease plaque.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2020 professional literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to this work to cover this broad topic. Specific subject areas addressed include prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders (TMDs); sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence day-to-day dental treatment decisions with a keen eye on future trends in the profession. With the tremendous volume of dentistry and related literature being published today, this review cannot possibly be comprehensive. The purpose is to update interested readers and provide important resource material for those interested in pursuing greater detail. It remains our intent to assist colleagues in navigating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the dental patients they encounter.

Co-production of Xylooligosaccharides and Xylose From Poplar Sawdust by Recombinant Endo-1,4-β-Xylanase and β-Xylosidase Mixture Hydrolysis

As is well-known, endo-1,4-β-xylanase and β-xylosidase are the rate-limiting enzymes in the degradation of xylan (the major hemicellulosic component), main functions of which are cleavaging xylan to release xylooligosaccharides (XOS) and xylose that these two compounds have important application value in fuel, food, and other industries. This study focuses on enzymatic hydrolysis of poplar sawdust xylan for production of XOS and xylose by a GH11 endo-1,4-β-xylanase MxynB-8 and a GH39 β-xylosidase Xln-DT. MxynB-8 showed excellent ability to hydrolyze hemicellulose of broadleaf plants, such as poplar. Under optimized conditions (50°C, pH 6.0, dosage of 500 U/g, substrate concentration of 2 mg/mL), the final XOS yield was 85.5%, and the content of XOS2-3 reached 93.9% after 18 h. The enzymatic efficiency by MxynB-8 based on the poplar sawdust xylan in the raw material was 30.5%. Xln-DT showed excellent xylose/glucose/arabinose tolerance, which is applied as a candidate to apply in degradation of hemicellulose. In addition, the process and enzymatic mode of poplar sawdust xylan with MxynB-8 and Xln-DT were investigated. The results showed that the enzymatic hydrolysis yield of poplar sawdust xylan was improved by adding Xln-DT, and a xylose-rich hydrolysate could be obtained at high purity, with the xylose yield of 89.9%. The enzymatic hydrolysis yield was higher (32.2%) by using MxynB-8 and Xln-DT together. This study provides a deep understanding of double-enzyme synergetic enzymolysis of wood polysaccharides to valuable products.