Increased bone volume and bone mineral content in xylitol-fed aged rats

A systematic review and meta-analysis of the role of sugar-free chewing gum on Streptococcus mutans

Background

Preventive strategies targeting Streptococcus mutans may be effective in reducing the global burden of caries. The aim of the current systematic review of published literature was to determine the difference in level of Streptococcus mutans in adults and children who chew sugar-free gum (SFG), compared with those who did not chew gum, who chewed a control gum or received alternatives such as probiotics or fluoride varnish.

Methods

Systematic review (PROSPERO registration No. CRD42018094676) of controlled trials with adult and child participants where chewing of SFG was the main intervention. Databases searched (1 Jan 1946 to 31 August 2020): MEDLINE, EMBASE, PsycINFO, Scopus, Web of Science, Allied and Complimentary Medicine Database, Cochrane Central Register of Controlled Trials (CENTRAL), Open Grey, PROSPERO and the Cochrane library of systematic reviews. ‘Search terms included Medical Subject Headings, and free text to cover the following range of constructs: chewing gum, sugar free, oral health, caries, xerostomia, periodontal disease. Data extraction and Risk of Bias assessment was undertaken by three researchers using a modified version of the Cochrane RoB tool (version 1). Data synthesis was conducted using meta-analysis in STATA.

Results

Thirteen studies of SFG with micro-organisms as outcomes were identified. The use of SFG significantly reduced the load of Streptococcus mutans (effect size − 0.42; 95% CI − 0.60 to − 0.25) compared to all controls. In seven of the 13 studies the confidence intervals of the effect size estimate included zero, suggesting no effect of the intervention. Twelve trials used xylitol gum only as the basis of the intervention; xylitol gum significantly reduced the load of Streptococcus mutans (effect size − 0.46; 95% CI − 0.64 to − 0.28) in comparison to all controls. There was a moderate level of heterogeneity across the included studies. No adverse effects were recorded.

Conclusion

Chewing SFG reduces the load of Streptococcus mutans in the oral cavity in comparison to non-chewing controls. Considering the degree of variability in the effect and the moderate quality of the trials included, there is a need for future research exploring the use SFG as a preventive measure for reducing the cariogenic oral bacterial load.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01517-z.

Xylitol affects the intestinal microbiota and metabolism of daidzein in adult male mice

This study examined the effects of xylitol on mouse intestinal microbiota and urinary isoflavonoids. Xylitol is classified as a sugar alcohol and used as a food additive. The intestinal microbiota seems to play an important role in isoflavone metabolism. Xylitol feeding appears to affect the gut microbiota. We hypothesized that dietary xylitol changes intestinal microbiota and, therefore, the metabolism of isoflavonoids in mice. Male mice were randomly divided into two groups: those fed a 0.05% daidzein with 5% xylitol diet (XD group) and those fed a 0.05% daidzein-containing control diet (CD group) for 28 days. Plasma total cholesterol concentrations were significantly lower in the XD group than in the CD group (p < 0.05). Urinary amounts of equol were significantly higher in the XD group than in the CD group (p < 0.05). The fecal lipid contents (% dry weight) were significantly greater in the XD group than in the CD group (p < 0.01). The cecal microbiota differed between the two dietary groups. The occupation ratios of Bacteroides were significantly greater in the CD than in the XD group (p < 0.05). This study suggests that xylitol has the potential to affect the metabolism of daidzein by altering the metabolic activity of the intestinal microbiota and/or gut environment. Given that equol affects bone health, dietary xylitol plus isoflavonoids may exert a favorable effect on bone health.

Use of xylitol to enhance the therapeutic efficacy of polymethylmethacrylate-based antibiotic therapy in treatment of chronic osteomyelitis

Using a rabbit model of postsurgical osteomyelitis, we demonstrate that incorporation of xylitol into polymethylmethacrylate (PMMA) bone cement enhances the elution of daptomycin under in vivo conditions. We also demonstrate that this can be correlated with an improved therapeutic outcome in the treatment of a chronic bone infection following surgical debridement.

The effects of oral xylitol administration on bone density in rat femur

To examine the effects of oral xylitol administration on rat femur bone density, 36 four-week-old male Wistar rats divided into three groups were fed CE-2 diet (control, n = 12) alone or supplemented with 10% (n = 12) or 20% (n = 12) dietary xylitol for 40 days. Biochemical, morphological, and histological analyses were performed. The 10% and 20% xylitol groups showed higher levels of both serum Ca and alkaline phosphatase activity and lower levels of serum tartrate-resistant acid phosphatase than the control group. Although no significant differences in the three-dimensional bone structure or trabecular bone structure of the femur were observed, both xylitol groups showed significantly higher bone density than the control group. Compared to the control group, the 10% and 20% xylitol groups showed an increase in trabeculae. Thus, oral administration of xylitol appears to affect bone metabolism, leading to increased bone density in rat femur.

Xylitol and glycine fillers increase permeability of PMMA to enhance elution of daptomycin

The elution of antibiotics from hand mixed antibiotic-laden polymethylmethacrylate (PMMA) must be increased to achieve clinical performance equivalent to commercially manufactured antibiotic beads (not available in the USA) in the management of musculoskeletal infections. Adding fillers such as glycine and dextran to polymethylmethacrylate increases the elution of antibiotics from antibiotic-laden PMMA. We propose xylitol, a naturally occurring sweetener with direct antibiofilm properties, as a filler material. To compare the efficacy of xylitol and glycine as fillers on the elution of antibiotics from PMMA, elution studies were performed on mixtures of Palacos polymethylmethacrylate and daptomycin (1 gm) with xylitol or glycine as the filler (28 g). Xylitol and glycine enhanced the daptomycin activity eluted from the polymethylmethacrylate. Xylitol was more effective than glycine, having a greater increase in daptomycin release at all data points; on day one xylitol increased the elution of daptomycin 2.67 times whereas glycine increased it 1.78 times also on day one. The eluant concentration of daptomycin remained higher longer for xylitol; 3.90 microg/mL for xylitol versus 2.25 microg/mL for glycine on day 9. Xylitol is inexpensive and readily available. It can be hand mixed with PMMA, and is more effective than glycine as a filler to enhance daptomycin release. Considering possible antibiofilm activity, xylitol may be a more advantageous choice.

Effects of a long-term dietary xylitol supplementation on collagen content and fluorescence of the skin in aged rats

BACKGROUND

Dietary xylitol has been shown to increase the amounts of newly synthesized collagen, and to decrease fluorescence of the collagenase-soluble fraction in the skin of both healthy and diabetic rats. As in diabetic rats, a decreased rate of collagen synthesis and increased collagen fluorescence has also been detected in the skin of aged rats. We hypothesize that dietary xylitol supplementation may protect against these changes during aging.

OBJECTIVE

The purpose of the present study was to investigate whether a long-term dietary supplementation can protect against the decrease in the amounts of newly synthesized collagen, and against the increase in fluorescence in the collagenase-soluble fraction in the skin of aged rats.

METHODS

Twenty-four male Sprague-Dawley rats were used in the study. After weaning, the rats were divided into 2 groups of 12 animals. The rats in the control group were fed a basal RM1 diet, while the rats in the experimental group were fed the same diet supplemented with 10% xylitol. After 20 months, the rats were killed and pieces of skin from their dorsal areas were excised. The thickness of the samples was measured with a micrometer screw gauge. The collagen contents of rat skin were measured as hydroxyproline, and glycosylation as fluorescent intensity of collagen. Statistical significances of the differences between the groups were determined using the unpaired t test.

RESULTS

No general side effects were detected in the rats during the experimental period. The skin of the xylitol-fed rats was a little thicker than that of the control rats. The hydroxyproline content of the acid-soluble fraction was significantly greater in the xylitol group as compared to the controls. However, there were no significant differences in the hydroxyproline content of the collagenase-soluble fraction between the groups. The fluorescence of the collagenase-soluble fraction was significantly smaller in the xylitol-fed aged rats than in the aged rats fed the basal diet.

CONCLUSIONS

The results of this study indicate that xylitol caused an increase in the amount of newly synthesized collagen and a decrease in collagen fluorescence in the skin of aged rats.