Key messages:
- The results of this review support the use of xylitol as a sugar substitute to reduce cariogenic bacteria, possibly lowering the risk of dental caries and reducing the incidence of new dental caries.
- Further research is required to confirm xylitol’s clinical effectiveness and its dose for dental caries prevention.
Introduction
Dental caries is a significant health problem, affecting 60% to 90% of children and the majority of adults. Untreated dental caries in permanent teeth was estimated to occur in approximately 2.3 billion individuals, with an additional 532 million children affected. Untreated dental caries negatively affects the quality of life.
Various factors contribute to dental caries, including the interaction between certain oral bacteria and dietary carbohydrates. Several bacterial species, such as mutans streptococci, lactobacillus spp. and streptococcus sanguis, are associated with dental caries.
Dietary sugars are significantly associated with the development of dental caries. To mitigate this issue, sugar substitutes are often used to replace these sugars without affecting pH levels or causing carbohydrate fermentation. These substitutes are popular in food products because they mimic the sweet taste of regular sugars while helping to prevent dental caries.
There are two types of sugar substitutes: low-intensity sweeteners and high-intensity sweeteners. Low-intensity sweeteners, also known as sugar alcohols, have a sweet taste that is less intense than that of regular sugars. Commonly used low-intensity sweeteners include xylitol, sorbitol, and maltitol. High-intensity sweeteners, also known as non-nutritive sweeteners, provide little to no calories and are often used in beverages and candies. Common high-intensity sweeteners include aspartame, sucralose, and saccharin.
Researchers have studied the protective effects of low-intensity sweeteners (e.g., xylitol and sorbitol) against dental caries. Systematic reviews indicate that consuming xylitol may reduce the presence of cariogenic bacteria in saliva. The proposed mechanism by which xylitol prevents dental caries involves inhibiting bacterial adherence and biofilm formation in the oral cavity. However, most research has focused on the consumption of low-intensity sweeteners, particularly xylitol in the form of chewing gum. Other types of sugar substitutes, such as high-intensity sweeteners found in various food products, have not been adequately investigated. Additionally, there is a current lack of systematic reviews examining the effects of sugar substitutes on cariogenic bacteria in dental plaque and saliva, specifically related to dental caries.
Objective
This systematic review and meta-analysis investigated the effects of sugar substitute consumption on cariogenic bacteria in dental plaque and saliva.
Methods
PubMed, EMBASE, and Web of Science were systematically searched for prospective controlled trials published in English that investigated the effects of sugar substitute consumption on cariogenic bacteria in dental plaque and saliva. The primary outcome measured was the changes in cariogenic bacteria. Two independent reviewers screened the articles, and the quality of the studies was assessed using the Cochrane risk-of-bias tools.
Results
Out of 977 studies identified, 32 trials were included in the analysis. Nearly half of the included studies (14/32, 44%) had a high risk of bias. Most of the trials (31/32, 96.88%) investigated xylitol and other sugar alcohols (low-intensity sweeteners), such as sorbitol, erythritol, and maltitol. Only one trial investigated stevia, a high-intensity sweetener, and no studies on other high-intensity sweeteners, including sucralose, saccharin, or aspartame, were identified.
The majority of the studies (30/32, 93.75%) demonstrated that the consumption of low-intensity sweeteners resulted in a significant reduction in various types of cariogenic bacteria. The meta-analysis results indicated that consuming xylitol was more effective than no treatment in reducing cariogenic bacteria, particularly mutans streptococci, in both dental plaque and saliva.
Xylitol also reduced the amount of cariogenic bacteria more effectively than sorbitol or no treatment. This effect may occur because most cariogenic bacteria cannot ferment xylitol, while sorbitol can be fermented to a limited extent. Additionally, none of the studies included in the analysis reported any adverse effects.
Conclusions
This review presents evidence that xylitol, a low-intensity sweetener used in food products, has a positive effect on reducing cariogenic bacteria in dental plaque and saliva. Currently, there is limited clinical evidence of the role of high-intensity sweeteners in reducing cariogenic bacteria. More research is required to confirm xylitol’s clinical effectiveness and its dose for preventing caries. Further investigation into the role of high-intensity sweeteners in caries prevention and oral health is necessary to establish their benefits and potential side effects.
