Xylitol gummy bear snacks: a school-based randomized clinical trial

BMC Oral Health Xylitol gummy bear snacks: a school-based randomized clinical trial Kiet A Ly 2 Christine A Riedy 2 Peter Milgrom 2 Marilynn Rothen 0 2 Marilyn C Roberts 1 2 Lingmei Zhou 2 0 Regional Clinical Dental Research Center, University of Washington , Seattle, WA 98195 , USA 1 Department of Environmental Health & Occupational Sciences, University of Washington , Seattle, WA 98195 , USA 2 Northwest/Alaska Center to Reduce Oral Health Disparities, Department of Dental Public Health Sciences , Box 357475 , University of Washington , Seattle, WA 98195-7475 , USA Background: Habitual consumption of xylitol reduces mutans streptococci (MS) levels but the effect on Lactobacillus spp. is less clear. Reduction is dependent on daily dose and frequency of consumption. For xylitol to be successfully used in prevention programs to reduce MS and prevent caries, effective xylitol delivery methods must be identified. This study examines the response of MS, specifically S. mutans/sobrinus and Lactobacillus spp., levels to xylitol delivered via gummy bears at optimal exposures. Methods: Children, first to fifth grade (n = 154), from two elementary schools in rural Washington State, USA, were randomized to xylitol 15.6 g/day (X16, n = 53) or 11.7 g/day (X12, n = 49), or maltitol 44.7 g/ day (M45, n = 52). Gummy bear snacks were pre-packaged in unit-doses, labeled with ID numbers, and distributed three times/day during school hours. No snacks were sent home. Plaque was sampled at baseline and six weeks and cultured on modified Mitis Salivarius agar for S. mutans/sobrinus and Rogosa SL agar for Lactobacillus spp. enumeration. Results: There were no differences in S. mutans/sobrinus and Lactobacillus spp. levels in plaque between the groups at baseline. At six weeks, log10 S. mutans/sobrinus levels showed significant reductions for all groups (p = 0.0001): X16 = 1.13 (SD = 1.65); X12 = 0.89 (SD = 1.11); M45 = 0.91 (SD = 1.46). Reductions were not statistically different between groups. Results for Lactobacillus spp. were mixed. Group X16 and M45 showed 0.31 (SD = 2.35), and 0.52 (SD = 2.41) log10 reductions, respectively, while X12 showed a 0.11 (SD = 2.26) log10 increase. These changes were not significant. Post-study discussions with school staff indicated that it is feasible to implement an in-classroom gummy bear snack program. Parents are accepting and children willing to consume gummy bear snacks daily. Conclusion: Reductions in S. mutans/sobrinus levels were observed after six weeks of gummy bear snack consumption containing xylitol at 11.7 or 15.6 g/day or maltitol at 44.7 g/day divided in three exposures. Lactobacillus spp. levels were essentially unchanged in all groups. These results suggest that a xylitol gummy bear snack may be an alternative to xylitol chewing gum for dental caries prevention. Positive results with high dose maltitol limit the validity of xylitol findings. A larger clinical trial is needed to confirm the xylitol results. Trial registration: [ISRCTN63160504] - Background Mutans streptococci (MS), more specifically S. mutans and S. sobrinus, are implicated in the development of dental caries in humans [1]. Xylitol, a naturally occurring sugar alcohol approved for use in food by the U.S. Food and Drug Administration (FDA) since 1963, has been shown to reduce MS levels in plaque and saliva and to markedly reduce tooth decay. Studies involving schoolchildren demonstrated that habitual use decreased dental caries. A recent review summarized the availability of xylitol-containing products on the internet and in supermarkets and other commercial outlets in the U.S. and included an assessment of their potential to provide a minimally effective dose (6 g) to reduce MS and tooth decay [2]. The review reports that, aside from chewing gum and lozenges, there have been few clinical studies performed on other xylitol-containing products. In all, the existing studies suggested that xylitol can reduce MS levels in saliva and plaque and reduce tooth decay. However, these prospective trials were not designed to assess the relationship between dose or frequency of xylitol use and reductions in MS level or tooth decay. To fill this gap, our group conducted studies to determine the minimal effective dose [3] and frequency [4] of xylitol use when delivered via chewing gum. These studies concluded that xylitol chewing gum dose of 6.9 to 10.3 g divided into at least three uses per day is efficacious in reducing MS, specifically S. mutans and S. sobrinus (herein referred to as S. mutans/sobrinus), level in plaque and saliva. On the other hand, 3.4 g/day or frequencies of use less than 3 times/day were not statistically different from controls even though small reductions were observed. Xylitol chewing gum and lozenges are widely available and used by consumers in Europe and in Korea, Japan, Thailand, and China. Finland was the first country to implement a national campaign, "Smart Habits" xylitol, to promote xylitol use to reduce tooth decay in children [5]. Similar promotions are occurring in other European and Asian countries especially Japan and Korea where xylitol chewing gum has captured nearly 50% of the chewing gum market. More recently, the U.S. Army implemented the "Look for Xylitol First" initiative to promote xylitol use among deployed troops to improve their oral health [6] and have begun to include xylitol chewing gum in "meals ready to eat" (MRE) rations. Similar programs to address tooth decay in U.S. children have not been adopted in part because chewing gum and hard candies consumption are considered choking hazards and thus not acceptable xylitol delivery vehicles for children [7]. For xylitol to be successfully used in oral health prevention programs for U.S. children, effective means of delivering xylitol in a therapeutic dose and frequency must be identified. The purpose of this RCT was to test the hypothesis that six weeks of habitual consumption of a xylitol gummy bear snack is effective in reducing S. mutans/sobrinus in plaque and to lay the groundwork for a dental caries trial. This study also evaluated the effect of xylitol on Lactobacillus spp. Methods Subjects Subjects (n = 154) were first to fifth grade children attending Morton and White Pass elementary schools in rural Washington State, USA. The children were initially presented a skit with an oral health message during a general assembly to introduce them to the University of Washington research team. A partnership between the research team and each school was established. The school sent parents an informational letter describing the study and asked permission for their child's participation in the "Gummy Bear Study" (see Additional file 1). Parents interested in having their children participate signed and returned the enclosed consent form along with a brief general health questionnaire (see Additional file 2). Children with reported antibiotic use during the previous two weeks or (...truncated)