Because recurrent episodes of acute otitis media can lead to long-term sequelae such as learning disabilities, prevention of this condition would be more effective than separate treatment of each episode. Prophylaxis with antibiotics is often effective but can cause the development of resistant bacteria. The sweetening agent xylitol has been shown to prevent dental caries by inhibiting growth of Streptococcus mutans and has also been shown to inhibit growth of Streptococcus pneumoniae. Uhari and colleagues conducted a three-month randomized controlled trial to compare the effectiveness of xylitol syrup, chewing gum and lozenges in the prevention of acute otitis media in children.

Healthy children were recruited from 34 day care centers in Finland. History and risk factors for acute otitis media were obtained from the parents of each child. Children were not admitted to the study until all ear effusions were cleared, as determined by tympanometry and pneumatic otoscopy. A total of 857 children were screened and randomized to receive chewing gum, lozenges or syrup on the basis of their ability to chew gum. Each preparation was taken five times per day. Any child who developed symptoms of respiratory infection was examined by a nurse. Tympanometry was performed within three days of onset of symptoms. If the tympanogram was normal, the child was re-examined weekly. If results were abnormal, pneumatic otoscopy was performed. Acute otitis media was diagnosed if the child had the following: abnormal findings on tympanometry, middle ear effusion, symptoms of acute respiratory infection and signs of tympanic membrane inflammation. Children with acute otitis media were treated with antibiotics for seven days and reexamined weekly until the end of the study period.

At least one occurrence of acute otitis media was noted in 49 children (28 percent) in the control group receiving gum, 29 children (16 percent) in the group receiving xylitol gum, 39 children (22 percent) in the group receiving xylitol lozenges, 68 children (41 percent) in the control group receiving syrup and 46 children (29 percent) in the group receiving xylitol syrup. Some children had more than one episode of acute otitis media; the group receiving xylitol syrup had approximately 30 percent fewer episodes of acute otitis media than their counterparts who received control syrup. This difference was statistically significant. There was a decrease of approximately 40 percent in episodes of acute otitis media in those who received xylitol gum compared with those who received control gum. The patients receiving xylitol syrup and xylitol gum were given significantly fewer antibiotics than those in the control groups. The most common side effect was abdominal discomfort.

The authors conclude that xylitol chewing gum and xylitol syrup were associated with a significant reduction in the occurrence of acute otitis media and antibiotic use in children in day care centers. In a related editorial, Wright is cautiously optimistic about an agent that can decrease the occurrence of acute otitis media and the use of antibiotics. However, as he points out, “a biologically plausible mechanism of action” is missing, and the adverse effects of using such a substance throughout early childhood are unknown. In another editorial, Mitchell notes that xylitol is not readily available in the United States. This preliminary study is promising; however, further study is needed to determine the full range of adverse effects, to find the optimal dosage of xylitol and to determine the duration of xylitol's prophylactic benefits.