Alan Greene, M.D., F.A.A.P.

Q: My 7-month old has developed his first ear infection, and our doctor has started him on antibiotics. My question, however, is about the naturally-occurring substance, xylitol. It is sold in sugar-substitute form, toothpaste, and chewing gum. I recently read an article about xylitol aiding in ear infections. My question is, does this help? If so, how much and how often should I give it to my baby? He has 3 teeth, and uses a toothbrush for teething. Can I sprinkle a little of the "sugar" on the toothbrush? Thank you!

Christine Dwyer
Cincinnati, Ohio

A: The xylophone is a percussion instrument consisting of a series of wooden bars of increasing lengths, which when struck makes sounds of the musical scale. The "xyl" in xylophone comes from the Greek word xylan, meaning wood. A xylophone makes sound from wood; xylitol is a sugar made from wood.

Xylitol, also called wood sugar, can be made from the cell walls of most land plants. Xylan, the naturally occurring substance that yields xylitol when refined, is found most commonly in straw, corncobs, oat hulls, cottonseed hulls, and wood. Xylitol is a common food sweetener. Unlike most sugars which have 6 carbon atoms, this naturally sweet substance has only five.

While other sugars tend to promote the growth of bacteria, xylitol has been proven to inhibit the growth of bacteria. In particular it has been shown to be effective in preventing dental cavities by inhibiting Strep mutans, the main bacteria responsible for cavities.

Since the major cause of ear infections is Strep pneumo, a species of bacteria closely related to Strep mutans, perhaps xylitol would prove effective in preventing ear infections. Researchers from Finland tested this hypothesis and published the results of their investigation in the British Medical Journal (November 1996).

The study included 306 children in day care nurseries, most of whom had a history of repeated ear infections. Half of the children chewed xylitol-sweetened gum (2 pieces, 5 times a day -- after all meals and snacks); the other half chewed ordinary gum at the same frequency. During the 2 months of the study, 21% of the regular gum chewers, but only 12% of the xylitol group, had one or more ear infections. Gum chewing by itself, by promoting swallowing and thus clearance of the middle ear, probably prevents some ear infections. The sugar in the regular-sugar-sweetened gum may have offset this effect by promoting bacterial growth in the children who chewed this ordinary gum. By contrast, in this study, xylitol dropped the incidence of ear infections by almost half!

In the xylitol group, children took a total of 8.4 grams of xylitol daily. Most experienced no side effects, but two of them developed diarrhea -- a known side effect of xylitol and other sweeteners.

A small number of children, almost all of them of Jewish descent, have a congenital enzyme defect making them unable to digest xylitol. This condition is called pentosuria. There are no associated disabilities.

No treatment, and no dietary restriction, is necessary. The xylitol is absorbed into the body and then excreted in the urine. The only problem arising from pentosuria is that children having this sugar in the urine are sometimes mistakenly diagnosed with diabetes, and receive diabetic treatment. Pentosuria has no relationship to diabetes. Children with pentosuria could still use xylitol to prevent ear infections.

This Finnish study, making use of the natural, gentle antibiotic properties of plants, is an exciting development. While much research remains to be done (e.g. the optimal amounts and delivery systems), xylitol seems to be a safe and effective way to reduce the number of ear infections. I suspect it will also prove useful in preventing sinus infections, since the same bacteria are involved.