In the January 27th issue of the British Medical Journal, researchers describe a new way to fight bacteria with bacteriaand protect children who suffer from recurrent ear infections (otitis media). Kristian Roos and colleagues at Lundby Hospital in Gothenburg, Sweden, wondered whether infection-prone children might be treated simply by beefing up their own bodies' first line of defense: the natural flora in the upper respiratory tract. A robust colony of alpha-streptococcal bacteria, they reasoned, might run interference against pathogenic, or disease-causing, bacteria, preventing them from taking hold.

To test the idea, the researchers identified a group of 108 children with frequent ear infections between six months and six years old, and gave them all a 10-day course of antibiotics. Next they divided the children into two groups and gave them either a placebo solution or alpha-streptococcal bacteria sprayed into the nose for the next 10 days. After 60 days the kids received a second dose of either bacteria or placebo. And at the three-month mark, the scientists found that 42 percent of the children given the streptococcal spray were healthy, whereas only 22 percent of those given placebo were infection-free.

"Most antibiotics used to treat infections in the upper respiratory tract have an impact on the normal bacterial flora," the authors write. "As these bacteria are part of the body's natural defense, treatment with antibiotics abates this part of the defense system and thus facilitates colonization with pathogenic bacteria. Paradoxically, repeated courses of antibiotics might contribute to recurrent infections in children who are prone to otitis."