Can Good Bacteria Really Fight the Flu?

New evidence suggests that probiotics -- good bacteria that can aid immune function -- can have a preventive effect for cold and flu viruses.

In a study sponsored by Danisco, a Danish nutritional supplement company that makes probiotics products, researchers found that a six-month course of probiotics was a safe and effective way to ward off flu symptoms and reduce their duration in 3- to 5-year-olds.

"There was definitely a need to show a prophylactic benefit of probiotic consumption, especially in children," said Gregory Leyer, the former head of research and development at Danisco's Madison, Wis., offices and the author of the study, published today in the journal Pediatrics.

But infectious disease experts caution that there are several things to consider when looking at the study's results, chief among them being that the study was sponsored by a company that manufactures probiotic products as well as the study being conducted on children in China rather than in North America.

Nearly 250 kids were treated twice daily for six months. One group of children received a single strain of the probiotic called Lactobacillus acidophilus, one group received a combination of the L acidophilus and Bifidobacterium probiotics, and a third group received a placebo.