While the H1N1 swine flu virus is currently going off the radar in some circles after the Centers for Disease Control and Prevention and the Department of Health and Human Services said closing schools with reported cases was unnecessary, probiotics may help protect against other more common strains which afflict millions of Americans every year.

Probiotics, the good bacteria often made from dairy products, have been considered by some healthcare professionals to be an option in treating certain diseases, but a study in Postgraduate Medicine reveals that one type of probiotic solution may have preventive properties.

Small-scale research into a variant of bacillus coagulan found that immune system measurements in the blood were improved by up to 20 times after patients were given the strain as a supplement over a 30-day period.

"These results demonstrate the ability of [the probiotic] to boost the immune system of healthy adults against viruses that cause some of the most common human illnesses," said lead author Dr Mira Baron.

The CDC estimates that up to one-fifth of Americans contract one form of the flu or another each year, and that approximately 36,000 may succumb to it, especially those with weak immune systems, children and the elderly.