A study published in the March issue of Postgraduate Medicine suggests that a strain of probiotic bacteria, GanedenBC30, increases the body’s immune response to viruses that cause common viral respiratory tract infections such as colds and flu.

Probiotics are live microorganisms similar to those found naturally in the body’s digestive system and have been known to help reduce symptoms of digestive disorders such as irritable bowel syndrome, diarrhea, gas and bloating.

In the Ganeden study, 10 healthy adults were exposed to viruses following a 30-day regimen of GanedenBC30, which is marketed as a dietary supplement called Sustenex. Results showed a 250 percent increase in TNF-alpha, a key immune marker, with adenovirus and a 1709 percent increase in TNF-alpha levels with influenza A.

The study helps support the theory about the beneficial effects of GanedenBC30 on the immune system and adds to the emerging body of evidence that probiotics can benefit healthy people as well as those with specific health issues, the study author said.

Every year, an average of 5 to 20 percent of people in the U.S. contract the flu, more than 200,000 people are hospitalized with flu-related complications and approximately 36,000 people die from the flu.