The influenza viruses are the devastating viruses that cause the flu. They highly communicable and can cause pneumonia, ear infections, sinus infections, asthma and even diabetes. Basically, they are really nasty bugs that people have been suffering from, and trying to get rid of, for at least the last 2000 years. One possible treatment, which is now being explored, is the use of probiotics to prevent flu and its virulence. Scientists in Japan recently tested how one type of probiotic, Bifidobacterium longum, could combat the flu in mice. They published their results in Microbiology and Immunology.
Mice were divided into two groups, one which received the B. longum for 17 consecutive days in their drinking water, and one which did not. On day 14 of the study all the mice were infected with flu via injection. The researchers then monitored all of the mice to see the effect of the probiotics. Surprisingly, the mice which received the probiotics had improved clinical symptoms as compared to those that did not. For example, the mortality rate dropped from 70% to 35% after 12 days in those mice that had been given probiotics. In addition, the probiotics seemed to help with breathing and general activity as well as kept mice from losing as much weight as the control mice. Beyond this, the probiotics appeared to decrease the proliferation of the influenza in the respiratory tract, which resulted in a suppression of overall inflammation as compared to the mice without probiotics. Finally the researchers presented evidence for several possible pathways by which the probiotics were helping the mice.
This study is fascinating in that it shows a simple, yet powerful tool to alleviate the flu in mice. It also begs for a follow-up study to see if the same type of probiotic response would be observed in mice infected with rhinoviruses, the cause of the common cold. While we here at the AMI encourage everyone to get vaccinated for the flu, if for whatever reason you cannot, perhaps consider eating a bit more yogurt this winter.