News Life Antibiotics may make fighting flu harder Drugs hit beneficial bacteria that keep immune system alert By Tina Hesman Saey March 14, 2011 at 4:22 pm - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Click to share on Facebook (Opens in new window) Facebook Click to share on Reddit (Opens in new window) Reddit Click to share on X (Opens in new window) X Click to print (Opens in new window) Print Taking antibiotics when they aren’t necessary could make the flu or other viral infections worse, a new study suggests. Mice on antibiotics can’t fight the flu as well as mice that haven’t taken the drugs, say researchers from Yale.