Probiotics could be used to protect critically ill patients from developing pneumonia, according to scientists. The friendly bacteria can block the colonization by dangerous bugs of the airways of ventilated patients. The probiotic solution performed just as well as normal antiseptics used to keep pneumonia-causing bacteria at bay, the journal Critical Care reported. Being more natural it could pose fewer side effects. A probiotic that adheres to mouth lining will be able to work around the clock, unlike antiseptics which wear off after a few hours.