Doctors and patients must cope with the ever-growing threat of hospital-acquired infections, many of which are caused by 'superbugs' that have evolved resistance to mainstay antibiotics. Researchers are now exploring ways to use 'probiotics', or friendly bacteria, to counteract pathogenic bacteria responsible for these infections.

A new pilot study suggests that probiotics might help prevent ventilator-associated pneumonia (VAP), one of the most common hospital-acquired infections. VAP occurs when pathogenic microbes, often originating in the mouth or throat, travel down the breathing tube and into the lungs.

Healthcare workers typically swab a patient's mouth with an antiseptic such as chlorhexidine, which can cause allergic reactions, before inserting the tube into the airways. But now a team led by Bengt Klarin of the University Hospital in Lund, Sweden has found evidence that Lactobacillus plantarum 299, a bacterium commonly found in fermented foods, might work just as well as chlorhexidine in preventing harmful bacteria from contaminating breathing tubes. In a randomized controlled trial of 50 ventilated subjects, Klarin and his colleagues found that subjects swabbed with the friendly bacteria solution had no more pathogenic bacteria residing in their upper throats than those swabbed with chlorhexidine (Crit. Care, doi:10.1186/cc7109; 2008).

Klarin's team recently published another study suggesting that individuals given probiotic-containing food alongside their antibiotic treatments might face a lower risk of developing infections with Clostridium difficile, a bacterium that can cause life-threatening gastrointestinal infections (Acta. Anaesthesiol. Scand. 52, 1096–1102; 2008).

Hospitals should be focused on implementing proven, traditional mechanisms of infection control such as environmental cleaning and prudent use of antibiotics, says William Jarvis, a consulting epidemiologist with the Washington, DC–based Association for Professionals in Infection Control and Epidemiology. However, these methods are not foolproof, he acknowledges. “Other interventions such as the use of probiotics need to be evaluated,” Jarvis says.

Breathing easy: Bacteria might help Credit: Pixland/Corbis