Probiotic yogurts curb hospital infections

Study’s authors, surprised by ‘very large’ results, tell decision-makers to look at changing practices

The dairy aisle may contain an important weapon in the fight against C. difficile, a deadly infection that can wreak havoc in hospitals and nursing homes.

The medical use of probiotics, including yogurt, could significantly reduce the adverse effects of C. difficile, according to a new study from The Hospital for Sick Children and McMaster University.

Published Monday in Annals of Internal Medicine, the study compiled findings from 20 trials conducted from 1989 to 2010, which administered different strains, doses and forms of probiotics to nearly 4,000 patients also taking antibiotics. Overall, use of probiotics cut down on new cases of C. difficileassociated diarrhea by two-thirds, with no serious side effects.

The results came as a surprise to lead author Dr. Bradley Johnston, a scientist and clinical epidemiologist at SickKids and associate professor at University of Toronto, who described the rate of risk reduction as “very large.” “Probiotics are underutilized,” he said. “Decision-makers need to look at this study and consider a change in practice.” Precisely how probiotics keep the nasty symptoms of C. difficile, short for clostridium difficile, at bay “remains somewhat unclear,” Johnston said. But he suspects that the live microorganisms may replace the “good bacteria” that are eliminated when antibiotics are used to prevent or treat infection. There are several important caveats, however. To be most effective, patients required a dose of more than 10 billion colony forming units (CFU) per day, a concentration found in some commercially available probiotic capsules, powders and yogurts. (The brand Culturelle boasts at least 10 billion live cells in its probiotic supplements.) The findings apply only to certain species of the active bacteria. “It’s not a magic bullet, that if you give any yogurt you’re going to prevent in 66 per cent of cases,” Johnston said.

The study results were well-received by Pat Campbell, president and CEO of the Ontario Hospital Association, who said in an email that “the province’s hospitals are absolutely open to these findings.”

C. difficile is the leading cause of infectious diarrhea in hospitals and long-term care facilities. Ontario’s Health ministry tracked 75 outbreaks in 47 hospitals from 2009 to 2011. But 2008 rules requiring hospitals to publicly report new cases appear to have made an impact: a recent study found rates of C. difficile fell by more than one-quarter — or 1,970 cases — after 2008.