Probiotics reduce C. difficile in hospitalized patients on antibiotics, review finds

In 19 randomized controlled trials of 6,261 hospitalized patients on antibiotics, the incidence of C. difficile was 1.6% among patients taking probiotics compared to 3.9% in controls.

The risk of developing Clostridium difficile is significantly lower in hospitalized patients who take probiotics soon after starting antibiotics, a recent systematic review found.

Researchers included 19 randomized controlled trials with 6,261 hospitalized patients on antibiotics to evaluate the incidence of C. difficile with and without probiotics. The incidence of C. difficile was 1.6% among patients taking probiotics compared to 3.9% in controls (P<0.001). Results were published online by Gastroenterology on Feb. 10.

Taking probiotics was associated with a more than 50% decrease in risk of C. difficile (relative risk, 0.42; 95% CI, 0.30 to 0.57), the study found. Probiotics were significantly more effective when given within two days of antibiotic initiation (relative risk of C. difficile, 0.32; 95% CI, 0.22 to 0.48) rather than later (relative risk, 0.70; 95% CI, 0.40 to 1.23). This study may be the first to demonstrate the importance of early probiotic administration, the authors said.

Previous systematic reviews have demonstrated the efficacy of probiotics in preventing C. difficile, but this strategy is still not widely used, perhaps because the large PLACIDE trial failed to find benefit, the authors suggested. Possible explanations for the findings of that trial include a lower than expected C. difficile incidence rate and the administration of probiotics as late as seven days after antibiotic initiation.

Based on this review's findings, early probiotics could potentially prevent more than 100,000 cases of C. difficile per year, the authors calculated. They noted that the findings are applicable only to nonpregnant, immune-competent hospitalized adults who do not have prosthetic heart valves and are not in the ICU. The review also found no convincing evidence that any formulation, delivery method, or probiotic dose is superior to another, so future research is needed on that question.

“Nevertheless, there is sufficient data to recommend higher doses of Lactobacillus or Lactobacillus in combination with another species, as either a drink or capsule, within 2 days of the first antibiotic dose for most hospitalized adults,” the authors wrote. “Clinical practice guidelines should be updated to reflect the evidence presented here.”