Probiotics: More Evidence of Efficacy
Published: May 31, 2013 | Updated: May 31, 2013, By Charlene Laino , Senior Writer, Gupta Guide. Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner
Probiotic supplements are a cheap, safe, and effective way to prevent Clostridium difficile-associated diarrhea, according to a systematic review by the Cochrane Collaboration.
In a case-analysis of 23 trials involving 4,213 people, prophylactic probiotics reduced the risk of C. difficile diarrhea by 64%, compared with people given no treatment or placebo, reported Bradley Johnston, MD, of The Hospital for Sick Children Research Institute in Toronto, and colleagues.
Specifically, the incidence of C. difficile diarrhea was 2.0% in the probiotic group compared with 5.5% in the placebo or no treatment control group (RR 0.36; 95% CI 0.26-0.51).
The findings add to a growing body of evidence that prophylaxis with probiotics confers protection against diarrhea in people taking antibiotics. That protection comes via a variety of mechanisms -- improving the microbial balance of the host, counteracting disturbances in intestinal ?ora, and reducing the risk of colonization by pathogenic bacteria, the researchers wrote.
Johnston noted that probiotics are becoming increasingly available as capsules and dairy-based food supplements in health food stores and supermarkets.
The cost is generally low, about $15 to $40 for a month supply online. In contrast, the estimated cost of treating primary C. dif?cile infections ranges from $2,871 to $4,846 per case in the U.S. Recurrent cases run $13,655 to $18,067.
The incidence of C. dif?cile infection, a secondary outcome, was 12.6% in the probiotics group compared with 12.7% in the placebo or no treatment control group (RR 0.89; 95% CI 0.6-1.24).
"This suggests that probiotics act to prevent the symptoms of C. difficile infection rather than to prevent the infection itself," said Johnston.
Adverse events were assessed in 26 studies involving 3,964 participants. The pooled analysis showed probiotics reduced the risk of adverse events by 20% (RR 0.80; 95% CI 0.68-0.95).
In both treatment and control groups, the most common adverse events included abdominal cramping, nausea, fever, soft stools, ?atulence, and taste disturbance.
"Importantly, these results were similar whether considering trials in adults versus children, lower versus higher doses, different probiotic species, or higher versus lower risk of bias. Our judgment is that the overall evidence warrants moderate con?dence in this large relative risk reduction," Johnston concluded.
Further study is needed to determine why taking probiotics in combination with antibiotics helped to prevent C. difficile diarrhea, but did not reduce C. dif?cile infections, Johnston said.
Patients asking for advice should be told to look for a brand they trust and whose label offers detailed information on what bacteria they contain, Mark H. Mellow, MD, director of the Inteiris Digestive Health Center in Oklahoma City, told a recent seminar.
Use of probiotics is popular among patients -- and regularly advocated in TV and print ads. Do you recommend probiotics to your patients embarking on a course of antibiotics? Let us know by Adding Your Knowledge below. -- Sanjay Gupta, MD
The authors had no disclosures.
Mellow had no disclosures.