Tuesday, August 20, 2013

Probiotics for the Prevention of Diarrhea

I have previously blogged about probiotics and antibiotic associated diarrhea. New data however has emerged challenging previous conclusions. I now stand corrected.

Are probiotics really useful for the prevention of antibiotic associated diarrhea and C.difficile infection? Here is an article published in The Lancet that suggests otherwise.

The most recent study was multicenter randomized, double-blind, placebo-controlled trial of inpatients aged 65 years and older and exposed to one or more oral or parenteral antibiotics. Participants were randomized to receive either a multistrain preparation of lactobacilli and bifidobacteria, with a total of 6 × 1010 organisms, one per day for 21 days, or an identical placebo. Patients, study staff, and specimen and data analysts were masked to assignment. The primary outcomes were occurrence of antibiotic associated diarrhea (AAD) within 8 weeks and C difficile diarrhoea (CDD) within 12 weeks.
Of  the 17,420 patients screened, 1493 were randomly assigned to the microbial preparation group and 1488 to the placebo group. 1470 and 1471, respectively, were included in the analyses of the primary endpoints. AAD (including CDD) occurred in 159 (10·8%) participants in the microbial preparation group and 153 (10·4%) participants in the placebo group (relative risk [RR] 1·04; 95% CI 0·84-1·28; p=0·71). 
Probiotics were not efffective in preventing either antibiotic associated diarrhea or C.difficile infection

We still have much to learn about the pathophysiology and prevention of antibiotic associated diarrhea.