Probiotic Yogurt for the Prevention of Antibiotic-associated Diarrhea in Adults A Randomized Double-blind Placebo-controlled Trial

Goal: To evaluate the effect of yogurt supplemented with probiotic bacteria on the prevention of antibiotic-associated diarrhea (AAD) in hospitalized patients. Background: Diarrhea following antibiotic administration is a frequent clinical problem. The usefulness of probiotics for the prevention of AAD in the hospitalized adult population remains unclear. Study: A randomized, double-blind, placebo-controlled clinical trial was conducted in hospitalized patients who started antibiotic treatment. Patients were randomized (2:2:1) to receive a daily amount of 200 mL of placebo-yogurt (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus), 200 mL of probiotic yogurt (previous plus Lactobacillus acidophilus La-5, Bifidobacterium animalis subsp. lactis Bb-12 and Lactobacillus casei subsp. casei Lc-01 or no yogurt (unblinded control) within 48 hours of beginning the antibiotic therapy and up to 5 days after stopping the antibiotic. Patients were followed up with for 1 month to determine occurrence of diarrhea. Results: We included 314 patients, mean age 76 years. The rate of diarrhea was 23.0% in the probiotic group versus 17.6% in the placebo group, absolute risk reduction -5.35% (95% confidence interval, -15.4% to 4.7%; P=0.30). Rate of diarrhea was similar in the unblinded external control and in the blinded study groups combined (20.9% vs. 20.2% respectively; P=0.91). There was no difference in the duration of diarrhea, maximum number of bowel movements or prolonged admission because of diarrhea among the groups. All-cause mortality did not differ between groups. Conclusions: The combined probiotic strains LA-5, BB-12, and LC-01 do not have an effect in the prevention of AAD in hospitalized patients.