Effect of a lactobacilli preparation on traveler's diarrhea. A randomized, double blind clinical trial.

The effectiveness of prophylactic ingestion of a commercial preparation of lactobacilli (Lactinex) for the prevention or modification of traveler's diarrhea was tested in a randomized double blind clinical trial in 50 volunteer travelers to Mexico from the United States. Twenty-six subjects received the lactobacilli preparation and 24 received placebo. The incidence of diarrhea and its duration during the 4 weeks of observation were quite similar for the two preparations: 35% for lactobacilli-treated subjects and 29% for placebo subjects. Typically, the diarrhea was mild, lasting 2 days. From the observations during this study we conclude that prophylactic ingestion of lactobacilli for 1 week does not reduce the incidence or duration of traveler's diarrhea either during the period of ingestion or during the following 3 weeks.