Probiotics for prophylaxis of traveler’s diarrhea

Are probiotics an option in the prophylaxis of traveler’s diarrhea?

Mark S. Riddle, MD: Unfortunately, the data right now for probiotics are not there either. There have been several studies with various probiotics—various types of probiotics, dosages, populations—and there have been systematic reviews of those. Overall the bottom line is that there is so many inconsistencies in what was tested, how they were tested, how the follow-up was done that there is not supporting evidence right now to suggest that probiotics will prevent traveler’s diarrhea.

There is one product, Saccharomyces boulardii, a yeast. It has been shown in 2 clinical trials to have marginal effectiveness in prevention of traveler’s diarrhea, but again, those studies are challenged by their design, follow-up, and lack of microbiology confirmation to provide a strong recommendation.

I think it is an important area of research. I think we know that some people get sick and some people do not get sick when they travel. Part of that is probably genetics, but part of that is probably the microbiome. We are just not smart enough yet to know what it is about the microbiome that will prevent us from getting these traveler’s infections. I think that there will be a lot more research involved in that area in the next few years.