New study strengthens evidence for probiotics in
Montezuma’s revenge can make you miserable, especially when you’re on vacation and trying to enjoy yourself. A speedy return to health is the top priority for most of us. Keeping hydrated, with water or rehydration solutions, is important, but doesn’t actually stop diarrhea symptoms.
Researchers have been looking into probiotics—the so-called “friendly” bacteria that live naturally in our digestive systems. The theory is that probiotic bacteria make the digestive tract a hostile environment for disease-causing germs, by competing for food, increasing acidity, and blocking access to cells.
So, could taking extra probiotic bacteria, through supplements (capsules or fermented drinks), help treat diarrhea?
There have been lots of studies, looking at different types of probiotics. Most of the research has been done in children, and much of it in less developed parts of the world, where stomach upsets are more common because of the difficulty in getting clean water.
Perhaps because of the variation in the studies, it’s been hard to come to conclusions about the overall effect of probiotics. Fortunately, researchers have now completed a mammoth summary of all the evidence about probiotics for diarrhea, which came to clear conclusions.
Most of the studies show a beneficial effect from taking probiotics. The size of the effect varied a lot, but the average was that people were sick for one day less. They also needed to use the bathroom less often, by the second day after treatment.
It’s frustrating that we can’t tell you which probiotic supplements work best, in which circumstances. Unfortunately, the studies covered too many different types for the researchers to say with any confidence which ones worked.
However, the researchers did confine their survey to studies with a named probiotic, rather than simply, say, fermented yogurt. So if you’re looking for a supplement, be sure it’s confirmed to contain at least one specific probiotic organism.
What you need to know. If you or your child has an attack of diarrhea, the most important thing is to stay hydrated, by drinking enough water or rehydration drinks. Taking small, frequent sips works best.
If you or your child has an attack of diarrhea, the most important thing is to stay hydrated, by drinking enough water or rehydration drinks. Taking small, frequent sips works best.
If you wish to try supplements of probiotics, either as capsules or drinks, this review of studies suggests they may help you recover faster.
—Anna Sayburn, patient editor, BMJ Group
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Find out whether probiotics are supplements you should consider and look up your safety and effectiveness information on your supplements in our Natural Medicines database (available to subscribers).