Research on the effects of probiotics

To find out how well probiotics help against acute diarrhea, researchers from the Cochrane Collaboration analyzed relevant studies in this area. They found 63 studies looking at the effectiveness of probiotics for acute diarrhea. Just overAbout 8,000 people took part in these studies.

Most of the participants were children whose diarrhea lasted less than two weeks. They took probiotics in various forms, such as yogurts, milk, special infant formula, as a powder or in capsules.

Probiotics can make diarrhea go away faster

The research showed that probiotics help: They shortened the illness by one day on average. In some studies, researchers counted how many of the people had no more diarrhea after three days:

• Without treatment: About 34 out of 100 people who didn’t take probiotics were diarrhea-free after three days.
• With treatment: About 55 out of 100 people who took probiotics were diarrhea-free after three days.

In other words, probiotics made the diarrhea go away faster in 21 out of 100 people.

But it isn’t clear whether some probiotic foods and products are more effective than others. So there may be differences between yogurt, capsules and powder, or between lactic acid bacteria and other microorganisms.

Side effects

There were hardly any reports of side effects in these studies. Overall, the probiotic products were well tolerated. But there’s a chance that the bacteria or yeast in probiotics may sometimes cause infections themselves in people who have a very weak immune system or particular serious illnesses.

Sources

• Allen SJ, Martinez EG, Gregorio GV, Dans LF. Probiotics for treating acute infectious diarrhoea. Cochrane Database Syst Rev 2010; (11): CD003048. [PMC free article: PMC6532699] [PubMed: 21069673]
• Bernaola Aponte G, Bada Mancilla CA, Carreazo NY, Rojas Galarza RA. Probiotics for treating persistent diarrhoea in children. Cochrane Database Syst Rev 2013; (8): CD007401. [PMC free article: PMC6532736] [PubMed: 23963712]

• IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

  Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. We do not offer individual consultations.

  Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.