Evidence for using a probiotic for preventing antibiotic-associated diarrhoea

There is some evidence from trials that probiotics may prevent antibiotic-associated diarrhoea in some adults and children. But limitations with the trials mean that the true effect of probiotics is uncertain, as is the most effective product or dose.

Limitations of evidence

There is not enough evidence to determine the following about probiotics:

  • The minimum dose that is effective for preventing antibiotic-associated diarrhoea
  • How well they work for different age groups
  • Whether they prevent diarrhoea caused by Clostridium difficile (which can lead to more serious complications)
  • How different probiotics compare in effectiveness and safety
  • The best length of time to take them for
  • Whether the effect of a probiotic differs depending on the type of antibiotic taken or for how long the antibiotic is taken.1

Meta-analyses of randomised controlled trials have found a reduced incidence of antibiotic-associated diarrhoea in some patient groups who took probiotics.1,2 However weaknesses in how the trials were conducted mean that their results may not be reliable.1 Some trials did not include enough people to detect a true treatment effect, and in many trials information about some patients was left out of the analysis, which could skew the results.1

There is insufficient evidence to recommend any particular probiotic or dose for people receiving antibiotic therapy.3,4

One trial involving 31 adults in hospital reported that a probiotic containing the strain Lactobacillus reuteri reduced the incidence of antibiotic-associated diarrhoea. This result could also be due to chance, given that few people were in the trial and not all of their data were available to be analysed.5

In a trial involving 40 children, supplementation with this probiotic strain was shown to reduce the frequency and severity of gastrointestinal adverse effects associated with a specific antibiotic regimen (anti-H.pylori).6 But it is unclear from the published report of this trial whether or not the probiotic affected the incidence of diarrhoea.6

People with antibiotic-associated diarrhoea should see their doctor first

If a person experiences intolerable diarrhoea during or following antibiotic use (e.g. 3 or more abnormally loose stools in 24 hours) they should see their doctor. Although it’s usually recommended to stop the antibiotic4, the doctor may also need to review other possible causes of diarrhoea, and determine if a different antibiotic or other treatment is required.

People also need to consider whether they need to take a probiotic, for example, they may be prescribed a type of antibiotic that they usually tolerate well.

Supplements can have side effects

Trials generally found similar rates of adverse effects between people taking probiotics (including the strain Lactobacillus reuteri) and those taking placebo (dummy pill).1,5–7 However, because reporting of adverse events in some of the trials was poor, and some trials only involved small numbers of people, the true incidence of adverse effects may be different.

In addition, there are few data on the safety of using probiotics in young children, older people, and people whose immune system is impaired. Probiotics should not be used in newborn infants or in people who are severely immunocompromised1,3 because serious infections have been reported in these groups while taking probiotics.1,4 

  • Johnston BC, Supina AL, Ospina M, et al. Probiotics for the prevention of pediatric antibiotic-associated diarrhea. Cochrane database of systematic reviews 2007:CD004827. www.ncbi.nlm.nih.gov/pubmed/17443557
  • Kale-Pradhan PB, Jassal HK, Wilhelm SM. Role of Lactobacillus in the prevention of antibiotic-associated diarrhea: a meta-analysis. Pharmacotherapy 2010;30:119-26. www.ncbi.nlm.nih.gov/pubmed/20099986
  • Rossi S, ed. Australian Medicines Handbook. Adelaide, 2011.
  • Gastrointestinal Writing Group. Therapeutic Guidelines: Gastrointestinal. Version 5 ed. Melbourne: Therapeutic Guidelines Ltd, 2011.
  • Cimperman L, Bayless G, Best K, et al. A Randomized, Double-blind, Placebo-controlled Pilot Study of Lactobacillus reuteri ATCC 55730 for the Prevention of Antibiotic-associated Diarrhea in Hospitalized Adults. Journal of clinical gastroenterology 2011;45:785-9. www.ncbi.nlm.nih.gov/pubmed/21552138
  • Lionetti E, Miniello VL, Castellaneta SP, et al. Lactobacillus reuteri therapy to reduce side-effects during anti-Helicobacter pylori treatment in children: a randomized placebo controlled trial. Alimentary pharmacology & therapeutics 2006;24:1461-8. www.ncbi.nlm.nih.gov/pubmed/17032283
  • Francavilla R, Lionetti E, Castellaneta SP, et al. Inhibition of Helicobacter pylori infection in humans by Lactobacillus reuteri ATCC 55730 and effect on eradication therapy: a pilot study. Helicobacter 2008;13:127-34. www.ncbi.nlm.nih.gov/pubmed/18321302