Probiotics for the prevention of pediatric antibiotic-associated diarrhea

Probiotics, the "good" bacteria in many dietary supplements, might counteract an unpleasant side effect for children on antibiotics, according to a new systematic review.

Antibiotics commonly used to treat children with conditions such as respiratory tract and skin infections can cause antibiotic-associated diarrhea (AAD). Estimates indicate that between 11 percent and 40 percent of children taking antibiotics suffer from AAD.

Parents have routinely given children over-the-counter diarrhea medicines, such as Kaopectate or Imodium A-D, but some are turning to other remedies. One alternative has been to give probiotics — dietary supplements containing healthy bacteria or yeasts that can help to restore the body's natural balance.

The systematic review aimed to assess whether probiotics actually reduce the incidence of AAD in children and if children should take probiotics over common diarrhea medications on a routine basis.

“Probiotics offer an excellent safety profile in healthy children and seem to be effective in preventing AAD in children,” said review co-author Sunita Vohra, M.D. “Public interest in natural health products is high and given how commonly diarrhea occurs in children prescribed antibiotics, we think that many families will be interested in our findings.”

The review appears in the current issue of The Cochrane Library , a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

AAD occurs when antibiotics disturb the body's natural balance of “good” and “bad” bacteria and thereby interfere with normal digestion. AAD symptoms include frequent watery bowel movements and abdominal cramps. Those with severe cases can suffer from dehydration and electrolyte imbalances.

The Cochrane reviewers analyzed 10 studies that tested 1,986 children from birth to 18 years old, who received antibiotics to treat a medical condition along with probiotics to prevent AAD. Children were given between five and 15 days of oral antibiotics such as amoxicillin, cefotaximine and erythromycin.

The probiotics given to children included Lactobacillus GG, Lactobacillus sporogenes, Streptococcus thermophilus and Saccharomyces boulardii. Daily doses varied from 20 billion to 40 billion colony-forming units.

The studies used various methods to compare children who received probiotics to those who received another type of treatment— a placebo, conventional antidiarrheal medications or no treatment at all.

“Conventional antidiarrheal medications may also be effective, but unless the diarrhea is severe, parents and health care providers are generally averse to prescribing a second medication,” said Vohra, associate professor in the department of pediatrics at the University of Alberta in Canada.

Results from nine studies found that probiotics reduced the incidence of AAD, and four studies reported that probiotics shortened the average duration of diarrhea symptoms by about three-quarters of a day.

Choosing between over-the-counter medicines and probiotics may not be the issue for parents and children in some parts of the world, according to Alfred Bartlett, M.D., a pediatrician and senior advisor for child survival at the U.S. Agency for International Development.

Bartlett said his agency's work in numerous countries has shown that replacing fluids to prevent dehydration, providing proper nutrition and administering zinc supplements have proven key to treating diarrhea in children.

“There's been on-again-off-again talk about probiotics for diarrhea, but the science is not solid enough to make a major program investment in more research,” Bartlett said. “In comparison, there have been multiple trials done around the world that have proven fluids, feeding and zinc are effective.”

Although the Cochrane findings were statistically significant, the reviewers concluded that there was not sufficient evidence to advise physicians to recommend probiotics to prevent AAD routinely. They did reveal, however, that Lactobacillus GG or Saccharomyces boulardii appear to be the most effective. According to Vohra, these supplements will garner more attention in the future

“In modern medical school curriculum, physicians have not been taught extensively about many natural health products and probiotics have generally been overlooked,” Vohra said. “This is changing, and we are aware of at least some hospitals that now carry probiotics on formulary.”

The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. Visit http://www.cochrane.org for more information.

Johnston BC, et al. Probiotics for the prevention of pediatric antibiotic-associated diarrhea. Cochrane Database of Systematic Reviews 2007, Issue 2.