Published in the Journal of the American Medical Association (JAMA) the new meta-analysis reveals that consumption of ‘friendly bacteria’ in the form of probiotics in foods such as yogurt is associated with a reduced risk of antibiotic-associated diarrhoea – a common adverse effect of antibiotic use.
"The use of antibiotics that disturb the gastrointestinal flora [microbes] is associated with clinical symptoms such as diarrhoea, which occurs in as many as 30 percent of patients,” explained the researchers – who were led by Susanne Hempel of US based nonprofit institution RAND Corporation.
“Antibiotic-associated diarrhoea (AAD) is an important reason for non-adherence with antibiotic treatment," said the researchers, who noted that probiotics could potentiall maintain or restore gut microbial ecology during, or after, antibiotic treatment.
"There is an increasing interest in probiotic interventions, and evidence for the effectiveness of probiotics in preventing or treating AAD is also increasing … In summary, our review found sufficient evidence to conclude that adjunct probiotic administration is associated with a reduced risk of AAD,” concluded Hempel and her colleagues.
By pooling evidence from 63 clinical trials, involving data from over 11,000 particiapnts, the researchers reveal that use of probiotics is associated with a 42% lower risk of developing diarrhoea when taking antibiotics – compared to not using probiotics
"We found a clear beneficial effect of probiotics in preventing or treating antibiotic-associated diarrhoea," said study co-author Sydne Newberry – also of RAND.
"However, more work is needed to determine which types of probiotics work best, which patients are most likely to benefit from probiotics and whether there are any risks in using them."
Hempel and her colleagues reviewed data from 11,811 participants in 63 randomised, controlled trials (RCTs) assessing AAD and probiotics – defined as Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, and/or Bacillus.
The majority of the RCTs used Lactobacillus-based interventions alone or in combination with other genera, however the authors said that strains were poorly documented.
Across the 63 RCTs the team found that probiotic use was associated with a 42% lower risk of developing diarrhea compared with a control group not using probiotics. Hempel added that results were “consistent across a number of subgroup and sensitivity analyses.”
As such, the RAND analysis estimates that 13 people would need to use probiotics in order to prevent one case of antibiotic-associated diarrhea. However, the researchers said the evidence was insufficient to show which strain of probiotic was better.
The team said future efforts to study the effects of probiotics should try to determine whether some strains or combinations of probiotics work better than others, or work best with specific antibiotics.
Volume 307, Issue 18, Pages 1959-1969, doi:10.1001/jama.2012.3507
“Probiotics for the Prevention and Treatment of Antibiotic-Associated Diarrhea. A Systematic Review and Meta-analysis”
Authors: S. Hempel, S.J. Newberry, A.R. Maher, Z. Wang, J.N. V. Miles, et al