The researchers explained:
"The use of antibiotics that disturb the gastrointestinal flora [microbes] is associated with clinical symptoms such as diarrhea, which occurs in as many as 30 percent of patients.
Symptoms range from mild and self-limiting to severe, particularly in Clostridium difficile infections, and antibiotic-associated diarrhea (AAD) is an important reason for nonadherence with antibiotic treatment.
Potentially, probiotics maintain or restore gut microecology (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."
Susanne Hempel, Ph.D., of RAND Health, Santa Monica, Calif., and her team searched databases in order to identify randomized controlled trials (RCTs) involving probiotic use (Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, and/or Bacillus) for the prevention or treatment of AAD. In total, 82 trials met inclusion criteria.
The researchers found that most of the trials used either Lactobacillus-based interventions alone or in conjunction with other genera (a subdivision of a family of organisms); strains were not well documented.
63 of the 82 trials reported the number of participants randomized to both treatment groups, as well as the number of participants with diarrhea. Combined, the 63 trials included 11,811 participants. The researchers found that participants who consumed probiotics were 42% less likely to develop diarrhea than participants assigned to a control group. According to the researchers, the result was consistent across numerous subgroup and sensitivity analyses. The treatment effect equates to a number needed to treat of 13.
The authors explained that the findings in the pooled results varied significantly. In addition, they found that there was not enough evidence to determine if this association differs systematically by population, probiotic preparation, or antibiotic characteristic.
The researchers conclude:
"In summary, our review found sufficient evidence to conclude that adjunct probiotic administration is associated with a reduced risk of AAD. This generalized conclusion likely obscures heterogeneity in effectiveness among the patients, the antibiotics, and the probiotic strains or blends.
Future studies should assess these factors and explicitly assess the possibility of adverse events to better refine our understanding of the use of probiotics to prevent AAD."
Written By Grace Rattue