Our findings illuminate the benefits of probiotics in preventing both AAD and CDI in the specific patient population of adult inpatients requiring antibiotics. On the basis of the current review, probiotics can be recommended for such patients in the absence of contraindications; however, the prevalence of AAD and CDI should be taken into consideration before guidelines are developed. The literature does not clearly indicate a favoured choice of probiotic, although there is stronger evidence for Lactobacillus-based formulations.
Many health care providers have been hesitant to adopt probiotics in routine practice, despite impressive effect sizes. This may be because of the small sample sizes in the individual trials, the high baseline rates of AAD and CDI in the larger, more recent trials, the clinical and statistical heterogeneity between trials, and the publication bias seen in this and other meta-analyses. While there may be a signal toward clinical improvement with this intervention, future RCTs should strive to recruit more patients and to strengthen their power to help bring probiotics to the bedside. Other research that will add to our current knowledge in this area might address whether there is greater benefit with the use of combination therapy over single-species probiotic formulations. The hypothesis of a dose–response effect requires further validation.