Our results showed that those who received probiotics with the initial CDI treatment were significantly less likely to have a recurrence than those who did not. Patients receiving probiotics in the later period (2011–2013) were 74% less likely to have a recurrence than patients in the earlier group (2009–2010). Despite the standard use of probiotics for primary CDI prevention at our institution, we could not show direct significance to the lack of probiotic use found in the identified CDI patients with this observational study design. The higher benefit in more recent years could possibly be attributed to the fact that these patients were much less likely to have received a PPI, that most had likely received probiotics concurrently plus 1 week after their antibiotic courses, and their antibiotic therapy was likely more focused and streamlined to prevent C. difficile infection. A meta-analysis of probiotic efficacy in primary CDI prevention suggested that probiotics can lead to a 64% reduction in the incidence of CDI, in addition to reducing GI-associated symptoms related to infection or antibiotic use [9]. A dose-response study of the efficacy of a probiotic formula showed a lower incidence of CDI, 1.2% for higher dose vs. 9.4% for lower dose vs. 23.8% for placebo [15]. Maziade et al [16] added prophylactic probiotics to a bundle of standard preventative measures for C. difficile infections, and were able to show an enhanced and sustained decrease in CDI rates (73%) and recurrences (39%). However, many of the probiotic studies which have studied the relationship to CDI have been criticized for reporting abnormally high rates of infection [9,16] missing data, a lack of controls or excessive patient exclusion criteria [17,18] The more recent PLACIDE study by Allen et al [19] was a large multicenter randomized controlled trial that did not show any benefit to CDI prevention with probiotics; however, with 83% of screened patients excluded, the patients were low risk, with the resulting CDI incidence (0.99%) too low to show a benefit. Acid suppression was also not revealed in the specific CDI cases, and others have found this to be a significant risk factor [5–7].
Limitations of this study include the study design (an observational, retrospective analysis), the small size of our facility, and the difficulty in obtaining probiotic history prior to admission in some cases. Due to a change in computer systems, hospital orders for GI prophylaxis agents could not be obtained for 2009–2010. Due to the fact that we instituted our interventions somewhat concurrently, it is difficult to analyze their individual impact. Randomized controlled trials evaluating the combined role of probiotics, GI prophylaxis, and antibiotic pressure in CDI are needed to further define the importance of this approach.
Corresponding author: Bridget Olson, RPh, Sharp Coronado Hospital & Villa Coronado Long-Term Care Facility, 250
Prospect Pl., Coronado CA 92118, bridget.olson@sharp.com.
Financial disclosures: None.
Author contributions: conception and design, BO, TH, KW, RO; analysis and interpretation of data, RAF; drafting of article, BO, RAF; critical revision of the article, RAF, JH, TH; provision of study materials or patients, BO; statistical expertise, RAF; administrative or technical support, KW, RO; collection and assembly of data, BO.