Review Finds CDI Prevention Strategies Show Promise, but More Phase 3 Studies Needed

Strategies designed to prevent Clostridioides difficile infection (CDI) by restoring the health of patients’ gut microbiomes have shown promise, but a new review argues more, larger trials are needed to confirm the efficacy of the approach.

The study authors noted that significant advances have been made in preventing both primary and secondary CDI infections in recent years. In their review, they sought to summarize the findings from phase 2 and 3 studies published in the past 5 years in order to provide an updated assessment of emerging infection-control strategies. Their findings were published in Microorganisms.

The authors found several strategies for preventing primary infection of CDI in their research. Among them was enhanced infection control programs designed to prevent transmission at health care facilities. The literature affirmed that practices such as antibiotic stewardship, patient isolation, and early detection are meaningful strategies.

In addition to reducing inappropriate antibiotic prescriptions, studies have also evaluated whether the use of antibiotics as prophylactics might prevent primary CDI in high-risk patients. Some studies found prophylactic vancomycin reduced CDI incidence—although the study authors noted that current guidelines do not recommend such usage of antibiotics.

They said one of the most active areas of research relates to the use of probiotics to prevent CDI, but they noted that only 5 randomized controlled trials have been published in which CDI prevention was the primary outcome. Those studies found that probiotics have promise, with the caveat that the efficacy of probiotics is typically specific to the strain of the probiotic and the disease it is designed to prevent.

“Thus, the efficacy should be judged for each probiotic strain or mixture of strains separately, and conclusions should not be made based on pooled different types of probiotics,” they said.

Turning to prevention of secondary CDI, the authors said probiotics have similarly shown signs of efficacy, but that there is a dearth of phase 3 randomized controlled trials to confirm the findings of earlier-stage research.

Medical Research, Phases of Vaccine Clinical Trials: © Olivier Le Moal - stock.adobe.com

Instead, most of the research into secondary prevention strategies has focused on fecal microbiota therapy and live biotherapeutic products, they said.

Fecal microbiota transplantation has shown high rates of efficacy at preventing recurrence, with an average cure rate of 86%, the authors said. However, the procedure carries the risk of simultaneously transplanting pathogens from the donor stool, such as SARS-CoV-2. The other drawback, the investigators added, is that many patients find the procedure unappealing.

The use of live biotherapeutic products can address those concerns, as doses undergo extensive screening for pathogens and at least 1 product studied can be delivered in an oral capsule. These, too, have shown promise in clinical trials, and the FDA has approved 2 such therapies.

Overall, the authors said the strategies currently being investigated appear to be sound, but they reiterated that it is important to gain a better understanding of exactly how and why they are working.

“As the main factor for Clostridioides difficile infections is the disruption of the normally protective intestinal microbiome, strategies aimed at restoring the microbiome seem most rational; although, more large randomized controlled trials are needed that document the shifts in the microbiome population,” they concluded.

Reference

McFarland LV, Goldstein EJC, Kullar R. Microbiome-related and infection control approaches to primary and secondary prevention of Clostridioides difficile Infections. Microorganisms. Published online June 9, 2023. doi:10.3390/microorganisms11061534