Transplantation with frozen fecal samples is just as effective as using fresh samples in fighting CDI, a new study suggests.
The study - led by Dr. Christine H. Lee, of McMaster University in Ontario, Canada - is published in JAMA.
Recurrence of Clostridium difficile infection (CDI) is of particular concern in a health care setting.
According to the study authors, previous studies have demonstrated that 10-50% of recurring CDI cases may be due to reinfections, rather than recurrence of the initial infection, which suggests that agitated microbiota plays a role in reinfection.
Furthermore, more than 60% of patients with CDI experience subsequent infections.
Officials from the Centers for Disease Control and Prevention (CDC) note that C. difficile was estimated to cause nearly half a million infections in the US in 2011, and 29,000 died within 30 days of being initially diagnosed.
'No differences in adverse or serious events between treatment groups'
Although treatment options for recurrent CDI are limited, restoring "good" bacteria in the gut through fecal microbiota transplantation (FMT) has proven itself as an effective treatment.
Fast facts about CDI
- Health care workers can spread the bacteria to patients through hand contact
- Symptoms include watery diarrhea, fever, loss of appetite, nausea and abdominal pain
- People who require prolonged use of antibiotics and the elderly are at greater risk.
Using frozen-and-thawed FMT offers several advantages, including lower costs (as a result of a reduction in number and frequency of donor screenings), immediate availability and easier delivery and storage options.
Until now, however, previous studies have not directly compared the effectiveness of frozen FMT with fresh FMT.
As such, the researchers randomly assigned 232 adults with recurrent or refractory CDI to receive either frozen or fresh FMT through an enema. In total, 114 patients received frozen FMT and 118 received fresh between July 2012-September 2014.
Results showed that the proportion of patients whose diarrhea was resolved without relapse at 13 weeks was 83.5% for those in the frozen FMT group, compared with 85% for the fresh FMT group.
The researchers conclude that there are no differences in adverse or serious events between treatment groups.
"Given the potential advantages of providing frozen FMT, its use is a reasonable option in this setting," they write.
'Best evidence to date supporting use of frozen stool'
Despite the large sample size, the researchers admit some limitations to their study. Firstly, their 13-week follow-up period is not long enough to assess long-term safety of the treatment.
Additionally, there was a low number of stool donors, which they say could be considered a limitation.
They note that the long-term safety of FMT needs to be fully investigated through extended follow-up of the patients, and as such, they are currently conducting a 10-year follow-up investigation to fully flesh out the long-term positive or negative outcomes.
In an accompanying editorial, Drs. Pretti Malani and Krishna Rao, of the University of Michigan-Ann Arbor, write that the study's results present the "best evidence to date supporting the use of frozen stool," adding that it will "likely expand the availability of FMT for patients with recurrent CDI."
"The ability to use frozen stool eliminates many of the logistical burdens inherent to FMT, because stool collection and processing need not be tied to the procedure date and time.
This study also provides greater support for the practice of using centralized stool banks, which could further remove barriers to FMT by making available to clinicians safe, screened stool that can be shipped and stored frozen and thawed for use as needed."
They add that procedure costs could also decrease, given that donor screening is expensive.
Medical News Today recently reported on a study that suggested exercise in early life affects the gut flora, promoting better health later on.