atients given fecal microbiota transplants (FMTs) to treat recurrent Clostridium difficile infections (RCDI) cleared the bacteria in just days, and their intestinal microbiota were restored nearly to a pre-C. diff state within a year, according to a longitudinal study published in PLOS ONE today (November 26).
The study “adds a puzzle piece to the overall picture of the importance of the stool microbiome in health as well as disease,” David Suskind from Seattle Children’s Hospital and the University of Washington School of Medicine, who was not involved in the work, told The Scientist in an e-mail. “This study also confirms the restorative powers of fecal transplant on microbial diversity and its positive effects on clinical outcomes.”
Researchers from the University of Maryland School of Medicine’s Institute for Genome Sciences and Sinai Hospital in Baltimore used 16S rRNA gene amplicon pyrosequencing to track microbial events associated with RCDI and FMT treatment over time in 14 RCDI patients receiving transplants, as well as their donors, for up to one year post-treatment.
Through this analysis, the team both confirmed that RCDI is associated with reduced diversity and compositional changes in the fecal microbiota and evaluated post-FMT microbiota dynamics. “When we compare sick patients and healthy individuals’ microbiota composition, we see that there is not just higher diversity, but also a lot of intra-individual variation in the rare members between healthy individuals, and it seems to be exactly that fraction [of diversity] that is lost in the sick patients,” Fricke said. “So [sick patients] kind of get reduced to a more common core of shared species, and the rest is filled up by a few, very dominant ‘bad bacteria’”—such as Streptococci and Gram-negative Enterobacteria or Enteroccoci—he added.