Most institutions utilize fresh feces, necessitating collection
and processing on the day of planned FMT. Hamilton
et al. [17] have adopted an approach of using highly filtered
human microbiota mixed with a cryoprotectant and then
frozen for storage at −80 °C until required for use. This
processing removes the fecal smell and reduces the volume
of the filtrate. Use of such a standardized, purified tissue has been shown to have equivalent clinical efficacy in CDI to
that of fresh, partly filtered feces. Furthermore, detailed
microbiological studies with 16S rRNA gene sequencing
demonstrated stable “engraftment” or “implantation” of donor
microbiota with the frozen product [27•], with dramatic
shifts in recipient gut microbial communities noted after
transplantation.