Identification of key taxa that favor intestinal colonization of Clostridium difficile in an adult Chinese population.

Fecal microbial transplantation provides a high curative rate for recurrent Clostridium difficile infection (CDI). However, limitations associated with FMT drive the need to identify key taxa for selective probiotic therapy for prevention, treatment and cure of human CDI. CDI-associated changes in gut microbiota were investigated in adult patients in the Western countries and among infant population in China. However, there has been no such study involving adult patients in China. Therefore, using high throughput sequencing of the 16S ribosomal RNA V3 region and real-time quantitative polymerase chain reaction, we identified CDI-associated key taxa by comparing the fecal microbiota composition of 15 adult patients with CDI with those of 18 individuals with C. difficile-negative nosocomial diarrhea (CDN) and 25 healthy control subjects. Reduced fecal bacterial diversity and dramatic shifts of intestinal microbial composition in CDI and CDN groups were observed compared with healthy controls. Putative butyrate-producing anaerobic bacteria were significantly depleted whereas endotoxin-producing opportunistic pathogens and lactate-producing phylotypes increased dramatically in patients with CDI compared with healthy controls. Further screening of specific microbes causing diarrheal diseases and resistance against CDI is necessary.