Microbiota composition of suspensions used for human fecal microbiota transplantation. Human microbiota-associated mice were generated by human fecal microbiota transplantation of secondary abiotic mice by gavage on three consecutive days (as described in methods). (A) Microbiota composition of suspensions used for gavage was quantitatively assessed by culture of enterobacteria (EB), enterococci (EC), Gram-positive rods (GPR), Bacteroides/Prevotella spp. (B/P), Clostridium/Eubacterium spp. (C/E), and total bacterial loads (TL) and expressed as colony forming units (CFU) per ml. (B) Microbiota survey was supplemented with quantitative molecular analysis of enterobacteria (EB), enterococci (EC), lactobacilli (LB), bifidobacteria (Bif), Bacteroides/Prevotella spp. (B/P), Clostridium coccoides group (Clocc), Clostridium leptum group (Clept), Mouse Intestinal Bacteroides (MIB), and total eubacterial loads (TL) by qRT-PCR (expressed as 16S rRNA gene numbers per ng DNA). Medians are shown