Figure 3 . Role of antibiotics and C. diffi cile in perturbing Intestinal homeostasis and the corrective effect of fecal microbiota transplantation (FMT).
Intestinal homeostasis ( a) is characterized by a diverse, stable microbiota. Antibiotic perturbation ( b– c) kills susceptible bacteria resulting in a less diverse
community structure with loss of colonization resistance. In the absence of opportunistic infection, the microbiota usually recovers its diversity ( d) to
re-establish homeostasis and colonization resistance ( a). Exposure to C. diffi cile ( e) after antibiotic perturbation ( b), however, can lead to persistent
dysbiosis ( f). Bacteriotherapy or FMT can disrupt the dysbiosis ( g) allowing clearance of C. diffi cile ( h) and re-establishment of intestinal homeostasis ( a).
Modifi ed from Lawley et al. ( 33 ).