Appendectomy and Clostridium difficile colitis: Relationships revealed by clinical observations and immunology

Figure 2 The cycle of microbiome depletion with antibiotics, the occurrence of Clostridium difficile colitis, and recovery of the microbiome. The cycle is initiated when the normal colon (A) is depleted of its microbiota using broad spectrum antibiotics (B). Although the microbiota often recovers spontaneously from such treatment, the patient is at risk of Clostridium difficile (C. difficile) colitis (C and D) in a fashion that is independent of the presence of an appendix. Although C. difficile colitis is often effectively treated with metronidazole or vancomycin (E), the microbiome can fail to normalize, leading to recurrent C. difficile colitis. This cycle of treatment followed by recurrence is indicated by the red arrows. The presence of a vermiform appendix enhances recovery (A and F) of a normal microbiome following C. difficile colitis (green arrow), thus averting the cycle of recurrent C. difficile colitis. Colonic microbiota transplants (CMT) are also effective at restoring the normal flora and interrupting the cycle of recurrent C. difficile colitis.