Oral administration would be the preferable route for non-severe and/or recurrent CDI allowing repeated treatment to take place due to lack of adverse humoral responses in circulation as indicated by clinical trials with orally delivered polyclonal antibodies against TNFα (AVX-470) for treatment of ulcerative colitis (Harris et al., 2016), a disease which is also associated with severe colon inflammation. This evidence concerns the gene TNF and clostridium difficile infection.