 Donor stool will be obtained from healthy donors. The donors will be interviewed to ensure they are in good health and will undergo a screening questionnaire to identify potential infectious risk which could be transferred by stool. Certain exclusion criteria will apply and donors will undergo testing of stool and serum. The donation process is safe for the donor Bakken et al. A selected healthy individual with a diverse microbial composition will preferentially be used as the donor candidate unless recipient wishes dictate the use of a designated donor. 