Translational Development of Microbiome‐Based Therapeutics: Kinetics of E. coli Nissle and Engineered Strains in Humans and Nonhuman Primates

Understanding the pharmacology of microbiome‐based therapeutics is required to support the development of new medicines. Strains of E. coli Nissle (EcN) were genetically modified and administered to cynomolgus monkeys at doses of 1 × 10 9 and 1 × 10 12 colony‐forming units (CFU)/day for 28 days. A clinical study to evaluate the exposure and clearance of EcN in healthy volunteers was also performed. Healthy subjects received oral doses of EcN, 2.5 to 25 × 10 9 CFU 3 times daily for 28 days or a single day. In cynomolgus monkeys, replicating strains yielded higher fecal concentrations than nonreplicating strains and persisted for longer following cessation of dosing. In the clinical study, all subjects cleared EcN following cessation of dosing with median clearance of 1 week. Quantitative methodology can be applied to microbiome‐based therapeutics, and similar kinetics and clearance were observed for EcN in cynomolgus monkeys and humans.