Safety and Tolerability of SYNB8802 in Healthy Adult Volunteers and Adult Subjects With Enteric Hyperoxaluria

This study is evaluating the safety, tolerability, kinetics, and pharmacodynamics of SYNB8802 within the following 2 study parts: Part 1 is an inpatient, placebo-controlled, multiple ascending dose (MAD) study in HV male and female subjects in up to 5 dose cohorts (6 treated: 3 placebo) for 5 days of dosing to identify the maximum tolerated dose (MTD). Part 2 is a placebo-controlled crossover study in up to 20 adult male and female subjects with EH secondary to Roux-en-Y bariatric surgery. Subjects will be randomized to receive either SYNB8802 (at or below the MTD from Part 1) or placebo for six days before crossing over to receive either placebo or SYNB8802 for another six days, respectively. This part of the study has been designed with the flexibility of being able to be conducted either at the clinical site or by a home healthcare professional at an alternative location (e.g., patient's home, hotel).