Virtualized clinical studies to assess the natural history and impact of gut microbiome modulation in non-hospitalized patients with mild to moderate COVID-19 a randomized, open-label, prospective study with a parallel group study evaluating the physiologic effects of KB109 on gut microbiota structure and function: a structured summary of a study protocol for a randomized controlled study

These 2 parallel studies (K031 and K032) aim to evaluate the safety of KB109 in addition to supportive self-care (SSC) compared with SSC alone in outpatients with mild to moderate coronavirus disease 2019 (COVID-19). KB109 is a novel synthetic glycan that was formulated to modulate the gut microbiome composition and metabolic output in order to increase beneficial short-chain fatty acid (SCFA) production in the gut. The K031 study is designed to evaluate the safety of KB109 and characterize its impact on the natural progression of COVID-19 in patients with mild to moderate disease. The K032 study is evaluating the effect of KB109 on the gut microbiota structure and function in this same patient population. Additionally, both studies are evaluating measures of health care utilization, quality of life (QOL), laboratory indices, biomarkers of inflammation, and serological measures of immunity in patients who received SSC alone or with KB109. Noteworthy aspects of these outpatient studies include study design measures aimed at limiting in-person interactions to minimize the risk of infection spread, such as use of online diaries, telemedicine, and at-home sample collection. K031 and K032 are randomized, controlled, open-label, clinical food studies. Inclusion Criteria: • Adults ≥18 years of age • Patients willing and able to give informed consent • Screening/randomization telemedicine visit within 2 days of testing positive test for COVID-19 ○ In K031 study, symptomatic patients at COVID-19 testing must report new or worsening symptoms at baseline that have not been present for more than 5 days ▪ Cardinal COVID-19 symptoms include fever, chills/repeated shaking with chills, cough, shortness of breath, headache, muscle pain, anosmia/ageusia, and sore throat. The 5 additional symptoms include gastrointestinal (GI) disturbance/symptoms (other than diarrhea), diarrhea, fatigue, nasal congestion, and chest tightness ○ In K031, at COVID-19 testing, pre-symptomatic patients must report new cardinal COVID-19 symptoms within 7 days of a positive test and they must be screened and randomized within 5 days of developing symptoms • Mild to moderate COVID-19 and self-reported outpatient management ○ In K032, mild to moderate COVID-19 was defined as having the following symptoms for no more than 72 hours before COVID-19 testing: a self- reported fever or cough (new or exacerbated) or presence of at least 2 of the following: anosmia, sore throat, or nasal congestion • Abilit