RecruitingPhase 1Drug trialTargeted Investigation of Microbiome 2 Treat Atopic Dermatitis (TIME-2)This is a Phase 1b, randomized, placebo/vehicle-controlled, double-blinded, multi-center trial. It is designed to assess the safety and efficacy of S. hominis A9 (ShA9) topical application as a treatment for atopic dermatitis (AD). The trial will enroll adults and pediatric participants with atopic dermatitis. The primary safety objective of this study is to compare the safety profile of ShA9 to placebo (vehicle) over 14 weeks of application, which includes an initial two-week period of co-treatment with topical corticosteroids (TCS). The primary efficacy objective of this study is to assess the ability of ShA9, compared to placebo (vehicle), to prolong the period of atopic dermatitis control over 12 weeks after conclusion of an initial two-week period of co-treatment with TCS.