A new strain of Christensenella minuta as a potential biotherapy for obesity and associated metabolic diseases Wilfrid Mazier, Katy Le Corf, Ccori Martinez, Héloïse Tudela, Déborah Kissi, Chrislain Coubart, Marion Soto, Frederic Elustondo, Georges Rawadi, Sandrine P. Claus Ysopia Bioscience, 17 place de la Bourse, 33076 Bordeaux, France This presentation will describe the preclinical steps that have led to the development of a novel strain of C. minuta as a Live Biotherapeutic Product, recently approved to be tested in humans by the FDA. The phase I clinical trial of this product has just been initiated in the US. Obesity is a complex multifactorial disease characterized by an imbalance of the gut microbiota, known as dysbiosis. A number of commensal and non-commensal bacterial strains have been proposed to restore host-microbiota symbiosis, but only few have demonstrated reproducible effects in preclinical models. Of these, the human gut commensal bacteria Christensenella minuta have been shown to hold great promise as an obesity therapy. In this presentation, we will describe a novel strain of C. minuta (strain DSM 33407) isolated from a healthy individual with strong anti-obesity potential assessed in both in vitro and in vivo preclinical models. We will explain how C. minuta DSM 33407 protects from diet-induced obesity and regulates associated metabolic markers such as glycemia and leptin through important modulations of the intestinal microbiota and associated functions. In particular, we will show how this microbe regulates hepatic lipid metabolism through a strong inhibition of de novo lipogenesis. Together, these data indicate that C. minuta DSM 33407 is a convincing therapeutic candidate for the management of obesity and associated metabolic disorders. C. minuta DSM 33407 is now being evaluated for safety and tolerability in humans in a phase I clinical study.