A bacterium belonging to a novel bacterial genus, Dysosmobacter. Also, the therapeutic, nutraceutical and cosmetic use thereof. The uses include methods for treating a disorder, promoting weight loss, decreasing food intake, increasing muscle mass, decreasing fat mass, increasing satiety, and/or decreasing weight gain associated with food intake in a subject, including administering to the subject at least one isolated bacterium belonging to the genus Dysosmobacter and/or a variant thereof and/or fragments thereof.