A process for extracting an active principle from yeast whereby the active principle is used to retard the degradation of the dermo-epidermal junction to improve the surface condition of the skin. The process includes forming a mixture of solubilized ground yeast in a basic medium, hydrolyzing the proteins of the mixture in a basic medium, agitating the mixture for 8 to 52 hours, filtering the mixture to separate the soluble and insoluble phases, washing with water so as to purify the active ingredient, concentrating and filtering to increase an active oligosaccharide fraction, and sterile filtering the active fraction. The active fraction is characterized by a quantity of dry material between 10 and 200 g/l, a quantity of total sugar between 10 and 100 g/l, a weight ratio of sugar/protein, and a pH between 4 and 10.