The main objective is for students to recognize that the human being constitutes a huge ecosystem where thousands of microorganisms cohabit, that in this human microbiome, the oral cavity constitutes the most diverse subsystem and that the oral microbiome, in addition to being rich, is complex and includes factors relating to microbial species, but also to the host and external environment. Finally, it is essential that students understand which factors (microbial, host and external environment) combine to establish a dynamic balance responsible for the individual's health. Biomedical Sciences students must also understand the challenges in research related to this environment both in microbiological terms and in terms of designing innovative forms of prevention, diagnosis and therapy.