The first International Conference on Oral Mucosal Immunity and Microbiome (OMIM) aimed to highlight cutting-edge basic and translational research from an oral immunological and microbiological perspective. Oral diseases with a microbial etiology are the most prevalent chronic diseases of humans. Whilst not life-threatening, they can significantly compromise quality of life, are associated with increased risk for certain systemic diseases, and pose heavy financial burdens to national health systems. Hence, periodontal and peri-implant diseases, dental caries, root canal infections and mucosal infections are significant global public health problems.