How can bacteria in the respiratory tract maintain our health and prevent infections from occurring? To answer this question, a better characterization of the collection of bacteria that are present in this human body niche is necessary. A good starting point is the identification of all bacteria that are present under healthy conditions. Therefore, we set up a large-scale citizen-science study, where we collected samples from 100 enthusiastic healthy volunteers. These volunteers were willing to donate a swab sample of their nose and nasopharynx. The bacterial DNA from all these samples was collected.
After processing of all these samples, we got a better idea about the bacteria that are present in the nose of healthy people. Our results, published in Frontiers in Microbiology, show that overall, the healthy nose and nasopharynx are mostly dominated by only a few bacterial species. Furthermore, these bacterial profiles in the nasopharynx could be grouped into at least four bacterial types (you can compare this to blood types) dependent on the bacterium that is most present: a type dominated by Moraxella, by Streptococcus or by Fusobacterium, and finally a mixed type of Staphylococcus, Dolosigranulum and Corynebacterium. Almost all individuals could be grouped into one of these four bacterial types. Interestingly, in the nose, only the Moraxella and the mixed type were found.