Largest study of the nose and mouth microbiome to date

Our bodies are populated by a vast number of microbes, collectively known as our microbiome. These microbes perform many functions that are essential to human health. Up to now, most attention has been paid to the composition and function of the gut microbiome, yet information on microbes in other body niches, like the airways, was lacking. In a large population-based study researchers from the Institute for Public Health and the Environment (RIVM), the University Medical Center Utrecht (UMCU), the Centre for Inflammation Research (CIR), and Utrecht University (UU) provide the largest characterization of the upper airway microbiome to date.

The researchers, including CIR's Professor Debby Bogaert characterized the nasopharyngeal (back of the nose) and oral microbial communities of 3,160 healthy Dutch individuals across all age groups, ranging from newborns until elderly individuals. They found that the microbes in the back of the nose exhibited a strong relationship with age, both in terms of number and types of microbes. From puberty onward these microbial communities also varied significantly with sex. In addition, environmental factors (such as season of sampling) were mainly linked to the types of microbes present in the back of the nose. Lifestyle factors, like smoking and diet, were interestingly more strongly associated with the oral microbial communities. Importantly, the researchers showed that microbial communities were different in people who recently had experienced respiratory symptoms, or who had recovered from a pneumonia in recent years, highlighting the link between microbial communities in the upper airways and respiratory health.

This study represents the most complete atlas of the microbial communities in the upper airways of healthy individuals to date. The results form an important basis for further studies regarding the role of our resident microbes in infection susceptibility and severity across the lifespan and the factors influencing this process.

The study was published in Cell in an article entitled 'Host and environmental factors shape upper airway microbiota and respiratory health across the human lifespan'.