Study finds, the upper respiratory microbiome is influenced by age, sex, and lifestyle factors

In a recent study published in the journal Cell, a team of researchers in the Netherlands analysed nasopharyngeal, oropharyngeal, and saliva samples across various age groups and analysed the microbial composition of these samples to determine the association between the microbiota in the upper respiratory tract and the health of the host and environmental factors.

There is now extensive evidence showing that microbial communities within the human body are crucial for health and disease. Although much of the research has concentrated on the gut microbiome, studies have demonstrated that the microbiome of the upper respiratory tract is closely connected to respiratory health. It plays a significant role in influencing susceptibility to respiratory infections.

In this study, researchers examined the microbiome composition and diversity in nasopharyngeal, oropharyngeal, and saliva samples from a cross-section of the Dutch population. Their aim was to characterise changes in the upper respiratory tract microbiome across different stages of life and investigate its associations with the host and environmental factors.

The researchers also conducted a complete linkage hierarchical clustering analysis to investigate the community structures within the oral and nasopharyngeal niches. Furthermore, they explored the relationship between variations in the upper respiratory tract microbiome and various environmental factors, including the season of sampling, socioeconomic status, lifestyle, antibiotic use, diet, household composition, and contact with animals, children, elderly individuals, or patients in a work setting.

The study found that the microbiome composition in the upper respiratory tract, especially in the nasopharyngeal niche, was strongly correlated with and underwent maturation with age. The upper respiratory tract microbiota also exhibited distinct patterns within different niches. The microbiome in the nasopharynx of younger individuals had a higher density of total bacteria but lower diversity.

In conclusion, the study examined the microbial composition and diversity within the upper respiratory tract's oral and nasopharyngeal niches. The results suggested that the upper respiratory tract microbiome showed development and maturation patterns associated with age and sex in the nasopharyngeal niche, while in the oral niche, the associations were with lifestyle factors such as tobacco, antibiotics, and alcohol use.

References: Odendaal, M., de, Franz, E., Mei, C., Groot, J. A., Logchem, van, Hasrat, R., Kuiling, S., Pijnacker, R., Mariman, R., Trzciński, K., van, Sanders, E. A. M., Smit, L. A. M., Bogaert, D., & Bosch, T. (n.d.). 2024. Host and environmental factors shape upper airway microbiota and respiratory health across the human lifespan. Cell. DOI:10.1016/j.cell.2024.07.008 https://www.cell.com/cell/fulltext/S0092-8674(24)00768-2